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Sample records for andstrongly deformed structure

  1. Extremely deformable structures

    CERN Document Server

    2015-01-01

    Recently, a new research stimulus has derived from the observation that soft structures, such as biological systems, but also rubber and gel, may work in a post critical regime, where elastic elements are subject to extreme deformations, though still exhibiting excellent mechanical performances. This is the realm of ‘extreme mechanics’, to which this book is addressed. The possibility of exploiting highly deformable structures opens new and unexpected technological possibilities. In particular, the challenge is the design of deformable and bi-stable mechanisms which can reach superior mechanical performances and can have a strong impact on several high-tech applications, including stretchable electronics, nanotube serpentines, deployable structures for aerospace engineering, cable deployment in the ocean, but also sensors and flexible actuators and vibration absorbers. Readers are introduced to a variety of interrelated topics involving the mechanics of extremely deformable structures, with emphasis on ...

  2. Deformed configurations, band structures and spectroscopic ...

    Indian Academy of Sciences (India)

    2014-03-20

    Mar 20, 2014 ... The deformed configurations and rotational band structures in =50 Ge and Se nuclei are studied by deformed Hartree–Fock with quadrupole constraint and angular momentum projection. Apart from the `almost' spherical HF solution, a well-deformed configuration occurs at low excitation. A deformed ...

  3. Stochastic deformation of a thermodynamic symplectic structure

    OpenAIRE

    Kazinski, P. O.

    2008-01-01

    A stochastic deformation of a thermodynamic symplectic structure is studied. The stochastic deformation procedure is analogous to the deformation of an algebra of observables like deformation quantization, but for an imaginary deformation parameter (the Planck constant). Gauge symmetries of thermodynamics and corresponding stochastic mechanics, which describes fluctuations of a thermodynamic system, are revealed and gauge fields are introduced. A physical interpretation to the gauge transform...

  4. Deformed configurations, band structures and spectroscopic ...

    Indian Academy of Sciences (India)

    2014-03-20

    Mar 20, 2014 ... Our study gives insight into possible deformed structures at spherical shell closure. ... Considerable experimental and theoretical efforts ... True deformation effects can be seen only by considering configuration mixing.

  5. Deformation Characteristics of Composite Structures

    Directory of Open Access Journals (Sweden)

    Theddeus T. AKANO

    2016-08-01

    Full Text Available The composites provide design flexibility because many of them can be moulded into complex shapes. The carbon fibre-reinforced epoxy composites exhibit excellent fatigue tolerance and high specific strength and stiffness which have led to numerous advanced applications ranging from the military and civil aircraft structures to the consumer products. However, the modelling of the beams undergoing the arbitrarily large displacements and rotations, but small strains, is a common problem in the application of these engineering composite systems. This paper presents a nonlinear finite element model which is able to estimate the deformations of the fibre-reinforced epoxy composite beams. The governing equations are based on the Euler-Bernoulli beam theory (EBBT with a von Kármán type of kinematic nonlinearity. The anisotropic elasticity is employed for the material model of the composite material. Moreover, the characterization of the mechanical properties of the composite material is achieved through a tensile test, while a simple laboratory experiment is used to validate the model. The results reveal that the composite fibre orientation, the type of applied load and boundary condition, affect the deformation characteristics of the composite structures. The nonlinearity is an important factor that should be taken into consideration in the analysis of the fibre-reinforced epoxy composites.

  6. Structural refinement and coarsening in deformed metals

    DEFF Research Database (Denmark)

    Hansen, N.; Huang, X.; Xing, Q.

    2005-01-01

    The microstructural refinement by plastic deformation is analysed in terms of key parameters, the spacing between and the misorientation angle across the boundaries subdividing the structure. Coarsening of such structures by annealing is also characterised. For both deformed and annealed structur...

  7. Deformation twinning in a creep-deformed nanolaminate structure

    International Nuclear Information System (INIS)

    Hsiung, Luke L

    2010-01-01

    The underlying mechanism of deformation twinning occurring in a TiAl-(γ)/Ti 3 Al-(α 2 ) nanolaminate creep deformed at elevated temperatures has been studied. Since the multiplication and propagation of lattice dislocations in both γ and α 2 thin lamellae are very limited, the total flow of lattice dislocations becomes insufficient to accommodate the accumulated creep strains. Consequently, the movement of interfacial dislocations along the laminate interfaces, i.e., interface sliding, becomes an alternative deformation mode of the nanolaminate structure. Pile-ups of interfacial dislocations occur when interfacial ledges and impinged lattice dislocations act as obstacles to impede the movement of interfacial dislocations. Deformation twinning can accordingly take place to relieve a stress concentration resulting from the pile-up of interfacial dislocations. An interface-controlled twinning mechanism driven by the pile-up and dissociation of interfacial dislocations is accordingly proposed.

  8. Deformation twinning in a creep-deformed nanolaminate structure

    Science.gov (United States)

    Hsiung, Luke L.

    2010-10-01

    The underlying mechanism of deformation twinning occurring in a TiAl-(γ)/Ti3Al-(α2) nanolaminate creep deformed at elevated temperatures has been studied. Since the multiplication and propagation of lattice dislocations in both γ and α2 thin lamellae are very limited, the total flow of lattice dislocations becomes insufficient to accommodate the accumulated creep strains. Consequently, the movement of interfacial dislocations along the laminate interfaces, i.e., interface sliding, becomes an alternative deformation mode of the nanolaminate structure. Pile-ups of interfacial dislocations occur when interfacial ledges and impinged lattice dislocations act as obstacles to impede the movement of interfacial dislocations. Deformation twinning can accordingly take place to relieve a stress concentration resulting from the pile-up of interfacial dislocations. An interface-controlled twinning mechanism driven by the pile-up and dissociation of interfacial dislocations is accordingly proposed.

  9. Deformed metals - structure, recrystallisation and strength

    DEFF Research Database (Denmark)

    Hansen, Niels; Juul Jensen, Dorte

    2011-01-01

    It is shown how new discoveries and advanced experimental techniques in the last 25 years have led to paradigm shifts in the analysis of deformation and annealing structures of metals and in the way the strength of deformed samples is related to structural parameters. This is described in three...

  10. Study of fine structure of deformed hafnium

    International Nuclear Information System (INIS)

    Voskresenskaya, L.A.; Petukhova, A.S.; Kovalev, K.S.

    1978-01-01

    Variations in the hafnium fine structure following the cold plastic deformation have been studied. The fine structure condition has been studied through the harmonic analysis of the profile of the X-ray diffraction line, obtained at the DRON-I installation. Received has been the dependence of the crystal lattice microdistortions value on the deformation extent for hafnium. This dependence is compared with the corresponding one for zirconium. It is found out that at all the deformations the microdistortion distribution is uniform. The microdistortion value grows with the increase in the compression. During the mechanical impact higher microdistortions of the crystal lattice occur in the hafnium rather than in zirconium

  11. Structure of deformed metals. Struktura deformirovannykh metallov

    Energy Technology Data Exchange (ETDEWEB)

    Bernshtein, M L

    1977-01-01

    A teaching aid for students at metallurgical and machine-building institutions of higher learning. It can also be used by engineering-technical personnel and scientists. A presentation is made of physical concepts on the mechanism of plastic deformation and its effect on fine structure, structure and properties of metals and alloys. An examination is made of the processes of recovery, polygonization and recrystallization during the heating of cold-deformed metals. The influence of thermal deformation is described to account for the interaction between admixture atoms and dislocations, phase and structural transformations. An examination is made of the phenomenon of superplasticity. Special attention is given to the process of hot deformation. An analysis is made of phenomena at the basis of hardening steel as a result of thermo-mechanical processing, including controlled rolling.

  12. Fine structure in deformed proton emitting nuclei

    International Nuclear Information System (INIS)

    Sonzogni, A. A.; Davids, C. N.; Woods, P. J.; Seweryniak, D.; Carpenter, M. P.; Ressler, J. J.; Schwartz, J.; Uusitalo, J.; Walters, W. B.

    1999-01-01

    In a recent experiment to study the proton radioactivity of the highly deformed 131 Eu nucleus, two proton lines were detected. The higher energy one was assigned to the ground-state to ground-state decay, while the lower energy, to the ground-state to the 2 + state decay. This constitutes the first observation of fine structure in proton radioactivity. With these four measured quantities, proton energies, half-life and branching ratio, it is possible to determine the Nilsson configuration of the ground state of the proton emitting nucleus as well as the 2 + energy and nuclear deformation of the daughter nucleus. These results will be presented and discussed

  13. Deformations of Geometric Structures in Topological Sigma Models

    International Nuclear Information System (INIS)

    Bytsenko, A. A.

    2010-01-01

    We study a Lie algebra of formal vector fields W n with it application to the perturbative deformed holomorphic symplectic structure in the A-model, and a Calabi-Yau manifold with boundaries in the B-model. We show that equivalent classes of deformations are described by a Hochschild cohomology of the DG-algebra A = (A,Q), Q = ∂-bar+∂ deform, which is defined to be the cohomology of (-1) n Q+d Hoch . Here ∂-bar is the initial non-deformed BRST operator while ∂ deform is the deformed part whose algebra is a Lie algebra of linear vector fields gl n .

  14. Hopf structure and Green ansatz of deformed parastatistics algebras

    Energy Technology Data Exchange (ETDEWEB)

    Aneva, Boyka [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, bld. Tsarigradsko chaussee 72, BG-1784 Sofia (Bulgaria); Popov, Todor [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, bld. Tsarigradsko chaussee 72, BG-1784 Sofia (Bulgaria)

    2005-07-22

    Deformed parabose and parafermi algebras are revised and endowed with Hopf structure in a natural way. The noncocommutative coproduct allows for construction of parastatistics Fock-like representations, built out of the simplest deformed Bose and Fermi representations. The construction gives rise to quadratic algebras of deformed anomalous commutation relations which define the generalized Green ansatz.

  15. In-situ studies of bulk deformation structures: Static properties under load and dynamics during deformation

    DEFF Research Database (Denmark)

    Jakobsen, Bo

    2006-01-01

    The main goal of the study presented in this thesis was to perform in-situ investigations on deformation structures in plastically deformed polycrystalline copper at low degrees of tensile deformation (model system for cell forming pure fcc metals. Anovel synchrotron...... grains in polycrystalline samples during tensile deformation. We have shown that the resulting 3D reciprocal space maps from tensile deformed copper comprise a pronounced structure, consisting of bright sharp peaks superimposed on a cloud of enhanced intensity. Based on the integrated intensity......, the width of the peaks, and spatial scanning experiments it is concluded that the individual peaks arise from individual dislocation-free regions (the subgrains) in the dislocation structure. The cloud is attributed to the dislocation rich walls. Samples deformed to 2% tensile strain were investigated under...

  16. Deformations of symplectic Lie algebroids, deformations of holomorphic symplectic structures, and index theorems

    DEFF Research Database (Denmark)

    Nest, Ryszard; Tsygan, Boris

    2001-01-01

    Recently Kontsevich solved the classification problem for deformation quantizations of all Poisson structures on a manifold. In this paper we study those Poisson structures for which the explicit methods of Fedosov can be applied, namely the Poisson structures coming from symplectic Lie algebroids......, as well as holomorphic symplectic structures. For deformations of these structures we prove the classification theorems and a general a general index theorem....

  17. Deformation compatibility control for engineering structures methods and applications

    CERN Document Server

    Zhu, Hanhua; Chen, Mengchong; Deng, Jianliang

    2017-01-01

    This book presents essential methods of deformation compatibility control, and explicitly addresses the implied conditions on the methods’ deformation compatibility. Consequently, these conditions can be considered in engineering structure design, while the conditions on stable equilibrium can be taken into account in the design method. Thus, the designed deformation and the actual deformation of the respective structure are approximately identical, guaranteeing both the flexibility of the construction material in force transmission and the equilibrium of force in the structure. Though equilibrium theory in engineering structures has been extensively studied, there has been comparatively little research on compatibility. In the limited researches available, the topics are primarily the theories and assumptions on the deformation compatibility, while few systematic works focus on the mechanical theoretical principles and methods of deformation compatibility control. As such, the flexibility of the constructi...

  18. Study of structural changes during deformation of polycrystal vanadium

    International Nuclear Information System (INIS)

    Zubets, Yu.E.; Manilov, V.A.; Sarzhan, G.F.; Trefilov, V.I.; Firstov, S.A.

    1978-01-01

    Investigated were the polycrystalline vanadium dislocation structure formed within the range of temperatures between 20 and 1000 deg C and in the interval of deformations between 5 and 94%. The diagram of states was established in the temperature vs. degree of deformation coordinates from electron microscopy data. It was shown that a deformation of 5-7% leads to the appearance in the structure of incorrect shape dislocations with a lot of jogs and kinks. The density of relatively homogeneously distributed dislocations increases with the degree of deformation up to the latter's value of 50%. At a deformation greater than 50%, there forms a cellular structure, there remaining ranges where no cellular structure is formed. Thus, there appears a two-component texture with a different level of internal stresses. Annealing of such a material gives rise to areas of different types of cellular structure

  19. Structural Characteristics and Physical Properties of Tectonically Deformed Coals

    OpenAIRE

    Yiwen Ju; Zhifeng Yan; Xiaoshi Li; Quanlin Hou; Wenjing Zhang; Lizhi Fang; Liye Yu; Mingming Wei

    2012-01-01

    Different mechanisms of deformation could make different influence on inner structure and physical properties of tectonically deformed coal (TDC) reservoirs. This paper discusses the relationship between macromolecular structure and physical properties of the Huaibei-Huainan coal mine areas in southern North China. The macromolecular structure and pore characteristics are systematically investigated by using techniques such as X-ray diffraction (XRD), high-resolution transmission electron mic...

  20. Long-term Deformation Measurements of Atypical Roof Timber Structures

    Directory of Open Access Journals (Sweden)

    Jiří Bureš

    2014-06-01

    Full Text Available The paper includes conclusions from evaluation of results obtained from long-termmeasuring of innovative atypical roof timber structures. Based on the results ofmeasurements of vertical and horizontal deformation components it is possible to analyzethe real behavior of structures in given conditions. By assessing deformations in variousstages, including particularly external and internal environment temperatures, relative airhumidity and moisture content of wood, decisive parameters for real structure behaviorcan be established. The data are processed from period 2001 – 2013.

  1. Formation of disorientations in dislocation structures during plastic deformation

    DEFF Research Database (Denmark)

    Pantleon, W.

    2002-01-01

    Disorientations developing during plastic deformation in dislocation structures are investigated. Based on expected mechanisms for the formation of different types of dislocation boundaries (statistical trapping of dislocations or differently activated slip systems) the formation of the disorient...

  2. Bicrossproduct structure and graded contractions of deformed algebras

    International Nuclear Information System (INIS)

    Perez Bueno, J.C.

    1997-01-01

    It is shown that all members in the family of deformed Hopf algebras corresponding to the graded contractions of the inhomogeneous algebras iso(p,q), p + q = N, have a bicrossproduct structure. (author)

  3. Effect of deformation on the structural state of piracetam

    Science.gov (United States)

    Kanunnikova, O. M.; Mikhailova, S. S.; Karban', O. V.; Mukhgalin, V. V.; Aksenova, V. V.; Sen'kovskii, B. V.; Pechina, E. A.; Lad'yanov, V. I.

    2016-04-01

    The effect of various deformation actions on the structure-phase transformations in piracetam of modifications I and II with a sodium acetate addition is studied. Mechanical activation and pressing are shown to cause the polymorphic transformation of modification I into modification II, and modification III forms predominantly during severe plastic deformation by torsion. The structural difference between the piracetam molecules of modifications I and II is found to be retained in aqueous solutions.

  4. Displacement and deformation measurement for large structures by camera network

    Science.gov (United States)

    Shang, Yang; Yu, Qifeng; Yang, Zhen; Xu, Zhiqiang; Zhang, Xiaohu

    2014-03-01

    A displacement and deformation measurement method for large structures by a series-parallel connection camera network is presented. By taking the dynamic monitoring of a large-scale crane in lifting operation as an example, a series-parallel connection camera network is designed, and the displacement and deformation measurement method by using this series-parallel connection camera network is studied. The movement range of the crane body is small, and that of the crane arm is large. The displacement of the crane body, the displacement of the crane arm relative to the body and the deformation of the arm are measured. Compared with a pure series or parallel connection camera network, the designed series-parallel connection camera network can be used to measure not only the movement and displacement of a large structure but also the relative movement and deformation of some interesting parts of the large structure by a relatively simple optical measurement system.

  5. Control and large deformations of marginal disordered structures

    Science.gov (United States)

    Murugan, Arvind; Pinson, Matthew; Chen, Elizabeth

    Designed deformations, such as origami patterns, provide a way to make easily controlled mechanical metamaterials with tailored responses to external forces. We focus on an often overlooked regime of origami - non-linear deformations of large disordered origami patterns with no symmetries. We find that practical questions of control in origami have counterintuitive answers, because of intimate connections to spin glasses and neural networks. For example, 1 degree of freedom origami structures are actually difficult to control about the flat state with a single actuator; the actuator is thrown off by an exponential number of `red herring' zero modes for small deformations, all but one of which disappear at larger deformations. Conversely, structures with multiple programmed motions are much easier to control than expected - in fact, they are as easy to control as a dedicated single-motion structure if the number of programmed motions is below a threshold (`memory capacity').

  6. Late-Paleozoic-Mesozoic deformational and deformation related metamorphic structures of Kuznetsk-Altai region

    Science.gov (United States)

    Zinoviev, Sergei

    2014-05-01

    Kuznetsk-Altai region is a part of the Central Asian Orogenic Belt. The nature and formation mechanisms of the observed structure of Kuznetsk-Altai region are interpreted by the author as the consequence of convergence of Tuva-Mongolian and Junggar lithospheric block structures and energy of collision interaction between the blocks of crust in Late-Paleozoic-Mesozoic period. Tectonic zoning of Kuznetsk-Altai region is based on the principle of adequate description of geological medium (without methods of 'primary' state recovery). The initial indication of this convergence is the crust thickening in the zone of collision. On the surface the mechanisms of lateral compression form a regional elevation; with this elevation growth the 'mountain roots' start growing. With an approach of blocks an interblock elevation is divided into various fragments, and these fragments interact in the manner of collision. The physical expression of collision mechanisms are periodic pulses of seismic activity. The main tectonic consequence of the block convergence and collision of interblock units is formation of an ensemble of regional structures of the deformation type on the basis of previous 'pre-collision' geological substratum [Chikov et al., 2012]. This ensemble includes: 1) allochthonous and autochthonous blocks of weakly deformed substratum; 2) folded (folded-thrust) systems; 3) dynamic metamorphism zones of regional shears and main faults. Characteristic of the main structures includes: the position of sedimentary, magmatic and PT-metamorphic rocks, the degree of rock dynamometamorphism and variety rock body deformation, as well as the styles and concentrations of mechanic deformations. 1) block terranes have weakly elongated or isometric shape in plane, and they are the systems of block structures of pre-collision substratum separated by the younger zones of interblock deformations. They stand out among the main deformation systems, and the smallest are included into the

  7. Formation of diapiric structure in the deformation zone, central ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    serpentinite layer existing near the base of the crust that is interpreted to have been formed at mid-ocean ... Keywords. Diffusive plate boundary; deformation zone; diapiric structure; serpentinized peridotites; crustal structure; ... calculated by applying Eotvos correction and nor- ..... trend of the basement and flat Moho, and.

  8. Thermally assisted deformation of structural superplastics and ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    constant.) (xii) It has been suggested that the self and the solute diffusivities are enhanced and the .... In this paper, only a summary of the important experimental results that a viable theory of structural ..... Experimental verification. Mater. Sci.

  9. QuikForm: Intelligent deformation processing of structural alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bourcier, R.J.; Wellman, G.W.

    1994-09-01

    There currently exists a critical need for tools to enhance the industrial competitiveness and agility of US industries involved in deformation processing of structural alloys. In response to this need, Sandia National Laboratories has embarked upon the QuikForm Initiative. The goal of this program is the development of computer-based tools to facilitate the design of deformation processing operations. The authors are currently focusing their efforts on the definition/development of a comprehensive system for the design of sheet metal stamping operations. The overall structure of the proposed QuikForm system is presented, and the focus of their thrust in each technical area is discussed.

  10. Co2 injection into oil reservoir associated with structural deformation

    KAUST Repository

    El-Amin, Mohamed

    2012-01-01

    In this work, the problem of structural deformation with two-phase flow of carbon sequestration is presented. A model to simulate miscible CO2 injection with structural deformation in the aqueous phase is established. In the first part of this paper, we developed analytical solution for the problem under consideration with certain types of boundary conditions, namely, Dirichlet and Neumann boundary conditions. The second part concerns to numerical simulation using IMPDES scheme. A simulator based on cell-centered finite difference method is used to solve this equations system. Distributions of CO2 saturation, and horizontal and vertical displacements have been introduced.

  11. Evaluation of soft sediment deformation structures along the Fethiye ...

    Indian Academy of Sciences (India)

    Burdur city is located on lacustrine sedimentary deposits at the northeastern end of the Fethiye–Burdur Fault Zone (FBFZ) in SW Turkey. Fault steps were formed in response to vertical displacement along normal fault zones in these deposits. Soft sediment deformation structures were identified at five sitesin lacustrine ...

  12. Structure, deformation, and failure of flow-oriented semicrystalline polymers

    NARCIS (Netherlands)

    Schrauwen, B.A.G.; Breemen, van L.C.A.; Spoelstra, A.B.; Govaert, L.E.; Peters, G.W.M.; Meijer, H.E.H.

    2004-01-01

    This study deals with the influence of processing induced crystalline orientation on the macroscopic deformation and failure behavior of thin samples of polyethylene and polypropylene. Distribution and structure of flow-induced orientations were characterized by optical microscopy, X-ray diffraction

  13. Characteristics of aluminum alloy microplastic deformation in different structural states

    Energy Technology Data Exchange (ETDEWEB)

    Seregin, G.V.; Efimenko, L.L.; Leonov, M.V. [Novosibirsk Pedagogical Inst. (Russian Federation)

    1995-07-01

    The solution to the problem of improving the mechanical properties (including cyclic strength) of structural materials is largely dependent on our knowledge of the laws governing the development of microplastic deformations in them. The effect of heat and mechanical treatment on the elastoplastic properties and fatigue resistance of the commercial aluminum alloys AK4-1 and D16 is analyzed.

  14. High-Resolution Reciprocal Space Mapping for Characterizing Deformation Structures

    DEFF Research Database (Denmark)

    Pantleon, Wolfgang; Wejdemann, Christian; Jakobsen, Bo

    2014-01-01

    With high-angular resolution three-dimensional X-ray diffraction (3DXRD), quantitative information is gained about dislocation structures in individual grains in the bulk of a macroscopic specimen by acquiring reciprocal space maps. In high-resolution 3D reciprocal space maps of tensile......-deformed copper, individual, almost dislocation-free subgrains are identified from high-intensity peaks and distinguished by their unique combination of orientation and elastic strain; dislocation walls manifest themselves as a smooth cloud of lower intensity. The elastic strain shows only minor variations within...... dynamics is followed in situ during varying loading conditions by reciprocal space mapping: during uninterrupted tensile deformation, formation of subgrains is observed concurrently with broadening of Bragg reflections shortly after the onset of plastic deformation. When the traction is terminated, stress...

  15. EARTHQUAKE-INDUCED DEFORMATION STRUCTURES AND RELATED TO EARTHQUAKE MAGNITUDES

    Directory of Open Access Journals (Sweden)

    Savaş TOPAL

    2003-02-01

    Full Text Available Earthquake-induced deformation structures which are called seismites may helpful to clasify the paleoseismic history of a location and to estimate the magnitudes of the potention earthquakes in the future. In this paper, seismites were investigated according to the types formed in deep and shallow lake sediments. Seismites are observed forms of sand dikes, introduced and fractured gravels and pillow structures in shallow lakes and pseudonodules, mushroom-like silts protruding laminites, mixed layers, disturbed varved lamination and loop bedding in deep lake sediments. Earthquake-induced deformation structures, by benefiting from previous studies, were ordered according to their formations and earthquake magnitudes. In this order, the lowest eartquake's record is loop bedding and the highest one is introduced and fractured gravels in lacustrine deposits.

  16. Crustal structure and tectonic deformation of the southern Ecuadorian margin

    Science.gov (United States)

    Calahorrano, Alcinoe; Collot, Jean-Yves; Sage, Françoise; Ranero, César R.

    2010-05-01

    Multichannel seismic lines acquired during the SISTEUR cruise (2000) provide new constraints on the structure and deformation of the subduction zone at the southern Ecuadorian margin, from the deformation front to the continental shelf of the Gulf of Guayaquil. The pre-stack depth migrated images allows to characterise the main structures of the downgoing and overriding plates and to map the margin stratigraphy in order to propose a chronology of the deformation, by means of integrating commercial well data and industry seismic lines located in the gulf area. The 100-km-long seismic lines show the oceanic Nazca plate underthrusting the South American plate, as well as the subduction channel and inter-plate contact from the deformation front to about 90 km landward and ~20 km depth. Based on seismic structure we identify four upper-plate units, consisting of basement and overlaying sedimentary sequences A, B and C. The sedimentary cover varies along the margin, being few hundreds of meters thick in the lower and middle slope, and ~2-3 km thick in the upper slope. Exceptionally, a ~10-km -thick basin, here named Banco Peru basin, is located on the upper slope at the southernmost part of the gulf. This basin seems to be the first evidence of the Gulf of Guayaquil opening resulting from the NE escaping of the North Andean Block. Below the continental shelf, thick sedimentary basins of ~6 to 8 km occupy most of the gulf area. Tectonic deformation across most of the upper-plate is dominated by extensional regime, locally disturbed by diapirism. Compression evidences are restricted to the deformation front and surrounding areas. Well data calibrating the seismic profiles indicate that an important portion of the total thickness of the sedimentary coverage of the overriding plate are Miocene or older. The data indicate the extensional deformation resulting from the NE motion of the North Andean Block and the opening of the Gulf of Guayaquil, evolves progressively in age

  17. Remote sensing image stitch using modified structure deformation

    Science.gov (United States)

    Pan, Ke-cheng; Chen, Jin-wei; Chen, Yueting; Feng, Huajun

    2012-10-01

    To stitch remote sensing images seamlessly without producing visual artifact which is caused by severe intensity discrepancy and structure misalignment, we modify the original structure deformation based stitching algorithm which have two main problems: Firstly, using Poisson equation to propagate deformation vectors leads to the change of the topological relationship between the key points and their surrounding pixels, which may bring in wrong image characteristics. Secondly, the diffusion area of the sparse matrix is too limited to rectify the global intensity discrepancy. To solve the first problem, we adopt Spring-Mass model and bring in external force to keep the topological relationship between key points and their surrounding pixels. We also apply tensor voting algorithm to achieve the global intensity corresponding curve of the two images to solve the second problem. Both simulated and experimental results show that our algorithm is faster and can reach better result than the original algorithm.

  18. Intermediate size inducer pump - structural analysis and transient deformation studies

    International Nuclear Information System (INIS)

    Cheng, T.K.; Nishizaka, J.N.

    1979-05-01

    This report summarizes the structural and thermal transient deformation analysis of the Intermediate Size Inducer Pump. The analyses were performed in accordance to the requirements of N266ST310001, the specification for the ISIP. Results of stress analysis indicate that the thermal transient stress and strain are within the stress strain limits of RDT standard F9-4 which was used as a guide

  19. Dislocation Structures in Creep-deformed Polycrystalline MgO

    DEFF Research Database (Denmark)

    Bilde-Sørensen, Jørgen

    1972-01-01

    dislocation segments lie in their slip or climb planes. On the basis of this structure, a model is proposed in which glide is the principal cause of deformation but the rate-limiting process, i.e. annealing of the network, is diffusion-controlled. Theoretical estimates and experimental results agree within 1...... energy of 76 ± 12 kcal/mol. The creep rate is independent of grain size. The dislocation structure was investigated by transmission electron microscopy. The total dislocation density follows the relation, σ=bG√ρ, commonly found for metals. The dislocations form a 3-dimensional network in which many...

  20. Fast Detection of Material Deformation through Structural Dissimilarity

    Energy Technology Data Exchange (ETDEWEB)

    Ushizima, Daniela; Perciano, Talita; Parkinson, Dilworth

    2015-10-29

    Designing materials that are resistant to extreme temperatures and brittleness relies on assessing structural dynamics of samples. Algorithms are critically important to characterize material deformation under stress conditions. Here, we report on our design of coarse-grain parallel algorithms for image quality assessment based on structural information and on crack detection of gigabyte-scale experimental datasets. We show how key steps can be decomposed into distinct processing flows, one based on structural similarity (SSIM) quality measure, and another on spectral content. These algorithms act upon image blocks that fit into memory, and can execute independently. We discuss the scientific relevance of the problem, key developments, and decomposition of complementary tasks into separate executions. We show how to apply SSIM to detect material degradation, and illustrate how this metric can be allied to spectral analysis for structure probing, while using tiled multi-resolution pyramids stored in HDF5 chunked multi-dimensional arrays. Results show that the proposed experimental data representation supports an average compression rate of 10X, and data compression scales linearly with the data size. We also illustrate how to correlate SSIM to crack formation, and how to use our numerical schemes to enable fast detection of deformation from 3D datasets evolving in time.

  1. Structure and properties of copper after large strain deformation

    Energy Technology Data Exchange (ETDEWEB)

    Rodak, Kinga; Molak, Rafal M.; Pakiela, Zbigniew

    2010-05-15

    Structure and properties of Cu in dependence on strain (from {epsilon}{proportional_to} 0.9 to {epsilon}{proportional_to} 15) during multi-axial compression processing at room temperature was investigated. The evolution of dislocation structure, misorientation distribution and crystallite size were observed by using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) equipment with electron back scattered diffraction (EBSD) facility. The mechanical properties of yield strength (YS), ultimate tensile strength (UTS) and uniform elongation was performed on MTS QTest/10 machine equipped with digital image correlation method (DIC). The structure-flow stress relationship of multi-axial compression processing material at strains {epsilon}{proportional_to} 3.5 and {epsilon}{proportional_to} 5.5 is discussed. It is found that processing does not produce any drastic changes in deformation structure and the microstructural refinement is slow. These results indicate that dynamic recrystallization plays an important role during multi-axial compression process in this range of deformation (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Ocean acidification causes structural deformities in juvenile coral skeletons.

    Science.gov (United States)

    Foster, Taryn; Falter, James L; McCulloch, Malcolm T; Clode, Peta L

    2016-02-01

    Rising atmospheric CO2 is causing the oceans to both warm and acidify, which could reduce the calcification rates of corals globally. Successful coral recruitment and high rates of juvenile calcification are critical to the replenishment and ultimate viability of coral reef ecosystems. Although elevated Pco2 (partial pressure of CO2) has been shown to reduce the skeletal weight of coral recruits, the structural changes caused by acidification during initial skeletal deposition are unknown. We show, using high-resolution three-dimensional x-ray microscopy, that ocean acidification (Pco2 ~900 μatm, pH ~7.7) not only causes reduced overall mineral deposition but also a deformed and porous skeletal structure in newly settled coral recruits. In contrast, elevated temperature (+3°C) had little effect on skeletal formation except to partially mitigate the effects of elevated Pco2. The striking structural deformities we observed show that new recruits are at significant risk, being unable to effectively build their skeletons in the Pco2 conditions predicted to occur for open ocean surface waters under a "business-as-usual" emissions scenario [RCP (representative concentration pathway) 8.5] by the year 2100.

  3. Evolution of the structure and the phase composition of a bainitic structural steel during plastic deformation

    Science.gov (United States)

    Nikitina, E. N.; Glezer, A. M.; Ivanov, Yu. F.; Aksenova, K. V.; Gromov, V. E.; Kazimirov, S. A.

    2017-10-01

    The evolution of the phase composition and the imperfect substructure of the 30Kh2N2MFA bainitic structural steel subjected to compressive deformation by 36% is quantitatively analyzed. It is shown that deformation is accompanied by an increase in the scalar dislocation density, a decrease in the longitudinal fragment sizes, an increase in the number of stress concentrators, the dissolution of cementite particles, and the transformation of retained austenite.

  4. Structural deformation and intertube conductance of crossed carbon nanotube

    International Nuclear Information System (INIS)

    Yoon, Young-Gui; Mazzoni, Mario S.C.; Choi, Hyoung J.; Ihm, Jisoon; Louie, Steven G.

    2000-01-01

    We present a first-principles study of the structure and quantum electronic conductance of junctions consisting of two crossed (5,5) single-walled carbon nanotubes. The structures are determined by constrained minimization of total energy at a given force between the two tubes, simulating the effects of substrate-tube attraction or an applied force. We find that the intertube contact distance is very sensitive to the applied force in the range of 0-10 nN. The intertube conductance is sizable for realistic deformation expected from substrate interaction. The results explain the recent transport data on crossed nanotubes and show that these systems may be potentially useful as electromechanical devices

  5. Structural Deformation and Intertube Conductance of Crossed Carbon Nanotube Junctions

    International Nuclear Information System (INIS)

    Yoon, Young-Gui; Mazzoni, Mario S. C.; Choi, Hyoung Joon; Ihm, Jisoon; Louie, Steven G.

    2001-01-01

    We present a first-principles study of the structure and quantum electronic conductance of junctions consisting of two crossed (5,5) single-walled carbon nanotubes. The structures are determined by constrained minimization of total energy at a given force between the two tubes, simulating the effects of substrate-tube attraction or an applied force. We find that the intertube contact distance is very sensitive to the applied force in the range of 0--10nN. The intertube conductance is sizable for realistic deformation expected from substrate interaction. The results explain the recent transport data on crossed nanotubes and show that these systems may be potentially useful as electromechanical devices

  6. Effect of deformation diagram on molybdenum structure and properties

    International Nuclear Information System (INIS)

    Larin, Eh.N.; Abalikhin, A.A.; Kolikov, A.P.; Ushakova, N.E.

    1984-01-01

    Effect of deformation diagram on a tendency to lamination and mechanical properties of disks made of molybdenum alloy is studied. Investigated samples were subjected to hot rolling or forging. X-ray structural analysis of texture is carried out along with estimation of the level of mechanical properties across item cross section. Sample mechanical bending tests were conducted. Sample microstructure is also studied. It is shown that rolled molybdenum has a tendency to lamination, but forged molybdenum is free of such a tendency. Forged sample ductility is practically equal in all directionse but rolled sample ductility in a surface layer is high and decreases with depth. A conclusion is drawn that forged sample grains in a setting surface are equiaxial, but distinct deformation texture is observed for rolled samples and their grains are elongated in the direction of rolling. A conclusion is made that a flow diagram of the process of disk fabrication by forging or stamping ppovides a necessary complex of physicomechanical properties of metal as compared to polling, and metal discharge coefficient decreases sharply in this case

  7. Modeling level structures of odd-odd deformed nuclei

    International Nuclear Information System (INIS)

    Hoff, R.W.; Kern, J.; Piepenbring, R.; Boisson, J.P.

    1984-01-01

    A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation were derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings were used. Calculated and experimental level structures for 238 Np, 244 Am, and 250 Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Corresponding average deviations for five rare-earth nuclei are 47 keV and 7%. Several applications of this modeling technique are discussed. 18 refs., 5 figs., 4 tabs

  8. A study of the deformability of composite rods with end fittings for truss structures

    Energy Technology Data Exchange (ETDEWEB)

    Stepanychev, E I; Novikov, V V; Sukhanov, A V; Lapotkin, V A; Postnov, A N [Moskovskii Aviatsionnyi Tekhnologicheskii Institut, Moscow (USSR)

    1989-04-01

    A method is proposed for studying the deformability characteristics of composite rods with end fittings under static loading. Three types of connectors for tubular composite rods are examined from the standpoint of deformability, and differences in the deformability of the central part of a rod and of the connection zone are discussed. The effect of thermal cycling on the deformability of structures of this type is analyzed. 7 refs.

  9. STRUCTURAL AND MECHANICAL CHARACTERIZATION OF DEFORMED POLYMER USING CONFOCAL RAMAN MICROSCOPY AND DSC

    Directory of Open Access Journals (Sweden)

    Birgit Neitzel

    2016-02-01

    Full Text Available Polymers have various interesting properties, which depend largely on their inner structure. One way to influence the macroscopic behaviour is the deformation of the polymer chains, which effects the change in microstructure. For analyzing the microstructure of non-deformed and deformed polymer materials, Raman spectroscopy as well as differential scanning calorimetry (DSC were used. In the present study we compare the results for crystallinity measurements of deformed polymers using both methods in order to characterize the differences in micro-structure due to deformation. The study is ongoing, and we present the results of the first tests.

  10. Structure of deformed wing virus, a major honey bee pathogen.

    Science.gov (United States)

    Škubník, Karel; Nováček, Jiří; Füzik, Tibor; Přidal, Antonín; Paxton, Robert J; Plevka, Pavel

    2017-03-21

    The worldwide population of western honey bees ( Apis mellifera ) is under pressure from habitat loss, environmental stress, and pathogens, particularly viruses that cause lethal epidemics. Deformed wing virus (DWV) from the family Iflaviridae , together with its vector, the mite Varroa destructor , is likely the major threat to the world's honey bees. However, lack of knowledge of the atomic structures of iflaviruses has hindered the development of effective treatments against them. Here, we present the virion structures of DWV determined to a resolution of 3.1 Å using cryo-electron microscopy and 3.8 Å by X-ray crystallography. The C-terminal extension of capsid protein VP3 folds into a globular protruding (P) domain, exposed on the virion surface. The P domain contains an Asp-His-Ser catalytic triad that is, together with five residues that are spatially close, conserved among iflaviruses. These residues may participate in receptor binding or provide the protease, lipase, or esterase activity required for entry of the virus into a host cell. Furthermore, nucleotides of the DWV RNA genome interact with VP3 subunits. The capsid protein residues involved in the RNA binding are conserved among honey bee iflaviruses, suggesting a putative role of the genome in stabilizing the virion or facilitating capsid assembly. Identifying the RNA-binding and putative catalytic sites within the DWV virion structure enables future analyses of how DWV and other iflaviruses infect insect cells and also opens up possibilities for the development of antiviral treatments.

  11. Nuclear structure at high-spin and large-deformation

    International Nuclear Information System (INIS)

    Shimizu, Yoshifumi R.

    2000-01-01

    Atomic nucleus is a finite quantal system and shows various marvelous features. One of the purposes of the nuclear structure study is to understand such features from a microscopic viewpoint of nuclear many-body problem. Recently, it is becoming possible to explore nuclear states under 'extreme conditions', which are far different from the usual ground states of stable nuclei, and new aspects of such unstable nuclei attract our interests. In this lecture, I would like to discuss the nuclear structure in the limit of rapid rotation, or the extreme states with very large angular momenta, which became accessible by recent advent of large arrays of gamma-ray detecting system; these devices are extremely useful to measure coincident multiple γ-rays following heavy-ion fusion reactions. Including such experimental aspects as how to detect the nuclear rotational states, I review physics of high-spin states starting from the elementary subjects of nuclear structure study. In would like also to discuss the extreme states with very large nuclear deformation, which are easily realized in rapidly rotating nuclei. (author)

  12. Computational mesh generation for vascular structures with deformable surfaces

    International Nuclear Information System (INIS)

    Putter, S. de; Laffargue, F.; Breeuwer, M.; Vosse, F.N. van de; Gerritsen, F.A.; Philips Medical Systems, Best

    2006-01-01

    Computational blood flow and vessel wall mechanics simulations for vascular structures are becoming an important research tool for patient-specific surgical planning and intervention. An important step in the modelling process for patient-specific simulations is the creation of the computational mesh based on the segmented geometry. Most known solutions either require a large amount of manual processing or lead to a substantial difference between the segmented object and the actual computational domain. We have developed a chain of algorithms that lead to a closely related implementation of image segmentation with deformable models and 3D mesh generation. The resulting processing chain is very robust and leads both to an accurate geometrical representation of the vascular structure as well as high quality computational meshes. The chain of algorithms has been tested on a wide variety of shapes. A benchmark comparison of our mesh generation application with five other available meshing applications clearly indicates that the new approach outperforms the existing methods in the majority of cases. (orig.)

  13. Speckle photography applied to measure deformations of very large structures

    Science.gov (United States)

    Conley, Edgar; Morgan, Chris K.

    1995-04-01

    Fundamental principles of mechanics have recently been brought to bear on problems concerning very large structures. Fields of study include tectonic plate motion, nuclear waste repository vault closure mechanisms, the flow of glacier and sea ice, and highway bridge damage assessment and residual life prediction. Quantitative observations, appropriate for formulating and verifying models, are still scarce however, so the need to adapt new methods of experimental mechanics is clear. Large dynamic systems often exist in environments subject to rapid change. Therefore, a simple field technique that incorporates short time scales and short gage lengths is required. Further, the measuring methods must yield displacements reliably, and under oft-times adverse field conditions. Fortunately, the advantages conferred by an experimental mechanics technique known as speckle photography nicely fulfill this rather stringent set of performance requirements. Speckle seemed to lend itself nicely to the application since it is robust and relatively inexpensive. Experiment requirements are minimal -- a camera, high resolution film, illumination, and an optically rough surface. Perhaps most important is speckle's distinct advantage over point-by-point methods: It maps the two dimensional displacement vectors of the whole field of interest. And finally, given the method's high spatial resolution, relatively short observation times are necessary. In this paper we discuss speckle, two variations of which were used to gage the deformation of a reinforced concrete bridge structure subjected to bending loads. The measurement technique proved to be easily applied, and yielded the location of the neutral axis self consistently. The research demonstrates the feasibility of using whole field techniques to detect and quantify surface strains of large structures under load.

  14. Polycrystal deformation and single crystal deformation: Dislocation structure and flow stress in copper

    DEFF Research Database (Denmark)

    Huang, X.; Borrego, A.; Pantleon, W.

    2001-01-01

    of microstructures have been identified. A correlation is found between microstructure and grain orientation, which agrees well with earlier observations in tensile deformed aluminum polycrystals and copper single crystals. The stress–strain curve of the copper polycrystal is calculated with good accuracy from...

  15. Hamiltonian structure of isospectral deformation equation and semi-classical approximation to factorized S-matrices

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.; Chudnovsky, G.V.

    1980-01-01

    We consider semi-classical approximation to factorized S-matrices. We show that this new class of matrices, called s-matrices, defines Hamiltonian structures for isospectral deformation equations. Concrete examples of factorized s-matrices are constructed and they are used to define Hamiltonian structure for general two-dimensional isospectral deformation systems. (orig.)

  16. Structural Changes in Deformed Soft Magnetic Ni-Based Metallic Glass

    NARCIS (Netherlands)

    Jurikova, A.; Csach, K.; Miskuf, J.; Ocelik, V.

    The effects of intensive plastic deformation of the soft magnetic metallic glass Ni Si 13 on the structural relaxation were examined. The enthalpy changes studied by differential scanning calorimetry revealed that the intensive plastic deformation was associated with the partial structural

  17. A simulation model for analysing brain structure deformations

    Energy Technology Data Exchange (ETDEWEB)

    Bona, Sergio Di [Institute for Information Science and Technologies, Italian National Research Council (ISTI-8211-CNR), Via G Moruzzi, 1-56124 Pisa (Italy); Lutzemberger, Ludovico [Department of Neuroscience, Institute of Neurosurgery, University of Pisa, Via Roma, 67-56100 Pisa (Italy); Salvetti, Ovidio [Institute for Information Science and Technologies, Italian National Research Council (ISTI-8211-CNR), Via G Moruzzi, 1-56124 Pisa (Italy)

    2003-12-21

    Recent developments of medical software applications from the simulation to the planning of surgical operations have revealed the need for modelling human tissues and organs, not only from a geometric point of view but also from a physical one, i.e. soft tissues, rigid body, viscoelasticity, etc. This has given rise to the term 'deformable objects', which refers to objects with a morphology, a physical and a mechanical behaviour of their own and that reflects their natural properties. In this paper, we propose a model, based upon physical laws, suitable for the realistic manipulation of geometric reconstructions of volumetric data taken from MR and CT scans. In particular, a physically based model of the brain is presented that is able to simulate the evolution of different nature pathological intra-cranial phenomena such as haemorrhages, neoplasm, haematoma, etc and to describe the consequences that are caused by their volume expansions and the influences they have on the anatomical and neuro-functional structures of the brain.

  18. Structural aspects of elastic deformation of a metallic glass

    International Nuclear Information System (INIS)

    Hufnagel, T. C.; Ott, R. T.; Almer, J.

    2006-01-01

    We report the use of high-energy x-ray scattering to measure strain in a Zr 57 Ti 5 Cu 20 Ni 8 Al 10 bulk metallic glass in situ during uniaxial compression in the elastic regime up to stresses of approximately 60% of the yield stress. The strains extracted in two ways--directly from the normalized scattering data and from the pair correlation functions--are in good agreement with each other for length scales greater than 4 A. The elastic modulus calculated on the basis of this strain is in good agreement with that reported for closely related amorphous alloys based on macroscopic measurements. The strain measured for atoms in the nearest-neighbor shell, however, is smaller than that for more distant shells, and the effective elastic modulus calculated from the strain on this scale is therefore larger, comparable to crystalline alloys of similar composition. These observations are in agreement with previously proposed models in which the nominally elastic deformation of a metallic glass has a significant anelastic component due to atomic rearrangements in topologically unstable regions of the structure. We also observe that the distribution of the atomic-level stresses in the glass becomes more uniform during loading. This implies that the stiffness of metallic glasses may have an entropic contribution, analogous to the entropic contribution in rubber elasticity

  19. Exploring of PST-TBPM in Monitoring Dynamic Deformation of Steel Structure in Vibration

    Science.gov (United States)

    Chen, Mingzhi; Zhao, Yongqian; Hai, Hua; Yu, Chengxin; Zhang, Guojian

    2018-01-01

    In order to monitor the dynamic deformation of steel structure in the real-time, digital photography is used in this paper. Firstly, the grid method is used correct the distortion of digital camera. Then the digital cameras are used to capture the initial and experimental images of steel structure to obtain its relative deformation. PST-TBPM (photographing scale transformation-time baseline parallax method) is used to eliminate the parallax error and convert the pixel change value of deformation points into the actual displacement value. In order to visualize the deformation trend of steel structure, the deformation curves are drawn based on the deformation value of deformation points. Results show that the average absolute accuracy and relative accuracy of PST-TBPM are 0.28mm and 1.1‰, respectively. Digital photography used in this study can meet accuracy requirements of steel structure deformation monitoring. It also can warn the safety of steel structure and provide data support for managers’ safety decisions based on the deformation curves on site.

  20. Complex structure-induced deformations of σ-models

    Energy Technology Data Exchange (ETDEWEB)

    Bykov, Dmitri [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,Am Mühlenberg 1, D-14476 Potsdam-Golm (Germany); Steklov Mathematical Institute of Russ. Acad. Sci.,Gubkina str. 8, 119991 Moscow (Russian Federation)

    2017-03-24

    We describe a deformation of the principal chiral model (with an even-dimensional target space G) by a B-field proportional to the Kähler form on the target space. The equations of motion of the deformed model admit a zero-curvature representation. As a simplest example, we consider the case of G=S{sup 1}×S{sup 3}. We also apply a variant of the construction to a deformation of the AdS{sub 3}×S{sup 3}×S{sup 1} (super-)σ-model.

  1. String field theory. Algebraic structure, deformation properties and superstrings

    International Nuclear Information System (INIS)

    Muenster, Korbinian

    2013-01-01

    This thesis discusses several aspects of string field theory. The first issue is bosonic open-closed string field theory and its associated algebraic structure - the quantum open-closed homotopy algebra. We describe the quantum open-closed homotopy algebra in the framework of homotopy involutive Lie bialgebras, as a morphism from the loop homotopy Lie algebra of closed string to the involutive Lie bialgebra on the Hochschild complex of open strings. The formulation of the classical/quantum open-closed homotopy algebra in terms of a morphism from the closed string algebra to the open string Hochschild complex reveals deformation properties of closed strings on open string field theory. In particular, we show that inequivalent classical open string field theories are parametrized by closed string backgrounds up to gauge transformations. At the quantum level the correspondence is obstructed, but for other realizations such as the topological string, a non-trivial correspondence persists. Furthermore, we proof the decomposition theorem for the loop homotopy Lie algebra of closed string field theory, which implies uniqueness of closed string field theory on a fixed conformal background. Second, the construction of string field theory can be rephrased in terms of operads. In particular, we show that the formulation of string field theory splits into two parts: The first part is based solely on the moduli space of world sheets and ensures that the perturbative string amplitudes are recovered via Feynman rules. The second part requires a choice of background and determines the real string field theory vertices. Each of these parts can be described equivalently as a morphism between appropriate cyclic and modular operads, at the classical and quantum level respectively. The algebraic structure of string field theory is then encoded in the composition of these two morphisms. Finally, we outline the construction of type II superstring field theory. Specific features of the

  2. Formality theory from Poisson structures to deformation quantization

    CERN Document Server

    Esposito, Chiara

    2015-01-01

    This book is a survey of the theory of formal deformation quantization of Poisson manifolds, in the formalism developed by Kontsevich. It is intended as an educational introduction for mathematical physicists who are dealing with the subject for the first time. The main topics covered are the theory of Poisson manifolds, star products and their classification, deformations of associative algebras and the formality theorem. Readers will also be familiarized with the relevant physical motivations underlying the purely mathematical construction.

  3. Detailed analysis of surface asperity deformation mechanism in diffusion bonding of steel hollow structural components

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C. [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Laboratoire de Mecanique des Contacts et des Structures (LaMCoS), INSA Lyon, 20 Avenue des Sciences, F-69621 Villeurbanne Cedex (France); Li, H. [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Li, M.Q., E-mail: zc9997242256@126.com [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China)

    2016-05-15

    Graphical abstract: This study focused on the detailed analysis of surface asperity deformation mechanism in diffusion bonding of steel hollow structural component. A special surface with regular patterns was processed to be joined so as to observe the extent of surface asperity deformation under different applied bonding pressures. Fracture surface characteristic combined with surface roughness profiles distinctly revealed the enhanced surface asperity deformation as the applied pressure increases. The influence of surface asperity deformation mechanism on joint formation was analyzed: (a) surface asperity deformation not only directly expanded the interfacial contact areas, but also released deformation heat and caused defects, indirectly accelerating atomic diffusion, then benefits to void shrinkage; (b) surface asperity deformation readily introduced stored energy difference between two opposite sides of interface grain boundary, resulting in strain induced interface grain boundary migration. In addition, the influence of void on interface grain boundary migration was analyzed in detail. - Highlights: • A high quality hollow structural component has been fabricated by diffusion bonding. • Surface asperity deformation not only expands the interfacial contact areas, but also causes deformation heat and defects to improve the atomic diffusion. • Surface asperity deformation introduces the stored energy difference between the two opposite sides of interface grain boundary, leading to strain induced interface grain boundary migration. • The void exerts a dragging force on the interface grain boundary to retard or stop interface grain boundary migration. - Abstract: This study focused on the detailed analysis of surface asperity deformation mechanism in similar diffusion bonding as well as on the fabrication of high quality martensitic stainless steel hollow structural components. A special surface with regular patterns was processed to be joined so as to

  4. Soft sediment deformation structures in the Maastrichtian Ajali Formation Western Flank of Anambra Basin, Southern Nigeria

    Science.gov (United States)

    Olabode, Solomon Ojo

    2014-01-01

    Soft sediment deformation structures were recognized in the Maastrichtian shallow marine wave to tide influenced regressive sediments of Ajali Formation in the western flank of Anambra basin, southern Nigerian. The soft sediment deformation structures were in association with cross bedded sands, clay and silt and show different morphological types. Two main types recognised are plastic deformations represented by different types of recumbent folds and injection structure represented by clastic dykes. Other structures in association with the plastic deformation structures include distorted convolute lamination, subsidence lobes, pillars, cusps and sand balls. These structures are interpreted to have been formed by liquefaction and fluidization mechanisms. The driving forces inferred include gravitational instabilities and hydraulic processes. Facies analysis, detailed morphologic study of the soft sediment deformation structures and previous tectonic history of the basin indicate that the main trigger agent for deformation is earthquake shock. The soft sediment deformation structures recognised in the western part of Anambra basin provide a continuous record of the tectonic processes that acted on the regressive Ajali Formation during the Maastrichtian.

  5. Morphology, deformation, and defect structures of TiCr2 in Ti-Cr alloys

    International Nuclear Information System (INIS)

    Chen, K.C.; Allen, S.M.; Livingston, J.D.

    1992-01-01

    The morphologies and defect structures of TiCr 2 in several Ti-Cr alloys have been examined by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM), in order to explore the room-temperature deformability of the Laves phase TiCr 2 . The morphology of the Laves phase was found to be dependent upon alloy composition and annealing temperature. Samples deformed by compression have also been studied using TEM. Comparisons of microstructures before and after deformation suggest an increase in twin, stacking fault, and dislocation density within the Laves phase, indicating some but not extensive room-temperature deformability

  6. Induced deformation of the canonical structure and UV/IR duality in (1+1)D

    International Nuclear Information System (INIS)

    Grigorio, L. S.; Guimaraes, M. S.; Wotzasek, C.

    2008-01-01

    The purpose of this work is twofold. Working in the framework of (1+1)D Lorentz violating field theories, we will investigate first the general claim that fermionic interactions may be equivalent to a deformation of the canonical structure of the theory. Second, the deformed theory will be studied using duality reasoning to address the behavior of the infrared and ultraviolet regimes

  7. Determination of Velocity And Acceleration of Structural Deformation ...

    African Journals Online (AJOL)

    This paper outlines the procedure of geodetic monitoring system of circular oil storage ... In this study, only tank 6 was used as case study scenario for the determination of ... In this study, deformation analysis by Kalman Filter technique of the ...

  8. Cracking in reinforced concrete structures due to imposed deformations

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, A.

    1997-04-01

    This thesis is concerned with modeling of the cracking process in reinforced concrete due to imposed deformations. Cracking is investigated both at early ages, during hydration, and at mature age when the final properties of the concrete are reached. One of the most important material characteristics of the concrete at early ages, the Young`s modulus is determined by means of a dynamic method called the resonance frequency method. 40 refs

  9. Dislocations structure in copper cyclically deformed in low amplitude of deformation

    International Nuclear Information System (INIS)

    Lopes, L.C.R.

    1982-07-01

    The evolution of the dislocation structure during the fatigue life of copper, was observed. Fatigue tests were performed, in annealed polycristals, with constant plastic strain amplitude, and interrupted at different percentages of their fatigue lives. Optical and Scanning Electron Microscopy were used for surface analysis and Transmission Electron Microscopy for structural observations. (E.G.) [pt

  10. Structural defects in natural plastically deformed diamonds: Evidence from EPR spectroscopy

    Science.gov (United States)

    Mineeva, R. M.; Titkov, S. V.; Speransky, A. V.

    2009-06-01

    Structural defects formed as a result of plastic deformation in natural diamond crystals have been studied by EPR spectroscopy. The spectra of brown, pink-brown, black-brown, pink-purple, and gray plastically deformed diamonds of type Ia from deposits in Yakutia and the Urals were recorded. The results of EPR spectroscopy allowed us to identify various deformation centers in the structure of natural diamonds and to show that nitrogen centers were transformed under epigenetic mechanical loading. Abundant A centers, consisting of two isomorphic nitrogen atoms located in neighboring structural sites, were destroyed as a result of this process to form a series of N1, N4, W7, M2, and M3 nitrogen centers. Such centers are characterized by an anisotropic spatial distribution and a positive charge, related to the mechanism of their formation. In addition, N2 centers (probably, deformation-produced dislocations decorated by nitrogen) were formed in all plastically deformed diamonds and W10 and W35 centers (the models have not been finally ascertained) were formed in some of them. It has been established that diamonds with various types of deformation-induced color contain characteristic associations of these deformation centers. The diversity of associations of deformation centers indicates appreciable variations in conditions of disintegration of deep-seated rocks, transfer of diamonds to the Earth’s surface, and formation of kimberlitic deposits. Depending on the conditions of mechanical loading, the diamond crystals were plastically deformed by either dislocation gliding or mechanical twinning. Characteristic features of plastic deformation by dislocation gliding are the substantial prevalence of the N2 centers over other deformation centers and the occurrence of the high-spin W10 and W35 centers. The attributes of less frequent plastic deformation by mechanical twinning are unusual localization of the M2 centers and, in some cases, the N1 centers in microtwinned

  11. Earthquake-induced soft-sediment deformation structures in Late Pleistocene lacustrine deposits of Issyk-Kul lake (Kyrgyzstan)

    Science.gov (United States)

    Gladkov, A. S.; Lobova, E. U.; Deev, E. V.; Korzhenkov, A. M.; Mazeika, J. V.; Abdieva, S. V.; Rogozhin, E. A.; Rodkin, M. V.; Fortuna, A. B.; Charimov, T. A.; Yudakhin, A. S.

    2016-10-01

    This paper discusses the composition and distribution of soft-sediment deformation structures induced by liquefaction in Late Pleistocene lacustrine terrace deposits on the southern shore of Issyk-Kul Lake in the northern Tien Shan mountains of Kyrgyzstan. The section contains seven deformed beds grouped in two intervals. Five deformed beds in the upper interval contain load structures (load casts and flame structures), convolute lamination, ball-and-pillow structures, folds and slumps. Deformation patterns indicate that a seismic trigger generated a multiple slump on a gentle slope. The dating of overlying subaerial deposits suggests correlation between the deformation features and strong earthquakes in the Late Pleistocene.

  12. Fluid-structure interaction analysis of deformation of sail of 30-foot yacht

    Science.gov (United States)

    Bak, Sera; Yoo, Jaehoon; Song, Chang Yong

    2013-06-01

    Most yacht sails are made of thin fabric, and they have a cambered shape to generate lift force; however, their shape can be easily deformed by wind pressure. Deformation of the sail shape changes the flow characteristics over the sail, which in turn further deforms the sail shape. Therefore, fluid-structure interaction (FSI) analysis is applied for the precise evaluation or optimization of the sail design. In this study, fluid flow analyses are performed for the main sail of a 30-foot yacht, and the results are applied to loading conditions for structural analyses. By applying the supporting forces from the rig, such as the mast and boom-end outhaul, as boundary conditions for structural analysis, the deformed sail shape is identified. Both the flow analyses and the structural analyses are iteratively carried out for the deformed sail shape. A comparison of the flow characteristics and surface pressures over the deformed sail shape with those over the initial shape shows that a considerable difference exists between the two and that FSI analysis is suitable for application to sail design.

  13. Fluid-structure interaction analysis of deformation of sail of 30-foot yacht

    Directory of Open Access Journals (Sweden)

    Sera Bak

    2013-06-01

    Full Text Available Most yacht sails are made of thin fabric, and they have a cambered shape to generate lift force; however, their shape can be easily deformed by wind pressure. Deformation of the sail shape changes the flow characteristics over the sail, which in turn further deforms the sail shape. Therefore, fluid-structure interaction (FSI analysis is applied for the precise evaluation or optimization of the sail design. In this study, fluid flow analyses are performed for the main sail of a 30-foot yacht, and the results are applied to loading conditions for structural analyses. By applying the supporting forces from the rig, such as the mast and boom-end outhaul, as boundary conditions for structural analysis, the deformed sail shape is identified. Both the flow analyses and the structural analyses are iteratively carried out for the deformed sail shape. A comparison of the flow characteristics and surface pressures over the deformed sail shape with those over the initial shape shows that a considerable difference exists between the two and that FSI analysis is suitable for application to sail design.

  14. Shear Creep Simulation of Structural Plane of Rock Mass Based on Discontinuous Deformation Analysis

    Directory of Open Access Journals (Sweden)

    Guoxin Zhang

    2017-01-01

    Full Text Available Numerical simulations of the creep characteristics of the structural plane of rock mass are very useful. However, most existing simulation methods are based on continuum mechanics and hence are unsuitable in the case of large displacements and deformations. The discontinuous deformation analysis method proposed by Genhua is a discrete one and has a significant advantage when simulating the contacting problem of blocks. In this study, we combined the viscoelastic rheological model of Burgers with the discontinuous deformation analysis (DDA method. We also derived the recurrence formula for the creep deformation increment with the time step during numerical simulations. Based on the minimum potential energy principle, the general equilibrium equation was derived, and the shear creep deformation in the structural plane was considered. A numerical program was also developed and its effectiveness was confirmed based on the curves obtained by the creep test of the structural plane of a rock mass under different stress levels. Finally, the program was used to analyze the mechanism responsible for the creep features of the structural plane in the case of the toppling deformation of the rock slope. The results showed that the extended DDA method is an effective one.

  15. Lifetime Reliability Estimate and Extreme Permanent Deformations of Randomly Excited Elasto-Plastic Structures

    DEFF Research Database (Denmark)

    Nielsen, Søren R.K.; Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1983-01-01

    plastic deformation during several loadings can be modelled as a filtered Poisson process. Using the Markov property of this quantity the considered first-passage problem as well as the related extreme distribution problems are then solved numerically, and the results are compared to simulation studies.......A method is presented for life-time reliability' estimates of randomly excited yielding systems, assuming the structure to be safe, when the plastic deformations are confined below certain limits. The accumulated plastic deformations during any single significant loading history are considered...

  16. Evaluation of structural deformations of a mechanical connecting unit oxidizer supplies by thermo-mechanical simulation

    International Nuclear Information System (INIS)

    Kim, Sang Woo

    2016-01-01

    A Mechanical connecting unit (MCU) used in ground facilities for a Liquid propellant rocket (LPR) acts as a bridge between the onboard system and the ground oxidizer filling system. It should be resistant to structural deformations in order to guarantee successful supply of a cryogenic oxidizer and high pressure gases without reduction of sealing capability. The MCU consists of many components and linkages and operates under harsh conditions induced by a cryogenic oxidizer, high pressure gases and other mechanical forces. Thus, the evaluation of structural deformation of the MCU considering complex conditions is expensive and time consuming. The present study efficiently evaluates the structural deformations of the key components of the MCU by Thermo-mechanical simulation (TMS) based on the superposition principle. Deformations due to the mechanical loadings including weights, pressures, and spring forces are firstly evaluated by using a non-linear flexible body simulation module (FFlex) of Multi-body dynamics (MBD) software, RecurDyn. Then, thermal deformations for the deformed geometries obtained by RecurDyn were subsequently calculated. It was conducted by using a Finite element (FE) analysis software, ANSYS. The total deformations for the onboard plate and multi-channel plate in the connecting section due to the mechanical and thermal loadings were successfully evaluated. Moreover, the outer gaps at six points between two plates were calculated and verified by comparison to the measured data. Their values and tendencies showed a good agreement. The author concluded that the TMS using MBD software considering flexible bodies and an FE simulator can efficiently evaluate structural deformations of the MCU operating under the complex load and boundary conditions

  17. Evaluation of structural deformations of a mechanical connecting unit oxidizer supplies by thermo-mechanical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Woo [Dept. of Mechanical Engineering, Institute of Machine Convergence Technology, Hankyong National University, Anseong (Korea, Republic of)

    2016-10-15

    A Mechanical connecting unit (MCU) used in ground facilities for a Liquid propellant rocket (LPR) acts as a bridge between the onboard system and the ground oxidizer filling system. It should be resistant to structural deformations in order to guarantee successful supply of a cryogenic oxidizer and high pressure gases without reduction of sealing capability. The MCU consists of many components and linkages and operates under harsh conditions induced by a cryogenic oxidizer, high pressure gases and other mechanical forces. Thus, the evaluation of structural deformation of the MCU considering complex conditions is expensive and time consuming. The present study efficiently evaluates the structural deformations of the key components of the MCU by Thermo-mechanical simulation (TMS) based on the superposition principle. Deformations due to the mechanical loadings including weights, pressures, and spring forces are firstly evaluated by using a non-linear flexible body simulation module (FFlex) of Multi-body dynamics (MBD) software, RecurDyn. Then, thermal deformations for the deformed geometries obtained by RecurDyn were subsequently calculated. It was conducted by using a Finite element (FE) analysis software, ANSYS. The total deformations for the onboard plate and multi-channel plate in the connecting section due to the mechanical and thermal loadings were successfully evaluated. Moreover, the outer gaps at six points between two plates were calculated and verified by comparison to the measured data. Their values and tendencies showed a good agreement. The author concluded that the TMS using MBD software considering flexible bodies and an FE simulator can efficiently evaluate structural deformations of the MCU operating under the complex load and boundary conditions.

  18. Mechanical design of deformation compensated flexural pivots structured for linear nanopositioning stages

    Science.gov (United States)

    Shu, Deming; Kearney, Steven P.; Preissner, Curt A.

    2015-02-17

    A method and deformation compensated flexural pivots structured for precision linear nanopositioning stages are provided. A deformation-compensated flexural linear guiding mechanism includes a basic parallel mechanism including a U-shaped member and a pair of parallel bars linked to respective pairs of I-link bars and each of the I-bars coupled by a respective pair of flexural pivots. The basic parallel mechanism includes substantially evenly distributed flexural pivots minimizing center shift dynamic errors.

  19. Deformation mechanisms of a porous structure of the poly(ethylene terephthalate) nuclear track membrane

    International Nuclear Information System (INIS)

    Ovchinnikov, V.V.

    1989-01-01

    The deformation mechanisms of a porous structure of the nuclear track membrane made of poly(ethylene terephthalate) are investigated in the temperature range from 333 to 473 K. It is shown that the pore size of the membrane can both decrease and increase. The analytical equation based on the Alfrey mechanical approach to the relaxation deformation of polymers describes the experimental data satisfactorily over the whole range of temperatures and pore radii of the membranes. 21 refs.; 5 figs.; 3 tabs

  20. Micro-structural evolution in plastically deformed crystalline materials

    DEFF Research Database (Denmark)

    Nellemann, Christopher

    predictions for the two models to be obtained. Application of the two models to the pure shear boundary value problem is used to characterize plastic behavior, which also allows for the identification of inherent properties through closed form expressions. Single crystal Monazite containing a void is studied......Two rate-independent strain gradient crystal plasticity models are developed and applied in numerical studies designed to identify the properties inherent to model predictions of plastic deformation. The two models incorporate gradients of slip into the framework of conventional crystal plasticity...... in order to model size-dependent plasticity effects. This gradient dependence is achieved by relating a slip measure which combines both slip and their gradients to a shear hardening curve, as commonly done in conventional plasticity theories. Finite element codes are implemented which allow for numerical...

  1. Influence of deformation on structural-phase state of weld material in St3 steel

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Alexander, E-mail: galvas.kem@gmail.ru; Ababkov, Nicolay, E-mail: n.ababkov@rambler.ru; Ozhiganov, Yevgeniy, E-mail: zhigan84@mail.ru [Kuzbass State Technical University, 25-54, Krasnaya Str., 650000, Kemerovo (Russian Federation); LLC “Kuzbass Center of Welding and Control”, 33/2, Lenin Str., 650055, Kemerovo (Russian Federation); Kozlov, Eduard, E-mail: kozlov@tsuab.ru [Kuzbass State Technical University, 25-54, Krasnaya Str., 650000, Kemerovo (Russian Federation); Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); Popova, Natalya, E-mail: natalya-popova-44@mail.ru [Kuzbass State Technical University, 25-54, Krasnaya Str., 650000, Kemerovo (Russian Federation); Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); Institute of Strength Physics and Materials Science, SB RAS, 2/4, Akademicheskii Ave., 634021, Tomsk (Russian Federation); Nikonenko, Elena, E-mail: vilatomsk@mail.ru [Kuzbass State Technical University, 25-54, Krasnaya Str., 650000, Kemerovo (Russian Federation); Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); National Research Tomsk Polytechnic University, 30, Lenin Str., 634050, Tomsk (Russian Federation); Zboykova, Nadezhda, E-mail: tezaurusn@gmail.com; Koneva, Nina, E-mail: koneva@tsuab.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation)

    2016-01-15

    The structural-phase condition of the weld material subjected to the plastic deformation was investigated using the translucent diffraction electron microscopy method. The investigations were carried out near the joint of the weld and the base metal. The seam was done by the method of manual arc welding without artificial defects. The St3 steel was taken as the welded material. Influence of the plastic deformation on morphology, phase composition, defect structure and its parameters of weld metal was revealed. All investigations were done at the distance of 0.5 mm from the joint of the weld and the base metal at the deformation degrees from 0 to 5% and after destruction of a sample. It was established that deformation of the sample did not lead to qualitative changes in the structure (the structure is still presented by ferrite-pearlite mixture) but changed the quantitative parameters of the structure, namely, with the increase of plastic deformation a part of the pearlite component becomes more and more imperfect. In the beginning it turns into the destroyed pearlite then into ferrite, the volume fraction of pearlite is decreased. The polarization of dislocation structure takes place but it doesn’t lead to the internal stresses that can destroy the sample.

  2. The mechanical properties of austenite stainless steel 304 after structural deformation through cold work

    Energy Technology Data Exchange (ETDEWEB)

    Mubarok, Naila; Manaf, Azwar, E-mail: azwar@ui.ac.id [PPS Materials Science, FMIPA-Universitas Indonesia, Depok 16424 (Indonesia); Notonegoro, Hamdan Akbar [Mechanical Engineering Dept., FT-Universitas Sultan Ageng Tirtayasa,Cilegon 42435 (Indonesia); Thosin, Kemas Ahmad Zaini [Pusat Penelitian Fisika,LIPI, Serpong (Indonesia)

    2016-06-17

    The 304 stainless steel (SS) type is widely used in oil and gas operations due to its excellent corrosion resistance. However, the presence of the fine sand particles and H{sub 2}S gas contained in crude oil could lead the erosion and abrasion in steel. In this study, cold rolled treatments were conducted to the 304 SS in order to increase the wear resistance of the steel. The cold work has resulted in thickness reduction to 20%, 40% and 60% of the original. Various microstructural characterizations were used to analyze the effect of deformation. The hardness characterization showed that the initial hardness value increased from 145 HVC to 395 HVC as the level of deformation increase. Further, the wear resistance increased with the deformation rate from 0% to 40% and subsequently decreased from 40% to 60% deformation rate. Microstructural characterization shows that the boundary change to coincide by 56 µm, 49 µm, 45 µm, and 43 µm width and the grain go to flatten and being folded like needles. The effect of deformation on the grain morphology and structure was also studied by optical metallography and X-Ray Diffraction. It is shown that the deformation by means of a cold rolled process has transformed the austenite structure into martensitic structure.

  3. Influence of Plastic Deformation on Martensitic Transformation During Hot Stamping of Complex Structure Auto Parts

    Science.gov (United States)

    Shen, Yuhan; Song, Yanli; Hua, Lin; Lu, Jue

    2017-04-01

    The ultra-high strength steel auto parts manufactured by hot stamping are widely applied for weight reduction and safety improvement. During the hot stamping process, hot forming and quenching are performed in one step wherein plastic deformation and phase transformation simultaneously take place and affect each other. Thereinto, the influence of deformation on martensitic transformation is of great importance. In the present paper, the influence of plastic deformation on martensitic transformation during hot stamping of complex structure auto parts was investigated. For this purpose, a B-pillar reinforced panel in B1500HS steel was manufactured by hot stamping, and the process was simulated by finite element software based on a thermo-mechanical-metallurgical coupled model. Considering various deformation degrees, the microstructures and mechanical properties at four typical locations of the hot stamped B-pillar reinforced panel were detected. The results show that the martensitic content and the microhardness increase with the increase in the deformation amount. There are two reasons causing this phenomenon: (1) the increase in mechanical driving force and (2) the increased probability of the martensitic nucleation at crystal defects. The x-ray diffraction analysis indicates the carbon enrichment in retained austenite which results from the carbon diffusion during the low-carbon martensite formation. Furthermore, the carbon content decreases with the increase in the deformation amount, because the deformation of austenite suppresses the carbon diffusion.

  4. Deformable meshes for medical image segmentation accurate automatic segmentation of anatomical structures

    CERN Document Server

    Kainmueller, Dagmar

    2014-01-01

    ? Segmentation of anatomical structures in medical image data is an essential task in clinical practice. Dagmar Kainmueller introduces methods for accurate fully automatic segmentation of anatomical structures in 3D medical image data. The author's core methodological contribution is a novel deformation model that overcomes limitations of state-of-the-art Deformable Surface approaches, hence allowing for accurate segmentation of tip- and ridge-shaped features of anatomical structures. As for practical contributions, she proposes application-specific segmentation pipelines for a range of anatom

  5. Mechanical and structural behaviour of uranium α, β, γ phases during plastic deformation

    International Nuclear Information System (INIS)

    Prunier, C.; Collot, C.

    1981-06-01

    High temperature behaviour of rich and poor uranium alloys in α, β and γ crystalline structures is studied: dynamic recrystallization phenomena begins only in α and β phases high temperature range, high strength and brittle β phase shows a very large ductility above 700 0 C. Dynamic recrystallization in γ phase rich alloys is observed only if large energy is available. Recrystallization is a thermal actived phenomena localised at grain boundary, dependant with alloy concentration and crystalline structure. β phase activation energy and deformation rate for dynamic recrystallization beginning are the most important in relation with structure complexity; both temperature and rate deformation are dynamic recrystallization factors [fr

  6. On the modelling of the dynamics of elastically deformable floating structures

    DEFF Research Database (Denmark)

    Seng, Sopheak; Malenica, Sime; Jensen, Jørgen Juncher

    2015-01-01

    In this paper we are reexamining the dynamic equations of an elastically deformable floating structure to identify and evaluate the contribution from the inertia cross coupling terms which commonly have been neglected due to the assumption of small structural deformation. Numerical experiments...... on two vessels, a flexible barge, and a full scale ultra large container vessel, are designed for revealing the magnitude of errors introduced into the numerical solutions when these inertia cross coupling terms have been ignored. The results shows that in realistic conditions with strong structural...

  7. Soft-Sediment Deformation Structures Interpreted as Seismites in the Kolankaya Formation, Denizli Basin (SW Turkey)

    Science.gov (United States)

    Topal, Savaş; Özkul, Mehmet

    2014-01-01

    The NW-trending Denizli basin of the SW Turkey is one of the neotectonic grabens in the Aegean extensional province. It is bounded by normal faults on both southern and northern margins. The basin is filled by Neogene and Quaternary terrestrial deposits. Late Miocene- Late Pliocene aged Kolankaya formation crops out along the NW trending Karakova uplift in the Denizli basin. It is a typical fluviolacustrine succession that thickens and coarsens upward, comprising poorly consolidated sand, gravelly sand, siltstone and marl. Various soft-sediment deformation structures occur in the formation, especially in fine- to medium grained sands, silts and marls: load structures, flame structures, clastic dikes (sand and gravely-sand dike), disturbed layers, laminated convolute beds, slumps and synsedimentary faulting. The deformation mechanism and driving force for the soft-sediment deformation are related essentially to gravitational instability, dewatering, liquefaction-liquidization, and brittle deformation. Field data and the wide lateral extent of the structures as well as regional geological data show that most of the deformation is related to seismicity and the structures are interpreted as seismites. The existence of seismites in the Kolankaya Formation is evidence for continuing tectonic activity in the study area during the Neogene and is consistent with the occurrence of the paleoearthquakes of magnitude >5. PMID:25152909

  8. Deciphering the shape and deformation of secondary structures through local conformation analysis

    Directory of Open Access Journals (Sweden)

    Camproux Anne-Claude

    2011-02-01

    Full Text Available Abstract Background Protein deformation has been extensively analysed through global methods based on RMSD, torsion angles and Principal Components Analysis calculations. Here we use a local approach, able to distinguish among the different backbone conformations within loops, α-helices and β-strands, to address the question of secondary structures' shape variation within proteins and deformation at interface upon complexation. Results Using a structural alphabet, we translated the 3 D structures of large sets of protein-protein complexes into sequences of structural letters. The shape of the secondary structures can be assessed by the structural letters that modeled them in the structural sequences. The distribution analysis of the structural letters in the three protein compartments (surface, core and interface reveals that secondary structures tend to adopt preferential conformations that differ among the compartments. The local description of secondary structures highlights that curved conformations are preferred on the surface while straight ones are preferred in the core. Interfaces display a mixture of local conformations either preferred in core or surface. The analysis of the structural letters transition occurring between protein-bound and unbound conformations shows that the deformation of secondary structure is tightly linked to the compartment preference of the local conformations. Conclusion The conformation of secondary structures can be further analysed and detailed thanks to a structural alphabet which allows a better description of protein surface, core and interface in terms of secondary structures' shape and deformation. Induced-fit modification tendencies described here should be valuable information to identify and characterize regions under strong structural constraints for functional reasons.

  9. Deciphering the shape and deformation of secondary structures through local conformation analysis.

    Science.gov (United States)

    Baussand, Julie; Camproux, Anne-Claude

    2011-02-01

    Protein deformation has been extensively analysed through global methods based on RMSD, torsion angles and Principal Components Analysis calculations. Here we use a local approach, able to distinguish among the different backbone conformations within loops, α-helices and β-strands, to address the question of secondary structures' shape variation within proteins and deformation at interface upon complexation. Using a structural alphabet, we translated the 3 D structures of large sets of protein-protein complexes into sequences of structural letters. The shape of the secondary structures can be assessed by the structural letters that modeled them in the structural sequences. The distribution analysis of the structural letters in the three protein compartments (surface, core and interface) reveals that secondary structures tend to adopt preferential conformations that differ among the compartments. The local description of secondary structures highlights that curved conformations are preferred on the surface while straight ones are preferred in the core. Interfaces display a mixture of local conformations either preferred in core or surface. The analysis of the structural letters transition occurring between protein-bound and unbound conformations shows that the deformation of secondary structure is tightly linked to the compartment preference of the local conformations. The conformation of secondary structures can be further analysed and detailed thanks to a structural alphabet which allows a better description of protein surface, core and interface in terms of secondary structures' shape and deformation. Induced-fit modification tendencies described here should be valuable information to identify and characterize regions under strong structural constraints for functional reasons.

  10. Test and analysis of thermal ratcheting deformation for 316L stainless steel cylindrical structure

    International Nuclear Information System (INIS)

    Lee, Hyeong Yeon; Kim, Jong Bum; Lee, Jae Han

    2002-01-01

    In this study, the progressive inelastic deformation, so called, thermal ratchet phenomenon which can occur in high temperature structures of liquid metal simulated with thermal ratchet structural test facility and 316L stainless steel test cylinder. The thermal ratchet deformation at the reactor baffle cylinder of the liquid metal reactor can occur due to the moving temperature distribution along the axial direction as the sodium free surface moves up and down under the cyclic heat-up and cool-down transients. The ratchet deformation was measured with the laser displacement sensor and LVDTs after cooling the structural specimen which is heated up to 550 degree C with steep temperature gradients along the axial direction. The temperature distribution of the test cylinder along the axial direction was measured with 28 channels of thermocouples and was used for the ratchet analysis. The thermal ratchet deformation was analyzed with the constitutive equation of nonlinear combined hardening model which was implemented as ABAQUS user subroutine and the analysis results were compared with those of the test. Thermal ratchet load was applied 9 times and the residual displacement after 9 cycles of thermal load was measured to be 1.79 mm. The ratcheting deformation shapes obtained by the analysis with the combined hardening model were in reasonable agreement with those of the structural tests

  11. Bridge Structure Deformation Prediction Based on GNSS Data Using Kalman-ARIMA-GARCH Model.

    Science.gov (United States)

    Xin, Jingzhou; Zhou, Jianting; Yang, Simon X; Li, Xiaoqing; Wang, Yu

    2018-01-19

    Bridges are an essential part of the ground transportation system. Health monitoring is fundamentally important for the safety and service life of bridges. A large amount of structural information is obtained from various sensors using sensing technology, and the data processing has become a challenging issue. To improve the prediction accuracy of bridge structure deformation based on data mining and to accurately evaluate the time-varying characteristics of bridge structure performance evolution, this paper proposes a new method for bridge structure deformation prediction, which integrates the Kalman filter, autoregressive integrated moving average model (ARIMA), and generalized autoregressive conditional heteroskedasticity (GARCH). Firstly, the raw deformation data is directly pre-processed using the Kalman filter to reduce the noise. After that, the linear recursive ARIMA model is established to analyze and predict the structure deformation. Finally, the nonlinear recursive GARCH model is introduced to further improve the accuracy of the prediction. Simulation results based on measured sensor data from the Global Navigation Satellite System (GNSS) deformation monitoring system demonstrated that: (1) the Kalman filter is capable of denoising the bridge deformation monitoring data; (2) the prediction accuracy of the proposed Kalman-ARIMA-GARCH model is satisfactory, where the mean absolute error increases only from 3.402 mm to 5.847 mm with the increment of the prediction step; and (3) in comparision to the Kalman-ARIMA model, the Kalman-ARIMA-GARCH model results in superior prediction accuracy as it includes partial nonlinear characteristics (heteroscedasticity); the mean absolute error of five-step prediction using the proposed model is improved by 10.12%. This paper provides a new way for structural behavior prediction based on data processing, which can lay a foundation for the early warning of bridge health monitoring system based on sensor data using sensing

  12. Bridge Structure Deformation Prediction Based on GNSS Data Using Kalman-ARIMA-GARCH Model

    Directory of Open Access Journals (Sweden)

    Jingzhou Xin

    2018-01-01

    Full Text Available Bridges are an essential part of the ground transportation system. Health monitoring is fundamentally important for the safety and service life of bridges. A large amount of structural information is obtained from various sensors using sensing technology, and the data processing has become a challenging issue. To improve the prediction accuracy of bridge structure deformation based on data mining and to accurately evaluate the time-varying characteristics of bridge structure performance evolution, this paper proposes a new method for bridge structure deformation prediction, which integrates the Kalman filter, autoregressive integrated moving average model (ARIMA, and generalized autoregressive conditional heteroskedasticity (GARCH. Firstly, the raw deformation data is directly pre-processed using the Kalman filter to reduce the noise. After that, the linear recursive ARIMA model is established to analyze and predict the structure deformation. Finally, the nonlinear recursive GARCH model is introduced to further improve the accuracy of the prediction. Simulation results based on measured sensor data from the Global Navigation Satellite System (GNSS deformation monitoring system demonstrated that: (1 the Kalman filter is capable of denoising the bridge deformation monitoring data; (2 the prediction accuracy of the proposed Kalman-ARIMA-GARCH model is satisfactory, where the mean absolute error increases only from 3.402 mm to 5.847 mm with the increment of the prediction step; and (3 in comparision to the Kalman-ARIMA model, the Kalman-ARIMA-GARCH model results in superior prediction accuracy as it includes partial nonlinear characteristics (heteroscedasticity; the mean absolute error of five-step prediction using the proposed model is improved by 10.12%. This paper provides a new way for structural behavior prediction based on data processing, which can lay a foundation for the early warning of bridge health monitoring system based on sensor data

  13. q-deformed phase-space and its lattice structure

    International Nuclear Information System (INIS)

    Wess, J.

    1998-01-01

    Quantum groups lead to an algebraic structure that can be realized on quantum spaces. These are non-commutative spaces that inherit a well-defined mathematical structure from the quantum group symmetry. In turn, such quantum spaces can be interpreted as non-commutative configuration spaces for physical systems. We study the non-commutative Euclidean space that is based on the quantum group SO q (3)

  14. STUDYING DEFORMATIONS OF AN FLAT TRUSS STRUCTURE STATICALLY INDETERMINATED EXTERNALLY

    Directory of Open Access Journals (Sweden)

    Kirsanov Mikhail Nikolaevich

    2017-08-01

    Full Text Available A flat statically determinate parallel-chord truss structure has a cross-shaped grid and rests upon two rigid pin-bearing supports. Loads in bars are determined in a symbol form using the method of joint isolation by the computer mathematics Maple system. The peculiarity of the considered truss structure is its external static indeterminacy. In fact, all efforts and reactions of supports can be determined from the equilibrium conditions. But the inconvenience is necessary to consider the equilibrium of all the nodes of the truss. The Ritter cross-section method is not applicable to this truss structure. The sections that cut the truss into two parts and pass through the three rods, here exist only for several rods of the extreme panels. The purpose of this paper is to calculate a truss structure with a different number of panels in analytical and numerical form. Finite element calculation method with the use of software LISA 8.0 is applied. It’s noted that a truss structure is kinetically changeable when the number of spans is odd. The corresponding plan of probable velocities is given. In order to receive analytic dependence of deflection on the span number, the induction method and Maxwell-Moor formula has been applied. The operators of the compilation and solution of recurrence equations are involved in determining the general terms of the coefficient sequences. The formulas for calculation of loads in the most compressed bars of a truss structure were received.

  15. Quantitative description of changes in the structure in austenitic steels after hot temperature deformation

    International Nuclear Information System (INIS)

    Kuc, D.; Rodak, K.; Niewielski, G.; Hetmanczyk, M.

    1998-01-01

    An investigation on the structural changes in austenitic hard deformable Cr-Mn and Cr-Ni steels during dynamic recrystallization has been presented in the paper. The influence of the factors (strain rate, deformation, temperature) on the geometric characteristic of grains has been taken into consideration. Investigation of the structure were performed using metallographic microscope and transmission electron microscope. The results of researched should widen the theoretical background in order to the model of phenomena, which accompany the dynamic recovery and dynamic recrystallization. (author)

  16. Measurement of deforming mode of lattice truss structures under impact loading

    Directory of Open Access Journals (Sweden)

    Zhao H.

    2012-08-01

    Full Text Available Lattice truss structures, which are used as a core material in sandwich panels, were widely investigated experimentally and theoretically. However, explanation of the deforming mechanism using reliable experimental results is almost rarely reported, particularly for the dynamic deforming mechanism. The present work aimed at the measurement of the deforming mode of lattice truss structures. Indeed, quasi-static and Split Hopkinson Pressure Bar (SHPB tests have been performed on the tetrahedral truss cores structures made of Aluminum 3003-O. Global values such as crushing forces and displacements between the loading platens are obtained. However, in order to understand the deforming mechanism and to explain the observed impact strength enhancement observed in the experiments, images of the truss core element during the tests are recorded. A method based on the edge detection algorithm is developed and applied to these images. The deforming profiles of one beam are extracted and it allows for calculating the length of beam. It is found that these lengths diminish to a critical value (due to compression and remain constant afterwards (because of significant bending. The comparison between quasi-static and impact tests shows that the beam were much more compressed under impact loading, which could be understood as the lateral inertia effect in dynamic bucking. Therefore, the impact strength enhancement of tetrahedral truss core sandwich panel can be explained by the delayed buckling of beam under impact (more compression reached, together with the strain hardening of base material.

  17. Real-time deformations of organ based on structural mechanics for surgical simulators

    Science.gov (United States)

    Nakaguchi, Toshiya; Tagaya, Masashi; Tamura, Nobuhiko; Tsumura, Norimichi; Miyake, Yoichi

    2006-03-01

    This research proposes the deformation model of organs for the development of the medical training system using Virtual Reality (VR) technology. First, the proposed model calculates the strains of coordinate axis. Secondly, the deformation is obtained by mapping the coordinate of the object to the strained coordinate. We assume the beams in the coordinate space to calculate the strain of the coordinate axis. The forces acting on the object are converted to the forces applied to the beams. The bend and the twist of the beams are calculated based on the theory of structural mechanics. The bend is derived by the finite element method. We propose two deformation methods which differ in the position of the beams in the coordinate space. One method locates the beams along the three orthogonal axes (x, y, z). Another method locates the beam in the area where the deformation is large. In addition, the strain of the coordinate axis is attenuated in proportion to the distance from the point of action to consider the attenuation of the stress which is a viscoelastic feature of the organs. The proposed model needs less computational cost compared to the conventional deformation method since our model does not need to divide the object into the elasticity element. The proposed model was implemented in the laparoscopic surgery training system, and a real-time deformation can be realized.

  18. Using Ground Radar Interferometry for Precise Determining of Deformation and Vertical Deflection of Structures

    Science.gov (United States)

    Talich, Milan

    2017-12-01

    The paper describes possibilities of the relatively new technics - ground based radar interferometry for precise determining of deformation of structures. Special focus on the vertical deflection of bridge structures and on the horizontal movements of high-rise buildings and structural objects is presented. The technology of ground based radar interferometry can be used in practice to the contactless determination of deformations of structures with accuracy up to 0.01 mm in real time. It is also possible in real time to capture oscillations of the object with a frequency up to 50 Hz. Deformations can be determined simultaneously in multiple places of the object, for example a bridge structure at points distributed on the bridge deck at intervals of one or more meters. This allows to obtain both overall and detailed information about the properties of the structure during the dynamic load and monitoring the impact of movements either individual vehicles or groups. In the case of high-rise buildings, it is possible to monitor the horizontal vibration of the whole object at its different height levels. It is possible to detect and determine the compound oscillations that occur in some types of buildings. Then prevent any damage or even disasters in these objects. In addition to the necessary theory basic principles of using radar interferometry for determining of deformation of structures are given. Practical examples of determining deformation of bridge structures, water towers reservoirs, factory chimneys and wind power plants are also given. The IBIS-S interferometric radar of the Italian IDS manufacturer was used for the measurements.

  19. Deformation structure analysis of material at fatigue on the basis of the vector field

    Science.gov (United States)

    Kibitkin, Vladimir V.; Solodushkin, Andrey I.; Pleshanov, Vasily S.

    2017-12-01

    In the paper, spatial distributions of deformation, circulation, and shear amplitudes and shear angles are obtained from the displacement vector field measured by the DIC technique. This vector field and its characteristics of shears and vortices are given as an example of such approach. The basic formulae are also given. The experiment shows that honeycomb deformation structures can arise in the center of a macrovortex at developed plastic flow. The spatial distribution of local circulation and shears is discovered, which coincides with the deformation structure but their amplitudes are different. The analysis proves that the spatial distribution of shear angles is a result of maximum tangential and normal stresses. The anticlockwise circulation of most local vortices obeys the normal Gaussian law in the area of interest.

  20. Auxetic hexachiral structures with wavy ligaments for large elasto-plastic deformation

    Science.gov (United States)

    Zhu, Yilin; Wang, Zhen-Pei; Hien Poh, Leong

    2018-05-01

    The hexachiral structure is in-plane isotropic in small deformation. When subjected to large elasto-plastic deformation, however, the hexachiral structure tends to lose its auxeticity and/or isotropy—properties which are desirable in many potential applications. The objective of this study is to improve these two mechanical properties, without significantly compromising the effective yield stress, in the regime with significant material and geometrical nonlinearity effects. It is found that the deformation mechanisms underlying the auxeticity and isotropy properties of a hexachiral structure are largely influenced by the extent of rotation of the central ring in a unit cell. To facilitate the development of this deformation mechanism, an improved design with wavy ligaments is proposed. The improved performance of the proposed hexachiral structure is demonstrated. An initial study on possible applications as a protective material is next carried out, where the improved hexachiral design is shown to exhibit higher specific energy absorption capacity compared to the original design, as well as standard honeycomb structures.

  1. Magnetic structure and lattice deformation in UO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Aksenov, V L; Frauenheim, T; Sikora, V [Joint Inst. for Nuclear Research, Dubna (USSR)

    1981-12-21

    The magnetic phase transition in UO/sub 2/ is studied by means of a group theoretical analysis and the admitted symmetry groups in the low temperature phase are determined. With the help of the neutron diffraction data of Faber and Lander a three-arm magnetic and crystallographic structure with two types of translational domains is found and a new interpretation of the experiment of Faber and Lander is given.

  2. Lithospheric structure and deformation of the North American continent

    OpenAIRE

    Magdala Tesauro; Mikhail Kaban; S. Cloetingh; W. D. Mooney

    2013-01-01

    We estimate the integrated strength and elastic thickness (Te) of the North American lithosphere based on thermal, density and structural (seismic) models of the crust and upper mantle. The temperature distribution in the lithosphere is estimated considering for the first time the effect of composition as a result of the integrative approach based on a joint analysis of seismic and gravity data. We do this via an iterative adjustment of the model. The upper mantle temperatures are initially e...

  3. Symmetry analysis in the investigation of the order-disorder phase transition and possible structural deformations

    Energy Technology Data Exchange (ETDEWEB)

    Gurin, O V; Syromyatnikov, V N [AN SSSR, Sverdlovsk. Inst. Fiziki Metallov; Sikora, W [Joint Inst. for Nuclear Research, Dubna (USSR)

    1984-08-01

    Order-disorder phase transitions for the Me-X structures in Nb-H(D) hydrides with hydrogen (deuterium) ordering over the 12d tetrahedral interstices of the GAMMAsub(c)sup(v) lattice and for the Me-X and Me-X/sub 2/ oxides in the Ta-O system with oxygen ordering over octahedral 6b interstices are presented. The concentration of interstitial atoms is assumed to be constant. All possible models of ordered structures with a GAMMAsub(o)sup(b) lattice were determined using symmetry analysis. The possible structural deformations consistent with each variant of the ordering of the interstitial atoms were also considered. The structural deformations include the displacements of the metal atoms and of the centres of the interstices which were deduced using symmetry analysis. The results of the analysis of the final structure symmetry raise the question of understanding the nature of superstructure reflections in neutron diffraction patterns.

  4. System and process for ultrasonic characterization of deformed structures

    Science.gov (United States)

    Panetta, Paul D [Williamsburg, VA; Morra, Marino [Richland, WA; Johnson, Kenneth I [Richland, WA

    2011-11-22

    Generally speaking, the method of the present invention is performed by making various ultrasonic scans at preselected orientations along the length of a material being tested. Data from the scans are then plotted together with various calculated parameters that are calculated from this data. Lines or curves are then fitted to the respective plotted points. Review of these plotted curves allows the location and severity of defects within these sections to be determined and quantified. With this information various other decisions related to how, when or whether repair or replacement of a particular portion of a structure can be made.

  5. Algebraic structure of the Green's ansatz and its q-deformed analogue

    International Nuclear Information System (INIS)

    Palev, T.D.

    1994-08-01

    The algebraic structure of the Green's ansatz is analyzed in such a way that its generalization to the case of q-deformed para-Bose and para-Fermi operators is becoming evident. To this end the underlying Lie (super) algebraic properties of the parastatistics are essentially used. (author). 41 refs

  6. Modelling and Simulation of Structural Deformation of Isothermal Subsurface Flow and Carbon Dioxide Injection

    KAUST Repository

    El-Amin, Mohamed

    2011-05-15

    Injection of CO2 in hydrocarbon reservoir has double benefit. On the one hand, it is a profitable method due to issues related to global warming, and on the other hand it is an effective mechanism to enhance hydrocarbon recovery. Such injection associates complex processes involving, e.g., solute transport of dissolved materials, in addition to local changes in density of the phases. Also, increasing carbon dioxide injection may cause a structural deformation of the medium, so it is important to include such effect into the model. The structural deformation modelling in carbon sequestration is important to evaluate the medium stability to avoid CO2 leakage to the atmosphere. On the other hand, geologic formation of the medium is usually heterogeneous and consists of several layers of different permeability. In this work we conduct numerical simulation of two-phase flow in a heterogeneous porous medium domain with dissolved solute transport as well as structural deformation effects. The solute transport of the dissolved component is described by concentration equation. The structural deformation for geomechanics is derived from a general local differential balance equation with neglecting the local mass balance of solid phase and the inertial force term. The flux continuity condition is used at interfaces between different permeability layers of the heterogeneous medium. We analyze the vertical migration of a CO2 plume injected into a 2D layered reservoir. Analysis of distribution of flow field components such as saturation, pressures, velocities, and CO2 concentration are presented.

  7. Tailoring dislocation structures and mechanical properties of nanostructured metals produced by plastic deformation

    DEFF Research Database (Denmark)

    Huang, Xiaoxu

    2009-01-01

    The presence of a dislocation structure associated with low-angle dislocation boundaries and interior dislocations is a common and characteristic feature in nanostructured metals produced by plastic deformation, and plays an important role in determining both the strength and ductility...

  8. The general form of the relaxation of a purely interfacial energy for structured deformations

    Czech Academy of Sciences Publication Activity Database

    Šilhavý, Miroslav

    2017-01-01

    Roč. 5, č. 2 (2017), s. 191-215 ISSN 2326-7186 Institutional support: RVO:67985840 Keywords : structured deformations * relaxation * subadditive envelope * interfacial energy Subject RIV: BA - General Mathematics OBOR OECD: Applied mathematics http://msp.org/memocs/2017/5-2/p04.xhtml

  9. Evolution of deformation structures under varying loading conditions followed in situ by high angular resolution 3DXRD

    DEFF Research Database (Denmark)

    Pantleon, Wolfgang; Wejdemann, Christian; Jakobsen, B.

    2009-01-01

    copper to different loading conditions are presented: during uninterrupted tensile deformation, formation of subgrains can be observed concurrently with broadening of the Bragg reflection shortly after onset of plastic deformation. With continued tensile deformation, the subgrain structure develops...... intermittently. When the traction is terminated, stress relaxation occurs and number, size and orientation of subgrains are found to be constant. The subgrain structure freezes and only a minor clean-up of the dislocation structure is observed. When changing the tensile direction after pre-deformation in tension...

  10. Deformations in structure of the scapolites from northeast, Brazil

    International Nuclear Information System (INIS)

    Gouveia, A.H.C.; Villarroel, H.S.

    1979-01-01

    Scapolites are relatively common constituents of calcium-rich metamorphic rocks. They can be considered as members of the solid solution series marialite and meionite. Relationship between the optical properties, chemical composition and X-ray diffraction data shows that scapolites from northern Brazil are mizzonites and meionites. The structures of these minerals are compatible only with a primitive lattice. The d hkl peaks of natural scapolites are outside the range shown by the two pure end-members of the series, and the unit-cell dimensions increase with percentage of (K+SO 4 ). X-ray diffraction powder data for natural tetragonal and orthorhombic calcium-rich scapolites are detailed in five tables. (author) [pt

  11. Mechanical deformation of atomic-scale metallic contacts: Structure and mechanisms

    DEFF Research Database (Denmark)

    Sørensen, Mads Reinholdt; Brandbyge, Mads; Jacobsen, Karsten Wedel

    1998-01-01

    We have simulated the mechanical deformation of atomic-scale metallic contacts under tensile strain using molecular dynamics and effective medium theory potentials. The evolution of the structure of the contacts and the underlying deformation mechanisms are described along with the calculated......, but vacancies can be permanently present. The transition states and energies for slip mechanisms have been determined using the nudged elastic band method, and we find a size-dependent crossover from a dislocation-mediated slip to a homogeneous slip when the contact diameter becomes less than a few nm. We show...

  12. Further Development of Ko Displacement Theory for Deformed Shape Predictions of Nonuniform Aerospace Structures

    Science.gov (United States)

    Ko, William L.; Fleischer, Van Tran

    2009-01-01

    The Ko displacement theory previously formulated for deformed shape predictions of nonuniform beam structures is further developed mathematically. The further-developed displacement equations are expressed explicitly in terms of geometrical parameters of the beam and bending strains at equally spaced strain-sensing stations along the multiplexed fiber-optic sensor line installed on the bottom surface of the beam. The bending strain data can then be input into the displacement equations for calculations of local slopes, deflections, and cross-sectional twist angles for generating the overall deformed shapes of the nonuniform beam. The further-developed displacement theory can also be applied to the deformed shape predictions of nonuniform two-point supported beams, nonuniform panels, nonuniform aircraft wings and fuselages, and so forth. The high degree of accuracy of the further-developed displacement theory for nonuniform beams is validated by finite-element analysis of various nonuniform beam structures. Such structures include tapered tubular beams, depth-tapered unswept and swept wing boxes, width-tapered wing boxes, and double-tapered wing boxes, all under combined bending and torsional loads. The Ko displacement theory, combined with the fiber-optic strain-sensing system, provide a powerful tool for in-flight deformed shape monitoring of unmanned aerospace vehicles by ground-based pilots to maintain safe flights.

  13. Radiative processes as a condensation phenomenon and the physical meaning of deformed canonical structures

    International Nuclear Information System (INIS)

    Gamboa, J.; Mendez, F.; Grigorio, L.S.; Guimaraes, M.S.; Wotzasek, C.

    2008-01-01

    We study the radiative corrections of QED 3 from the dual point of view and show that this process is the exact dual to the Julia-Toulouse mechanism introduced by Quevedo and Trugenberger [F. Quevedo, C.A. Trugenberger, Nucl. Phys. B 501 (1997) 143] some years ago. We discuss the physics behind this mechanism that involves condensation of topological defects. It is shown that the dual Stuckelberg mechanism is responsible for the 'rank-jump' phenomenon that transforms the scalar field (dual to Maxwell in this dimensionality) into the vectorial self-dual field. This phenomenon is studied using the ideas of noncommutative fields theory that examines possible deformations of the canonical structure of some well-known models in (2+1)D. A deformation is constructed linking the massless scalar field theory with the self-dual theory. This is the exact dual of the known deformation connecting the Maxwell theory with the Maxwell-Chern-Simons theory. Duality, radiative corrections, the Julia-Toulouse mechanism and canonical deformations are then used to establish a web of relations between the mentioned theories and to propose a physical picture of the deformation procedure adopted

  14. Extracting a Purely Non-rigid Deformation Field of a Single Structure

    Science.gov (United States)

    Demirci, Stefanie; Manstad-Hulaas, Frode; Navab, Nassir

    During endovascular aortic repair (EVAR) treatment, the aortic shape is subject to severe deformation that is imposed by medical instruments such as guide wires, catheters, and the stent graft. The problem definition of deformable registration of images covering the entire abdominal region, however, is highly ill-posed. We present a new method for extracting the deformation of an aneurysmatic aorta. The outline of the procedure includes initial rigid alignment of two abdominal scans, segmentation of abdominal vessel trees, and automatic reduction of their centerline structures to one specified region of interest around the aorta. Our non-rigid registration procedure then only computes local non-rigid deformation and leaves out all remaining global rigid transformations. In order to evaluate our method, experiments for the extraction of aortic deformation fields are conducted on 15 patient datasets from endovascular aortic repair (EVAR) treatment. A visual assessment of the registration results were performed by two vascular surgeons and one interventional radiologist who are all experts in EVAR procedures.

  15. Large Deformation of an Elastic Rod with Structural Anisotropy Subjected to Fluid Flow

    Science.gov (United States)

    Hassani, Masoud; Mureithi, Njuki; Gosselin, Frederick

    2015-11-01

    In the present work, we seek to understand the fundamental mechanisms of three-dimensional reconfiguration of plants by studying the large deformation of a flexible rod in fluid flow. Flexible rods made of Polyurethane foam and reinforced with Nylon fibers are tested in a wind tunnel. The rods have bending-torsion coupling which induces a torsional deformation during asymmetric bending. A mathematical model is also developed by coupling the Kirchhoff rod theory with a semi-empirical drag formulation. Different alignments of the material frame with respect to the flow direction and a range of structural properties are considered to study their effect on the deformation of the flexible rod and its drag scaling. Results show that twisting causes the flexible rods to reorient and bend with the minimum bending rigidity. It is also found that the drag scaling of the rod in the large deformation regime is not affected by torsion. Finally, using a proper set of dimensionless numbers, the state of a bending and twisting rod is characterized as a beam undergoing a pure bending deformation.

  16. Deformation behavior of dragonfly-inspired nodus structured wing in gliding flight through experimental visualization approach.

    Science.gov (United States)

    Zhang, Sheng; Sunami, Yuta; Hashimoto, Hiromu

    2018-04-10

    Dragonfly has excellent flight performance and maneuverability due to the complex vein structure of wing. In this research, nodus as an important structural element of the dragonfly wing is investigated through an experimental visualization approach. Three vein structures were fabricated as, open-nodus structure, closed-nodus structure (with a flex-limiter) and rigid wing. The samples were conducted in a wind tunnel with a high speed camera to visualize the deformation of wing structure in order to study the function of nodus structured wing in gliding flight. According to the experimental results, nodus has a great influence on the flexibility of the wing structure. Moreover, the closed-nodus wing (with a flex-limiter) enables the vein structure to be flexible without losing the strength and rigidity of the joint. These findings enhance the knowledge of insect-inspired nodus structured wing and facilitate the application of Micro Air Vehicle (MAV) in gliding flight.

  17. Deformation bands and dislocation structures of [1-bar 5 5] coplanar double-slip-oriented copper single crystal under cyclic deformation

    International Nuclear Information System (INIS)

    Li, Y.; Li, S.X.; Li, G.Y.

    2004-01-01

    The features of surface morphology and dislocation structure of [1-bar 5 5] coplanar double-slip-oriented copper single crystal under cyclic deformation at a constant plastic shear strain amplitude of 2x10 -3 were studied using optical microscope (OP) and electron channelling contrast imaging (ECCI) in the scanning electron microscope (SEM). Experimental results show that there are two sets of the secondary type of deformation band (DBII) formed in the specimen. The geometry relationship of the two sets of deformation bands (DBs) and slip band (SB) are given. The habit planes of DBIIs are close to (1-bar 0 1) and (1-bar 1 0) plane, respectively. The surface dislocation structures in the specimen including vein, irregular dislocation cells and dislocation walls were also observed. The typical dislocation structure in DBII is the dislocation walls

  18. Deformation analysis and prediction of bank protection structure with river level fluctuations

    Science.gov (United States)

    Hu, Rui; Xing, Yixuan

    2017-04-01

    Bank structure is an important barrier to maintain the safety of the embankment. The deformation of bank protection structure is not only affected by soil pressure caused by the excavation of the riverway, but also by the water pressure caused river water level fluctuations. Thus, it is necessary to establish a coupled soil-water model to analyze the deformation of bank structure. Based on Druck-Prager failure criteria and groundwater seepage theory, a numerical model of bank protection structure with consideration of the pore water pressure of soil mass is established. According to the measured river level data with seasonal fluctuating, numerical analysis of the deformation of bank protection structure is implemented. The simulation results show that the river water level fluctuation has clear influence on the maximum lateral displacement of the pile. Meanwhile, the distribution of plastic zone is related to the depth of groundwater level. Finally, according to the river water level data of the recent ten years, we analyze the deformation of the bank structure under extreme river level. The result shows that, compared with the scenario of extreme high river level, the horizontal displacement of bank protection structure is larger (up to 65mm) under extreme low river level, which is a potential risk to the embankment. Reference Schweiger H F. On the use of drucker-prager failure criteria for earth pressure problems[J]. Computers and Geotechnics, 1994, 16(3): 223-246. DING Yong-chun,CHENG Ze-kun. Numerical study on performance of waterfront excavation[J]. Chinese Journal of Geotechnical Engineering,2013,35(2):515-521. Wu L M, Wang Z Q. Three gorges reservoir water level fluctuation influents on the stability of the slope[J]. Advanced Materials Research. Trans Tech Publications, 2013, 739: 283-286.

  19. Formation of Quenching Structures in the Steel 35 by Deform Cutting

    Directory of Open Access Journals (Sweden)

    A. G. Degtyareva

    2014-01-01

    Full Text Available In industry different methods of surface hardening are widely used to increase reliability and durability of friction unit parts. Among these methods are areas of focus based on deformcutting technology (DC i.e. method of chip-free mechanical treatment.It is shown that DC method allows us to produce through- or partial-hardening surface layers of a large thickness (0,4…1.5mm on steel with no additional heat sources. The standard metal-cutting equipment and common tools are used for deform-cutting process.The significant heat generation in the deform-cutting zone and mechanical effect from the tool allow us to heat undercut layers to the phase transformation point to have the hardening structure as a result of heat removal to the cold balk. The hardening structure formation occurs at significant heating and cooling rate (106C/c with large degrees and rates of strain.The deform-cutting modes and working face tool grinding determine the type and properties of the hardening structure. To produce the hardening structure would require the heat transfer and force action augmentation while treatment.These researches deal with through- and partial surface hardening samples produced by turning steel 35 shafts. While through hardening the phase transformation carry among the whole thickness of the undercut layer; while partial hardening the hardening interlayer formed on the side of the cutting tool contact.The depth of hardening zone of samples with through hardening layers is 0,5 mm; the depth of hardening zone of partial hardening samples is 0,8 mm. Micro-hardness of the through hardening layers is 653 HV0,1 and 485 HV0,1 for the partial hardening layers. The metallographic analysis shows that the hardening zone formed while deform cutting has disperse structure; there are ferrite ghosts in it.The tempering at temperatures of 200 – 700C showed that the micro-hardness of the hardening structures formed while deform cutting is larger than the micro

  20. Severe plastic deformation effect on structure and mechanical properties of Al-Mg-Li system alloys

    International Nuclear Information System (INIS)

    Kolobov, Yu.R.; Najdenkin, E.V.; Dudarev, E.F.; Bakach, G.P.; Pochivalov, Yu.I.; Girsova, N.V.; Ivanov, M.B.

    2002-01-01

    The study on the structural-phase states and mechanical properties of the industrial aluminium alloys Al - 5.5% Mg - 2.2% Li - 0.12% Zr, percent by weight and Al - 5% Mg - 2.2% Li -0.12% Zr - 0.2% Sc percent by weight, obtained by the impact of the intensive plastic deformation, is carried out in comparison with the initial polycrystalline state. It is established that the homogeneous ultrafine-grained structure with the second phase particles, located primarily by the grain boundaries, is formed in the studied samples by the above-mentioned treatment. Such a character of the structure leads to the shift of the temperature-velocity interval of the superplastic properties to the area of lower temperatures and higher deformation velocities [ru

  1. Motion and deformation estimation from medical imagery by modeling sub-structure interaction and constraints

    KAUST Repository

    Sundaramoorthi, Ganesh

    2012-09-13

    This paper presents a novel medical image registration algorithm that explicitly models the physical constraints imposed by objects or sub-structures of objects that have differing material composition and border each other, which is the case in most medical registration applications. Typical medical image registration algorithms ignore these constraints and therefore are not physically viable, and to incorporate these constraints would require prior segmentation of the image into regions of differing material composition, which is a difficult problem in itself. We present a mathematical model and algorithm for incorporating these physical constraints into registration / motion and deformation estimation that does not require a segmentation of different material regions. Our algorithm is a joint estimation of different material regions and the motion/deformation within these regions. Therefore, the segmentation of different material regions is automatically provided in addition to the image registration satisfying the physical constraints. The algorithm identifies differing material regions (sub-structures or objects) as regions where the deformation has different characteristics. We demonstrate the effectiveness of our method on the analysis of cardiac MRI which includes the detection of the left ventricle boundary and its deformation. The experimental results indicate the potential of the algorithm as an assistant tool for the quantitative analysis of cardiac functions in the diagnosis of heart disease.

  2. Formation of diapiric structure in the deformation zone, central Indian Ocean: A model from gravity and seismic reflection data

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.; Rao, D.G.; Neprochnov, Y.P.

    Analyses of bathymetry, gravity and seismic reflection data of the diffusive plate boundary in the central Indian Ocean reveal a new kind of deformed structure besides the well-reported structures of long-wavelength anticlinal basement rises...

  3. Predicting welding distortion in a panel structure with longitudinal stiffeners using inherent deformations obtained by inverse analysis method.

    Science.gov (United States)

    Liang, Wei; Murakawa, Hidekazu

    2014-01-01

    Welding-induced deformation not only negatively affects dimension accuracy but also degrades the performance of product. If welding deformation can be accurately predicted beforehand, the predictions will be helpful for finding effective methods to improve manufacturing accuracy. Till now, there are two kinds of finite element method (FEM) which can be used to simulate welding deformation. One is the thermal elastic plastic FEM and the other is elastic FEM based on inherent strain theory. The former only can be used to calculate welding deformation for small or medium scale welded structures due to the limitation of computing speed. On the other hand, the latter is an effective method to estimate the total welding distortion for large and complex welded structures even though it neglects the detailed welding process. When the elastic FEM is used to calculate the welding-induced deformation for a large structure, the inherent deformations in each typical joint should be obtained beforehand. In this paper, a new method based on inverse analysis was proposed to obtain the inherent deformations for weld joints. Through introducing the inherent deformations obtained by the proposed method into the elastic FEM based on inherent strain theory, we predicted the welding deformation of a panel structure with two longitudinal stiffeners. In addition, experiments were carried out to verify the simulation results.

  4. Semantic modeling of the structural and process entities during plastic deformation of crystals and rocks

    Science.gov (United States)

    Babaie, Hassan; Davarpanah, Armita

    2016-04-01

    We are semantically modeling the structural and dynamic process components of the plastic deformation of minerals and rocks in the Plastic Deformation Ontology (PDO). Applying the Ontology of Physics in Biology, the PDO classifies the spatial entities that participate in the diverse processes of plastic deformation into the Physical_Plastic_Deformation_Entity and Nonphysical_Plastic_Deformation_Entity classes. The Material_Physical_Plastic_Deformation_Entity class includes things such as microstructures, lattice defects, atoms, liquid, and grain boundaries, and the Immaterial_Physical_Plastic_Deformation_Entity class includes vacancies in crystals and voids along mineral grain boundaries. The objects under the many subclasses of these classes (e.g., crystal, lattice defect, layering) have spatial parts that are related to each other through taxonomic (e.g., Line_Defect isA Lattice_Defect), structural (mereological, e.g., Twin_Plane partOf Twin), spatial-topological (e.g., Vacancy adjacentTo Atom, Fluid locatedAlong Grain_Boundary), and domain specific (e.g., displaces, Fluid crystallizes Dissolved_Ion, Void existsAlong Grain_Boundary) relationships. The dynamic aspect of the plastic deformation is modeled under the dynamical Process_Entity class that subsumes classes such as Recrystallization and Pressure_Solution that define the flow of energy amongst the physical entities. The values of the dynamical state properties of the physical entities (e.g., Chemical_Potential, Temperature, Particle_Velocity) change while they take part in the deformational processes such as Diffusion and Dislocation_Glide. The process entities have temporal parts (phases) that are related to each other through temporal relations such as precedes, isSubprocessOf, and overlaps. The properties of the physical entities, defined under the Physical_Property class, change as they participate in the plastic deformational processes. The properties are categorized into dynamical, constitutive

  5. Role of structural inheritance on present-day deformation in intraplate domains

    Science.gov (United States)

    Tarayoun, A.; Mazzotti, S.; Gueydan, F.

    2017-12-01

    Understanding the role of structural inheritance on present day surface deformation is a key element for better characterizing the dynamism of intraplate earthquakes. Current deformation and seismicity are poorly understood phenomenon in intra-continental domains. A commonly used hypothesis, based on observations, suggests that intraplate deformation is related to the reactivation of large tectonic paleo-structures, which can act as locally weakened domains. The objective of our study is to quantify the impact of these weakened areas on present-day strain localizations and rates. We combine GPS observations and numerical modeling to analyze the role of structural inheritance on strain rates, with specific observations along the St. Lawrence Valley of eastern Canada. We processed 143 GPS stations from five different networks, in particular one dense campaign network situated along a recognized major normal faults system of the Iapetus paleo-rift, in order to accurately determine the GPS velocities and strain rates. Results of strain rates show magnitude varying from 1.5x10-10 to 6.8x10-9 yr-1 in the St Lawrence valley. Weakened area strain rates are up to one order of magnitude higher than surrounding areas. We compare strain rates inferred from GPS and the new postglacial rebound model. We found that GPS signal is one order of magnitude higher in the weakened zone, which is likely due to structural inheritance. The numerical modeling investigates the steady-state deformation of the continental lithosphere with presence of a weak area. Our new approach integrates ductile structural inheritance using a weakening coefficient that decreases the lithosphere strength at different depths. This allows studying crustal strain rates mainly as a function of rheological contrast and geometry of the weakened domains. Comparison between model predictions and observed GPS strain rates will allow us to investigate the respective role of crustal and mantle tectonic inheritance.

  6. Correlation between locally deformed structure and oxide film properties in austenitic stainless steel irradiated with neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Chimi, Yasuhiro, E-mail: chimi.yasuhiro@jaea.go.jp [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kitsunai, Yuji [Nippon Nuclear Fuel Development, 2163 Narita-cho, Oarai-machi, Higashi-ibaraki-gun, Ibaraki 311-1313 (Japan); Kasahara, Shigeki [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Chatani, Kazuhiro; Koshiishi, Masato [Nippon Nuclear Fuel Development, 2163 Narita-cho, Oarai-machi, Higashi-ibaraki-gun, Ibaraki 311-1313 (Japan); Nishiyama, Yutaka [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan)

    2016-07-15

    To elucidate the mechanism of irradiation-assisted stress corrosion cracking (IASCC) in high-temperature water for neutron-irradiated austenitic stainless steels (SSs), the locally deformed structures, the oxide films formed on the deformed areas, and their correlation were investigated. Tensile specimens made of irradiated 316L SSs were strained 0.1%–2% at room temperature or at 563 K, and the surface structures and crystal misorientation among grains were evaluated. The strained specimens were immersed in high-temperature water, and the microstructures of the oxide films on the locally deformed areas were observed. The appearance of visible step structures on the specimens' surface depended on the neutron dose and the applied strain. The surface oxides were observed to be prone to increase in thickness around grain boundaries (GBs) with increasing neutron dose and increasing local strain at the GBs. No penetrative oxidation was observed along GBs or along surface steps. - Highlights: • Visible step structures depend on the neutron dose and the applied strain. • Local strain at grain boundaries was accumulated with the neutron dose. • Oxide thickness increases with neutron dose and local strain at grain boundaries. • No penetrative oxidation was observed along grain boundaries or surface steps.

  7. Superposed ruptile deformational events revealed by field and VOM structural analysis

    Science.gov (United States)

    Kumaira, Sissa; Guadagnin, Felipe; Keller Lautert, Maiara

    2017-04-01

    Virtual outcrop models (VOM) is becoming an important application in the analysis of geological structures due to the possibility of obtaining the geometry and in some cases kinematic aspects of analyzed structures in a tridimensional photorealistic space. These data are used to gain quantitative information on the deformational features which coupled with numeric models can assist in understands deformational processes. Old basement units commonly register superposed deformational events either ductile or ruptile along its evolution. The Porongos Belt, located at southern Brazil, have a complex deformational history registering at least five ductile and ruptile deformational events. In this study, we presents a structural analysis of a quarry in the Porongos Belt, coupling field and VOM structural information to understand process involved in the last two deformational events. Field information was acquired using traditional structural methods for analysis of ruptile structures, such as the descriptions, drawings, acquisition of orientation vectors and kinematic analysis. VOM was created from the image-based modeling method through photogrammetric data acquisition and orthorectification. Photogrammetric data acquisition was acquired using Sony a3500 camera and a total of 128 photographs were taken from ca. 10-20 m from the outcrop in different orientations. Thirty two control point coordinates were acquired using a combination of RTK dGPS surveying and total station work, providing a precision of few millimeters for x, y and z. Photographs were imported into the Photo Scan software to create a 3D dense point cloud from structure from-motion algorithm, which were triangulated and textured to generate the VOM. VOM was georreferenced (oriented and scaled) using the ground control points, and later analyzed in OpenPlot software to extract structural information. Data was imported in Wintensor software to obtain tensor orientations, and Move software to process and

  8. The deformation twin in lamellar Ti 3Al/TiAl structure

    Science.gov (United States)

    Zhang, J. X.; Ye, H. Q.

    2003-04-01

    A Ti-48Al-2Cr (at.%) alloy consisting of γ+α 2 lamellar structure was deformed in compression at room temperature. Study by high resolution electron microscopy was carried out on the characteristic of induced γ T/α 2 interface. During deformation the γ T/α 2 interface presents a stepped structure and the γ/α 2 interface remains straight. The formation mechanism of γ T associated with misfit dislocations is proposed. 1/2[01 1¯] γ interfacial dislocation in the γ/α 2 interface can dissociate into a 1/6[ 1¯1 2¯] γ partial dislocation which glides on the ( 1¯11) γ plane and causes γ T to form.

  9. Creep deformation and rupture behavior of type 304/308 stainless steel structural weldments

    International Nuclear Information System (INIS)

    McAfee, W.J.; Richardson, M.; Sartory, W.K.

    1977-01-01

    The creep deformation and rupture of type 304/308 stainless steel structural weldments at 593 0 C (1100 0 F) was experimentally investigated to study the comparative behavior of the base metal and weld metal constituents. The tests were conducted in support of ORNL's program to develop high-temperature structural design methods applicable to liquid-metal fast breeder reactor (LMFBR) system components that operate in the creep range. The specimens used were thin-walled, right circular cylinders capped with either flat or hemispherical heads and tested under internal gas pressure. Circumferential welds were located in different regions of the cylinder or head and, with one exception, were geometrically duplicated by all base metal regions in companion specimens. Results are presented on the comparative deformation and rupture behavior of selected points in the base metal and weldment regions of the different specimens and on the overall surface strains for selected specimens

  10. A Numerical Analysis on the Local Deformation of a Spacer Grid Structure for Nuclear Fuel Cells

    International Nuclear Information System (INIS)

    Jang, Myung-Geun; Na, Geum Ju; Kim, Jong-Bong; Shin, Hyunho

    2016-01-01

    The result of a preliminary numerical investigation on local deformation characteristics of a multi-layered spacer-grid structure with five guide tubes is reported based on implicit finite element analysis. For the numerical analysis, displacements of top and bottom cross sections of each guide tube in a single-layer model were constrained while a lateral displacement was imposed on the single layer. Unlike the impact hammer test that is generally employed to characterize the deformation characteristics of the space-grid structure, the buckling phenomenon occurs locally in this study; it takes place at the inner grids around each tube and the degree of bucking is more apparent for tubes near the lateral surface where the lateral displacement was imposed. (paper)

  11. A nonlinear deformed su(2) algebra with a two-color quasitriangular Hopf structure

    International Nuclear Information System (INIS)

    Bonatsos, D.; Daskaloyannis, C.; Kolokotronis, P.; Ludu, A.; Quesne, C.

    1997-01-01

    Nonlinear deformations of the enveloping algebra of su(2), involving two arbitrary functions of J 0 and generalizing the Witten algebra, were introduced some time ago by Delbecq and Quesne. In the present paper, the problem of endowing some of them with a Hopf algebraic structure is addressed by studying in detail a specific example, referred to as scr(A) q + (1). This algebra is shown to possess two series of (N+1)-dimensional unitary irreducible representations, where N=0,1,2,hor-ellipsis. To allow the coupling of any two such representations, a generalization of the standard Hopf axioms is proposed by proceeding in two steps. In the first one, a variant and extension of the deforming functional technique is introduced: variant because a map between two deformed algebras, su q (2) and scr(A) q + (1), is considered instead of a map between a Lie algebra and a deformed one, and extension because use is made of a two-valued functional, whose inverse is singular. As a result, the Hopf structure of su q (2) is carried over to scr(A) q + (1), thereby endowing the latter with a double Hopf structure. In the second step, the definition of the coproduct, counit, antipode, and scr(R)-matrix is extended so that the double Hopf algebra is enlarged into a new algebraic structure. The latter is referred to as a two-color quasitriangular Hopf algebra because the corresponding scr(R)-matrix is a solution of the colored Yang endash Baxter equation, where the open-quotes colorclose quotes parameters take two discrete values associated with the two series of finite-dimensional representations. copyright 1997 American Institute of Physics

  12. Forecasting of mechanical - and structural behavior of 316 austenitic stainless steels by deformation charts

    International Nuclear Information System (INIS)

    Monteiro, S.N.

    1980-01-01

    The utilization of deformation charts applied to AISI 316 austenitic stainless steel with the purpose of foreseeing its behavior associated with structural and mechanical phenomena, is evaluated. The ocurrence of phenomena such as dynamic aging, martensite transformation, static aging, failure at creep curve, cells, subgrains and boundary slips is discussed in the different regions of the chart. A practical example of the charts' utilization for components of fast reactors is finally presented. (Author) [pt

  13. Local deformation method for measuring element tension in space deployable structures

    Directory of Open Access Journals (Sweden)

    Belov Sergey

    2017-01-01

    Full Text Available The article describes the local deformation method to determine the tension of cord and thin membrane elements in space deployable structure as antenna reflector. Possible measuring instrument model, analytical and numerical solutions and experimental results are presented. The boundary effects on measurement results of metallic mesh reflector surface tension are estimated. The study case depicting non-uniform reflector surface tension is considered.

  14. Influence of Severe Plastic Deformation on Mechanical Properties and Structure of Aluminium Alloys

    Directory of Open Access Journals (Sweden)

    Ondřej Hilšer

    2016-09-01

    Full Text Available Article is devoted to analysis of ECAP (Equal Channel Angular Pressing method, which uses a high degree of deformation to achieve a very fine-grained structure of formed material. Utilization of The ECAP technology enables attainment of required properties of selected materials by using of severe plastic deformation (SPD methods. In the experimental part the influence of the number of passes through forming tool with classical geometry (angle of 90° between channels was studied to achieve maximum hardening (expressed by deformation resistance and achieved value of hardness HV10. Also the metallographic analysis (detection of achieved grain refinement was carried out. From comparison of results achieved at both alloys it can be stated that for given forming by ECAP method the EN AW-8006 alloy is preferable, because higher strength degree was obtained by achieving of very fine grained structure. When using the same method of forming by ECAP method the EN AW-2024 alloy has lower hardening and structure refinement.

  15. An introductory review on gravitational-deformation induced structures, fabrics and modeling

    Science.gov (United States)

    Jaboyedoff, Michel; Penna, Ivanna; Pedrazzini, Andrea; Baroň, Ivo; Crosta, Giovanni B.

    2013-10-01

    Recent studies have pointed out a similarity between tectonics and slope tectonic-induced structures. Numerous studies have demonstrated that structures and fabrics previously interpreted as of purely geodynamical origin are instead the result of large slope deformation, and this led in the past to erroneous interpretations. Nevertheless, their limit seems not clearly defined, but it is somehow transitional. Some studies point out continuity between failures developing at surface with upper crust movements. In this contribution, the main studies which examine the link between rock structures and slope movements are reviewed. The aspects regarding model and scale of observation are discussed together with the role of pre-existing weaknesses in the rock mass. As slope failures can develop through progressive failure, structures and their changes in time and space can be recognized. Furthermore, recognition of the origin of these structures can help in avoiding misinterpretations of regional geology. This also suggests the importance of integrating different slope movement classifications based on distribution and pattern of deformation and the application of structural geology techniques. A structural geology approach in the landslide community is a tool that can greatly support the hazard quantification and related risks, because most of the physical parameters, which are used for landslide modeling, are derived from geotechnical tests or the emerging geophysical approaches.

  16. Optimisation by plastic deformation of structural and mechanical uranium alloys properties

    International Nuclear Information System (INIS)

    Prunier, Claude.

    1981-08-01

    Structural and mechanical properties evolution of rich and poor uranium alloys are investigated. Good usual properties are obtained with few metallic additions with a limited effect giving a fine and isotrope grain structure. Amelioration is observed with heat treatment from β and γ phases high temperature range. However, dynamic recrystallisation, related to hot working, is the better phenomena to maximize the usual mechanical and structural properties. So high temperature behaviour of rich and poor uranium alloys in α, β and γ crystalline structure is studied: - dynamic recrystallisation phenomena begins only in α, and β phases high temperature range; - high strength and brittle β phase shows a very large ductility above 700 deg C. Recrystallisation is a thermal actived phenomena localised at grain boundary, dependant with alloys concentration and crystalline structure. β phase activation energy and deformation rate for dynamic recrystallisation beginning are most important, than α and γ phases in relation with quadratic structure complexity. Both temperature and deformation rate are the main dynamic recrystallisation factors. Optimal usual mechanical and structural properties obtained by hot working (forging, milling) are sensible to hydrogen embrittlement [fr

  17. Evidence for cross rift structural controls on deformation and seismicity at a continental rift caldera

    Science.gov (United States)

    Lloyd, Ryan; Biggs, Juliet; Wilks, Matthew; Nowacki, Andy; Kendall, J.-Michael; Ayele, Atalay; Lewi, Elias; Eysteinsson, Hjálmar

    2018-04-01

    In continental rifts structural heterogeneities, such as pre-existing faults and foliations, are thought to influence shallow crustal processes, particularly the formation of rift faults, magma reservoirs and surface volcanism. We focus on the Corbetti caldera, in the southern central Main Ethiopian Rift. We measure the surface deformation between 22nd June 2007 and 25th March 2009 using ALOS and ENVISAT SAR interferograms and observe a semi-circular pattern of deformation bounded by a sharp linear feature cross-cutting the caldera, coincident with the caldera long axis. The signal reverses in sign but is not seasonal: from June to December 2007 the region south of this structure moves upwards 3 cm relative to the north, while from December 2007 until November 2008 it subsides by 2 cm. Comparison of data taken from two different satellite look directions show that the displacement is primarily vertical. We discuss potential mechanisms and conclude that this deformation is associated with pressure changes within a shallow (statistically consistent with this fault structure, indicating that the fault has also controlled the migration of magma from a reservoir to the surface over tens of thousands of years. Spatial patterns of seismicity are consistent with a cross-rift structure that extents outside the caldera and to a depth of ∼30 km, and patterns of seismic anisotropy suggests stress partitioning occurs across the structure. We discuss the possible nature of this structure, and conclude that it is most likely associated with the Goba-Bonga lineament, which cross-cuts and pre-dates the current rift. Our observations show that pre-rift structures play an important role in magma transport and shallow hydrothermal processes, and therefore they should not be neglected when discussing these processes.

  18. CFD simulations of flow erosion and flow-induced deformation of needle valve: Effects of operation, structure and fluid parameters

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hongjun, E-mail: ticky863@126.com [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan (China); State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, Sichuan (China); Pan, Qian; Zhang, Wenli; Feng, Guang; Li, Xue [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan (China)

    2014-07-01

    Highlights: • A combined FSI–CFD and DPM computational method is used to investigate flow erosion and deformation of needle valve. • The numerical model is validated with the comparison of measured and predicted erosion rate. • Effects of operation, structure and fluid parameters on flow erosion and flow-induced deformation are discussed. • Particle diameter has the most significant effect on flow erosion. • Inlet rate has the most obvious effect on flow-induced deformation. - Abstract: A three-dimensional fluid–structure interaction (FSI) computational model coupling with a combined continuum and discrete model has been used to predict the flow erosion rate and flow-induced deformation of needle valve. Comparisons with measured data demonstrate good agreement with the predictions of erosion rate. The flow field distribution of gas-particle flow and the erosion rate and deformation of valve core are captured under different operating and structural conditions with different fluid parameters. The effects of inlet velocity, valve opening and inlet valve channel size, particle concentration, particle diameter and particle phase components are discussed in detail. The results indicate that valve tip has the most severe erosion and deformation, and flow field, erosion rate and deformation of valve are all sensitive to inlet condition changes, structural changes and fluid properties changes. The effect of particle diameter on erosion is the most significant, while the influence of inlet rate on deformation is the greatest one.

  19. Analysis of High Temperature Deformed Structure and Dynamic Precipitation in W9Mo3Cr4V Steel

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    With TEM、SEM, various high-temperature deformed structures inW9Mo3Cr4V steel were investigated. The sub-structures,recrystallized nuclei, as well as the dynamic precipitation were also studied and analyzed. The relationship between recrystallized structures and dynamic precipitation was discussed. The results showed that the deformed structures in W9Mo3Cr4V steel are more complicated than those in low alloy steels. Because W9Mo3Cr4V steel is a high-speed steel, there are a large number of residual carbides on the matrix. Also, much dynamic precipitating carbides will precipitate during deformation at high temperature.

  20. Multi-trace deformations in AdS/CFT. Exploring the vacuum structure of the deformed CFT

    Energy Technology Data Exchange (ETDEWEB)

    Papadimitriou, I. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[Center for Mathematical Physics, Hamburg (Germany)

    2007-03-15

    We present a general and systematic treatment of multi-trace deformations in the AdS/CFT correspondence in the large N limit, pointing out and clarifying subtleties relating to the formulation of the boundary value problem on a conformal boundary. We then apply this method to study multi-trace deformations in the presence of a scalar VEV, which requires the coupling to gravity to be taken into account. We show that supergravity solutions subject to 'mixed' boundary conditions are in one-to-one correspondence with critical points of the holographic effective action of the dual theory in the presence of a multi-trace deformation, and we find a number of new exact analytic solutions involving a minimally or conformally coupled scalar field satisfying 'mixed' boundary conditions. These include the generalization to any dimension of the instanton solution recently found in hep-th/0611315. Finally, we provide a systematic method for computing the holographic effective action in the presence of a multi-trace deformation in a derivative expansion away from the conformal vacuum using Hamilton-Jacobi theory. Requiring that this effective action exists and is bounded from below reproduces recent results on the stability of the AdS vacuum in the presence of 'mixed' boundary conditions. (orig.)

  1. Multi-trace deformations in AdS/CFT. Exploring the vacuum structure of the deformed CFT

    International Nuclear Information System (INIS)

    Papadimitriou, I.

    2007-03-01

    We present a general and systematic treatment of multi-trace deformations in the AdS/CFT correspondence in the large N limit, pointing out and clarifying subtleties relating to the formulation of the boundary value problem on a conformal boundary. We then apply this method to study multi-trace deformations in the presence of a scalar VEV, which requires the coupling to gravity to be taken into account. We show that supergravity solutions subject to 'mixed' boundary conditions are in one-to-one correspondence with critical points of the holographic effective action of the dual theory in the presence of a multi-trace deformation, and we find a number of new exact analytic solutions involving a minimally or conformally coupled scalar field satisfying 'mixed' boundary conditions. These include the generalization to any dimension of the instanton solution recently found in hep-th/0611315. Finally, we provide a systematic method for computing the holographic effective action in the presence of a multi-trace deformation in a derivative expansion away from the conformal vacuum using Hamilton-Jacobi theory. Requiring that this effective action exists and is bounded from below reproduces recent results on the stability of the AdS vacuum in the presence of 'mixed' boundary conditions. (orig.)

  2. Structure of collective bands and deformations in {sup 74,76}Kr

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, K.C. [Physics Department, F M College, Balasore, 756 001 (India); Sahu, R. [Physics Department, Berhampur University, Berhampur, 760 007 (India)

    2000-08-01

    The structure of collective bands in {sup 74,76}Kr is studied within the framework of the deformed configuration mixing shell model based on Hartree-Fock states. The active single-particle orbits are 1p{sub 3/2}, 0f{sub 5/2}, 1p{sub 1/2} and 0g{sub 9/2} with {sup 56}Ni as the inert core. A modified Kuo interaction has been used for the above configuration space. The {sup 74}Kr nucleus is found to be the most deformed nucleus among the krypton isotopes which is in agreement with experiment. The deformation is found to decrease for the {sup 76}Kr isotope. The calculated positive- and negative-parity bandsagree quite well with the experiment for both the nuclei. A number of excited bands is also predicted. We have also calculated B(E2) values and compared them with available experimental data. The structure of the strongly coupled band built on K = 4{sup (+)} in {sup 76}Kr is also studied. (author)

  3. Structure of collective bands and deformations in 74,76Kr

    International Nuclear Information System (INIS)

    Tripathy, K.C.; Sahu, R.

    2000-01-01

    The structure of collective bands in 74,76 Kr is studied within the framework of the deformed configuration mixing shell model based on Hartree-Fock states. The active single-particle orbits are 1p 3/2 , 0f 5/2 , 1p 1/2 and 0g 9/2 with 56 Ni as the inert core. A modified Kuo interaction has been used for the above configuration space. The 74 Kr nucleus is found to be the most deformed nucleus among the krypton isotopes which is in agreement with experiment. The deformation is found to decrease for the 76 Kr isotope. The calculated positive- and negative-parity bands agree quite well with the experiment for both the nuclei. A number of excited bands is also predicted. We have also calculated B(E2) values and compared them with available experimental data. The structure of the strongly coupled band built on K = 4 (+) in 76 Kr is also studied. (author)

  4. First-principles study of electronic structure of deformed carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Kazuchika Iwami, Hidekazu Goto, Kikuji Hirose and Tomoya Ono

    2007-01-01

    Full Text Available On the basis of density functional theory, we study the electronic structures of five types of carbon nanotubes: the non-deformed (6,6 tube, the uniformly stretched tube along the tube axis, the uniformly compressed tube, the partially stretched tube and the partially compressed tube. The electron charge density increases at the compressed C–C bond of the partially stretched tube, while the density decreases at the stretched C–C bond of the partially stretched tube. In addition, the a1 and e1 states of the (6,6 tube contribute to the bonding along the tube axis and the a2 and e2 states are the bonds connecting the atoms in the same layers. Thus, the energy bands of the a1 and e1 states are sensitively affected by the deformation of the tubes along the tube axis.

  5. Influence of preliminary plastic deformation on plasticity characteristics and structure of armco-iron

    International Nuclear Information System (INIS)

    Vergazov, A.N.; Rybin, V.V.; Meshkov, Yu.Ya.; Moskvina, V.A.; Serditova, T.N.

    1990-01-01

    Effect of preliminary plastic deformation (PPD) by drawing on the maximum plasticity characteristics (critical rupture strain) ε c , general δ and uniform δ p relative elongation and on the structure of armco-iron in a wide range of PPD degree change (e=0-4.6) is studied. It is ascertained that with e growth the metal plastic properties at T test =77 and 293 K change in a different way. In particular, the critical strain ε c increases monotonously at 77 K and reduces at 293 K. It is shown that all changes of mechanical characteristics observed with e increase are conditioned by the development of fragmentation process in armco-iron. The data obtained are discussed from the veiwpoint of the developed plastic deformation physics concepts

  6. Deformation analysis of a film-overlapped micro-pump membrane structure

    International Nuclear Information System (INIS)

    Lee, Fu-Shin; Wang, Pi-Wen; Chen, Chih-Hsiung

    2008-01-01

    A novel approach is developed to study a film-overlapped membrane structure. Meanwhile, the established model is employed to design the micro-pump membrane structure and to evaluate its pumping efficiency. Two-dimensional coupling effects between the overlapping actuator films and the deformable membrane are thoroughly investigated, including the influences on the membrane from the overlapping films' elongation effects, Poisson's ratio effects and shear strain effects. Overall deformations and interactions for the three-layer membrane structures are accurately calculated through exercising the developed model, in contrast to what difficulties are usually encountered in carrying out FEM methods with very thin elements meshed for the actuator films. Furthermore, this study demonstrates that the high stiffness of the actuating metal films needs to be reflected in the equivalent stiffness of the membrane structures, especially when the sizes of the actuator films become compatible with the sizes of the membranes. Hence, the optimal micro-pumping efficiency of a membrane structure is acquired upon exercising the developed model, and larger sizes of the actuating films do not definitely obtain larger pumping efficiencies for the electromagnetically actuated micro-pumps

  7. Dislocation structure evolution in 304L stainless steel and weld joint during cyclic plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hao; Jing, Hongyang; Zhao, Lei; Han, Yongdian; Lv, Xiaoqing [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300072 (China); Xu, Lianyong, E-mail: xulianyong@tju.edu.cn [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Advanced Joining Technology, Tianjin 300072 (China)

    2017-04-06

    Dislocation structures and their evolution of 304L stainless steel and weld metal made with ER308L stainless steel welding wire subjected to uniaxial symmetric strain-controlled loading and stress-controlled ratcheting loading were observed by transmission electron microscopy (TEM). The correlation between the cyclic response and the dislocation structure has been studied. The experiment results show that the cyclic behaviour of base metal and weld metal are different. The cyclic behaviour of the base metal consists of primary hardening, slight softening and secondary hardening, while the weld metal shows a short hardening within several cycles followed by the cyclic softening behaviour. The microscopic observations indicate that in base metal, the dislocation structures evolve from low density patterns to those with higher dislocation density during both strain cycling and ratcheting deformation. However, the dislocation structures of weld metal change oppositely form initial complicated structures to simple patterns and the dislocation density gradually decrease. The dislocation evolution presented during the strain cycling and ratcheting deformation is summarized, which can qualitatively explain the cyclic behaviour and the uniaxial ratcheting behaviour of two materials. Moreover, the dislocation evolution in the two types of tests is compared, which shows that the mean stress has an effect on the rate of dislocation evolution during the cyclic loading.

  8. PSP SAR interferometry monitoring of ground and structure deformations in the archeological site of Pompeii

    Science.gov (United States)

    Costantini, Mario; Francioni, Elena; Paglia, Luca; Minati, Federico; Margottini, Claudio; Spizzichino, Daniele; Trigila, Alessandro; Iadanza, Carla; De Nigris, Bruno

    2016-04-01

    The "Major Project Pompeii" (MPP) is a great collective commitment of different institututions and people to set about solving the serious problem of conservation of the largest archeological sites in the world. The ancient city of Pompeii with its 66 hectares, 44 of which are excaveted, is divided into 9 regiones (district), subdivided in 118 insulae (blocks) and almost 1500 domus (houses), and is Unesco site since 1996. The Italian Ministry for Heritage and Cultural Activities and Tourism (MiBACT) and Finmeccanica Group have sealed an agreement whereby the Finmeccanica Group will donate innovative technologies and services for monitoring and protecting the archaeological site of Pompeii. Moreover, the Italian Institute for Environment Protection and Research (ISPRA) - Geological Survey of Italy, was also involved to support the ground based analysis and interpretation of the measurements provided by the industrial team, in order to promote an interdisciplinary approach. In this work, we will focus on ground deformation measurements obtained by satellite SAR interferometry and on their interpretation. The satellite monitoring service is based on the processing of COSMO-SkyMed Himage data by the e-Geos proprietary Persistent Scatterer Pair (PSP) SAR interferometry technology. The PSP technique is a proven SAR interferometry method characterized by the fact of exploiting in the processing only the relative properties between close points (pairs) in order to overcome atmospheric artifacts (which are one of the main problems of SAR interferometry). Validations analyses showed that this technique applied to COSMO-SkyMed Himage data is able to retrieve very dense (except of course on vegetated or cultivated areas) millimetric deformation measurements with sub-metric localization. By means of the COSMO-SkyMed PSP SAR interferometry processing, a historical analysis of the ground and structure deformations occurred over the entire archaeological site of Pompeii in the

  9. Modeling programmable deformation of self-folding all-polymer structures with temperature-sensitive hydrogels

    International Nuclear Information System (INIS)

    Guo, Wei; Zhou, Jinxiong; Li, Meie

    2013-01-01

    Combination of soft active hydrogels with hard passive polymers gives rise to all-polymer composites. The hydrogel is sensitive to external stimuli while the passive polymer is inert. Utilizing the different behaviors of two materials subject to environmental variation, for example temperature, results in self-folding soft machines. We report our efforts to model the programmable deformation of self-folding structures with temperature-sensitive hydrogels. The self-folding structures are realized either by constructing a bilayer structure or by incorporating hydrogels as hinges. The methodology and the results may aid the design, control and fabrication of 3D complex structures from 2D simple configurations through self-assembly. (paper)

  10. Analysis of intelligent hinged shell structures: deployable deformation and shape memory effect

    Science.gov (United States)

    Shi, Guang-Hui; Yang, Qing-Sheng; He, X. Q.

    2013-12-01

    Shape memory polymers (SMPs) are a class of intelligent materials with the ability to recover their initial shape from a temporarily fixable state when subjected to external stimuli. In this work, the thermo-mechanical behavior of a deployable SMP-based hinged structure is modeled by the finite element method using a 3D constitutive model with shape memory effect. The influences of hinge structure parameters on the nonlinear loading process are investigated. The total shape memory of the processes the hinged structure goes through, including loading at high temperature, decreasing temperature with load carrying, unloading at low temperature and recovering the initial shape with increasing temperature, are illustrated. Numerical results show that the present constitutive theory and the finite element method can effectively predict the complicated thermo-mechanical deformation behavior and shape memory effect of SMP-based hinged shell structures.

  11. Analysis of intelligent hinged shell structures: deployable deformation and shape memory effect

    International Nuclear Information System (INIS)

    Shi, Guang-Hui; Yang, Qing-Sheng; He, X Q

    2013-01-01

    Shape memory polymers (SMPs) are a class of intelligent materials with the ability to recover their initial shape from a temporarily fixable state when subjected to external stimuli. In this work, the thermo-mechanical behavior of a deployable SMP-based hinged structure is modeled by the finite element method using a 3D constitutive model with shape memory effect. The influences of hinge structure parameters on the nonlinear loading process are investigated. The total shape memory of the processes the hinged structure goes through, including loading at high temperature, decreasing temperature with load carrying, unloading at low temperature and recovering the initial shape with increasing temperature, are illustrated. Numerical results show that the present constitutive theory and the finite element method can effectively predict the complicated thermo-mechanical deformation behavior and shape memory effect of SMP-based hinged shell structures. (paper)

  12. CHANGE IN DEFORMATION PROPERTIES MODELING OF CONCRETE IN PROTECTIVE STRUCTURES OF NUCLEAR REACTOR BY IONIZING RADIATION

    Directory of Open Access Journals (Sweden)

    E. K. Agakhanov

    2016-01-01

    Full Text Available The necessity of studying the effect impact of elementary particles impact on the strength and deformation materials properties used in protective constructions nuclear reactors and reactor technology has been stipulated. A nuclear reactor pressure vessel from prestressed concrete, combining the functions of biological protection is to be considered. The neutron flux problem distribution in the pressure vessel of a nuclear reactor has been solved. The solution is made in axisymmetric with the finite element method using a flat triangular finite element. Computing has been conducted in Matlab package. The comparison with the results has been obtained using the finite difference method, as well as the graphs of changes under the influence of radiation exposure and the elastic modulus of concrete radiation deformations have been constructed. The proposed method allows to simulate changes in the deformation properties of concrete under the influence of neutron irradiation. Results of the study can be used in the calculation of stress-strain state of structures, taking into account indirect heterogeneity caused by the physical fields influence.

  13. Structural consequences of diffuse traumatic brain injury: A large deformation tensor-based morphometry study

    Science.gov (United States)

    Kim, Junghoon; Avants, Brian; Patel, Sunil; Whyte, John; Coslett, H. Branch; Pluta, John; Detre, John A.; Gee, James C.

    2008-01-01

    Traumatic brain injury (TBI) is one of the most common causes of long-term disability. Despite the importance of identifying neuropathology in individuals with chronic TBI, methodological challenges posed at the stage of inter-subject image registration have hampered previous voxel-based MRI studies from providing a clear pattern of structural atrophy after TBI. We used a novel symmetric diffeomorphic image normalization method to conduct a tensor-based morphometry (TBM) study of TBI. The key advantage of this method is that it simultaneously estimates an optimal template brain and topology preserving deformations between this template and individual subject brains. Detailed patterns of atrophies are then revealed by statistically contrasting control and subject deformations to the template space. Participants were 29 survivors of TBI and 20 control subjects who were matched in terms of age, gender, education, and ethnicity. Localized volume losses were found most prominently in white matter regions and the subcortical nuclei including the thalamus, the midbrain, the corpus callosum, the mid- and posterior cingulate cortices, and the caudate. Significant voxel-wise volume loss clusters were also detected in the cerebellum and the frontal/temporal neocortices. Volume enlargements were identified largely in ventricular regions. A similar pattern of results was observed in a subgroup analysis where we restricted our analysis to the 17 TBI participants who had no macroscopic focal lesions (total lesion volume> 1.5 cm 3). The current study confirms, extends, and partly challenges previous structural MRI studies in chronic TBI. By demonstrating that a large deformation image registration technique can be successfully combined with TBM to identify TBI-induced diffuse structural changes with greater precision, our approach is expected to increase the sensitivity of future studies examining brain-behavior relationships in the TBI population. PMID:17999940

  14. Effect of thermomechanical conditions of deformation on structure and properties of tungsten wire

    International Nuclear Information System (INIS)

    Pavlov, I.M.; Ushakov, E.V.; Karavajtsev, V.I.; Drobysheva, E.K.; Tiraspol'skij, V.I.; Zelentsova, N.M.; Gruzdov, V.V.

    1983-01-01

    The purpose of the investigation is to specify the relation between conditions of plastic deformation of non-slacked tungsten, structure and properties of rods and wire. Planning multifactor experiments is chosen as the basic method for investigation. It is shown that rationai choice of plastic working conditions permits to reduce the tendency to lamination of tungsten wire. Growth of wire ductility is followed by decrease of its residual electroresistance. Rapid porocedure of return due to precipitation of dissolved admixtures is the main reason for improving plastic properties of the wire

  15. Structure of deformable diatomic molecules: a modified n-butane liquid

    International Nuclear Information System (INIS)

    Jang, Seanea; Kim, Soonchul; Lee, Songhi

    2005-01-01

    The density functional approximation for polyatomic molecules, which is based on the bridge function of the intermolecular interaction, was developed and applied to investigate the thermodynamic and the structural properties of deformable diatomic molecules. The Percus trick was employed to calculate the uniform structure of modified n-butane. The calculated static correlation functions were used to predict the density behaviors of a modified n-butane liquid at liquid-solid interfaces. The theoretical results show that (i) at low densities, the hypernetted-chain (HNC) equation compares with the density functional approximation based on the bridge function and that (ii) the relative population between the gauche and the trans states strongly affects the liquid structure at liquid-solid interfaces.

  16. Semiclassical shell structure of moments of inertia in deformed Fermi systems

    International Nuclear Information System (INIS)

    Magner, A.G.; Gzhebinsky, A.M.; Sitdikov, A.S.; Khamzin, A.A.; Bartel, J.

    2010-01-01

    The collective moment of inertia is derived analytically within the cranking model in the adiabatic mean-field approximation at finite temperature. Using the nonperturbative periodic-orbit theory the semiclassical shell-structure components of the collective moment of inertia are obtained for any potential well. Their relation to the free-energy shell corrections are found semiclassically as being given through the shell-structure components of the rigid-body moment of inertia of the statistically equilibrium rotation in terms of short periodic orbits. Shell effects in the moment of inertia disappear exponentially with increasing temperature. For the case of the harmonic-oscillator potential one observes a perfect agreement between semiclassical and quantum shell-structure components of the free energy and the moment of inertia for several critical bifurcation deformations and several temperatures. (author)

  17. PSP SAR interferometry monitoring of ground and structure deformations applied to archaeological sites

    Science.gov (United States)

    Costantini, Mario; Francioni, Elena; Trillo, Francesco; Minati, Federico; Margottini, Claudio; Spizzichino, Daniele; Trigila, Alessandro; Iadanza, Carla

    2017-04-01

    Archaeological sites and cultural heritage are considered as critical assets for the society, representing not only the history of region or a culture, but also contributing to create a common identity of people living in a certain region. In this view, it is becoming more and more urgent to preserve them from climate changes effect and in general from their degradation. These structures are usually just as precious as fragile: remote sensing technology can be useful to monitor these treasures. In this work, we will focus on ground deformation measurements obtained by satellite SAR interferometry and on the methodology adopted and implemented in order to use the results operatively for conservation policies in a Italian archaeological site. The analysis is based on the processing of COSMO-SkyMed Himage data by the e-GEOS proprietary Persistent Scatterer Pair (PSP) SAR interferometry technology. The PSP technique is a proven SAR interferometry technology characterized by the fact of exploiting in the processing only the relative properties between close points (pairs) in order to overcome atmospheric artefacts (which are one of the main problems of SAR interferometry). Validations analyses [Costantini et al. 2015] settled that this technique applied to COSMO-SkyMed Himage data is able to retrieve very dense (except of course on vegetated or cultivated areas) millimetric deformation measurements with sub-metric localization. Considering the limitations of all the interferometric techniques, in particular the fact that the measurement are along the line of sight (LOS) and the geometric distortions, in order to obtain the maximum information from interferometric analysis, both ascending and descending geometry have been used. The ascending analysis allows selecting measurements points over the top and, approximately, South-West part of the structures, while the descending one over the top and the South-East part of the structures. The interferometric techniques needs

  18. Simulation of CO2 Injection in Porous Media with Structural Deformation Effect

    KAUST Repository

    Negara, Ardiansyah

    2011-06-18

    Carbon dioxide (CO2) sequestration is one of the most attractive methods to reduce the amount of CO2 in the atmosphere by injecting it into the geological formations. Furthermore, it is also an effective mechanism for enhanced oil recovery. Simulation of CO2 injection based on a suitable modeling is very important for explaining the fluid flow behavior of CO2 in a reservoir. Increasing of CO2 injection may cause a structural deformation of the medium. The structural deformation modeling in carbon sequestration is useful to evaluate the medium stability to avoid CO2 leakage to the atmosphere. Therefore, it is important to include such effect into the model. The purpose of this study is to simulate the CO2 injection in a reservoir. The numerical simulations of two-phase flow in homogeneous and heterogeneous porous media are presented. Also, the effects of gravity and capillary pressure are considered. IMplicit Pressure Explicit Saturation (IMPES) and IMplicit Pressure-Displacements and an Explicit Saturation (IMPDES) schemes are used to solve the problems under consideration. Various numerical examples were simulated and divided into two parts of the study. The numerical results demonstrate the effects of buoyancy and capillary pressure as well as the permeability value and its distribution in the domain. Some conclusions that could be derived from the numerical results are the buoyancy of CO2 is driven by the density difference, the CO2 saturation profile (rate and distribution) are affected by the permeability distribution and its value, and the displacements of the porous medium go to constant values at least six to eight months (on average) after injection. Furthermore, the simulation of CO2 injection provides intuitive knowledge and a better understanding of the fluid flow behavior of CO2 in the subsurface with the deformation effect of the porous medium.

  19. Structural control of elastic moduli in ferrogels and the importance of non-affine deformations

    Science.gov (United States)

    Pessot, Giorgio; Cremer, Peet; Borin, Dmitry Y.; Odenbach, Stefan; Löwen, Hartmut; Menzel, Andreas M.

    2014-09-01

    One of the central appealing properties of magnetic gels and elastomers is that their elastic moduli can reversibly be adjusted from outside by applying magnetic fields. The impact of the internal magnetic particle distribution on this effect has been outlined and analyzed theoretically. In most cases, however, affine sample deformations are studied and often regular particle arrangements are considered. Here we challenge these two major simplifications by a systematic approach using a minimal dipole-spring model. Starting from different regular lattices, we take into account increasingly randomized structures, until we finally investigate an irregular texture taken from a real experimental sample. On the one hand, we find that the elastic tunability qualitatively depends on the structural properties, here in two spatial dimensions. On the other hand, we demonstrate that the assumption of affine deformations leads to increasingly erroneous results the more realistic the particle distribution becomes. Understanding the consequences of the assumptions made in the modeling process is important on our way to support an improved design of these fascinating materials.

  20. Structural developments in un-stabilized ultra low carbon steel during warm deformation and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Unnikrishnan, Rahul, E-mail: rahulunnikrishnannair@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Kumar, Amit, E-mail: chaudhary65amit@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Khatirkar, Rajesh K., E-mail: rajesh.khatirkar@gmail.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India); Shekhawat, Satish K., E-mail: satishshekhawat@gmail.com [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay (IITB), Powai, Mumbai 400076, Maharashtra (India); Sapate, Sanjay G., E-mail: sgsapate@yahoo.com [Department of Metallurgical and Materials Engineering, Visvesvaraya National Institute of Technology (VNIT), South Ambazari Road, Nagpur 440010, Maharashtra (India)

    2016-11-01

    In the present investigation, ultra low carbon steel samples were deformed in plane strain compression mode in a deformation simulator. The deformation was carried out at four different temperatures in the warm rolling region (293, 473, 673 and 873 K) upto 70% strain at two different strain rates (0.1/s and 1/s). Subsequently, all the deformed samples were fully recrystallized at 1073 K. Afterwards, all the deformed and fully recrystallized samples were subjected to detailed microstructural characterization using optical microscope, scanning electron microscope and electron backscattered diffraction. Bulk texture was measured for all the samples by X-ray diffraction. In-grain misorientation developments (kernel average misorientations) were estimated for the deformed γ-fibre (ND//<111>) and α-fibre (RD//<110>). Deformed γ-fibre showed an increase in in-grain misorientation at intermediate deformation temperatures. This increase was explained by using the plastic instability criterion. After complete recrystallization, the γ-fibre strengthened for deformation at lower temperatures (293 K and 473 K), while Goss texture developed for samples deformed at higher temperatures (673 K and 873 K). - Highlights: • ULC steel samples were deformed in near plane strain condition. • Microstructural developments were characterized using EBSD. • Increase in in-grain misorientation at intermediate deformation temperatures. • γ-fibre strengthened for low temperature deformation. • Goss texture developed for high temperature deformation.

  1. Off-Yrast low-spin structure of deformed nuclei at mass number A∼150

    Energy Technology Data Exchange (ETDEWEB)

    Krugmann, Andreas

    2014-07-14

    -spinflip parts of the cross section has been done. Here, for the first time, the Pygmy Dipole Resonance (PDR) has been identified in the heavy deformed nucleus {sup 154}Sm that appears as a double-hump structure in the E1 response. A possible interpretation of this double-hump structure in terms of a deformation splitting analogously to the Giant Dipole Resonance (GDR) has been given. In case of the spinflip cross section, a broad distribution in the excitation energy range between 6 and 12 MeV has been observed. The distribution and the extracted sum strength are in good accordance with previous experiments.

  2. Structural and magnetic study of mechanically deformed Fe rich FeAlSi ternary alloys

    International Nuclear Information System (INIS)

    Legarra, E.; Apiñaniz, E.; Plazaola, F.

    2012-01-01

    Highlights: ► Addition of Si to binary Fe–Al alloys makes the disordering more difficult. ► Si addition opposes the large volume increase found in FeAl alloys with deformation. ► Disordering induces a redistribution of non-ferrous atoms around Fe atoms in Fe 75 Al 25−x Si x and Fe 70 Al 30−x Si x . ► Addition of Si to binary Fe 75 Al 25 and Fe 70 Al 30 alloys opposes the magnetic behavior induced by Al in the magnetism of Fe. ► Si inhibits the para-ferro transition found in Fe 60 Al 40 alloy with disordering. - Abstract: In this work we study systematically the influence of different Al/Si ratios on the magnetic and structural properties of mechanically disordered powder Fe 75 Al 25−x Si x , Fe 70 Al 30−x Si x and Fe 60 Al 40−x Si x alloys by means of Mössbauer spectroscopy, X-ray diffraction and magnetic measurements. In order to obtain different stages of disorder the alloys were deformed by different methods: crushing induction melted alloys and ball milling annealed (ordered) alloys using different number of balls and speed. X-ray and Mössbauer data show that mechanical deformation induces the disordered A2 structure in these alloys. The results indicate that addition of Si to binary Fe–Al alloys makes the disordering more difficult. In addition, X-ray diffraction patterns show that the normalized lattice parameter variation of the disordered alloys of each composition decreases monotonically with Si content, indicating clearly that Si addition opposes the large volume increase found in FeAl alloys with deformation. The study of the hyperfine fields indicates that there is a redistribution of non-ferrous atoms around Fe atoms with the disordering; indeed, there is an inversion of the behavior of the hyperfine field of the Fe atoms. On the other hand, the magnetic measurements indicate that addition of Si to binary Fe 75 Al 25 and Fe 70 Al 30 alloys opposes the magnetic behavior induced by Al in the magnetism of Fe.

  3. Broadband Emission in Two-Dimensional Hybrid Perovskites: The Role of Structural Deformation.

    Science.gov (United States)

    Cortecchia, Daniele; Neutzner, Stefanie; Srimath Kandada, Ajay Ram; Mosconi, Edoardo; Meggiolaro, Daniele; De Angelis, Filippo; Soci, Cesare; Petrozza, Annamaria

    2017-01-11

    Only a selected group of two-dimensional (2D) lead-halide perovskites shows a peculiar broad-band photoluminescence. Here we show that the structural distortions of the perovskite lattice can determine the defectivity of the material by modulating the defect formation energies. By selecting and comparing two archetype systems, namely, (NBT) 2 PbI 4 and (EDBE)PbI 4 perovskites (NBT = n-butylammonium and EDBE = 2,2-(ethylenedioxy)bis(ethylammonium)), we find that only the latter, subject to larger deformation of the Pb-X bond length and X-Pb-X bond angles, sees the formation of V F color centers whose radiative decay ultimately leads to broadened PL. These findings highlight the importance of structural engineering to control the optoelectronic properties of this class of soft materials.

  4. Elasto-capillarity: deforming an elastic structure with a liquid droplet

    International Nuclear Information System (INIS)

    Roman, B; Bico, J

    2010-01-01

    Although negligible at macroscopic scales, capillary forces become dominant as the sub-millimetric scales of micro-electro-mechanical systems (MEMS) are considered. We review various situations, not limited to micro-technologies, where capillary forces are able to deform elastic structures. In particular, we define the different length scales that are relevant for 'elasto-capillary' problems. We focus on the case of slender structures (lamellae, rods and sheets) and describe the size of a bundle of wet hair, the condition for a flexible rod to pierce a liquid interface or the fate of a liquid droplet deposited on a flexible thin sheet. These results can be generalized to similar situations involving adhesion or fracture energy, which widens the scope of possible applications from biological systems, to stiction issues in micro-fabrication processes, the manufacturing of 3D microstructures or the formation of blisters in thin film coatings. (topical review)

  5. THE ANALYSIS OF INTENSE-DEFORMED MONOLITHIC CONCRETE STRIP STATE OF UNDERGROUND STRUCTURES OF NONCIRCULAR OUTLINE

    Directory of Open Access Journals (Sweden)

    Maria Aleksandrovna Bauer

    2017-12-01

    Full Text Available The research results of intense deformed state (IDS of the crepe and soil massif of un-derground structures having a non-circular outline with a depth of laying up to 50 m in unstable al-luvial rocks with dumps from 0.3 to 0.7 m are presented. The study was carried out by means of modeling the IDS of the soil massif and the hardening concrete of the monolithic support, erected after slaughter moving. To implement the proposed technological solutions ensuring the fixing of underground structures with monolithic concrete, it is necessary to use particularly fast solidifying compounds to exclude the use of temporary crepe. Based on the studies of a number of modifiers, various changes in mechanical properties of the most effective compositions have been established, which are used to simulate the concrete crepe of structures with time-varying characteristics. Purpose: the basis for using resource-saving technology for the construction of underground structures in a non-circular outline in a soil massif. Methods and methodology of the work: the studies were carried out by means of the finite element method (FEM using the optimal design of the experiment. Results: stress distributions were obtained in the hardening concrete crepe structures, stress concentration zones were established, displacement values in the soil massif and their spread on the surface were recieved. Areas of the result application: the results of research work can be used in the design of options for the construction of underground structures.

  6. Basement Structure and Styles of Active Tectonic Deformation in Central Interior Alaska

    Science.gov (United States)

    Dixit, N.; Hanks, C.

    2017-12-01

    Central Interior Alaska is one of the most seismically active regions in North America, exhibiting a high concentration of intraplate earthquakes approximately 700 km away from the southern Alaska subduction zone. Based on increasing seismological evidence, intraplate seismicity in the region does not appear to be uniformly distributed, but concentrated in several discrete seismic zones, including the Nenana basin and the adjacent Tanana basin. Recent seismological and neotectonics data further suggests that these seismic zones operate within a field of predominantly pure shear driven primarily by north-south crustal shortening. Although the location and magnitude of the seismic activity in both basins are well defined by a network of seismic stations in the region, the tectonic controls on intraplate earthquakes and the heterogeneous nature of Alaska's continental interior remain poorly understood. We investigated the current crustal architecture and styles of tectonic deformation of the Nenana and Tanana basins using existing geological, geophysical and geochronological datasets. The results of our study demonstrate that the basements of the basins show strong crustal heterogeneity. The Tanana basin is a relatively shallow (up to 2 km) asymmetrical foreland basin with its southern, deeper side controlled by the northern foothills of the central Alaska Range. Northeast-trending strike-slip faults within the Tanana basin are interpreted as a zone of clockwise crustal block rotation. The Nenana basin has a fundamentally different geometry; it is a deep (up to 8 km), narrow transtensional pull-apart basin that is deforming along the left-lateral Minto Fault. This study identifies two distinct modes of tectonic deformation in central Interior Alaska at present, and provides a basis for modeling the interplay between intraplate stress fields and major structural features that potentially influence the generation of intraplate earthquakes in the region.

  7. Structural deformation upon protein-protein interaction: a structural alphabet approach.

    Science.gov (United States)

    Martin, Juliette; Regad, Leslie; Lecornet, Hélène; Camproux, Anne-Claude

    2008-02-28

    In a number of protein-protein complexes, the 3D structures of bound and unbound partners significantly differ, supporting the induced fit hypothesis for protein-protein binding. In this study, we explore the induced fit modifications on a set of 124 proteins available in both bound and unbound forms, in terms of local structure. The local structure is described thanks to a structural alphabet of 27 structural letters that allows a detailed description of the backbone. Using a control set to distinguish induced fit from experimental error and natural protein flexibility, we show that the fraction of structural letters modified upon binding is significantly greater than in the control set (36% versus 28%). This proportion is even greater in the interface regions (41%). Interface regions preferentially involve coils. Our analysis further reveals that some structural letters in coil are not favored in the interface. We show that certain structural letters in coil are particularly subject to modifications at the interface, and that the severity of structural change also varies. These information are used to derive a structural letter substitution matrix that summarizes the local structural changes observed in our data set. We also illustrate the usefulness of our approach to identify common binding motifs in unrelated proteins. Our study provides qualitative information about induced fit. These results could be of help for flexible docking.

  8. Structural deformation upon protein-protein interaction: A structural alphabet approach

    Directory of Open Access Journals (Sweden)

    Lecornet Hélène

    2008-02-01

    Full Text Available Abstract Background In a number of protein-protein complexes, the 3D structures of bound and unbound partners significantly differ, supporting the induced fit hypothesis for protein-protein binding. Results In this study, we explore the induced fit modifications on a set of 124 proteins available in both bound and unbound forms, in terms of local structure. The local structure is described thanks to a structural alphabet of 27 structural letters that allows a detailed description of the backbone. Using a control set to distinguish induced fit from experimental error and natural protein flexibility, we show that the fraction of structural letters modified upon binding is significantly greater than in the control set (36% versus 28%. This proportion is even greater in the interface regions (41%. Interface regions preferentially involve coils. Our analysis further reveals that some structural letters in coil are not favored in the interface. We show that certain structural letters in coil are particularly subject to modifications at the interface, and that the severity of structural change also varies. These information are used to derive a structural letter substitution matrix that summarizes the local structural changes observed in our data set. We also illustrate the usefulness of our approach to identify common binding motifs in unrelated proteins. Conclusion Our study provides qualitative information about induced fit. These results could be of help for flexible docking.

  9. Characteristic structures and properties of nanostructured metals prepared by plastic deformation

    DEFF Research Database (Denmark)

    Huang, Xiaoxu

    2011-01-01

    This chapter focuses on describing the characteristic microstructures of nanostructured metals produced by plastic deformation to ultrahigh strains and their correlation with hardening by annealing and softening by deformation. The results suggest that optimising microstructure and the mechanical...

  10. Multifractal Analysis of Seismically Induced Soft-Sediment Deformation Structures Imaged by X-Ray Computed Tomography

    Science.gov (United States)

    Nakashima, Yoshito; Komatsubara, Junko

    Unconsolidated soft sediments deform and mix complexly by seismically induced fluidization. Such geological soft-sediment deformation structures (SSDSs) recorded in boring cores were imaged by X-ray computed tomography (CT), which enables visualization of the inhomogeneous spatial distribution of iron-bearing mineral grains as strong X-ray absorbers in the deformed strata. Multifractal analysis was applied to the two-dimensional (2D) CT images with various degrees of deformation and mixing. The results show that the distribution of the iron-bearing mineral grains is multifractal for less deformed/mixed strata and almost monofractal for fully mixed (i.e. almost homogenized) strata. Computer simulations of deformation of real and synthetic digital images were performed using the egg-beater flow model. The simulations successfully reproduced the transformation from the multifractal spectra into almost monofractal spectra (i.e. almost convergence on a single point) with an increase in deformation/mixing intensity. The present study demonstrates that multifractal analysis coupled with X-ray CT and the mixing flow model is useful to quantify the complexity of seismically induced SSDSs, standing as a novel method for the evaluation of cores for seismic risk assessment.

  11. Experimental studies on local damage of reinforced concrete structures by the impact of deformable missiles-Part 1

    International Nuclear Information System (INIS)

    Muto, K.; Tachikawa, H.; Sugano, T.; Tsubota, H.; Kobayshi, H.; Kasai, Y.; Koshika, N.; Tsujimoto, T.

    1989-01-01

    Structural damage induced by an accidental aircraft crash into a reinforced concrete structure includes local damage caused by the engine, the rigid portion of the aircraft, and the global elasto-plastic structural response caused by the entire aircraft. Local damage consists of spalling of concrete from the front face of the target together with missile penetration into the target, scabbing of concrete from the rear face of the target and perforation of the missile through the target. The engine is a soft missile that deforms during impact. An experimental research program has been planned and executed to establish a rational evaluation method of the local damage by the deformable engine missiles

  12. Internal deformation in layered Zechstein-III K-Mg salts. Structures formed by complex deformation and high contrasts in viscosity observed in drill cores.

    Science.gov (United States)

    Raith, Alexander; Urai, Janos L.

    2016-04-01

    During the evaporation of a massive salt body, alternations of interrupted and full evaporation sequences can form a complex layering of different lithologies. Viscosity contrasts of up to five orders of magnitude between these different lithologies are possible in this environment. During the late stage of an evaporation cycle potassium and magnesium (K-Mg) salts are precipitated. These K-Mg salts are of economic interest but also a known drilling hazard due to their very low viscosity. How up to 200m thick layers of these evaporites affect salt deformation at different scales is not well known. A better understanding of salt tectonics with extreme mechanical stratification is needed for better exploration and production of potassium-magnesium salts and to predict the internal structure of potential nuclear waste repositories in salt. To gain a better understanding of the internal deformation of these layers we analyzed K-Mg salt rich drill cores out of the Zechstein III-1b subunit from the Veendam Pillow 10 km southeast of Groningen, near the city Veendam in the NE Netherlands. The study area has a complex geological history with multiple tectonic phases of extension and compression forming internal deformation in the pillow but also conserving most of the original layering. Beside halite the most common minerals in the ZIII-1b are carnallite, kieserite, anhydrite and bischofite alternating in thin layers of simple composition. Seismic interpretation revealed that the internal structure of the Veendam Pillow shows areas, in which the K-Mg salt rich ZIII 1b layer is much thicker than elsewhere, as a result of salt deformation. The internal structure of the ZIII-1b on the other hand, remains unknown. The core analysis shows a strong strain concentration in the weaker Bischofite (MgCl2*6H20) and Carnallite (KMgCl3*6H20) rich layers producing tectonic breccias and highly strained layers completely overprinting the original layering. Layers formed by alternating beds

  13. Effects of Structural Deformations on Optical Properties of Tetrabenzoporphyrins: Free-Bases and Pd Complexes

    Science.gov (United States)

    Lebedev, Artem Y.; Filatov, Mikhail A.; Cheprakov, Andrei V.; Vinogradov, Sergei A.

    2009-01-01

    A recently developed method of synthesis of π-extended porphyrins made it possible to prepare a series of tetrabenzoporphyrins (TBP) with different numbers of meso-aryl substituents. The photophysical parameters of free-bases and Pd complexes of meso-unsubstituted TBP’s, 5,15-diaryl-TBP’s (Ar2TBP’s) and 5,10,15,20-tetraaryl-TBP’s (Ar4TBP’s) were measured. For comparison, similarly meso-arylsubstituted porphyrins fused with nonaromatic cyclohexeno-rings, i.e. Arn-tetracyclohexenoporphyrins (ArnTCHP’s, n = 0, 2, 4), were also synthesized and studied. Structural information was obtained by ab initio (DFT) calculations and X-ray crystallography. It was found that: 1) Free-base Ar4TBP’s are strongly distorted out-of-plane (saddled), possess broadened, red-shifted spectra, short excited-state lifetimes and low fluorescence quantum yields (τfl = 2–3 ns, ϕfl = 0.02–0.03). These features are characteristic of other nonplanar free-base porphyrins, including Ar4TCHP’s. 2) Ar2TBP free-bases possess completely planar geometries, although with significant in-plane deformations. These deformations have practically no effect on the singlet excited-state properties of Ar2TBP’s as compared to planar meso-unsubstituted TBP’s. Both types of porphyrins retain strong fluorescence (τfl = 10–12 ns, ϕfl = 0.3–0.4), and their radiative rate constants (kr) are 3–4 times higher than those of planar H2TCHP’s. 3) Nonplanar deformations dramatically enhance nonradiative decay of triplet states of regular Pd porphyrins. For example, planar PdTCHP phosphoresces with high quantum yield (ϕphos = 0.45, τphos = 1118 µs), while saddled PdPh4TCHP is practically nonemissive. In contrast, both ruffled and saddled PdArnTBP’s retain strong phosphorescence at ambient temperatures (PdPh2TBP: τphos = 496 µs, ϕphos = 0.15; PdPh4TBP: τphos = 258 µs, ϕphos = 0.08). It appears that π-extension is capable of counterbalancing deleterious effects of nonplanar

  14. Finite Macro-Element Mesh Deformation in a Structured Multi-Block Navier-Stokes Code

    Science.gov (United States)

    Bartels, Robert E.

    2005-01-01

    A mesh deformation scheme is developed for a structured multi-block Navier-Stokes code consisting of two steps. The first step is a finite element solution of either user defined or automatically generated macro-elements. Macro-elements are hexagonal finite elements created from a subset of points from the full mesh. When assembled, the finite element system spans the complete flow domain. Macro-element moduli vary according to the distance to the nearest surface, resulting in extremely stiff elements near a moving surface and very pliable elements away from boundaries. Solution of the finite element system for the imposed boundary deflections generally produces smoothly varying nodal deflections. The manner in which distance to the nearest surface has been found to critically influence the quality of the element deformation. The second step is a transfinite interpolation which distributes the macro-element nodal deflections to the remaining fluid mesh points. The scheme is demonstrated for several two-dimensional applications.

  15. Adsorption-Induced Deformation of Hierarchically Structured Mesoporous Silica-Effect of Pore-Level Anisotropy.

    Science.gov (United States)

    Balzer, Christian; Waag, Anna M; Gehret, Stefan; Reichenauer, Gudrun; Putz, Florian; Hüsing, Nicola; Paris, Oskar; Bernstein, Noam; Gor, Gennady Y; Neimark, Alexander V

    2017-06-06

    The goal of this work is to understand adsorption-induced deformation of hierarchically structured porous silica exhibiting well-defined cylindrical mesopores. For this purpose, we performed an in situ dilatometry measurement on a calcined and sintered monolithic silica sample during the adsorption of N 2 at 77 K. To analyze the experimental data, we extended the adsorption stress model to account for the anisotropy of cylindrical mesopores, i.e., we explicitly derived the adsorption stress tensor components in the axial and radial direction of the pore. For quantitative predictions of stresses and strains, we applied the theoretical framework of Derjaguin, Broekhoff, and de Boer for adsorption in mesopores and two mechanical models of silica rods with axially aligned pore channels: an idealized cylindrical tube model, which can be described analytically, and an ordered hexagonal array of cylindrical mesopores, whose mechanical response to adsorption stress was evaluated by 3D finite element calculations. The adsorption-induced strains predicted by both mechanical models are in good quantitative agreement making the cylindrical tube the preferable model for adsorption-induced strains due to its simple analytical nature. The theoretical results are compared with the in situ dilatometry data on a hierarchically structured silica monolith composed by a network of mesoporous struts of MCM-41 type morphology. Analyzing the experimental adsorption and strain data with the proposed theoretical framework, we find the adsorption-induced deformation of the monolithic sample being reasonably described by a superposition of axial and radial strains calculated on the mesopore level. The structural and mechanical parameters obtained from the model are in good agreement with expectations from independent measurements and literature, respectively.

  16. Geodynamic movements and deformations of the Sudetic structural unit of the Bohemian Massif

    Science.gov (United States)

    Schenk, V.; Jechumtálová, Z.; Schenková, Z.; Kottnauer, P.

    2003-04-01

    The African plate pushes to European orogenic Alpine structures that transfer the compression further to Variscan structural units, including the Bohemian Massif. Central parts of the Bohemian Massif are relatively deep-seated and, therefore, some of marginal parts of the Massif and its border geological structures should be affected intensively and moved distinctly with respect to the central parts. The geodynamical GPS network EAST SUDETEN is located just over the area mentioned above, i.e. it covers both kinetically quasi-effected and quasi-non-effected structural blocks. GPS data observed already for six annual campaigns (1997-2002) were processed and movement vectors of individual network sites were assessed. Applied data processing did not allow errors in the horizontal direction 2 mm and in the vertical direction 5-6 mm to be exceeded. Since time series of coordinate changes for several network sites gave rather pronounce movement trends, preliminary deformations among individual structural blocks were evaluated and compared to other geological, geophysical and geodetic materials. The investigation has been supported by the Grant Agency of the Czech Republic, projects 205/97/0679 and 205/01/0480, and by the research programme of the Ministry of Education, Youth and Sport of the Czech Republic, project LN00A005 "Dynamics of the Earth".

  17. Dislocation structure evolution and characterization in the compression deformed Mn-Cu alloy

    International Nuclear Information System (INIS)

    Zhong, Y.; Yin, F.; Sakaguchi, T.; Nagai, K.; Yang, K.

    2007-01-01

    Dislocation densities and dislocation structure arrangements in cold compressed polycrystalline commercial M2052 (Mn-20Cu-5Ni-2Fe) high damping alloy with various strains were determined in scanning mode by X-ray peak profile analysis and electron backscatter diffraction (EBSD). The results indicate that the Mn-Cu-Ni-Fe alloy has an evolution behavior quite similar to the dislocation structure in copper. The dislocation arrangement parameter shows a local minimum in the transition range between stages III and IV that can be related to the transformation of the dislocation arrangement in the cell walls from a polarized dipole wall (PDW) into a polarized tile wall (PTW) structure. This evolution is further confirmed by the results of local misorientation determined by EBSD. In addition, during deformation, the multiplication of dislocation densities in the MnCu alloy is significantly slower than that in copper, and the transition of the dislocation structure is strongly retarded in the MnCu alloy compared with copper. These results can be explained by the mechanism of elastic anisotropy on the dislocation dynamics, as the elastic anisotropy in the MnCu alloy is larger than that in copper, which can strongly retard the multiplication of the dislocation population and the transformation of the dislocation structure. These results are important for research into the plastic working behavior of Mn-Cu-Ni-Fe high damping alloy

  18. Analysis of the overall structural behavior due to the impact of deformable missiles

    International Nuclear Information System (INIS)

    Ettouney, M.M.; Radini, R.R.; Hsueh, P.S.

    1979-01-01

    This paper presents a method of analysis to evaluate the overall behavior of reinforced concrete structures subjected to impact from deformable missiles. This method approaches the analysis in a very simple and practical way. The analysis is based on approximating the structure-missile system by a two-degree of freedom model. The two degrees of freedom model represents the missile and the structure, respectively. The hysteretic damping effects are considered implicitly through the nonlinearity of the two springs. Empirical formulas are presented for the evaluation of the dynamic properties of the nonlinear spring representing the concrete structure. The impact is simulated by applying an impulse on the two degrees of freedom system, then by the method of step by step numerical time integration (central difference formula is used) the time histories of the displacements and velocities of both the missile and structure are obtained. The numerical procedure is simple enough to be programmed by a hand or desk calculator which makes the method handy for most engineers and analysis. (orig.)

  19. Three-dimensional printing and deformation behavior of low-density target structures by two-photon polymerization

    Science.gov (United States)

    Liu, Ying; Stein, Ori; Campbell, John H.; Jiang, Lijia; Petta, Nicole; Lu, Yongfeng

    2017-08-01

    Two-photon polymerization (2PP), a 3D nano to microscale additive manufacturing process, is being used for the first time to fabricate small custom experimental packages ("targets") to support laser-driven high-energy-density (HED) physics research. Of particular interest is the use of 2PP to deterministically print low-density, low atomic-number (CHO) polymer matrices ("foams") at millimeter scale with sub-micrometer resolution. Deformation during development and drying of the foam structures remains a challenge when using certain commercial photo-resins; here we compare use of acrylic resins IP-S and IP-Dip. The mechanical strength of polymeric beam and foam structures is examined particularly the degree of deformation that occurs during the development and drying processes. The magnitude of the shrinkage in the two resins in quantified by printing sample structures and by use of FEA to simulate the deformation. Capillary drying forces are shown to be small and likely below the elastic limit of the core foam structure. In contrast the substantial shrinkage in IP-Dip ( 5-10%) cause large shear stresses and associated plastic deformation particularly near constrained boundaries such as the substrate and locations with sharp density variation. The inherent weakness of stitching boundaries is also evident and in certain cases can lead to delamination. Use of IP-S shows marked reduction in deformation with a minor loss of print resolution

  20. Analysis of mitochondrial 3D-deformation in cardiomyocytes during active contraction reveals passive structural anisotropy of orthogonal short axes.

    Directory of Open Access Journals (Sweden)

    Yael Yaniv

    Full Text Available The cardiomyocyte cytoskeleton, composed of rigid and elastic elements, maintains the isolated cell in an elongated cylindrical shape with an elliptical cross-section, even during contraction-relaxation cycles. Cardiomyocyte mitochondria are micron-sized, fluid-filled passive spheres distributed throughout the cell in a crystal-like lattice, arranged in pairs sandwiched between the sarcomere contractile machinery, both longitudinally and radially. Their shape represents the extant 3-dimensional (3D force-balance. We developed a novel method to examine mitochondrial 3D-deformation in response to contraction and relaxation to understand how dynamic forces are balanced inside cardiomyocytes. The variation in transmitted light intensity induced by the periodic lattice of myofilaments alternating with mitochondrial rows can be analyzed by Fourier transformation along a given cardiomyocyte axis to measure mitochondrial deformation along that axis. This technique enables precise detection of changes in dimension of ∼1% in ∼1 µm (long-axis structures with 8 ms time-resolution. During active contraction (1 Hz stimulation, mitochondria deform along the length- and width-axes of the cell with similar deformation kinetics in both sarcomere and mitochondrial structures. However, significant deformation anisotropy (without hysteresis was observed between the orthogonal short-axes (i.e., width and depth of mitochondria during electrical stimulation. The same degree of deformation anisotropy was also found between the myocyte orthogonal short-axes during electrical stimulation. Therefore, the deformation of the mitochondria reflects the overall deformation of the cell, and the apparent stiffness and stress/strain characteristics of the cytoskeleton differ appreciably between the two cardiomyocyte orthogonal short-axes. This method may be applied to obtaining a better understanding of the dynamic force-balance inside cardiomyocytes and of changes in the

  1. Investigating the Importance of 3D Structure & Topography in Seismic Deformation Modeling: Case Study of the April 2015 Nepal Earthquake

    Science.gov (United States)

    Langer, L.; Gharti, H. N.; Tromp, J.

    2017-12-01

    In recent years, observations of deformation at plate boundaries have been greatly improved by the development of techniques in space geodesy. However, models of seismic deformation remain limited and are unable to account for realistic 3D structure in topography and material properties. We demonstrate the importance of 3D structure using a spectral-element method that incorporates fault geometry, topography, and heterogeneous material properties in a (non)linear viscoelastic domain. Our method is benchmarked against Okada's analytical technique and the PyLith software package. The April 2015 Nepal earthquake is used as a case study to examine whether 3D structure can affect the predictions of seismic deformation models. We find that the inclusion of topography has a significant effect on our results.

  2. Post-assessment of pre-stressed containment structures by evaluation of monitored long term deformation results

    International Nuclear Information System (INIS)

    Wienand, B.

    2015-01-01

    The comparison of monitored long term deformations of containment structures with calculated values achieved by using design material parameters shows occasionally considerable deviations, partly caused by conservative assumptions in the containments design phase. Systematic post-assessment and adaption of the decisive parameters attains better coincidence. In the present investigation measured long-term deformations are first of all compared to pre-calculated values based on the material parameters defined in the design phase. Afterwards, the deformations deviations are minimized by repeating the calculation with assessed material parameters. This method appears to be a suitable method to predict the future containment structure long-term behavior and to achieve a possible life-time extension. The presented investigation was performed as part of NUGENIA ACCEPPT project which researches the ageing of concrete containment structures in nuclear power plants

  3. Contribution on the influence of transformation structures under consideration of austenite deformation

    International Nuclear Information System (INIS)

    Peisker, D.; Doktorowski, A.; Dittrich, D.

    2001-01-01

    Hot forming represents a substantial part of the manufacturing process of many steel products. The crucial microstructural transformation process, which influences the characteristics of a steel considerably, is undisputed the γ/α-transformation. A successful aid to the interpretation of possible microstructural transformation processes during cooling from the austenitizing or deformation temperature is the determination and handling of CCT diagrams. In this article two steels are examined which differ only in their titanium content. Dilatometric investigations were performed varying the three parameters' transformation temperature, strain and cooling strategy. The insights gathered are illustrated and discussed with the aid of CCT diagrams. An additional transformation below A c1 with a brief curing reheat up to A c3 + 20 K leads to a substantially finer structure. The exploitation of this effect may be of great industrial importance. (orig.)

  4. Dynamic nucleus deformability and its effect on the structure of photoabsorption cross section and photodisintegration characteristics

    International Nuclear Information System (INIS)

    Zhivopistsev, F.A.; Shitikova, K.V.

    1979-01-01

    Considered is a microscopic theory of specific highly excited states of atomic nuclei-gigantic dipole resonances. Special attention is paid to the effect of complex states of different nature on the structure of the gigantic resonance and characteristics of photodisintegration. The pinning process by more complex states (both of collective and noncollective nature) brings about a condition, when a number of quasiparticles is added to the filled shell, so that the spheric nucleus form would become unstable (to the change of surface properties, ect.). In this case the closed shell is broken, that causes an increase of deformability of the nucleus composition in a highly excited state. The statistical group of 2p2h, 3p3h, et. states is of great value in explanation of characteristics of atomic nuclei photodisintegration, for it provides a statistical, irreversible process of preequilibrium decomposition

  5. Effects of deformations and orientations on neutron-halo structure of light-halo nuclei

    International Nuclear Information System (INIS)

    Sawhney, Gudveen; Gupta, Raj K.; Sharma, Manoj K.

    2013-01-01

    The availability of radioactive nuclear beams have enabled to study the structure of nuclei far from the stability line, which in turn led to the discovery of neutron-halo nuclei. These nuclei, located near the neutron drip-line exhibit a high probability of presence of one or two loosely bound neutrons at a large distance from the rest of nucleons. The fragmentation behavior is studied for 13 cases of 1n-halo nuclei, which include 11 Be, 14 B, 15 C, 17 C, 19 C, 22 N, 22 O, 23 O, 24 O, 24 F, 26 F, 29 Ne and 31 Ne, using the cluster-core model (CCM) extended to include the deformations and orientations of nuclei

  6. Structural damping values as a function of dynamic response stress and deformation levels

    International Nuclear Information System (INIS)

    Stevenson, J.D.

    1980-01-01

    Damping as it is normally defined is the means by which the response motion of a structural system is reduced as the result of energy losses. However, as used in the context of nuclear plant design, the effects of changes in structural stiffness, geometry, support configuration, and modulus of elasticity are also usually lumped under the general heading of damping in current design methods. For convenience in structural design, damping in usually assumed as viscous in nature and in recognition of its use in modal response spectrum dynamic analysis is normally expressed as a percent of critical. In general, it should be understood that damping as used in design or analysis of nuclear plants is an experimentally determined factor which is used to make the results of linear elasticity analysis of dynamic systems agree reasonably well with observed experimental results. In this paper, damping data existing in the open literature applicable to nuclear power plant structures and equipment is summarized and statistically analyzed. Results of this analysis are used to develop damping trend curves which predict applicable damping values to be used in design at various levels of stress or deformation. (orig.)

  7. Modeling internal deformation of salt structures targeted for radioactive waste disposal

    International Nuclear Information System (INIS)

    Chemia, Zurab

    2008-01-01

    This thesis uses results of systematic numerical models to argue that externally inactive salt structures, which are potential targets for radioactive waste disposal, might be internally active due to the presence of dense layers or blocks within a salt layer. The three papers that support this thesis use the Gorleben salt diapir (NW Germany), which was targeted as a future final repository for high-grade radioactive waste, as a general guideline. The first two papers present systematic studies of the parameters that control the development of a salt diapir and how it entrains a dense anhydrite layer. Results from these numerical models show that the entrainment of a dense anhydrite layer within a salt diapir depends on four parameters: sedimentation rate, viscosity of salt, perturbation width and the stratigraphic location of the dense layer. The combined effect of these four parameters, which has a direct impact on the rate of salt supply (volume/area of the salt that is supplied to the diapir with time), shape a diapir and the mode of entrainment. Salt diapirs down-built with sedimentary units of high viscosity can potentially grow with an embedded anhydrite layer and deplete their source layer (salt supply ceases). However, when salt supply decreases dramatically or ceases entirely, the entrained anhydrite layer/segments start to sink within the diapir. In inactive diapirs, sinking of the entrained anhydrite layer is inevitable and strongly depends on the rheology of the salt, which is in direct contact with the anhydrite layer. During the post-depositional stage, if the effective viscosity of salt falls below the threshold value of around 10 18 -10 19 Pa s, the mobility of anhydrite blocks might influence any repository within the diapir. However, the internal deformation of the salt diapir by the descending blocks decreases with increase in effective viscosity of salt. The results presented in this thesis suggest that it is highly likely that salt structures

  8. Reactivated basement structures in the central Savannah River area and their relationship to coastal plain deformation

    International Nuclear Information System (INIS)

    Cumbest, R.J.; Price, V.; Temples, T.J.; Fallaw, W.C.; Snipes, D.S.

    1993-01-01

    Structural surface mapping and geophysical studies have identified several faults in the crystalline basement and overlying Coastal Plain sedimentary sequences in the central Savannah River area. Major subsurface basement shear zones occur parallel to and near Upper Three Runs Creek and Tinker Creek and are associated with linear aeromagnetic anomalies. Reflection seismic imaging of the basement shows a band of southeast dipping events parallel to Upper Three Runs Creek. Drill core from basement contain phyllonites, mylonites, fault breccia and pseudotachylite. The magnetic anomalies also mark the boundary separating greenschist facies metavolcanic rocks from amphibolite facies felsic gneiss, schist, and amphibolite. These features are similar to those that characterize other Paleozoic faults of the Eastern Piedmont Fault system. Reflection seismic imaging shows the sub-Cretaceous unconformity as well defined and easily identified event as well as easily traced laterally extensive events in Coastal Plain sequences. The unconformity and sedimentary sequences are faulted or deformed in several locations which also coincide with changes in dip of the unconformity. In the vicinity of Upper Three Runs Creek the unconformity shows a broad warping across which the elevation drops to the southeast and sedimentary sequences show a marked rate of thickening southeast. This indicates deformation of the basement exerted a control on deposition of the Coastal Plain sediments with down to the southeast movement. The basement shear zones are closely associated with the Dunbarton basin and are probable reactivated Paleozoic structures associated with extensional basin development as commonly seen associated with extensional basins on the east coast of North America

  9. Optimum stamping die structure based on analytical method of die deformation during draw process; Seikei katei no kanagata henkei kaiseki ni motozuku, press kanagata kozo no saitekika

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, T; Tamai, H [Mazda Motor Corp., Hiroshima (Japan)

    1997-10-01

    We measured an actual deformation and pressure distribution in draw process of bending cam, and analyzed deformation process of die structure, in order to eliminate adjusting work considering die deformation by stamping force. We studied die structure improvement with simulation based on analytical method. This report describes a sample of die structure improvement based on a simulation and actual measurement. 1 ref., 11 figs., 1 tab.

  10. Structural evolution of a deformed Σ=9 (122) grain boundary in silicon. A high resolution electron microscopy study

    International Nuclear Information System (INIS)

    Putaux, Jean-Luc

    1991-01-01

    This research thesis addresses the study by high resolution electron microscopy of the evolution of a silicon bi-crystal under deformation at different temperatures. The author notably studied the structural evolution of the boundary as well as that of grains at the vicinity of the boundary. Two observation scales have been used: the evolution of sub-structures of dislocations induced by deformation in grains and in boundary, and the structure of all defects at an atomic scale. After a presentation of experimental tools (the necessary perfect quality of the electronic optics is outlined), the author recalls some descriptive aspects of grain boundaries (geometric network concepts to describe coinciding networks, concepts of delimiting boundaries and of structural unit to describe grain boundary atomic structure), recalls the characteristics of the studied bi-crystal, and the conditions under which it is deformed. He presents the structures of all perfectly coinciding boundaries, describes defects obtained by deformation at the vicinity of the boundary, describes the entry of dissociated dislocations into the boundaries, and discusses the characterization of boundary dislocations (the notion of Burgers vector is put into question again), and the atomic mechanism of displacement of dislocations in boundaries [fr

  11. Soft-sediment deformations (convolute lamination and load structures) in turbidites as indicators of flow reflections against bounding slopes

    Science.gov (United States)

    Tinterri, Roberto; Muzzi Magalhaes, Pierre; Tagliaferri, Alessio; Cunha, Rogerio S.; Laporta, Michele

    2015-04-01

    Soft-sediment deformations, such as convolute laminations, load structures and water escapes are very rapid deformations that occur in unconsolidated sediments near the depositional surface during or shortly after deposition and before significant diagenesis. These types of deformations develop when primary stratifications are deformed by a system of driving forces, while the sediment is temporarily in a weakened state due to the action of a deformation mechanism know as liquidization. This deformation occurs if the applied stress exceeds the sediment strength, either through an increase in the applied stress or through a temporary reduction in sediment strength. Liquidization mechanisms can be triggered by several agents, such as seismic shaking, rapid sedimentation with high-fallout rates or cyclic-pressure variations associated with storm waves or breaking waves. Consequently, soft-sediment deformations can be produced by different processes and form ubiquitous sedimentary structures characterizing many sedimentary environments. However, even though these types of structures are relatively well-known in terms of geometry and sedimentary characteristics, many doubts arise when the understanding of deformation and trigger mechanisms is attempted. As stressed also by the recent literature, the main problem lies in the fact that the existing approaches for the identification of triggering agents rely on criteria that are not diagnostic or not applicable to outcrop-based studies, because they are not always based on detailed facies analysis related to a paleoenvironmental-context approach. For this reason, this work discusses the significance of particular types of soft-sediment deformations that are very common in turbidite deposits, namely convolute laminations and load structures, especially on the basis of a deep knowledge of the stratigraphic framework and geological setting in which these structures are inserted. More precisely, detailed facies analyses of the

  12. Modified Displacement Transfer Functions for Deformed Shape Predictions of Slender Curved Structures with Varying Curvatives

    Science.gov (United States)

    Ko, William L.; Fleischer, Van Tran

    2014-01-01

    To eliminate the need to use finite-element modeling for structure shape predictions, a new method was invented. This method is to use the Displacement Transfer Functions to transform the measured surface strains into deflections for mapping out overall structural deformed shapes. The Displacement Transfer Functions are expressed in terms of rectilinearly distributed surface strains, and contain no material properties. This report is to apply the patented method to the shape predictions of non-symmetrically loaded slender curved structures with different curvatures up to a full circle. Because the measured surface strains are not available, finite-element analysis had to be used to analytically generate the surface strains. Previously formulated straight-beam Displacement Transfer Functions were modified by introducing the curvature-effect correction terms. Through single-point or dual-point collocations with finite-elementgenerated deflection curves, functional forms of the curvature-effect correction terms were empirically established. The resulting modified Displacement Transfer Functions can then provide quite accurate shape predictions. Also, the uniform straight-beam Displacement Transfer Function was applied to the shape predictions of a section-cut of a generic capsule (GC) outer curved sandwich wall. The resulting GC shape predictions are quite accurate in partial regions where the radius of curvature does not change sharply.

  13. A workflow for sub-/seismic structure and deformation quantification of 3-D reflection seismic data sets across different scales

    Energy Technology Data Exchange (ETDEWEB)

    Krawczyk, C.M.; Lohr, T.; Oncken, O. [GFZ Potsdam (Germany); Tanner, D.C. [Goettingen Univ. (Germany). GZG; Endres, H. [RWTH Aachen (Germany)]|[TEEC, Isernhagen (Germany); Trappe, H.; Kukla, P. [TEEC, Isernhagen (Germany)

    2007-09-13

    The evolution of a sedimentary basin is mostly affected by deformation. Large-scale, subsurface deformation is typically identified by seismic data, sub-seismic small-scale fractures by well data. Between these two methods, we lack a deeper understanding of how deformation scales. We analysed a 3-D reflection seismic data set in the North German Basin, in order to determine the magnitude and distribution of deformation and its accumulation in space and time. A five-step approach is introduced for quantitative deformation and fracture prediction. An increased resolution of subtle tectonic lineaments is achieved by coherency processing, allowing to unravel the kinematics in the North German Basin from structural interpretation. Extensional events during basin initiation and later inversion are evident. 3-D retrodeformation shows major-strain magnitudes between 0-20% up to 1.3 km away from a fault trace, and variable deviations of associated extensional fractures. Good correlation of FMI data, strain distribution from retro-deformation and from geostatistic tools (see also Trappe et al., this volume) allows the validation of the results and makes the prediction of small-scale faults/fractures possible. The temporal component will be gained in the future by analogue models. The suggested workflow is applicable to reflection seismic surveys and yields in great detail both the tectonic history of a region as well as predictions for hydrocarbon plays or deep groundwater or geothermal reservoirs. (orig.)

  14. Crustal and uppermost mantle structure and deformation in east-central China

    Science.gov (United States)

    Li, H.; Yang, X.; Ouyang, L.; Li, J.

    2017-12-01

    We conduct a non-linear joint inversion of receiver functions and Rayleigh wave dispersions to obtain the crustal and upper mantle velocity structure in east-central China. In the meanwhile, the lithosphere and upper mantle deformation beneath east-central China is also evaluated with teleseismic shear wave splitting measurements. The resulting velocity model reveals that to the east of the North-South Gravity Lineament, the crust and the lithosphere are significantly thinned. Furthermore, three extensive crustal/lithospheric thinning sub-regions are clearly identified within the study area. This indicates that the modification of the crust and lithosphere in central-eastern China is non-uniform due to the heterogeneity of the lithospheric strength. Extensive crustal and lithospheric thinning could occur in some weak zones such as the basin-range junction belts and large faults. The structure beneath the Dabie orogenic belt is complex due to the collision between the North and South China Blocks during the Late Paleozoic-Triassic. The Dabie orogenic belt is generally delineated by a thick crust with a mid-crust low-velocity zone and a two-directional convergence in the lithospheric scale. Obvious velocity contrast exhibits in the crust and upper mantle at both sides of the Tanlu fault, which suggests the deep penetration of this lithospheric-scale fault. Most of our splitting measurements show nearly E-W trending fast polarization direction which is slightly deviating from the direction of plate motion. The similar present-day lithosphere structure and upper mantle deformation may imply that the eastern NCC and the eastern SCB were dominated by a common dynamic process after late Mesozoic, i.e., the westward subduction of Pacific plate and the retreat of the subduction plate. The westward subduction of the Philippine plate and the long-range effects of the collision between the Indian plate and Eurasia plate during Cenozoic may have also contributed to the present

  15. EBSD and FIB/TEM examination of shape memory effect deformation structures in U-14 at.% Nb

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, A.J. [Materials Science and Technology Division, Mail Stop G770, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)], E-mail: aclarke@lanl.gov; Field, R.D.; McCabe, R.J.; Cady, C.M.; Hackenberg, R.E.; Thoma, D.J. [Materials Science and Technology Division, Mail Stop G770, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2008-06-15

    Detailed examinations of shape memory effect (SME) deformation structures in martensite of U-14 at.% Nb were performed with electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). An accommodation strain analysis, which has been previously used to predict SME deformation structures and texture evolution in polycrystalline material, was also performed. Martensite variants and twin relationships observed with EBSD after compressive or tensile deformation were determined to be consistent with those expected from calculated accommodation strains. Focused ion beam (FIB) was used to select twinned regions identified with EBSD for more detailed TEM analysis to verify the presence of these specific twins. The observed SME twinning systems in the martensite agree with previous TEM observations and the predicted {l_brace}1-bar76{r_brace} twinning system was observed experimentally for the first time in U-14 at.% Nb using these complementary techniques.

  16. Deformation-induced structural changes of amorphous Ni0.5Zr0.5 in molecular-dynamic simulations

    International Nuclear Information System (INIS)

    Brinkmann, K.

    2006-01-01

    The present work investigates the plastic deformation of metallic glasses by the aid of molecular-dynamic simulations. The parameters for the model system are adapted to those for a NiZr-alloy. In particular, the composition Ni 0.5 Zr 0.5 is used. The analyzed deformation simulations are conducted for small systems with 5184 atoms and large systems with 17500 atoms in a periodic simulation cell. The deformation simulations of pre-deformed samples are carried out either at constant shear-rate or at constant load, the latter mode modeling a creep experiment. Stress-strain curves for pre-deformed samples show a less pronounced stress-overshoot phenomenon. Creep-simulations of samples deformed beyond the yield region indicate a drastically reduced viscosity in these systems when compared to samples pre-deformed only up to the linear regime of the stress-strain curve. From analyzing the local atomic topology it is found that the transition from the highly viscous, hard-to-deform state of the undeformed or only weakly strained system into the easy-to-deform flow-state, present if the system is strained far beyond the yielding regime of the stress-strain curve, is connected with the formation of a region containing atoms with massive changes in their topology which is oriented along a diagonal plane of the simulation cell. The degree of localization of these deformation bands is influenced by temperature and shear-rate. In subsequent deformations of pre-deformed samples the regions with massive changes in the atomic topology are again susceptible to changes in the local atomic topology. By using methods from statistics, a significant difference in the distribution of atomic properties for the group of atoms with massive topology changes on the one hand and the group of atoms without changes in their topology on the other gets quantitatively ascertainable. From the differences in structural properties, e.g. potential energy, cage volumes, angular order parameters or atomic

  17. Location and extent of Tertiary structures in Cook Inlet Basin, Alaska, and mantle dynamics that focus deformation and subsidence

    Science.gov (United States)

    Haeussler, Peter J.; Saltus, Richard W.

    2011-01-01

    This report is a new compilation of the location and extent of folds and faults in Cook Inlet Basin, Alaska. Data sources are previously published maps, well locations, and seismic-reflection data. We also utilize interpretation of new aeromagnetic data and some proprietary seismic-reflection data. Some structures are remarkably well displayed on frequency-filtered aeromagnetic maps, which are a useful tool for constraining the length of some structures. Most anticlines in and around the basin have at least shows of oil or gas, and some structures are considered to be seismically active. The new map better displays the pattern of faulting and folding. Deformation is greatest in upper Cook Inlet, where structures are oriented slightly counterclockwise of the basin bounding faults. The north ends of these structures bend to the northeast, which gives a pattern consistent with right-transpressional deformation.

  18. Emergence of coherent localized structures in shear deformations of temperature dependent fluids

    KAUST Repository

    Katsaounis, Theodoros

    2016-11-25

    Shear localization occurs in various instances of material instability in solid mechanics and is typically associated with Hadamard-instability for an underlying model. While Hadamard instability indicates the catastrophic growth of oscillations around a mean state, it does not by itself explain the formation of coherent structures typically observed in localization. The latter is a nonlinear effect and its analysis is the main objective of this article. We consider a model that captures the main mechanisms observed in high strain-rate deformation of metals, and describes shear motions of temperature dependent non-Newtonian fluids. For a special dependence of the viscosity on the temperature, we carry out a linearized stability analysis around a base state of uniform shearing solutions, and quantitatively assess the effects of the various mechanisms affecting the problem: thermal softening, momentum diffusion and thermal diffusion. Then, we turn to the nonlinear model, and construct localized states - in the form of similarity solutions - that emerge as coherent structures in the localization process. This justifies a scenario for localization that is proposed on the basis of asymptotic analysis in \\\\cite{KT}.

  19. Gamma-ray beam attenuation to assess the influence of soil texture on structure deformation

    International Nuclear Information System (INIS)

    Pires, L.F.; Bacchi, O.O.S.; Dias, N.M.P.

    2006-01-01

    Gamma-ray beam attenuation is a non-invasive technique that permits analysis of soil porosity without disturbing the region of interest of the core sample. The technique has as additional advantage to allow measurements point by point on a millimetric scale in contrast to other methodologies that are invasive and analyze the soil properties in the bulk sample volume. Soil porosity can be used as an important parameter to quantify soil structural damages, which affect soil aeration, water movement and retention. In this study, porosities of three soils different in texture were measured at various positions in order to analyze the impact of the sampling procedure on the structure of each particular soil texture. The gamma-ray attenuation system consisted of an 241 Am radioactive source having an activity of 3.7 GBq, collimated with cylindrical lead collimators of 2 mm diameter. The results obtained show the presence of dense regions near the edges of samples and that different soil textures can suffer distinct deformations at sampling. (author)

  20. The Difference of Structural State and Deformation Behavior between Teenage and Mature Human Dentin

    Directory of Open Access Journals (Sweden)

    Peter Panfilov

    2016-01-01

    Full Text Available Objective. The cause of considerable elasticity and plasticity of human dentin is discussed in the relationship with its microstructure. Methods. Structural state of teenage and mature human dentin is examined by using XRD and TEM techniques, and their deformation behavior under compression is studied as well. Result. XRD study has shown that crystallographic type of calcium hydroxyapatite in human dentin (calcium hydrogen phosphate hydroxide Ca9HPO4(PO45OH; Space Group P63/m (176; a = 9,441 A; c = 6,881 A; c/a = 0,729; Crystallite (Scherrer 200 A is the same for these age groups. In both cases, dentin matrix is X-ray amorphous. According to TEM examination, there are amorphous and ultrafine grain phases in teenage and mature dentin. Mature dentin is stronger on about 20% than teenage dentin, while teenage dentin is more elastic on about 20% but is less plastic on about 15% than mature dentin. Conclusion. The amorphous phase is dominant in teenage dentin, whereas the ultrafine grain phase becomes dominant in mature dentin. Mechanical properties of human dentin under compression depend on its structural state, too.

  1. Emergence of coherent localized structures in shear deformations of temperature dependent fluids

    KAUST Repository

    Katsaounis, Theodoros; Olivier, Julien; Tzavaras, Athanasios

    2016-01-01

    Shear localization occurs in various instances of material instability in solid mechanics and is typically associated with Hadamard-instability for an underlying model. While Hadamard instability indicates the catastrophic growth of oscillations around a mean state, it does not by itself explain the formation of coherent structures typically observed in localization. The latter is a nonlinear effect and its analysis is the main objective of this article. We consider a model that captures the main mechanisms observed in high strain-rate deformation of metals, and describes shear motions of temperature dependent non-Newtonian fluids. For a special dependence of the viscosity on the temperature, we carry out a linearized stability analysis around a base state of uniform shearing solutions, and quantitatively assess the effects of the various mechanisms affecting the problem: thermal softening, momentum diffusion and thermal diffusion. Then, we turn to the nonlinear model, and construct localized states - in the form of similarity solutions - that emerge as coherent structures in the localization process. This justifies a scenario for localization that is proposed on the basis of asymptotic analysis in \\cite{KT}.

  2. A deformation of Sasakian structure in the presence of torsion and supergravity solutions

    International Nuclear Information System (INIS)

    Houri, Tsuyoshi; Takeuchi, Hiroshi; Yasui, Yukinori

    2013-01-01

    A deformation of Sasakian structure in the presence of totally skew-symmetric torsion is discussed on odd-dimensional manifolds whose metric cones are Kähler with torsion. It is shown that such a geometry inherits similar properties to those of Sasakian geometry. As their example, we present an explicit expression of local metrics. It is also demonstrated that our example of the metrics admits the existence of hidden symmetry described by non-trivial odd-rank generalized closed conformal Killing–Yano tensors. Furthermore, using these metrics as an ansatz, we construct exact solutions in five-dimensional minimal gauged/ungauged supergravity and 11-dimensional supergravity. Finally, the global structures of the solutions are discussed. We obtain regular metrics on compact manifolds in five dimensions, which give natural generalizations of Sasaki–Einstein manifolds Y p,q and L a,b,c . We also briefly discuss regular metrics on non-compact manifolds in 11 dimensions. (paper)

  3. Grain refinement by cold deformation and recrystallization of bainite and acicular ferrite structures of C-Mn steels

    International Nuclear Information System (INIS)

    Hossein Nedjad, S.; Zahedi Moghaddam, Y.; Mamdouh Vazirabadi, A.; Shirazi, H.; Nili Ahmadabadi, M.

    2011-01-01

    Research highlights: → Bainite showed weak property improvement after rolling and annealing. → Additions of titanium and titanium oxide stimulated acicular ferrite. → Acicular ferrite obtained by nanoparticles exhibited very high strength. → Rolling and annealing of acicular ferrite gave substantial property improvement. - Abstract: The propensity of bainite and acicular ferrite structures of experimental C-Mn steels for enhanced grain refinement by combining phase transformation and plastic deformation has been investigated. Formation of acicular ferrite structures were stimulated with a small amount of titanium and titanium oxide nanoparticles added into the molten steels of high Mn concentrations. Isothermal transformations into the bainite and acicular ferrite structures were performed for 1.8 ks at 823 K after preliminary austenitization for 1.8 ks at 1523 K. Cold rolling for 50% thickness reduction was conducted on the isothermally transformed structures. Subsequent annealing of the deformed structures was conducted for 3.6 ks at 773, 873 and 973 K. Optical microscopy, scanning electron microscopy and tensile test were used for characterization of the studied steels. Cold rolling and annealing of the transformed structures at 873 K resulted in strengthening at the expense of ductility where an initial stage of recrystallization is realized. Acicular ferrite obtained by the addition of titanium into the molten steel exhibited the remarkable improvement of tensile properties. Discontinuous recrystallization of the deformed structures at 973 K leads to the formation of fine grains wherein acicular structures represented more enhanced grain refinement than bainite.

  4. Deformation behavior of carbon-fiber reinforced shape-memory-polymer composites used for deployable structures (Conference Presentation)

    Science.gov (United States)

    Lan, Xin; Liu, Liwu; Li, Fengfeng; Pan, Chengtong; Liu, Yanju; Leng, Jinsong

    2017-04-01

    Shape memory polymers (SMPs) are a new type of smart material, they perform large reversible deformation with a certain external stimulus (e.g., heat and electricity). The properties (e.g., stiffness, strength and other mechanically static or quasi-static load-bearing capacity) are primarily considered for conventional resin-based composite materials which are mainly used for structural materials. By contrast, the mechanical actuating performance with finite deformation is considered for the shape memory polymers and their composites which can be used for both structural materials and functional materials. For shape memory polymers and their composites, the performance of active deformation is expected to further promote the development in smart active deformation structures, such as deployable space structures and morphing wing aircraft. The shape memory polymer composites (SMPCs) are also one type of High Strain Composite (HSC). The space deployable structures based on carbon fiber reinforced shape memory polymer composites (SMPCs) show great prospects. Considering the problems that SMPCs are difficult to meet the practical applications in space deployable structures in the recent ten years, this paper aims to research the mechanics of deformation, actuation and failure of SMPCs. In the overall view of the shape memory polymer material's nonlinearity (nonlinearity and stress softening in the process of pre-deformation and recovery, relaxation in storage process, irreversible deformation), by the multiple verifications among theory, finite element and experiments, one obtains the deformation and actuation mechanism for the process of "pre-deformation, energy storage and actuation" and its non-fracture constraint domain. Then, the parameters of SMPCs will be optimized. Theoretical analysis is realized by the strain energy function, additionally considering the interaction strain energy between the fiber and the matrix. For the common resin-based or soft

  5. Molecular Dynamics Simulation of Structural Characterization of Elastic and Inelastic Deformation in ZrCu Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Shidong Feng

    2014-01-01

    Full Text Available The nanoscopic deformation behaviors in a ZrCu metallic glass model during loading-unloading process under uniaxial compression have been analyzed on the basis of the molecular dynamics (MD. The reversible degree of shear origin zones (SOZs is used as the structural indicator to distinguish the elastic deformation and inelastic deformation of ZrCu metallic glass at the atomic level. We find that the formation of SOZs is reversible at the elastic stage but irreversible at the inelastic stage during the loading and unloading processes. At the inelastic stage, the full-icosahedra fraction in SOZs is quickly reduced with increased strain and the decreasing process is also irreversible during the unloading processes.

  6. Twist deformation in anticlinic antiferroelectric structure in smectic B.sub.2./sub. imposed by the surface anchoring

    Czech Academy of Sciences Publication Activity Database

    Lejček, Lubor; Novotná, Vladimíra; Glogarová, Milada

    2008-01-01

    Roč. 35, č. 1 (2008), s. 11-19 ISSN 0267-8292 R&D Projects: GA ČR GA202/05/0431 Institutional research plan: CEZ:AV0Z10100520 Keywords : smectic liquid crystals * bent-shaped molecules * anticlinic antiferroelectric structure * ferroelectric structure * twist deformation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.132, year: 2008

  7. Structural deformities of deciduous teeth in patients with hypophosphatemic vitamin D-resistant rickets

    International Nuclear Information System (INIS)

    Abe, K.; Ooshima, T.; Lily, T.S.; Yasufuku, Y.; Sobue, S.

    1988-01-01

    Structural deformities of deciduous teeth from patients with hypophosphatemic vitamin D-resistant rickets (HVDRR) (1 male and 2 female patients) were examined by means of transmitted light microscopy, contact microradiography, and x-ray microanalysis. Freshly extracted teeth were fixed in formalin and subsequently hemisected longitudinally through the midline. One half was prepared for ground sections and the other half for decalcified sections. Neither gross nor microscopic abnormalities were present in enamel of patients with HVDRR. The concentration of calcium and phosphorus and the calcium/phosphorus ratio of the enamel of patients with HVDRR were nearly equal to those of normal teeth, although the degree of radiopacity was less in HVDRR. On the other hand, numerous microscopic abnormalities in the dentin of patients with HVDRR were found, such as interglobular dentin, wide predentin zones, and tubular defects. The concentration of phosphorus in the dentin of a patient with familial HVDRR was extremely low. Furthermore, formation of reparative dentin was observed at the pulp horn of teeth in patients with HVDRR that had been subjected to definite attrition at the corresponding dentin site

  8. Determination of the object surface function by structured light: application to the study of spinal deformities

    International Nuclear Information System (INIS)

    Buendia, M.; Salvador, R.; Cibrian, R.; Sotoca, J.M.; Laguia, M.

    1999-01-01

    The projection of structured light is a technique frequently used to determine the surface shape of an object. In this paper, a new procedure is described that efficiently resolves the correspondence between the knots of the projected grid and those obtained on the object when the projection is made. The method is based on the use of three images of the projected grid. In two of them the grid is projected over a flat surface placed, respectively, before and behind the object; both images are used for calibration. In the third image the grid is projected over the object. It is not reliant on accurate determination of the camera and projector pair relative to the grid and object. Once the method is calibrated, we can obtain the surface function by just analysing the projected grid on the object. The procedure is especially suitable for the study of objects without discontinuities or large depth gradients. It can be employed for determining, in a non-invasive way, the patient's back surface function. Symmetry differences permit a quantitative diagnosis of spinal deformities such as scoliosis. (author)

  9. Nonlinearly deformed W∞ algebra and second hamiltonian structure of KP hierarchy

    International Nuclear Information System (INIS)

    Yu Feng; Wu Yongshi

    1992-01-01

    The characteristic nonlinearity of W N algebras, appropriate for their many applications in two-dimensional quantum physics, is lost in the usual large-N limits. In this paper we search for nonlinear extensions of the Virasoro algebra that incorporate all higher-spin currents with spin s≥2. We show that under certain natural homogeneity requirements, the Jacobi identities lead to a unique nonlinear, centerless deformation of classical w ∞ and W ∞ . The latter, which we call dW/dt ∞ , constitutes a universal W-algebra which is very likely to contain all W N algebras by reduction. Also it is closely related to the linear W 1+∞ by a set of interesting recursion relations, which suggests the isomorphism of dW/dt ∞ to the second hamiltonian structure of the KP hierarchy proposed by Dickey. The implications for the symmetries in two-dimensional quantum gravity and noncritical c≤1 strings in the context of the KP approach are discussed. (orig.)

  10. Coal Matrix Deformation and Pore Structure Change in High-Pressure Nitrogen Replacement of Methane

    Directory of Open Access Journals (Sweden)

    Xiaofeng Ji

    2018-01-01

    Full Text Available Coal matrix deformation is one of the main controlling factors for coal reservoir permeability changes in nitrogen foam fracturing. The characteristics and mechanism of coal matrix deformation during the process of adsorption/desorption were studied by isothermal adsorption/desorption experiments with methane and nitrogen. Based on the free-energy theories, the Langmuir equation, and elastic mechanics, mathematical models of coal matrix deformation were developed and the deformation characteristics in adsorption/desorption processes were examined. From the study, we deduced that the coal matrix swelling, caused by methane adsorption, was a Langmuir-type relationship with the gas pressure, and exponentially increased as the adsorption quantity increased. Then, the deformation rate and amplitude of the coal matrix decreased gradually with the increase of the pressure. At the following stage, where nitrogen replaces methane, the coal matrix swelling continued but the deformation amplitude decreased, which was only 19.60% of the methane adsorption stage. At the mixed gas desorption stage, the coal matrix shrank with the reduction of pressure and the shrinkage amount changed logarithmically with the pressure, which had the hysteresis effect when compared with the swelling in adsorption. The mechanism of coal matrix deformation was discussed through a comparison of the change of micropores, mesopores, and also part macropores in the adsorption process.

  11. Image-based correlation between the meso-scale structure and deformation of closed-cell foam

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yongle, E-mail: yongle.sun@manchester.ac.uk [School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Sackville Street, Manchester M13 9PL (United Kingdom); Zhang, Xun [Henry Moseley X-ray Imaging Facility, School of Materials, The University of Manchester, Upper Brook Street, Manchester M13 9PL (United Kingdom); Shao, Zhushan [School of Civil Engineering, Xi' an University of Architecture & Technology, Xi' an 710055 (China); Li, Q.M. [School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Sackville Street, Manchester M13 9PL (United Kingdom); State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2017-03-14

    In the correlation between structural parameters and compressive behaviour of cellular materials, previous studies have mostly focused on averaged structural parameters and bulk material properties for different samples. This study focuses on the meso-scale correlation between structure and deformation in a 2D foam sample generated from a computed tomography slice of Alporas™ foam, for which quasi-static compression was simulated using 2D image-based finite element modelling. First, a comprehensive meso-scale structural characterisation of the 2D foam was carried out to determine the size, aspect ratio, orientation and anisotropy of individual cells, as well as the length, straightness, inclination and thickness of individual cell walls. Measurements were then conducted to obtain the axial distributions of local structural parameters averaged laterally to compression axis. Second, the meso-scale deformation was characterised by cell-wall strain, cell area ratio, digital image correlation strain and local compressive engineering strain. According to the results, the through-width sub-regions over an axial length between the average (lower bound) and the maximum (upper bound) of cell size should be used to characterise the meso-scale heterogeneity of the cell structure and deformation. It was found that the first crush band forms in a sub-region where the ratio of cell-wall thickness to cell-wall length is a minimum, in which the collapse deformation is dominated by the plastic bending and buckling of cell walls. Other morphological parameters have secondary effect on the initiation of crush band in the 2D foam. The finding of this study suggests that the measurement of local structural properties is crucial for the identification of the “weakest” region which determines the initiation of collapse and hence the corresponding collapse load of a heterogeneous cellular material.

  12. Image-based correlation between the meso-scale structure and deformation of closed-cell foam

    International Nuclear Information System (INIS)

    Sun, Yongle; Zhang, Xun; Shao, Zhushan; Li, Q.M.

    2017-01-01

    In the correlation between structural parameters and compressive behaviour of cellular materials, previous studies have mostly focused on averaged structural parameters and bulk material properties for different samples. This study focuses on the meso-scale correlation between structure and deformation in a 2D foam sample generated from a computed tomography slice of Alporas™ foam, for which quasi-static compression was simulated using 2D image-based finite element modelling. First, a comprehensive meso-scale structural characterisation of the 2D foam was carried out to determine the size, aspect ratio, orientation and anisotropy of individual cells, as well as the length, straightness, inclination and thickness of individual cell walls. Measurements were then conducted to obtain the axial distributions of local structural parameters averaged laterally to compression axis. Second, the meso-scale deformation was characterised by cell-wall strain, cell area ratio, digital image correlation strain and local compressive engineering strain. According to the results, the through-width sub-regions over an axial length between the average (lower bound) and the maximum (upper bound) of cell size should be used to characterise the meso-scale heterogeneity of the cell structure and deformation. It was found that the first crush band forms in a sub-region where the ratio of cell-wall thickness to cell-wall length is a minimum, in which the collapse deformation is dominated by the plastic bending and buckling of cell walls. Other morphological parameters have secondary effect on the initiation of crush band in the 2D foam. The finding of this study suggests that the measurement of local structural properties is crucial for the identification of the “weakest” region which determines the initiation of collapse and hence the corresponding collapse load of a heterogeneous cellular material.

  13. Structural Evolution and Mobile Shale Deformation in the Eastern Niger Delta

    International Nuclear Information System (INIS)

    Wiener, R. W.; Aikhionbare, D. O. L.

    2002-01-01

    Regional cross-sections and restorations of the eastern delta constructed from 2D and 3D seismic data show the structural evolution of paired extensional contractional belts and the kinematic and geometric evolution of mobile shale. The delta consists of an updip extensional belt and downdip zones of transitional and contractional deformation linked by a regional detachment. The extensional belt is characterized by zones of N-dipping (counterregional) and S-dipping (regional) normal faults.In the regional fault trend, sediment accommodation space is created largely by lateral movement of mobile substrate due to sediment loading and gravity. The transitional belt is characterized by low relief, shale-cored detachment folds and normal faults. The contractional belt consists of 2 parts, the high relief shale-cored detachment fold belt (mobile shale) and the fold/thrust belt: In the mobile shale belt, anticlines are generally symmetric and characterized by parallel-folded cover and highly variable thickness in the underlying ductile shale zone.Palinspastic restoration of the mobile shale by area balance shows a high degree of lateral and vertical mobility. Isostatic restoration of the depositional wedge that is the precursor to the mobile shale suggests lateral movement of 10s of kms from the extensional to the contractional domain. The fold and thrust belt is characterized by a train of asymmetric fault-related folds. The zone of ductile substrate is thin in this area, which may account for the change in structural style from high relief detachment folds in the mobile shale belt to a more classic fold/thrust belt style to the south

  14. Deformation microstructures

    DEFF Research Database (Denmark)

    Hansen, N.; Huang, X.; Hughes, D.A.

    2004-01-01

    Microstructural characterization and modeling has shown that a variety of metals deformed by different thermomechanical processes follows a general path of grain subdivision, by dislocation boundaries and high angle boundaries. This subdivision has been observed to very small structural scales...... of the order of 10 nm, produced by deformation under large sliding loads. Limits to the evolution of microstructural parameters during monotonic loading have been investigated based on a characterization by transmission electron microscopy. Such limits have been observed at an equivalent strain of about 10...

  15. Effect of Various SPD Techniques on Structure and Superplastic Deformation of Two Phase MgLiAl Alloy

    Science.gov (United States)

    Dutkiewicz, Jan; Bobrowski, Piotr; Rusz, Stanislav; Hilser, Ondrej; Tański, Tomasz A.; Borek, Wojciech; Łagoda, Marek; Ostachowski, Paweł; Pałka, Paweł; Boczkal, Grzegorz; Kuc, Dariusz; Mikuszewski, Tomasz

    2018-03-01

    MgLiAl alloy containing 9 wt% Li and 1.5% Al composed of hexagonal α and bcc β phases was cast under protecting atmosphere and hot extruded. Various methods of severe plastic deformation were applied to study their effect on structure and grain refinement. Rods were subjected to 1-3 passes of Twist Channel Angular Pressing TCAP (with helical component), cyclic compression to total strain ɛ = 5 using MAXStrain Gleeble equipment, both performed at temperature interval 160-200 °C and, as third SPD method, KOBO type extrusion at RT. The TCAP pass resulted in grain refinement of α phase from 30 μm down to about 2 μm and that of β phase from 12 to 5 μm. Maxstrain cycling 10 × up to ɛ = 5 led to much finer grain size of 300 nm. KOBO method performed at RT caused average grain size refinement of α and β phases down to about 1 μm. Hardness of alloy decreased slightly with increasing number of TCAP passes due to increase of small void density. It was higher after MAXStrain cycling and after KOBO extrusion. TEM studies after TCAP passes showed higher dislocation density in the β region than in the α phase. Crystallographic relationship (001) α|| (110) β indicated parallel positioning of slip planes of both phases. Electron diffraction technique confirmed increase of grain misorientation with number of TCAP passes. Stress/strain curves recorded at temperature 200 °C showed superplastic forming after 1st and 3rd TCAP passes with better superplastic properties due to higher elongation with increasing number of passes. Values of strain rate sensitivity coefficient m were calculated at 0.29 after 3rd TCAP pass for strain rate range 10-5 to 5 × 10-3 s-1. Deformation by MAXStrain cycling caused much more effective grain refinement with fine microtwins in α phase. Superplastic deformation was also observed in alloy deformed by KOBO method, however the value of m = 0.21 was obtained at lower temperature of deformation equal to 160 °C and deformation rate in the

  16. Characterizing Cracking and Permanent Deformation; An Attempt for Predicting the End of the Structural Pavement Life

    NARCIS (Netherlands)

    Pramesti, F.P.; Molenaar, A.A.A.; van de Ven, M.F.C.

    2017-01-01

    Durable, therefore sustainable, road needs to attain specific characteristics, among others, resistance to permanent deformation and cracking. Determining the development of both characteristics are important to be able to predict pavement life and performance. In this research, permanent

  17. Motion and deformation estimation from medical imagery by modeling sub-structure interaction and constraints

    KAUST Repository

    Sundaramoorthi, Ganesh; Hong, Byungwoo; Yezzi, Anthony J.

    2012-01-01

    of cardiac MRI which includes the detection of the left ventricle boundary and its deformation. The experimental results indicate the potential of the algorithm as an assistant tool for the quantitative analysis of cardiac functions in the diagnosis of heart

  18. Structural analysis and implicit 3D modelling of Jwaneng Mine: Insights into deformation of the Transvaal Supergroup in SE Botswana

    Science.gov (United States)

    Creus, P. K.; Basson, I. J.; Stoch, B.; Mogorosi, O.; Gabanakgosi, K.; Ramsden, F.; Gaegopolwe, P.

    2018-01-01

    Country rock at Jwaneng Diamond Mine provides a rare insight into the deformational history of the Transvaal Supergroup in southern Botswana. The ca. 235 Ma kimberlite diatremes intruded into late Archaean to Early Proterozoic, mixed, siliciclastic-carbonate sediments, that were subjected to at least three deformational events. The first deformational event (D1), caused by NW-SE directed compression, is responsible for NE-trending, open folds (F1) with associated diverging, fanning, axial planar cleavage. The second deformational event (D2) is probably progressive, involving a clockwise rotation of the principal stress to NE-SW trends. Early D2, which was N-S directed, involved left-lateral, oblique shearing along cleavage planes that developed around F1 folds, along with the development of antithetic structures. Progressive clockwise rotation of far-field forces saw the development of NW-trending folds (F2) and its associated, weak, axial planar cleavage. D3 is an extensional event in which normal faulting, along pre-existing cleavage planes, created a series of rhomboid-shaped, fault-bounded blocks. Normal faults, which bound these blocks, are the dominant structures at Jwaneng Mine. Combined with block rotation and NW-dipping bedding, a horst-like structure on the northwestern limb of a broad, gentle, NE-trending anticline is indicated. The early compressional and subsequent extensional events are consistent throughout the Jwaneng-Ramotswa-Lobatse-Thabazimbi area, suggesting that a large area records the same fault geometry and, consequently, deformational history. It is proposed that Jwaneng Mine is at or near the northernmost limit of the initial, northwards-directed compressional event.

  19. Delineating shallow Neogene deformation structures in northeastern Pará State using Ground Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Dilce F. Rossetti

    2003-06-01

    Full Text Available The geological characterization of shallow subsurface Neogene deposits in northeastern Pará State using Ground Penetrating Radar (GPR revealed normal and reverse faults, as well as folds, not yet well documented by field studies. The faults are identified mostly by steeply-dipping reflections that sharply cut the nearby reflections causing bed offsets, drags and rollovers. The folds are recognized by reflections that are highly undulating, configuring broad concave and convex-up features that are up to 50 m wide and 80 to 90 ns deep. These deformation structures are mostly developed within deposits of Miocene age, though some of the faults might continue into younger deposits as well. Although the studied GPR sections show several diffractions caused by trees, differential degrees of moisture, and underground artifacts, the structures recorded here can not be explained by any of these ''noises''. The detailed analysis of the GPR sections reveals that they are attributed to bed distortion caused by brittle deformation and folding. The record of faults and folds are not widespread in the Neogene deposits of the Bragantina area. These GPR data are in agreement with structural models, which have proposed a complex evolution including strike-slip motion for this area from the Miocene to present.A caracterização geológica de depósitos neógenos ocorrentes em sub-superfície rasa no nordeste do Estado do Pará, usando Radar de Penetração no Solo (GPR, revelou a presença de falhas normais e reversas, bem como dobras, ainda não documentadas em estudos de campo prévios. As falhas são identificadas por reflexões inclinadas que cortam bruscamente reflexões vizinhas, causando freqüentes deslocamentos de camadas. As dobras são reconhecidas por reflexões fortemente ondulantes, configurando feições côncavas e convexas que medem até 50 m de amplitude e 80 a 90 m de profundidade. Estas estruturas deformacionais desenvolvem-se, principalmente

  20. Structural properties, deformation behavior and thermal stability of martensitic Ti-Nb alloys

    Energy Technology Data Exchange (ETDEWEB)

    Boenisch, Matthias

    2016-06-10

    Ti-Nb alloys are characterized by a diverse metallurgy which allows obtaining a wide palette of microstructural configurations and physical properties via careful selection of chemical composition, heat treatment and mechanical processing routes. The present work aims to expand the current state of knowledge about martensite forming Ti-Nb alloys by studying 15 binary Ti-c{sub Nb}Nb (9 wt.% ≤ c{sub Nb} ≤ 44.5 wt.%) alloy formulations in terms of their structural and mechanical properties, as well as their thermal stability. The crystal structures of the martensitic phases, α{sup '} and α'', and the influence of the Nb content on the lattice (Bain) strain and on the volume change related to the β → α{sup '}/α'' martensitic transformations are analyzed on the basis of Rietveld-refinements. The magnitude of the shuffle component of the β → α{sup '}/α'' martensitic transformations is quantified in relation to the chemical composition. The largest transformation lattice strains are operative in Nb-lean alloys. Depending on the composition, both a volume dilatation and contraction are encountered and the volume change may influence whether hexagonal martensite α{sup '} or orthorhombic martensite α'' forms from β upon quenching. The mechanical properties and the deformation behavior of martensitic Ti-Nb alloys are studied by complementary methods including monotonic and cyclic uniaxial compression, nanoindentation, microhardness and impulse excitation technique. The results show that the Nb content strongly influences the mechanical properties of martensitic Ti-Nb alloys. The elastic moduli, hardness and strength are minimal in the vicinity of the limiting compositions bounding the interval in which orthorhombic martensite α'' forms by quenching. Uniaxial cyclic compressive testing demonstrates that the elastic properties of strained samples are different than those of unstrained ones

  1. Activation of Actuating Hydrogels with WS2 Nanosheets for Biomimetic Cellular Structures and Steerable Prompt Deformation.

    Science.gov (United States)

    Zong, Lu; Li, Xiankai; Han, Xiangsheng; Lv, Lili; Li, Mingjie; You, Jun; Wu, Xiaochen; Li, Chaoxu

    2017-09-20

    Macroscopic soft actuation is intrinsic to living organisms in nature, including slow deformation (e.g., contraction, bending, twisting, and curling) of plants motivated by microscopic swelling and shrinking of cells, and rapid motion of animals (e.g., deformation of jellyfish) motivated by cooperative nanoscale movement of motor proteins. These actuation behaviors, with an exceptional combination of tunable speed and programmable deformation direction, inspire us to design artificial soft actuators for broad applications in artificial muscles, nanofabrication, chemical valves, microlenses, soft robotics, etc. However, so far artificial soft actuators have been typically produced on the basis of poly(N-isopropylacrylamide) (PNiPAM), whose deformation is motived by volumetric shrinkage and swelling in analogue to plant cells, and exhibits sluggish actuation kinetics. In this study, alginate-exfoliated WS 2 nanosheets were incorporated into ice-template-polymerized PNiPAM hydrogels with the cellular microstructures which mimic plant cells, yet the prompt steerable actuation of animals. Because of the nanosheet-reinforced pore walls formed in situ in freezing polymerization and reasonable hierarchical water channels, this cellular hybrid hydrogel achieves super deformation speed (on the order of magnitude of 10° s), controllable deformation direction, and high near-infrared light responsiveness, offering an unprecedented platform of artificial muscles for various soft robotics and devices (e.g., rotator, microvalve, aquatic swimmer, and water-lifting filter).

  2. Steel Processing Properties and Their Effect on Impact Deformation of Lightweight Structures

    Energy Technology Data Exchange (ETDEWEB)

    Simunovic, S

    2003-09-23

    The objective of the research was to perform a comprehensive computational analysis of the effects of material and process modeling approaches on performance of UltraLight Steel Auto Body (ULSAB) vehicle models. The research addressed numerous material related effects, impact conditions as well as analyzed the performance of the ULSAB vehicles in crashes against designs representing the current US vehicle fleet. This report is organized into three main sections. The first section describes the results of the computational analysis of ULSAB crash simulations that were performed using advanced material modeling techniques. The effects of strain-rate sensitivity on a high strength steel (HSS) intensive vehicle were analyzed. Frontal and frontal offset crash scenarios were used in a finite element parametric study of the ULSAB body structure. Comparisons are made between the crash results using the piece-wise-linear isotropic plasticity strain-rate dependent material model, and the isotropic plasticity material model based on quasi-static properties. The simulation results show the importance of advanced material modeling techniques for vehicle crash simulations due to strain-rate sensitivity and rapid hardening characteristics of advanced high strength steels. Material substitution was investigated for the main frontal crush structure using the material of similar yield stress a significantly different strain-rate and hardening characteristics. The objective of the research presented in Section 2 was to assess the influence of stamping process on crash response of ULSAB vehicle. Considered forming effects included thickness variations and plastic strain hardening imparted in the part forming process. The as-formed thickness and plastic strain for front crash parts were used as input data for vehicle crash analysis. Differences in structural performance between crash models with and without forming data were analyzed in order to determine the effects and feasibility of

  3. Superimposed deformation in seconds: breccias from the impact structure at Kentland, Indiana (USA)

    Science.gov (United States)

    Bjørnerud, M. G.

    1998-05-01

    Breccias from the central uplift at the Kentland, Indiana impact structure have outcrop and microscopic characteristics that give insight into events that may occur in a carbonate-dominated sedimentary sequence in the moments following hypervelocity impact. Three distinct types of brecciated rock bodies — fault breccias, breccia lenses, and breccia dikes — suggest multiple mechanisms of fragmentation. The fault breccias occur along steeply dipping faults that coincide with compositional discontinuities in the stratigraphic succession. The breccia lenses and dikes are less localized in occurrence and show no systematic spatial distribution or orientation. The fault breccias and breccia lenses show no consistent cross-cutting relationships, but both are transected by the breccia dikes. Textural analysis reveals significant differences in particle size distributions for the different breccias. The fault breccias are typically monomict, coarsest and least uniform in grain size, and yield the highest power-law exponent (fractal dimension) in plots of particle size vs. frequency. The polymict dike filling is finest and most uniform in grain size, has the lowest power-law exponent, and is locally laminated and size-sorted. SEM images of the dike-filling breccia show that fragmentation occurred to the scale of microns. Material within the breccia lenses has textural characteristics intermediate between the other two types, but the irregular morphology of these bodies suggests a mechanism of formation different from that of either of the other breccia categories. The breccia lenses and dikes both have sub-mm-scale spheroidal vugs that may have been formed by carbon dioxide bubbles released during sudden devolatilization of the carbonate country rock. Collectively, these observations shed light on the processes that occur during the excavation and modification phases of crater formation in carbonate strata — heterogeneous, polyphase, multiscale deformation accomplished

  4. High-pressure behavior of intermediate scapolite: compressibility, structure deformation and phase transition

    Science.gov (United States)

    Lotti, Paolo; Comboni, Davide; Merlini, Marco; Hanfland, Michael

    2018-05-01

    Scapolites are common volatile-bearing minerals in metamorphic rocks. In this study, the high-pressure behavior of an intermediate member of the scapolite solid solution series (Me47), chemical formula (Na1.86Ca1.86K0.23Fe0.01)(Al4.36Si7.64)O24[Cl0.48(CO3)0.48(SO4)0.01], has been investigated up to 17.79 GPa, by means of in situ single-crystal synchrotron X-ray diffraction. The isothermal elastic behavior of the studied scapolite has been described by a III-order Birch-Murnaghan equation of state, which provided the following refined parameters: V 0 = 1110.6(7) Å3, {K_{{V_0}}} = 70(2) GPa ({β _{{V_0}}} = 0.0143(4) GPa-1) and {K_{{V}}^' = 4.8(7). The refined bulk modulus is intermediate between those previously reported for Me17 and Me68 scapolite samples, confirming that the bulk compressibility among the solid solution increases with the Na content. A discussion on the P-induced structure deformation mechanisms of tetragonal scapolite at the atomic scale is provided, along with the implications of the reported results for the modeling of scapolite stability. In addition, a single-crystal to single-crystal phase transition, which is displacive in character, has been observed toward a triclinic polymorph at 9.87 GPa. The high-pressure triclinic polymorph was found to be stable up to the highest pressure investigated.

  5. Structural interpretations of deformation and fracture behavior of polypropylene/multi-walled carbon nanotube composites

    International Nuclear Information System (INIS)

    Ganss, Martin; Satapathy, Bhabani K.; Thunga, Mahendra; Weidisch, Roland; Poetschke, Petra; Jehnichen, Dieter

    2008-01-01

    The deformation and crack resistance behavior of polypropylene (PP) multi-walled carbon nanotube (MWNT) composites have been studied and their interrelation to the structural attributes studied by transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and polarization light microscopy has been discussed. The composites were produced from industrial available MWNT by extrusion melt-mixing and injection-molding. In stress-strain measurements a strong increase in the yield stress and the Young's modulus at low MWNT contents has been observed, which was attributed to an efficient load transfer between the carbon nanotubes and polypropylene matrix through a good polymer-nanotube adhesion as indicated by SEM. The extent of enhancement in mechanical properties above 1.5 wt.% of MWNT decreased due to an apparently increased tendency of clustering of carbon nanotubes. Several theoretical models have been taken into account to explain the mechanical properties and to demonstrate the applicability of such models to the system under investigation. The crack resistance behavior has been studied with the essential work of fracture (EWF) approach based on post-yield fracture mechanics (PYFM) concept. A maximum in the non-essential work of fracture was observed at 0.5 wt.% MWNT demonstrating enhanced toughness compared to pure PP, followed by a sharp decline as the MWNT content was increased to 1.5 wt.% reveals a ductile-to-semi-ductile transition. Studies on the kinetics of crack propagation aspects have revealed a qualitative picture of the nature of such a transition in the fracture modes

  6. Effects of FeSb6 octahedral deformations on the electronic structure of LaFe4Sb12

    KAUST Repository

    Pulikkotil, Jiji Thomas Joseph

    2011-09-01

    First-principles density functional based electronic structure calculations are performed in order to clarify the influence of FeSb6 octahedral deformations on the structural and electronic structure properties of LaFe 4Sb12. Our results show that octahedral tiltings correlate with the band dispersions and, consequently, the band masses. While total energy variation points at an enhanced role of lattice anharmonicity, flat bands emerge from a redistribution of the electronic states. © 2011 Elsevier B.V. All rights reserved.

  7. Orientation and structure development in poly(lactide) under uniaxial deformation

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Y.S. [School of Materials Science and Engineering, Nanyang Technological University, N4.1-02-06 Nanyang Avenue, Singapore 639798 (Singapore); Stachurski, Z.H. [Department of Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Venkatraman, S.S. [School of Materials Science and Engineering, Nanyang Technological University, N4.1-02-06 Nanyang Avenue, Singapore 639798 (Singapore)], E-mail: assubbu@ntu.edu.sg

    2008-10-15

    Semicrystalline poly(L-lactide), or PLLA, is used in many biomedical applications, including self-expanding stents. A network model is applied to describe the deformation behaviour of semicrystalline poly(L-lactide) obtained at different drawing temperatures. Based on the present results, it is suggested that the deformation behaviour of PLLA appears to follow pseudo-affine model at the macroscopic level, but it does not follow it at the molecular level. The development of molecular orientation during drawing in both crystalline and amorphous phases was characterized by means of optical birefringence and wide-angle X-ray diffraction (WAXD). In general, high orientation is achieved at the higher drawing temperature and it is found that the crystalline and amorphous phases respond differently to network deformation. At moderate deformation temperature, the development of crystalline orientation increases slowly at a low stretch ratio followed by a rapid rise in the degree of orientation as a result of crystal rotation and crystal slip, while the amorphous chains deform in pseudo-affine manner. Drawing at a high temperature shows rapid crystalline orientation development, even at a low stretch ratio of 1.5, while molecular alignment develops steadily in the amorphous phase.

  8. Process Modelling of Curing Process-Induced Internal Stress and Deformation of Composite Laminate Structure with Elastic and Viscoelastic Models

    Science.gov (United States)

    Li, Dongna; Li, Xudong; Dai, Jianfeng

    2018-06-01

    In this paper, two kinds of transient models, the viscoelastic model and the linear elastic model, are established to analyze the curing deformation of the thermosetting resin composites, and are calculated by COMSOL Multiphysics software. The two models consider the complicated coupling between physical and chemical changes during curing process of the composites and the time-variant characteristic of material performance parameters. Subsequently, the two proposed models are implemented respectively in a three-dimensional composite laminate structure, and a simple and convenient method of local coordinate system is used to calculate the development of residual stresses, curing shrinkage and curing deformation for the composite laminate. Researches show that the temperature, degree of curing (DOC) and residual stresses during curing process are consistent with the study in literature, so the curing shrinkage and curing deformation obtained on these basis have a certain referential value. Compared the differences between the two numerical results, it indicates that the residual stress and deformation calculated by the viscoelastic model are more close to the reference value than the linear elastic model.

  9. The Effect of Mechanical Characteristics of Basal Decollement and Basement Structures on Deformation of the Zagros Basin

    OpenAIRE

    Bahroudi, Abbas

    2003-01-01

    Two fundamental structural elements, basement architecture and basal decollement, play a significant role in the evolution of a tectonically active region. Using different approaches (field data, literature review and analogue models) this thesis demonstrates that these two elements affected the deformation style in the Zagros fold-thrust belt during Mesozoic extensional and Cenozoic contractional episodes. Reassessment of available data suggests a new configuration for the basement to Zagro...

  10. Soft-sediment deformation structures in cores from lacustrine slurry deposits of the Late Triassic Yanchang Fm. (central China

    Directory of Open Access Journals (Sweden)

    Yang Renchao

    2016-09-01

    Full Text Available The fine-grained autochthonous sedimentation in the deep part of a Late Triassic lake was frequently interrupted by gravity-induced mass flows. Some of these mass flows were so rich in water that they must have represented slurries. This can be deduced from the soft-sediment deformation structures that abound in cores from these lacustrine deposits which constitute the Yanchang Fm., which is present in the Ordos Basin (central China.

  11. Effects of Structural Deformations of the Crank-Slider Mechanism on the Estimation of the Instantaneous Engine Friction Torque

    Science.gov (United States)

    CHALHOUB, N. G.; NEHME, H.; HENEIN, N. A.; BRYZIK, W.

    1999-07-01

    The focus on the current study is to assess the effects of structural deformations of the crankshaft/connecting-rod/piston mechanism on the computation of the instantaneous engine friction torque. This study is performed in a fully controlled environment in order to isolate the effects of structural deformations from those of measurement errors or noise interference. Therefore, a detailed model, accounting for the rigid and flexible motions of the crank-slider mechanism and including engine component friction formulations, is considered in this study. The model is used as a test bed to generate the engine friction torque,Tfa, and to predict the rigid and flexible motions of the system in response to the cylinder gas pressure. The torsional vibrations and the rigid body angular velocity of the crankshaft, as predicted by the detailed model of the crank-slider mechanism, are used along with the engine load torque and the cylinder gas pressure in the (P-ω) method to estimate the engine friction torque,Tfe. This method is well suited for the purpose of this study because its formulation is based on the rigid body model of the crank-slider mechanism. The digital simulation results demonstrate that the exclusion of the structural deformations of the crank-slider mechanism from the formulation of the (P-ω) method leads to an overestimation of the engine friction torque near the top-dead-center (TDC) position of the piston under firing conditions. Moreover, for the remainder of the engine cycle, the estimated friction torque exhibits large oscillations and takes on positive numerical values as if it is inducing energy into the system. Thus, the adverse effects of structural deformations of the crank-slider mechanism on the estimation of the engine friction torque greatly differ in their nature from one phase of the engine cycle to another.

  12. Thermomechanical Modeling of Laser-Induced Structural Relaxation and Deformation of Glass: Volume Changes in Fused Silica at High Temperatures [Thermo-mechanical modeling of laser-induced structural relaxation and deformation of SiO2 glass

    Energy Technology Data Exchange (ETDEWEB)

    Vignes, Ryan M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Soules, Thomas F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Stolken, James S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Settgast, Randolph R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Elhadj, Selim [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Matthews, Manyalibo J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). National Ignition Facility and Photon Sciences; Mauro, J.

    2012-12-17

    In a fully coupled thermomechanical model of the nanoscale deformation in amorphous SiO2 due to laser heating is presented. Direct measurement of the transient, nonuniform temperature profiles was used to first validate a nonlinear thermal transport model. Densification due to structural relaxation above the glass transition point was modeled using the Tool-Narayanaswamy (TN) formulation for the evolution of structural relaxation times and fictive temperature. TN relaxation parameters were derived from spatially resolved confocal Raman scattering measurements of Si–O–Si stretching mode frequencies. These thermal and microstructural data were used to simulate fictive temperatures which are shown to scale nearly linearly with density, consistent with previous measurements from Shelby et al. Volumetric relaxation coupled with thermal expansion occurring in the liquid-like and solid-like glassy states lead to residual stresses and permanent deformation which could be quantified. But, experimental surface deformation profiles between 1700 and 2000 K could only be reconciled with our simulation by assuming a roughly 2 × larger liquid thermal expansion for a-SiO2 with a temperature of maximum density ~150 K higher than previously estimated by Bruckner et al. Calculated stress fields agreed well with recent laser-induced critical fracture measurements, demonstrating accurate material response prediction under processing conditions of practical interest.

  13. Elastic-plastic deformation of fiber composites with a tetragonal structure

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, E.IU.; Svistkova, L.A. (Permskii Politekhnicheskii Institut, Perm (USSR))

    1991-02-01

    Results of numerical solutions are presented for elastic-plastic problems concerning arbitrary loading of unidirectional composites in the transverse plane. The nucleation and evolution of microplastic zones in the matrix and the effect of this process on the macroscopic characteristics of the composite are discussed. Attention is also given to the effect of the fiber shape on the elastic-plastic deformation of the matrix and to deformation paths realized in simple microdeformation processes. The discussion is illustrated by results obtained for a composite consisting of a VT1-0 titanium alloy matrix reinforced by Ti-Mo fibers.

  14. Evolution of orientations and deformation structures within individual grains in cold rolled columnar grained nickel

    DEFF Research Database (Denmark)

    Wu, G.L.; Godfrey, A.; Winther, Grethe

    2011-01-01

    Columnar grained Ni is used as a model material allowing simultaneous non-surface investigations of the evolution of crystallographic orientations and deformation microstructures within individual grains as a function of rolling strain up to ε=0.7. Electron channelling contrast and electron...... backscattered diffraction are used to visualise microstructures and crystallographic orientations. It is found that both the microstructural and the textural development depend strongly on the initial grain orientation. A grain size effect is observed on the deformation-induced orientation scatter within...

  15. 3D EBSD charactyerization of deformation structures in commercial purity aluminum

    DEFF Research Database (Denmark)

    Fengxiang, Lin; Godfrey, A.; Juul Jensen, Dorte

    2010-01-01

    A method to map the microstructure in deformed aluminum in three dimensions is presented. The method employs serial sectioning by mechanical polishing, and electropolishing to obtain a good surface quality, and orientation mapping of individual grains in each section by electron backscattered...... are analyzed in terms of the deformation-induced orientation spread within each grain. In particular the advantage of using three dimensional data, as opposed to two dimensional data, is illustrated, by inclusion of information about the three dimensional morphology of a grain and its neighbors....

  16. Effects of Fault Segmentation, Mechanical Interaction, and Structural Complexity on Earthquake-Generated Deformation

    Science.gov (United States)

    Haddad, David Elias

    2014-01-01

    Earth's topographic surface forms an interface across which the geodynamic and geomorphic engines interact. This interaction is best observed along crustal margins where topography is created by active faulting and sculpted by geomorphic processes. Crustal deformation manifests as earthquakes at centennial to millennial timescales. Given that…

  17. Effects of crystal structure and grain orientation on the roughness of deformed polycrystalline metals

    NARCIS (Netherlands)

    Wouters, Onne; Vellinga, WP; van Tijum, Redmer; De Hosson, JTM

    Surface roughening during tensile deformation of polycrystalline aluminum, iron and zinc is investigated using white light confocal microscopy and orientation imaging microscopy. A height-height correlation technique is used to analyze the data. The surface obeys self-affine scaling on length scales

  18. Editorial: Introduction to the Special Issue ;Slope Tectonics: Inherited Structures, Morphology of Deformation and Catastrophic Failure;

    Science.gov (United States)

    Hermanns, R. L.; Oppikofer, T.; Jaboyedoff, M.; Clague, J. J.; Scarascia-Mugnozza, G.

    2017-07-01

    The "Conference on Slope Tectonics" has become an international scientific meeting point to present and discuss a variety of topics related to slope deformation and the deposits of related failures. The first conference took place on February 15-16, 2008 at University of Lausanne (Switzerland). It was followed by a second conference on September 6-10, 2011, in Austria (organized by the Geological Survey of Austria) and a third on September 8-12, 2014, in Norway (organized by the Geological Survey of Norway). The two later events included field trips. It has become a tradition that selected papers from these conference are published - papers from the first conference were published by the Geological Society as Special Publication 351 (Jaboyedoff, 2011), and those from the second conference were published in a special issue of Tectonophysics (Baron and Jaboyedoff, 2013). This special issue of Geomorphology is a collection of papers presented at the Norwegian Conference on Slope Tectonics. This collection of papers focuses on the role of tectonics in gravitationally induced rock-slope instabilities. The slopes either deform over long periods as deep-seated gravitational slope deformation (DSGSD) or more rapidly as rockslides or rock avalanches. The reconstruction of slope deformation is an integral part of the studies captured in this special issue.

  19. Tuning transport properties of graphene three-terminal structures by mechanical deformation

    Science.gov (United States)

    Torres, V.; Faria, D.; Latgé, A.

    2018-04-01

    Straintronic devices made of carbon-based materials have been pushed up due to the graphene high mechanical flexibility and the possibility of interesting changes in transport properties. Properly designed strained systems have been proposed to allow optimized transport responses that can be explored in experimental realizations. In multiterminal systems, comparisons between schemes with different geometries are important to characterize the modifications introduced by mechanical deformations, especially if the deformations are localized at a central part of the system or extended in a large region. Then, in the present analysis, we study the strain effects on the transport properties of triangular and hexagonal graphene flakes, with zigzag and armchair edges, connected to three electronic terminals, formed by semi-infinite graphene nanoribbons. Using the Green's function formalism with circular renormalization schemes, and a single band tight-binding approximation, we find that resonant tunneling transport becomes relevant and is more affected by localized deformations in the hexagonal graphene flakes. Moreover, triangular systems with deformation extended to the leads, like longitudinal three-folded type, are shown as an interesting scenario for building nanoscale waveguides for electronic current.

  20. Stochastic dislocation kinetics and fractal structures in deforming metals probed by acoustic emission and surface topography measurements

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradov, A. [Laboratory for the Physics of Strength of Materials and Intelligent Diagnostic Systems, Togliatti State University, Togliatti 445667 (Russian Federation); Laboratory of Hybrid Nanostructured Materials, NITU MISiS, Moscow 119490 (Russian Federation); Yasnikov, I. S. [Laboratory for the Physics of Strength of Materials and Intelligent Diagnostic Systems, Togliatti State University, Togliatti 445667 (Russian Federation); Estrin, Y. [Laboratory of Hybrid Nanostructured Materials, NITU MISiS, Moscow 119490 (Russian Federation); Centre for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, VIC 3800 (Australia)

    2014-06-21

    We demonstrate that the fractal dimension (FD) of the dislocation population in a deforming material is an important quantitative characteristic of the evolution of the dislocation structure. Thus, we show that peaking of FD signifies a nearing loss of uniformity of plastic flow and the onset of strain localization. Two techniques were employed to determine FD: (i) inspection of surface morphology of the deforming crystal by white light interferometry and (ii) monitoring of acoustic emission (AE) during uniaxial tensile deformation. A connection between the AE characteristics and the fractal dimension determined from surface topography measurements was established. As a common platform for the two methods, the dislocation density evolution in the bulk was used. The relations found made it possible to identify the occurrence of a peak in the median frequency of AE as a harbinger of plastic instability leading to necking. It is suggested that access to the fractal dimension provided by AE measurements and by surface topography analysis makes these techniques important tools for monitoring the evolution of the dislocation structure during plastic deformation—both as stand-alone methods and especially when used in tandem.

  1. Effect of microscopic structure on deformation in nano-sized copper and Cu/Si interfacial cracking

    Energy Technology Data Exchange (ETDEWEB)

    Sumigawa, Takashi, E-mail: sumigawa@cyber.kues.kyoto-u.ac.jp; Nakano, Takuya; Kitamura, Takayuki

    2013-03-01

    The purpose of this work is to examine the effect of microscopic structure on the mechanical properties of nano-sized components (nano-components). We developed a bending specimen with a substructure that can be observed by means of a transmission electron microscope (TEM). We examined the plastic behavior of a Cu bi-crystal and the Cu/Si interfacial cracking in a nano-component. TEM images indicated that an initial plastic deformation takes place near the interface edge (the junction between the Cu/Si interface and the surface) in the Cu film with a high critical resolved shear stress (400–420 MPa). The deformation developed preferentially in a single grain. Interfacial cracking took place at the intersection between the grain boundary and the Cu/Si interface, where a high stress concentration existed due to deformation mismatch. These results indicate that the characteristic mechanical behavior of a nano-component is governed by the microscopic stress field, which takes into account the crystallographic structure. - Highlights: ► A nano-component specimen including a bi-crystal copper layer was prepared. ► A loading test with in-situ transmission electron microscopy was conducted. ► The plastic and cracking behaviors were governed by microscopic stress. ► Stress defined under continuum assumption was still present in nano-components.

  2. Direct investigations of deformation and yield induced structure transitions in polyamide 6 below glass transition temperature with WAXS and SAXS

    DEFF Research Database (Denmark)

    Guo, Huilong; Wang, Jiayi; Zhou, Chengbo

    2015-01-01

    Deformation and yield induced structure transitions of polyamide 6 (PA6) were detected with the combination of the wide- and small-angle X-ray scattering (WAXS and SAXS) at 30 degrees C below glass transition temperature (T-g) of PA6. During deformation, gamma-alpha phase transition was found...... at elastic stage. The concentrated stress in crystals at elastic stage provided adequate energy for the direct gamma-alpha phase transition under T-g. The force to promote the gamma-phase into a phase directly is insufficient at the yield stage and a transient phase as a compromise was formed. The transient...... phase was confirmed by DSC measurements and assisted the gamma-alpha phase transition indirectly. The gamma-phase slips into incomplete fragments at yield point, and the parts along tensile direction are responsible for the formation of transient phase. The gamma-fragments after yield is oriented...

  3. Plastic deformation of uranium dioxide: observation of the sub-structures of dislocations

    International Nuclear Information System (INIS)

    Alamo, A.; Lefebvre, J.M.; Soullard, J.

    1978-01-01

    Single crystals of uranium dioxide were deformed in compression at imposed strain rates in the temperature range of 700 0 C to 1400 0 C. The crystals were oriented to promote slip over one or two slip systems of the family [100] and also on the [110] system. Thin films of the deformed specimens were examined by transmission electron microscopy. When [100] single glide system operates, the dislocation substructure consist of numerous dipoles, their edge components lying along directions. For the [100] double glide system the grain boundaries and dislocation hexagonal network are observed, the complexity of which increases with the nominal strain. Dislocation arrangments consisting of extensive cellular networks of tangling dislocations and hexagonal netting were detected for [110] system. The auxillary role of [111] planes on the dislocation cross slip from [100] and [110] system was demonstrated. Weak beam images suggest that dissociation of dislocations can occur. (Auth.)

  4. Three sets of crystallographic sub-planar structures in quartz formed by tectonic deformation

    Science.gov (United States)

    Derez, Tine; Pennock, Gill; Drury, Martyn; Sintubin, Manuel

    2016-05-01

    In quartz, multiple sets of fine planar deformation microstructures that have specific crystallographic orientations parallel to planes with low Miller-Bravais indices are commonly considered as shock-induced planar deformation features (PDFs) diagnostic of shock metamorphism. Using polarized light microscopy, we demonstrate that up to three sets of tectonically induced sub-planar fine extinction bands (FEBs), sub-parallel to the basal, γ, ω, and π crystallographic planes, are common in vein quartz in low-grade tectonometamorphic settings. We conclude that the observation of multiple (2-3) sets of fine scale, closely spaced, crystallographically controlled, sub-planar microstructures is not sufficient to unambiguously distinguish PDFs from tectonic FEBs.

  5. Fault structure analysis by means of large deformation simulator; Daihenkei simulator ni yoru danso kozo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Y.; Shi, B. [Geological Survey of Japan, Tsukuba (Japan); Matsushima, J. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1997-05-27

    Large deformation of the crust is generated by relatively large displacement of the mediums on both sides along a fault. In the conventional finite element method, faults are dealt with by special elements which are called joint elements, but joint elements, elements microscopic in width, generate numerical instability if large shear displacement is given. Therefore, by introducing the master slave (MO) method used for contact analysis in the metal processing field, developed was a large deformation simulator for analyzing diastrophism including large displacement along the fault. Analysis examples were shown in case the upper basement and lower basement were relatively dislocated with the fault as a boundary. The bottom surface and right end boundary of the lower basement are fixed boundaries. The left end boundary of the lower basement is fixed, and to the left end boundary of the upper basement, the horizontal speed, 3{times}10{sup -7}m/s, was given. In accordance with the horizontal movement of the upper basement, the boundary surface largely deformed. Stress is almost at right angles at the boundary surface. As to the analysis of faults by the MO method, it has been used for a single simple fault, but should be spread to lots of faults in the future. 13 refs., 2 figs.

  6. Sparse Representation of Deformable 3D Organs with Spherical Harmonics and Structured Dictionary

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2011-01-01

    Full Text Available This paper proposed a novel algorithm to sparsely represent a deformable surface (SRDS with low dimensionality based on spherical harmonic decomposition (SHD and orthogonal subspace pursuit (OSP. The key idea in SRDS method is to identify the subspaces from a training data set in the transformed spherical harmonic domain and then cluster each deformation into the best-fit subspace for fast and accurate representation. This algorithm is also generalized into applications of organs with both interior and exterior surfaces. To test the feasibility, we first use the computer models to demonstrate that the proposed approach matches the accuracy of complex mathematical modeling techniques and then both ex vivo and in vivo experiments are conducted using 3D magnetic resonance imaging (MRI scans for verification in practical settings. All results demonstrated that the proposed algorithm features sparse representation of deformable surfaces with low dimensionality and high accuracy. Specifically, the precision evaluated as maximum error distance between the reconstructed surface and the MRI ground truth is better than 3 mm in real MRI experiments.

  7. Structure and performance of anisotropic nanocrystalline Nd-Fe-B magnets fabricated by high-velocity compaction followed by deformation

    Science.gov (United States)

    Zhao, L. Z.; Deng, X. X.; Yu, H. Y.; Guan, H. J.; Li, X. Q.; Xiao, Z. Y.; Liu, Z. W.; Greneche, J. M.

    2017-12-01

    High-velocity compaction (HVC) has been proposed as an effective approach for the fabrication of nanocrystalline Nd-Fe-B magnets. In this work, the effect of powder size on the density of HVCed magnets has been studied and the anisotropic nanocrystalline Nd-Fe-B magnets were prepared by HVC followed by hot deformation (HD). It is found that a proper particle size range is beneficial to high density. The investigations on the microstructure, magnetic domain structure, and hyperfine structure, indicate that the deformed grain structure and the magnetic domain structure with uniform paramagnetic grain boundary phase give good magnetic properties of HVC + HDed magnets. These magnets also have good mechanical and anti-corrosion properties. The results indicate that HVC is not only a near-net-shape, room temperature and binder-free process but is also able to maintain uniform nanostructure and to achieve good magnetic properties in both isotropic and anisotropic magnets. As a result, HVC can be employed as an ideal alternative process for bonding or hot pressing for the conventional MQI, MQII and MQIII magnets.

  8. NOMAD-Ref: visualization, deformation and refinement of macromolecular structures based on all-atom normal mode analysis.

    Science.gov (United States)

    Lindahl, Erik; Azuara, Cyril; Koehl, Patrice; Delarue, Marc

    2006-07-01

    Normal mode analysis (NMA) is an efficient way to study collective motions in biomolecules that bypasses the computational costs and many limitations associated with full dynamics simulations. The NOMAD-Ref web server presented here provides tools for online calculation of the normal modes of large molecules (up to 100,000 atoms) maintaining a full all-atom representation of their structures, as well as access to a number of programs that utilize these collective motions for deformation and refinement of biomolecular structures. Applications include the generation of sets of decoys with correct stereochemistry but arbitrary large amplitude movements, the quantification of the overlap between alternative conformations of a molecule, refinement of structures against experimental data, such as X-ray diffraction structure factors or Cryo-EM maps and optimization of docked complexes by modeling receptor/ligand flexibility through normal mode motions. The server can be accessed at the URL http://lorentz.immstr.pasteur.fr/nomad-ref.php.

  9. Micro-Structural Evolution and Size-Effects in Plastically Deformed Single Crystals: Strain Gradient Continuum Modeling

    DEFF Research Database (Denmark)

    El-Naaman, Salim Abdallah

    the macroscopic effects related to strain gradients, most predict smooth micro-structures. The evolution of dislocation micro-structures, during plastic straining of ductile crystalline materials, is highly complex and nonuniform. Published experimental measurements on deformed metal crystals show distinct......An extensive amount of research has been devoted to the development of micro-mechanics based gradient plasticity continuum theories, which are necessary for modeling micron-scale plasticity when large spatial gradients of plastic strain appear. While many models have proven successful in capturing...... strain. It is clear that many challenges are associated with modeling dislocation structures, within a framework based on continuum fields, however, since the strain gradient effects are attributed to the dislocation micro-structure, it is a natural step, in the further development of gradient theories...

  10. Apparatus and method for determining stress and strain in pipes, pressure vessels, structural members and other deformable bodies

    International Nuclear Information System (INIS)

    Vachon, R.I.; Ranson, W.F.

    1987-01-01

    A method and apparatus for measuring stress and strain associated with a pipe, pressurized vessel, structural member or deformable body containing a flaw or stress concentration utilizes a laser beam to illuminate a surface being analyzed and an optical data digitizer to sense a signal provided by a speckle pattern produced by the light beam reflected from the illuminated surface. One signal is received from the surface in a reference condition and subsequent signals are received from the surface after surface deformation. The optical data digitizer provides the received signal to an image processor, and the processor stores the signals and correlates the deformed image received with the reference image and then sends this correlated information to a minicomputer which performs mathematical analyses of the signal to determine stress and strain associated with the surface. The apparatus is constructed as one integral unit, and further includes a digital and tape display, as well as a television monitor and an electro-optic range indicator. (author) 15 figs

  11. Measuring structure deformations of a composite glider by optical means with on-ground and in-flight testing

    Science.gov (United States)

    Bakunowicz, Jerzy; Święch, Łukasz; Meyer, Ralf

    2016-12-01

    In aeronautical research experimental data sets of high quality are essential to verify and improve simulation algorithms. For this reason the experimental techniques need to be constantly refined. The shape, movement or deformation of structural aircraft elements can be measured implicitly in multiple ways; however, only optical, correlation-based techniques are able to deliver direct high-order and spatial results. In this paper two different optical metrologies are used for on-ground preparation and the actual execution of in-flight wing deformation measurements on a PW-6U glider. Firstly, the commercial PONTOS system is used for static tests on the ground and for wind tunnel investigations to successfully certify an experimental sensor pod mounted on top of the test bed fuselage. Secondly, a modification of the glider is necessary to implement the optical method named image pattern correlation technique (IPCT), which has been developed by the German Aerospace Center DLR. This scientific technology uses a stereoscopic camera set-up placed inside the experimental pod and a stochastic dot matrix applied to the area of interest on the glider wing to measure the deformation of the upper wing surface in-flight. The flight test installation, including the preparation, is described and results are presented briefly. Focussing on the compensation for typical error sources, the paper concludes with a recommended procedure to enhance the data processing for better results. Within the presented project IPCT has been developed and optimized for a new type of test bed. Adapted to the special requirements of the glider, the IPCT measurements were able to deliver a valuable wing deformation data base which now can be used to improve corresponding numerical models and simulations.

  12. Comparison of computer simulated and observed force deformation characteristics of anti-seismic devices and isolated structures

    International Nuclear Information System (INIS)

    Bhoje, S.B.; Chellapandi, P.; Chetal, S.; Muralikrishna, R.; Salvaraj, T.

    2002-01-01

    The paper discusses the finite element analysis of the force deformation characteristics of high damping rubber bearings, lead rubber bearings and natural rubber bearings. The dynamic response of structures isolated using bearings is also presented. The general purpose finite element program ABAQUS has been used for the numerical predictions under monotonic loads. For computing the dynamic response, a simplified model of the rubber bearing in the form of elasto-plastic system is used. This equivalent model is implemented using the computer code CASTEM-2000 and the dynamic response is obtained. The numerical results are found to match well with the experimental results. (author)

  13. Subgrain and dislocation structure changes in hot-deformed high-temperature Fe-Ni austenitic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ducki, K.J.; Rodak, K.; Hetmanczyk, M.; Kuc, D

    2003-08-28

    The influence of plastic deformation on the substructure of a high-temperature austenitic Fe-Ni alloy has been presented. Hot-torsion tests were executed at constant strain rates of 0.1 and 1.0 s{sup -1}, at testing temperatures in the range 900-1150 deg. C. The examination of the microstructure was carried out, using transmission electron microscopy. Direct measurements on the micrographs allowed the calculation of structural parameters: the average subgrain area, and the mean dislocation density. A detailed investigation has shown that the microstructure is inhomogeneous, consisting of dense dislocation walls, subgrains and recrystallized regions.

  14. Subgrain and dislocation structure changes in hot-deformed high-temperature Fe-Ni austenitic alloy

    International Nuclear Information System (INIS)

    Ducki, K.J.; Rodak, K.; Hetmanczyk, M.; Kuc, D.

    2003-01-01

    The influence of plastic deformation on the substructure of a high-temperature austenitic Fe-Ni alloy has been presented. Hot-torsion tests were executed at constant strain rates of 0.1 and 1.0 s -1 , at testing temperatures in the range 900-1150 deg. C. The examination of the microstructure was carried out, using transmission electron microscopy. Direct measurements on the micrographs allowed the calculation of structural parameters: the average subgrain area, and the mean dislocation density. A detailed investigation has shown that the microstructure is inhomogeneous, consisting of dense dislocation walls, subgrains and recrystallized regions

  15. Deforming black hole and cosmological solutions by quasiperiodic and/or pattern forming structures in modified and Einstein gravity

    Science.gov (United States)

    Bubuianu, Laurenţiu; Vacaru, Sergiu I.

    2018-05-01

    We elaborate on the anholonomic frame deformation method, AFDM, for constructing exact solutions with quasiperiodic structure in modified gravity theories, MGTs, and general relativity, GR. Such solutions are described by generic off-diagonal metrics, nonlinear and linear connections and (effective) matter sources with coefficients depending on all spacetime coordinates via corresponding classes of generation and integration functions and (effective) matter sources. There are studied effective free energy functionals and nonlinear evolution equations for generating off-diagonal quasiperiodic deformations of black hole and/or homogeneous cosmological metrics. The physical data for such functionals are stated by different values of constants and prescribed symmetries for defining quasiperiodic structures at cosmological scales, or astrophysical objects in nontrivial gravitational backgrounds some similar forms as in condensed matter physics. It is shown how quasiperiodic structures determined by general nonlinear, or additive, functionals for generating functions and (effective) sources may transform black hole like configurations into cosmological metrics and inversely. We speculate on possible implications of quasiperiodic solutions in dark energy and dark matter physics. Finally, it is concluded that geometric methods for constructing exact solutions consist an important alternative tool to numerical relativity for investigating nonlinear effects in astrophysics and cosmology.

  16. Formation process of lamella structures by deformation in an Fe-Mn-Si-Cr-Ni shape memory alloy

    International Nuclear Information System (INIS)

    Kikuchi, T.; Kajiwara, S.; Tomota, Y.

    1995-01-01

    For Fe-Mn-Si-Cr-Ni shape memory alloys, it was previously found by HREM study that the formation of the nanometric lamella structures consisting of f.c.c. and h.c.p. phase is very important to exhibit good shape memory effect. In the present work, the formation process of such lamella structures has been studied in detail. The results are as follows. The transformation is initiated by random formation of extremely thin martensite plates with 1-2 nm width and then these plates are clustered and some of them coalesce to form thicker martensite plates with increasing deformation. The clustered regions are 400-600 nm wide and will correspond to the above mentioned lamella structures. These clustered regions are considered also to correspond to the thinnest martensite plate observable with optical microscope. In the optical microscopic scale, the thin martenite plates with the smallest width are formed rather uniformly in an austenite grain, and with further increasing deformation, they are clustered and coalesce into thicker plates with 3-8 μm width. (orig.)

  17. Plastic deformation of single crystals of WSi2 with the C11b structure

    International Nuclear Information System (INIS)

    Ito, K.; Yano, T.; Nakamoto, T.; Inui, H.; Yamaguchi, M.

    1999-01-01

    The deformation behavior of single crystals of WSi 2 has been investigated as a function of crystal orientation in the temperature range from room temperature to 1500 C in compression. Single crystals of WSi 2 can be deformed only at high temperatures above 1100 C, in contrast to MoSi 2 in which plastic flow is possible even at room temperature. Four slip systems, {110} left-angle 111 right-angle, {011} left-angle 100 right-angle, {023} left-angle 100 right-angle and (001)left-angle 100 right-angle, are identified. While the former three slip systems are operative also in MoSi 2 , the (001)left-angle 100 right-angle slip is only operative in WSi 2 . The (001)left-angle 100 right-angle slip in WSi 2 is the alternative to {013} left-angle 331 right-angle slip in MoSi 2 since they are operative in the same orientation range. Slip on {110} left-angle 331 right-angle is hardly observed in WSi 2 . The values of critical resolved shear stress (CRSS) for the commonly observed slip systems are much higher in WSi 2 than in MoSi 2 with the largest difference for {110} left-angle 111 right-angle slip. The higher CRSS values in WSi 2 are not only due to the intrinsic difference in the deformation behavior but also due to the existence of numerous grown-in stacking faults on (001)

  18. Strength and structure during hot deformation of nickel-base superalloys

    International Nuclear Information System (INIS)

    Ribeiro, N.D.; Sellars, C.M.

    1984-01-01

    The effect of deformational variables on the flow stress and microstructure developed by plane strain compression testing and experimental rolling of three otherwise well characterized nickel-base super alloys, Nimonic 80A, Nimonic 90 and Waspaloy are presented. Rolled or tested samples were sectioned longitudinally at mid-width and were prepared for optical metallography. X-ray analysis of particles observed in several samples was carried out on polished and lightly etehed surfaces using a diffractometer with CoKα radiation. For other samples, energy dispersive x-ray analysis was also carried out in a scanning microscope. (E.G.) [pt

  19. Formation of Quenching Structures in the Steel 35 by Deform Cutting

    OpenAIRE

    A. G. Degtyareva; V. V. Poptsov; V. N. Simonov; V. G. Vasilev; S. B. Varlamova

    2014-01-01

    In industry different methods of surface hardening are widely used to increase reliability and durability of friction unit parts. Among these methods are areas of focus based on deformcutting technology (DC) i.e. method of chip-free mechanical treatment.It is shown that DC method allows us to produce through- or partial-hardening surface layers of a large thickness (0,4…1.5mm) on steel with no additional heat sources. The standard metal-cutting equipment and common tools are used for deform-c...

  20. A Coupled CFD/FEM Structural Analysis to Determine Deformed Shapes of the RSRM Inhibitors

    Science.gov (United States)

    Dill, Richard A.; Whitesides, R. Harold

    1996-01-01

    Recent trends towards an increase in the stiffness of the acrylonitrile butadiene rubber (NBR) insulation material used in the construction of the redesigned solid rocket motor (RSRM) propellant inhibitors prompted questions about possible effects on RSRM performance. The specific objectives of the computational fluid dynamics (CFD) task included: (1) the definition of pressure loads to calculate the deformed shape of stiffer inhibitors, (2) the calculation of higher port velocities over the inhibitors to determine shifts in the vortex shedding or edge tone frequencies, and (3) the quantification of higher slag impingement and collection rates on the inhibitors and in the submerged nose nozzle cavity.

  1. Foliated Structure of The Kuranishi Space and Isomorphisms of Deformation Families of Compact Complex Manifolds

    OpenAIRE

    Meersseman, Laurent

    2009-01-01

    Consider the following uniformization problem. Take two holomorphic (parametrized by some analytic set defined on a neighborhood of $0$ in $\\Bbb C^p$, for some $p>0$) or differentiable (parametrized by an open neighborhood of $0$ in $\\Bbb R^p$, for some $p>0$) deformation families of compact complex manifolds. Assume they are pointwise isomorphic, that is for each point $t$ of the parameter space, the fiber over $t$ of the first family is biholomorphic to the fiber over $t$ of the second fami...

  2. Soft-sediment deformation structures in seismically affected deep-sea Miocene turbidites (Cilento Basin, southern Italy

    Directory of Open Access Journals (Sweden)

    Valente Alessio

    2014-07-01

    Full Text Available Soft-sediment deformation structures (SSDS are widespread in the upper part of the S. Mauro Formation (Cilento Group, Middle-Late Miocene. The succession is represented mainly by thick and very thick, massive, coarse-grained sandstones, deposited by rapid sedimentation of high-density turbidity currents. The most common SSDS are short pillars, dishes, sedimentary sills and convolutions. They occur mostly in the upper parts of sandstone beds. Vertical tubes of 4-5 cm in diameter and up to 50 cm long constitute the most striking structures. They begin in the middle part of sandstone beds, which are basically massive or contain faint dish structures. These tubes can bifurcate upwards and/ or pass into bedding-parallel veins or dikes. The vertical tubes sometimes form sand volcanoes on the then sedimentary surface.

  3. Field Investigation of Surface Deformation Induced by the 2016 Meinong Earthquake and its Implications to Regional Geological Structures

    Science.gov (United States)

    Yi, De-Cheng; Chuang, Ray Y.; Lin, Ching-Weei

    2017-04-01

    We demonstrate mapping results of a newly-identified active folding-associated fault in southwestern Taiwan, which was triggered by the distant ML 6.6 Meinong earthquake in 2016. The 14.6-km-deep main shock occurred in Meinong at 3:57 (GMT +08) on February 6th while a series of 21-27 km deep aftershocks were induced after 160 seconds in Guanmiao, where is 25km NW away from the epicenter of the main shock. The focal mechanism of the Meinong main shock shows a westward oblique thrust with the fault plane of 275°/42°/17° (strike/dip/rake) but Guanmiao aftershocks show the N-S striking eastward normal movement. The study area locates at an on-going fold-and-thrust belt close to the deformation front of Taiwan orogeny with high rates of convergence, uplift and erosion. The geology of SW Taiwan is characterized by the 3-km-thick mudstones with high fluid pressure underlying the loose sedimentary rocks forming mud diapirs or mud-core anticlines. The significance of the Meinong earthquake is (1) aftershocks are far away from the main shock, and (2) the surface cracks partially distributed systematically along lineaments observed from InSAR, which has never been recognized as geological structures before. This study aims to establish possible kinematic processes of shallow deformation induced by the Meinong earthquake. We mapped surface cracks around the lineaments by using hand-held GPS and measured surface cracks by the compass and vernier. Among 249 kinematic data measured from 244 observed surface cracks and ruptures, the type of deformation was mostly identified as dilation or lateral translation and only 4 data were compressional deformation. The overall surface displacement moved to the northwest and west, consistent with the regional coseismic movement. The opening of the surface cracks range from 0.5 to 105 mm and 85% of them are less than 10 mm. Preseismic deformed features such as failure of the retaining wall were also observed along the western and eastern

  4. Modified suture-bridge technique to prevent a marginal dog-ear deformity improves structural integrity after rotator cuff repair.

    Science.gov (United States)

    Ryu, Keun Jung; Kim, Bang Hyun; Lee, Yohan; Lee, Yoon Seok; Kim, Jae Hwa

    2015-03-01

    The arthroscopic suture-bridge technique has proved to provide biomechanically firm fixation of the torn rotator cuff to the tuberosity by increasing the footprint contact area and pressure. However, a marginal dog-ear deformity is encountered not infrequently when this technique is used, impeding full restoration of the torn cuff. To evaluate the structural and functional outcomes of the use of a modified suture-bridge technique to prevent a marginal dog-ear deformity compared with a conventional suture-bridge method in rotator cuff repair. Cohort study; Level of evidence 2. A consecutive series of 71 patients aged 50 to 65 years who underwent arthroscopic rotator cuff repair for full-thickness medium-sized to massive tears was evaluated. Patients were divided into 2 groups according to repair technique: a conventional suture-bridge technique (34 patients; group A) versus a modified suture-bridge technique to prevent a marginal dog-ear deformity (37 patients; group B). Radiographic evaluations included postoperative cuff integrity using MRI. Functional evaluations included pre- and postoperative range of motion (ROM), pain visual analog scale (VAS), the University of California, Los Angeles (UCLA) shoulder rating scale, the Constant score, and the American Shoulder and Elbow Surgeons (ASES) score. All patients were followed up clinically at a minimum of 1 year. When the 2 surgical techniques were compared, postoperative structural integrity by Sugaya classification showed the distribution of types I:II:III:IV:V to be 4:20:2:4:4 in group A and 20:12:4:0:1 in group B. More subjects in group B had a favorable Sugaya type compared with group A (P bridge technique repairs were found in the retear group (P = .03). There were significant differences between healed and retear groups in functional outcome scores, with worse results in the retear group. A modified suture-bridge technique to prevent a marginal dog-ear deformity provided better structural outcomes than a

  5. Piezoelectric and deformation potential effects of strain-dependent luminescence in semiconductor quantum well structures

    DEFF Research Database (Denmark)

    Zhang, Aihua; Peng, Mingzeng; Willatzen, Morten

    2017-01-01

    The mechanism of strain-dependent luminescence is important for the rational design of pressure-sensing devices. The interband momentum-matrix element is the key quantity for understanding luminescent phenomena. We analytically solved an infinite quantum well (IQW) model with strain, in the frame......The mechanism of strain-dependent luminescence is important for the rational design of pressure-sensing devices. The interband momentum-matrix element is the key quantity for understanding luminescent phenomena. We analytically solved an infinite quantum well (IQW) model with strain......, in the framework of the 6 × 6 k·p Hamiltonian for the valence states, to directly assess the interplay between the spin-orbit coupling and the strain-induced deformation potential for the interband momentum-matrix element. We numerically addressed problems of both the infinite and IQWs with piezoelectric fields...... to elucidate the effects of the piezoelectric potential and the deformation potential on the strain-dependent luminescence. The experimentally measured photoluminescence variatio½n as a function of pressure can be qualitatively explained by the theoretical results....

  6. Multi-matrix loop equations: algebraic and differential structures and an approximation based on deformation quantization

    International Nuclear Information System (INIS)

    Krishnaswami, Govind S.

    2006-01-01

    Large-N multi-matrix loop equations are formulated as quadratic difference equations in concatenation of gluon correlations. Though non-linear, they involve highest rank correlations linearly. They are underdetermined in many cases. Additional linear equations for gluon correlations, associated to symmetries of action and measure are found. Loop equations aren't differential equations as they involve left annihilation, which doesn't satisfy the Leibnitz rule with concatenation. But left annihilation is a derivation of the commutative shuffle product. Moreover shuffle and concatenation combine to define a bialgebra. Motivated by deformation quantization, we expand concatenation around shuffle in powers of q, whose physical value is 1. At zeroth order the loop equations become quadratic PDEs in the shuffle algebra. If the variation of the action is linear in iterated commutators of left annihilations, these quadratic PDEs linearize by passage to shuffle reciprocal of correlations. Remarkably, this is true for regularized versions of the Yang-Mills, Chern-Simons and Gaussian actions. But the linear equations are underdetermined just as the loop equations were. For any particular solution, the shuffle reciprocal is explicitly inverted to get the zeroth order gluon correlations. To go beyond zeroth order, we find a Poisson bracket on the shuffle algebra and associative q-products interpolating between shuffle and concatenation. This method, and a complementary one of deforming annihilation rather than product are shown to give over and underestimates for correlations of a gaussian matrix model

  7. Numerical analysis on interactions between fluid flow and structure deformation in plate-fin heat exchanger by Galerkin method

    Science.gov (United States)

    Liu, Jing-cheng; Wei, Xiu-ting; Zhou, Zhi-yong; Wei, Zhen-wen

    2018-03-01

    The fluid-structure interaction performance of plate-fin heat exchanger (PFHE) with serrated fins in large scale air-separation equipment was investigated in this paper. The stress and deformation of fins were analyzed, besides, the interaction equations were deduced by Galerkin method. The governing equations of fluid flow and heat transfer in PFHE were deduced by finite volume method (FVM). The distribution of strain and stress were calculated in large scale air separation equipment and the coupling situation of serrated fins under laminar situation was analyzed. The results indicated that the interactions between fins and fluid flow in the exchanger have significant impacts on heat transfer enhancement, meanwhile, the strain and stress of fins includes dynamic pressure of the sealing head and flow impact with the increase of flow velocity. The impacts are especially significant at the conjunction of two fins because of the non-alignment fins. It can be concluded that the soldering process and channel width led to structure deformation of fins in the exchanger, and degraded heat transfer efficiency.

  8. Ramifications of structural deformations on collapse loads of critically cracked pipe bends under in-plane bending and internal pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sasidharan, Sumesh; Arunachalam, Veerappan; Subramaniam, Shanmugam [Dept. of Mechanical Engineering, National Institute of Technology, Tiruchirappalli (India)

    2017-02-15

    Finite-element analysis based on elastic-perfectly plastic material was conducted to examine the influence of structural deformations on collapse loads of circumferential through-wall critically cracked 90 .deg. pipe bends undergoing in-plane closing bending and internal pressure. The critical crack is defined for a through-wall circumferential crack at the extrados with a subtended angle below which there is no weakening effect on collapse moment of elbows subjected to in-plane closing bending. Elliptical and semioval cross sections were postulated at the bend regions and compared. Twice-elastic-slope method was utilized to obtain the collapse loads. Structural deformations, namely, ovality and thinning, were each varied from 0% to 20% in steps of 5% and the normalized internal pressure was varied from 0.2 to 0.6. Results indicate that elliptic cross sections were suitable for pipe ratios 5 and 10, whereas for pipe ratio 20, semioval cross sections gave satisfactory solutions. The effect of ovality on collapse loads is significant, although it cancelled out at a certain value of applied internal pressure. Thinning had a negligible effect on collapse loads of bends with crack geometries considered.

  9. THE STRUCTURE OF THE LITHOSPHERIC MANTLE OF THE SIBERAIN CRATON AND SEISMODYNAMICS OF DEFORMATION WAVES IN THE BAIKAL SEISMIC ZONE

    Directory of Open Access Journals (Sweden)

    A. A. Stepashko

    2013-01-01

    Full Text Available  The evolution and specific features of seismogynamics of the Baikal zones are reviewed in the context of interactions between deep deformation waves and the regional structure of the lithospheric mantle. The study is based on a model of the mantle structure with reference to chemical compositions of mantle peridotites from ophiolotic series located in the south-western framing of the Siberian craton (Fig. 1. The chemical zonation of the lithospheric mantle at the regional scale is determined from results of analyses of the heterogeneity of compositions of peridotites (Fig. 2, Table 1 and variations of contents of whole rock major components, such as iron, magnesium and silica (Fig. 3. According to spatial variations of the compositions of peridotites, the mantle has the concentric zonal structure, and the content of SiO2 is regularly decreasing, while concentrations of FeO∑ and MgO are increasing towards the centre of such structure (Fig. 4. This structure belongs to the mantle of the Siberian craton, which deep edge extends beyond the surface contour of the craton and underlies the north-western segment of the Central Asian orogenic belt.Results of the studies of peridotites of the Baikal region are consistent with modern concepts [Snyder, 2002; O’Reilly, Griffin, 2006; Chen et al., 2009] that suggest that large mantle lenses underlie the Archaean cratons (Fig. 5. The lenses are distinguished by high-density ultrabasic rocks and compose high-velocity roots of cratons which have remained isolated from technic processes. Edges of the mantle lenses may extend a few hundred kilometers beyond the limits of the cratons and underlie orogenic belts that frame the cratons, and this takes place in the south-western segment of the Siberian craton.The revealed structure of the lithospheric mantle is consistent with independent results of seismic and magmatectonical studies of the region. The Angara geoblock is located above the central part of the

  10. Strength and Deformation Rate of Plate Boundaries: The Rheological Effects of Grain Size Reduction, Structure, and Serpentinization.

    Science.gov (United States)

    Montesi, L.; Gueydan, F.

    2016-12-01

    Global strain rate maps reveal 1000-fold contrasts between plate interiors, oceanic or continental diffuse plate boundaries and narrow plate boundaries. Here, we show that rheological models based on the concepts of shear zone localization and the evolution of rock structure upon strain can explain these strain rate contrasts. Ductile shear zones constitute a mechanical paradox in the lithosphere. As every plastic deformation mechanism is strain-rate-hardening, ductile rocks are expected to deform at low strain rate and low stress (broad zone of deformation). Localized ductile shear zones require either a localized forcing (locally high stress) or a thermal or structural anomaly in the shear zone; either can be inherited or develop progressively as rocks deform. We previously identified the most effective process at each depth level of the lithosphere. In the upper crust and middle crust, rocks fabric controls localization. Grain size reduction is the most efficient mechanism in the uppermost mantle. This analysis can be generalized to consider a complete lithospheric section. We assume strain rate does not vary with depth and that the depth-integrated strength of the lithospheric does not change over time, as the total force is controlled by external process such as mantle convection and plate and slab buoyancy. Reducing grain size from a coarse value typical of undeformed peridotite to a value in agreement with the stress level (piezometer) while letting that stress vary from depth to depth (the integrated stress remains the same) increases the lithospheric strain rate by about a factor of 1000. This can explain the development of diffuse plate boundaries. The slightly higher strain rate of continental plate boundary may reflect development of a layered rock fabric in the middle crust. Narrow plate boundaries require additional weakening process. The high heat flux near mid-ocean ridge implies a thin lithosphere, which enhances stress (for constant integrated

  11. Structural coarsening during annealing of an aluminum plate heavily deformed using ECAE

    DEFF Research Database (Denmark)

    Mishin, Oleg V.; Zhang, Yubin; Godfrey, A.

    2015-01-01

    The microstructure and softening behaviour have been investigated in an aluminum plate heavily deformed by equal channel angular extrusion and subsequently annealed at 170 °C. It is found that at this temperature the microstructure evolves by coarsening with no apparent signs of recrystallization...... even after 2 h of annealing. Both coarsening and softening are rapid within first 10 minutes of annealing followed by a slower evolution with increasing annealing duration. Evidence of triple junction (TJ) motion during coarsening is obtained by inspecting the microstructure in one region using...... the electron backscatter diffraction technique both before and after annealing for 10 minutes. The fraction of fast-migrating TJs is found to strongly depend of the type of boundaries composing a junction. The greatest fraction of fast-migrating TJs is in the group, where all boundaries forming a junction...

  12. Dislocation structures and mechanical behaviour of Ge single crystals deformed by compression

    International Nuclear Information System (INIS)

    Nyilas, K.; Dupas, C.; Kruml, T.; Zsoldos, L.; Ungar, T.; Martin, J.L.

    2004-01-01

    Stress-strain curves of germanium interrupted by dip tests reveal that the internal stresses ascend parallel to the applied stress in a strain-rate dependent way. To understand this peculiar behaviour, the dislocation microstructure has been characterized. Transmission electron microscopy images show that regions of high dislocation activity along the primary slip system are separated by dislocation-free zones. X-ray microdiffraction reveals that the dislocation density is fluctuating on a 100 μm scale. X-ray reciprocal-space mapping, together with scanning microdiffraction, shows that misoriented mosaic blocks are forming owing to the boundary conditions in the compression test. These preliminary results reveal deformation heterogeneity both at macroscopic and mesoscopic scales

  13. Direct determination of elastic strains and dislocation densities in individual subgrains in deformation structures

    DEFF Research Database (Denmark)

    Jakobsen, Bo; Poulsen, Henning Friis; Lienert, U.

    2007-01-01

    A novel synchrotron-based technique "high angular resolution 3DXRD" is presented in detail, and applied to the characterization of oxygen-free, high-conductivity copper at a tensile deformation of 2%. The position and shape in reciprocal space of 14 peaks originating from deeply embedded individual...... subgrains is reported. From this dataset the density of redundant dislocations in the individual subgrains is inferred to be below 12 × 1012 m-2 on average. It is found that the subgrains on average experience a reduction in strain of 0.9 × 10-4 with respect to the mean elastic strain of the full grain...

  14. The structural fabric and deformation history of a mountain logjam: cameras, creep, and catastrophe

    Science.gov (United States)

    Deshpande, N.; Crosby, B. T.

    2016-12-01

    Wood and sediment are integral agents in the river transport processes that facilitate the chemical and physical evolution of landscapes. As such, the two pose an almost poetic contrast to each other: wood is buoyant, organic and elongate while sediment is dead, dense, and round. Despite wide recognition of the value of wood to river corridors, our mechanistic understanding of logjam kinematics and mobility is limited. This is in part due to historic logging practices that alter forests and `natural' river-wood feedbacks as well as contemporary attitudes that regard logjams as a nuisance. Both severely limit our ability to observe logjams in the field. Existing physically-based rules for wood transport are insufficient for this task at hand; a simple force balance approach quickly breaks down in the face of the complexity of the underlying kinematic fabric. Here, we present the results of a yearlong survey of an actively deforming logjam in the Salmon River Mountains, central Idaho. We use interval photography, pressure transducer/water level loggers and total station measurements of 150 logs within the jam (about 10% of the total population), to document where and when logjams move. The mean cumulative magnitude of displacement during the high-flow period is 2.06 m +/- 1.51 m, much of which occurred during a single event. Smaller magnitude creeping movement also occurs as the jam experiences cyclic quasi-diel fluctuations in stage due to snowmelt-generated discharge. Our results highlight the interplay between horizontal drag forces and vertical buoyant forces in governing the network of frictional connections and subsequent deformation within the logjam.

  15. Development of a structural model for the nonlinear shear deformation behavior of a seismic isolator

    International Nuclear Information System (INIS)

    Lee, Jae Han; Koo, Gyeong Hoi; Yoo, Bong

    2002-02-01

    The seismic excitation test results of an isolated test structure for artificial time history excitation are summarized for structure models of the isolated structure and isolation bearing. To simulate the response characteristic of isolated structure, shear hysteresis curves of isolators are analyzed. A simple analysis model is developed representing the actual dynamic behaviors of the test model, and the seismic responses using the simple model of the isolated structure and structure models, which are developed such as linear and bilinear models for isolators, are performed and compared with those of the seismic tests. The developed bilinear model is well applicable only to large shear strain area of LLRB

  16. Near-surface structural model for deformation associated with the February 7, 1812, New Madrid, Missouri, earthquake

    Science.gov (United States)

    Odum, J.K.; Stephenson, W.J.; Shedlock, K.M.; Pratt, T.L.

    1998-01-01

    The February 7, 1812, New Madrid, Missouri, earthquake (M [moment magnitude] 8) was the third and final large-magnitude event to rock the northern Mississippi Embayment during the winter of 1811-1812. Although ground shaking was so strong that it rang church bells, stopped clocks, buckled pavement, and rocked buildings up and down the eastern seaboard, little coseismic surface deformation exists today in the New Madrid area. The fault(s) that ruptured during this event have remained enigmatic. We have integrated geomorphic data documenting differential surficial deformation (supplemented by historical accounts of surficial deformation and earthquake-induced Mississippi River waterfalls and rapids) with the interpretation of existing and recently acquired seismic reflection data, to develop a tectonic model of the near-surface structures in the New Madrid, Missouri, area. This model consists of two primary components: a northnorthwest-trending thrust fault and a series of northeast-trending, strike-slip, tear faults. We conclude that the Reelfoot fault is a thrust fault that is at least 30 km long. We also infer that tear faults in the near surface partitioned the hanging wall into subparallel blocks that have undergone differential displacement during episodes of faulting. The northeast-trending tear faults bound an area documented to have been uplifted at least 0.5 m during the February 7, 1812, earthquake. These faults also appear to bound changes in the surface density of epicenters that are within the modern seismicity, which is occurring in the stepover zone of the left-stepping right-lateral strike-slip fault system of the modern New Madrid seismic zone.

  17. Control over structure-specific flexibility improves anatomical accuracy for point-based deformable registration in bladder cancer radiotherapy.

    Science.gov (United States)

    Wognum, S; Bondar, L; Zolnay, A G; Chai, X; Hulshof, M C C M; Hoogeman, M S; Bel, A

    2013-02-01

    Future developments in image guided adaptive radiotherapy (IGART) for bladder cancer require accurate deformable image registration techniques for the precise assessment of tumor and bladder motion and deformation that occur as a result of large bladder volume changes during the course of radiotherapy treatment. The aim was to employ an extended version of a point-based deformable registration algorithm that allows control over tissue-specific flexibility in combination with the authors' unique patient dataset, in order to overcome two major challenges of bladder cancer registration, i.e., the difficulty in accounting for the difference in flexibility between the bladder wall and tumor and the lack of visible anatomical landmarks for validation. The registration algorithm used in the current study is an extension of the symmetric-thin plate splines-robust point matching (S-TPS-RPM) algorithm, a symmetric feature-based registration method. The S-TPS-RPM algorithm has been previously extended to allow control over the degree of flexibility of different structures via a weight parameter. The extended weighted S-TPS-RPM algorithm was tested and validated on CT data (planning- and four to five repeat-CTs) of five urinary bladder cancer patients who received lipiodol injections before radiotherapy. The performance of the weighted S-TPS-RPM method, applied to bladder and tumor structures simultaneously, was compared with a previous version of the S-TPS-RPM algorithm applied to bladder wall structure alone and with a simultaneous nonweighted S-TPS-RPM registration of the bladder and tumor structures. Performance was assessed in terms of anatomical and geometric accuracy. The anatomical accuracy was calculated as the residual distance error (RDE) of the lipiodol markers and the geometric accuracy was determined by the surface distance, surface coverage, and inverse consistency errors. Optimal parameter values for the flexibility and bladder weight parameters were determined

  18. Control over structure-specific flexibility improves anatomical accuracy for point-based deformable registration in bladder cancer radiotherapy

    International Nuclear Information System (INIS)

    Wognum, S.; Chai, X.; Hulshof, M. C. C. M.; Bel, A.; Bondar, L.; Zolnay, A. G.; Hoogeman, M. S.

    2013-01-01

    Purpose: Future developments in image guided adaptive radiotherapy (IGART) for bladder cancer require accurate deformable image registration techniques for the precise assessment of tumor and bladder motion and deformation that occur as a result of large bladder volume changes during the course of radiotherapy treatment. The aim was to employ an extended version of a point-based deformable registration algorithm that allows control over tissue-specific flexibility in combination with the authors’ unique patient dataset, in order to overcome two major challenges of bladder cancer registration, i.e., the difficulty in accounting for the difference in flexibility between the bladder wall and tumor and the lack of visible anatomical landmarks for validation. Methods: The registration algorithm used in the current study is an extension of the symmetric-thin plate splines-robust point matching (S-TPS-RPM) algorithm, a symmetric feature-based registration method. The S-TPS-RPM algorithm has been previously extended to allow control over the degree of flexibility of different structures via a weight parameter. The extended weighted S-TPS-RPM algorithm was tested and validated on CT data (planning- and four to five repeat-CTs) of five urinary bladder cancer patients who received lipiodol injections before radiotherapy. The performance of the weighted S-TPS-RPM method, applied to bladder and tumor structures simultaneously, was compared with a previous version of the S-TPS-RPM algorithm applied to bladder wall structure alone and with a simultaneous nonweighted S-TPS-RPM registration of the bladder and tumor structures. Performance was assessed in terms of anatomical and geometric accuracy. The anatomical accuracy was calculated as the residual distance error (RDE) of the lipiodol markers and the geometric accuracy was determined by the surface distance, surface coverage, and inverse consistency errors. Optimal parameter values for the flexibility and bladder weight

  19. Control over structure-specific flexibility improves anatomical accuracy for point-based deformable registration in bladder cancer radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wognum, S.; Chai, X.; Hulshof, M. C. C. M.; Bel, A. [Department of Radiotherapy, Academic Medical Center, Meiberdreef 9, 1105 AZ Amsterdam (Netherlands); Bondar, L.; Zolnay, A. G.; Hoogeman, M. S. [Department of Radiation Oncology, Daniel den Hoed Cancer Center, Erasmus Medical Center, Groene Hilledijk 301, 3075 EA Rotterdam (Netherlands)

    2013-02-15

    Purpose: Future developments in image guided adaptive radiotherapy (IGART) for bladder cancer require accurate deformable image registration techniques for the precise assessment of tumor and bladder motion and deformation that occur as a result of large bladder volume changes during the course of radiotherapy treatment. The aim was to employ an extended version of a point-based deformable registration algorithm that allows control over tissue-specific flexibility in combination with the authors' unique patient dataset, in order to overcome two major challenges of bladder cancer registration, i.e., the difficulty in accounting for the difference in flexibility between the bladder wall and tumor and the lack of visible anatomical landmarks for validation. Methods: The registration algorithm used in the current study is an extension of the symmetric-thin plate splines-robust point matching (S-TPS-RPM) algorithm, a symmetric feature-based registration method. The S-TPS-RPM algorithm has been previously extended to allow control over the degree of flexibility of different structures via a weight parameter. The extended weighted S-TPS-RPM algorithm was tested and validated on CT data (planning- and four to five repeat-CTs) of five urinary bladder cancer patients who received lipiodol injections before radiotherapy. The performance of the weighted S-TPS-RPM method, applied to bladder and tumor structures simultaneously, was compared with a previous version of the S-TPS-RPM algorithm applied to bladder wall structure alone and with a simultaneous nonweighted S-TPS-RPM registration of the bladder and tumor structures. Performance was assessed in terms of anatomical and geometric accuracy. The anatomical accuracy was calculated as the residual distance error (RDE) of the lipiodol markers and the geometric accuracy was determined by the surface distance, surface coverage, and inverse consistency errors. Optimal parameter values for the flexibility and bladder weight

  20. Effect of cyclic block loading on character of deformation and strength of structural materials in plane stressed state

    International Nuclear Information System (INIS)

    Kul'chitskij, N.M.; Troshchenko, A.V.; Koval'chuk, B.I.; Khamaza, L.A.; Nikolaev, I.A.

    1982-01-01

    The paper is concerned with choice of conditions for preliminary cyclic block loading, determination of fatigue failure resistance characteristics for various structural materials under regular and selected block loading, investigation of the preliminary cyclic loading effect on regularities of elastoplastic deformation of materials concerned in the biaxial stressed state. Under selected conditions of cyclic block loading the character of damage accumulation is close to the linear law for the materials of high-srength doped steel, and VT6 alloys of concern. These materials in the initial state and after preliminary cyclic loading are anisotropic. Axial direction is characterized by a higher plastic strain resistance for steel and tangential direction - for VT6 alloy. The generalized strain curves for the materials in question are not invariant as to the stressed state type. It is stated that the effect of preliminary unsteady cyclic loading on resistance and general regularities of material deformation in the complex stressed state is insignificant. It is observed that stress-strain properties of the materials tend to vary in the following way: plastic strain resistance of the steel lowers and that of VT6 rises, anisotropy of the materials somehow decreases. The variation in the material anisotropy may be attributed to a decrease in residual stresses resulting from preliminary cyclic loading

  1. A coupled hydraulic and structure-dynamic model for prediction of RCCA drop time under hypothetical FA deformation

    International Nuclear Information System (INIS)

    Ren, Mingmin; Dressel, Bernd

    2009-01-01

    The ability of the RCCA (Rod Control Cluster Assemblies) in a pressurized water reactor (PWR) to be fully inserted into the core and to reach the dashpot within a required time limit is one of the important safety requirements for quick shutdown. This kind of quick shutdown in a PWR is initiated by allowing the control rod with the drive rod together to fall into the core by gravity. During normal operation, the RCCA drop time is mainly influenced by the weight of control assembly, hydraulic resistance in the CRDM (Control Rod Drive Mechanism), control rod guide assembly and guide thimbles and by the mechanical friction forces between the RCCA and its surroundings. In the case of an accident, e.g. earthquake, an additional influence of horizontal vibrations of the RCCA and its surroundings has to be considered [1]. A coupled hydraulic and structure-dynamic model is presented in this paper for prediction of RCCA drop time down to dashpot under hypothetical fuel assembly (FA) deformations. This coupled model was verified by RCCA static and dynamic drop tests with a deformed FA and by RCCA drop tests under operational conditions. (orig.)

  2. Structural and mechanical behaviour of severe plastically deformed high purity aluminium sheets processed by constrained groove pressing technique

    International Nuclear Information System (INIS)

    Satheesh Kumar, S.S.; Raghu, T.

    2014-01-01

    Highlights: • High purity aluminium sheets constrained groove pressed up to plastic strain of 5.8. • Microstructural evolution studied by TEM and X-ray diffraction profile analysis. • Ultrafine grained structure with grain size ∼900 nm achieved in sheets. • Yield strength increased by 5.3 times and tensile strength doubled after first pass. • Enhanced deformation homogeneity seen with increased accumulated plastic strain. - Abstract: High purity aluminium sheets (∼99.9%) are subjected to intense plastic straining by constrained groove pressing method successfully up to 5 passes thereby imparting an effective plastic strain of 5.8. Transmission electron microscopy studies of constrained groove pressed sheets divulged significant grain refinement and the average grain sizes obtained after five pass is estimated to be ∼0.9 μm. In addition to that, microstructural evolution of constrained groove pressed sheets is characterized by X-ray diffraction peak profile analysis employing Williamson–Hall method and the results obtained fairly concur with electron microscopy findings. The tensile behaviour evolution with increased straining indicates substantial improvement of yield strength by ∼5.3 times from 17 MPa to 90 MPa during first pass corroborated to grain refinement observed. Marginal increase in strengths is noticed during second pass followed by minor drop in strengths attributed to predominance of dislocation recovery is noticed in subsequent passes. Quantitative assessment of degree of deformation homogeneity using microhardness profiles reveal relatively better strain homogeneity at higher number of passes

  3. Wobbling phonon excitations, coexisting with normal deformed structures in 163Lu

    International Nuclear Information System (INIS)

    Jensen, D.R.; Hagemann, G.B.; Hamamoto, I.; Oedegard, S.W.; Bergstroem, M.; Herskind, B.; Sletten, G.; Toermaenen, S.; Wilson, J.N.; Tjoem, P.O.; Spohr, K.; Huebel, H.; Goergen, A.; Schoenwasser, G.; Bracco, A.; Leoni, S.; Maj, A.; Petrache, C.M.; Bednarczyk, P.; Curien, D.

    2002-01-01

    Wobbling is a rotational mode unique to a triaxial body. The Lu-Hf isotopes with N∼94 at high spin provide a possible region of nuclei with pronounced triaxiality. We have investigated 163 Lu through the fusion-evaporation reaction 139 La( 29 Si,5n) 163 Lu with a beam energy of 152 MeV. Three excited bands decaying into the known, presumably triaxial, superdeformed (TSD) band built on the i 13/2 proton orbital are observed. The electromagnetic properties of the connecting transitions from the two strongest populated excited TSD bands have been investigated. New particle-rotor calculations in which one i 13/2 quasiproton is coupled to the core of triaxial shape produce a variety of bands, whose properties can clearly be interpreted either as 'wobbling' or 'cranking' motion of the core. Evidence for the assignment of the excited TSD bands as one, and possibly even two wobbling phonon modes built on the yrast TSD band in 163 Lu is given. These triaxial bands coexist with bands built on quasiparticle excitations in the normal deformed (ND) minimum for which new data are also presented

  4. Nuclear structure information studied through Dirac equation with deformed mean fields

    International Nuclear Information System (INIS)

    Dudek, J.

    2000-01-01

    Complete text of publication follows. Relativistic mean-field theory provides a formal expression for the Dirac equation for the nucleonic motion in an atomic nucleus. The 'potentials' within such a formalism are given in terms of the meson fields, the latter obtained through a coupled system of equations of the Klein-Grodon type. Usually the whole system is being solved by using a Hartree approximation by employing an iterative selfonsistent algorithms. On a more phenomenological level one can parametrize the potentials that enter into a Dirac equation rather than obtain the selfconsistently; such a simplification was suggested some time ago by the Munich group. We introduce a Woods-Saxon type parametrisation and verify by a non-linear search routine what are the 'best fit potential parameters' that reproduce the single particle excitations in the double-magic spherical nuclei as well as the band-head properties in some hundreds of deformed nuclei. Next, by introducing a low-energy reduction of the Dirac equation, one may obtain in a natural way a Pauli Schrodinger type equation with a position dependent effective mass. The role of the corresponding term in a description of single particle energies of the nucleons is illustrated and the implications for the cranking equation are discussed in some detail. (author)

  5. Glacio-tectonic thrust and deformation structures in the Vejle Fjord, Denmark revealed by high-resolution subbottom-profile data

    DEFF Research Database (Denmark)

    Andresen, Katrine Juul; Boldreel, Lars Ole; Wahlgreen, Katrine Bak

    Surface geomorphological features and partial cliff exposures up till now represent the predominant source of information of glaciation related deformation in Denmark. In this study we apply high-resolution marine reflection seismic data from the Vejle Fjord area, supported by gravity and Rumohr...... coring, to document intense glacio-tectonic deformation in the shallow subsurface of Denmark. The subbottom profiler seismic data have a peak frequency around 13 kHz and a vertical resolution in the order of 10-20 cm. The data reveal several variations of glacio-tectonic deformation structures, primarily...... movements from outcrops and shallow cores. The subbottom profiler data provides larger (longer and deeper) sectional views on for instance deformation and deposition complexes related to ice progressions and retreats and thus represents a very good supplement and valuable input to field mapping and outcrops...

  6. Effect of deformation on structure and reaction of Al isotopes using relativistic mean field densities in Glauber model

    Science.gov (United States)

    Panda, R. N.; Sharma, Mahesh K.; Panigrahi, M.; Patra, S. K.

    2018-06-01

    We have examined the ground state properties of Al isotopes towards the proton rich side from A = 22 to 28 using the well known relativistic mean field (RMF) formalism with NLSH parameter set. The calculated results are compared with the predictions of finite range droplet model and experimental data. The calculation is extended to estimate the reaction cross section for ^{22-28}Al as projectiles with ^{12}C as target. The incident energy of the projectiles are taken as 950 MeV/nucleon, for both spherical and deformed RMF densities as inputs in the Glauber model approximation. Further investigation of enhanced values of total reaction cross section for ^{23}Al and ^{24}Al in comparison to rest of the isotopes indicates the proton skin structure of these isotopes. Specifically, the large value of root mean square radius and total reaction cross section of ^{23}Al could not be ruled out the formation of proton halo.

  7. Analysis of Manufacturing-Induced Defects and Structural Deformations in Lithium-Ion Batteries Using Computed Tomography

    Directory of Open Access Journals (Sweden)

    Yi Wu

    2018-04-01

    Full Text Available Premature battery drain, swelling and fires/explosions in lithium-ion batteries have caused wide-scale customer concerns, product recalls, and huge financial losses in a wide range of products including smartphones, laptops, e-cigarettes, hoverboards, cars, and commercial aircraft. Most of these problems are caused by defects which are difficult to detect using conventional nondestructive electrical methods and disassembly-based destructive analysis. This paper develops an effective computed tomography (CT-based nondestructive approach to assess battery quality and identify manufacturing-induced defects and structural deformations in batteries. Several unique case studies from commercial e-cigarette and smartphone applications are presented to show where CT analysis methods work.

  8. Fine Structure in Proton Emission from the Deformed 141g.sHo and 141mHo

    International Nuclear Information System (INIS)

    Karny, M.; Rykaczewski, Krzysztof Piotr; Grzywacz, R.; Batchelder, J.C.; Bingham, C.R.; Goodin, C. T.; Gross, Carl J.; Hamilton, J.H.; Korgul, A.; Krolas, W.; Liddick, S. N.; Li, K.; Maier, Karl; Mazzocchi, C.; Piechaczek, A.; Shapira, Dan; Simpson, D.; Tantawy, M.N.; Winger, J.A.; Yu, Chang-Hong; Zganjar, E. F.

    2007-01-01

    Fine structure in proton emission from the deformed states 141g.s Ho (T 1/2 = 4.1 ms) and 141 mHo (T 1/2 = 7.4 (micro)s) has been discovered at Oak Ridge by detecting fusion evaporation residues with the Recoil Mass Spectrometer, Si-detectors and digital signal processing electronics. The branching ratios to the first 2 + excited state in 140 Dy were measured to be I p g.s. (2 + ) = 0.9±0.1% and I p m (2 + ) = 1.7±0.5%. A comparison of the available calculations to the experimental values calls for further development of the theoretical models

  9. Global case studies of soft-sediment deformation structures (SSDS: Definitions, classifications, advances, origins, and problems

    Directory of Open Access Journals (Sweden)

    G. Shanmugam

    2017-10-01

    Problems that hinder our understanding of SSDS still remain. They are: (1 vague definitions of the phrase “soft-sediment deformation”; (2 complex factors that govern the origin of SSDS; (3 omission of vital empirical data in documenting vertical changes in facies using measured sedimentological logs; (4 difficulties in distinguishing depositional processes from tectonic events; (5 a model-driven interpretation of SSDS (i.e., earthquake being the singular cause; (6 routine application of the genetic term “seismites” to the “SSDS”, thus undermining the basic tenet of process sedimentology (i.e., separation of interpretation from observation; (7 the absence of objective criteria to differentiate 21 triggering mechanisms of liquefaction and related SSDS; (8 application of the process concept “high-density turbidity currents”, a process that has never been documented in modern oceans; (9 application of the process concept “sediment creep” with a velocity connotation that cannot be inferred from the ancient record; (10 classification of pockmarks, which are hollow spaces (i.e., without sediments as SSDS, with their problematic origins by fluid expulsion, sediment degassing, fish activity, etc.; (11 application of the Earth's climate-change model; and most importantly, (12 an arbitrary distinction between depositional process and sediment deformation. Despite a profusion of literature on SSDS, our understanding of their origin remains muddled. A solution to the chronic SSDS problem is to utilize the robust core dataset from scientific drilling at sea (DSDP/ODP/IODP with a constrained definition of SSDS.

  10. Microstructure, plastic deformation and strengthening mechanisms of an Al–Mg–Si alloy with a bimodal grain structure

    International Nuclear Information System (INIS)

    Shakoori Oskooie, M.; Asgharzadeh, H.; Kim, H.S.

    2015-01-01

    Highlights: • Al6063 with bimodal grain structures was fabricated by a powder metallurgy route. • The bimodal alloys showed a reasonable ductility together with a high strength. • Grain boundary strengthening was reduced at higher fraction of coarse grains. • The enhanced tensile ductility was attributed to crack blunting and delamination. - Abstract: Al6063 alloys with bimodal grain size distributions comprised of ultrafine-grained (UFG) and coarse-grained (CG) regions were produced via mechanical milling followed by hot extrusion. High-energy planetary ball milling for 22.5 h with a rotational speed of 350 rpm was employed for the synthesis of nanocrystalline Al6063 powders. The as-milled Al6063 powders were mixed with 15, 30, and 45 vol.% of the unmilled powders and then the powder mixtures were consolidated via extrusion at 450 °C with an extrusion ratio of 9:1. The microstructure of the bimodal extrudates was investigated using optical microscope, transmission electron microscope (TEM) and field emission scanning electron microscope equipped with an electron backscattered diffraction (EBSD) detector. The deformation behavior was investigated by means of uniaxial tensile tests. The bimodal Al6063 exhibited balanced mechanical properties, including high yield stress and ultimate tensile strength resulting from the UFG regions together with reasonable ductility attained from the CG areas. The fracture surfaces demonstrated a ductile fracture mode, in which the dimple size was correlated with the grain structure. The strengthening mechanisms are discussed based on the dislocation models and the functions of the CGs in the deformation behavior and ductility enhancement of bimodal Al6063 are explored

  11. Distributed deformation structures in shallow water carbonates subsiding through a simple stress field (Jandaira Formation, NE Brazil)

    Science.gov (United States)

    Bertotti, Giovanni; Bisdom, Kevin; Bezerra, Hilario; Reijmer, John; Cazarin, Carol

    2016-04-01

    Despite the scarcity of major deformation structures such as folds and faults, the flat-lying, post-rift shallow water carbonates of the Jandaira Formation (Potiguar Basin, NE Brazil) display well-organized fracture systems distributed of tens of km2. Structures observed in the outcropping carbonates are sub-vertical, generally N-S trending mode I and hybrid veins and barren fractures, sub-vertical roughly E-W trending stylolites and sub-horizontal stylolites. These features developed during subsidence in a simple and constant stress field characterized by, beside gravity, a significant horizontal stress probably of tectonic origin. The corresponding depth curves have different origin and slopes and, therefore, cross each other resulting in position of the principal stresses which change with depth. As a result, the type and amount of fractures affecting subsiding rocks change despite the fact that the far-field stresses remain constant. Following early diagenesis and porosity elimination in the first 100-200m depth, Jandaira carbonates experienced wholesale fracturing at depths of 400-800m resulting in a network of NNW-NE trending fractures partly organized in conjugate sets with a low interfault angle and a sub-vertical intersection, and sub-vertical stylolites roughly perpendicular to the fractures. Intense fluid circulation was activated as a consequence through the carbonates. With increasing subsidence, sub-horizontal stylolites formed providing calcite which precipitated in the open fractures transforming them in veins. The Jandaira formation lost thereby the permeability it had reached during the previous stage. Because of the lack of major deformation, the outcrops of the Jandaira Formation is an excellent analog for carbonate reservoirs in the Middle East, South Atlantic and elsewhere.

  12. Soft-sediment deformation structures from an ice-marginal storm-tide interactive system, Permo-Carboniferous Talchir Formation, Talchir Coalbasin, India

    Science.gov (United States)

    Bhattacharya, H. N.; Bhattacharya, Biplab

    2010-01-01

    Permo-Carboniferous Talchir Formation, Talchir Coalbasin, India, records sedimentation during a phase of climatic amelioration in an ice-marginal storm-affected shelf. Evidences of subtidal processes are preserved only under thick mud drapes deposited during waning storm phases. Various soft-sediment deformation structures in some sandstone/siltstone-mudstone interbeds, like syn-sedimentary faults, deformed laminations, sand-silt flows, convolute laminations and various flame structures, suggest liquefaction and fluidization of the beds due to passage of syn-depositional seismic shocks. In the Late Paleozoic ice-marginal shelf, such earthquake tremors could be generated by crustal movements in response to glacioisostatic adjustments of the basin floor.

  13. Structural plasticity: how intermetallics deform themselves in response to chemical pressure, and the complex structures that result.

    Science.gov (United States)

    Berns, Veronica M; Fredrickson, Daniel C

    2014-10-06

    Interfaces between periodic domains play a crucial role in the properties of metallic materials, as is vividly illustrated by the way in which the familiar malleability of many metals arises from the formation and migration of dislocations. In complex intermetallics, such interfaces can occur as an integral part of the ground-state crystal structure, rather than as defects, resulting in such marvels as the NaCd2 structure (whose giant cubic unit cell contains more than 1000 atoms). However, the sources of the periodic interfaces in intermetallics remain mysterious, unlike the dislocations in simple metals, which can be associated with the exertion of physical stresses. In this Article, we propose and explore the concept of structural plasticity, the hypothesis that interfaces in complex intermetallic structures similarly result from stresses, but ones that are inherent in a defect-free parent structure, rather than being externally applied. Using DFT-chemical pressure analysis, we show how the complex structures of Ca2Ag7 (Yb2Ag7 type), Ca14Cd51 (Gd14Ag51 type), and the 1/1 Tsai-type quasicrystal approximant CaCd6 (YCd6 type) can all be traced to large negative pressures around the Ca atoms of a common progenitor structure, the CaCu5 type with its simple hexagonal 6-atom unit cell. Two structural paths are found by which the compounds provide relief to the Ca atoms' negative pressures: a Ca-rich pathway, where lower coordination numbers are achieved through defects eliminating transition metal (TM) atoms from the structure; and a TM-rich path, along which the addition of spacer Cd atoms provides the Ca coordination environments greater independence from each other as they contract. The common origins of these structures in the presence of stresses within a single parent structure highlights the diverse paths by which intermetallics can cope with competing interactions, and the role that structural plasticity may play in navigating this diversity.

  14. Electrical resistivity structure beneath the Hangai Dome, Mongolia: intraplate volcanism and deformation imaged with magnetotelluric data

    Science.gov (United States)

    Comeau, M. J.; Becken, M.; Kaeufl, J.; Kuvshinov, A. V.; Kamm, J.; Grayver, A.; Demberel, S.; Usnikh, S. U.; Batmagnai, E.; Tserendug, S.

    2017-12-01

    mantle ( 70 - 100 km) directly below the Hangai Dome can be explained by the presence of a small amount of partial melt. This zone likely represents the region of melt generation for intraplate volcanism and gives evidence for a small-scale (<100 km) asthenospheric upwelling, which contributes to intraplate deformation.

  15. Seismically-triggered soft-sediment deformation structures close to a major strike-slip fault system in the Eastern Alps (Hirlatz cave, Austria)

    Science.gov (United States)

    Salomon, Martina Lan; Grasemann, Bernhard; Plan, Lukas; Gier, Susanne; Schöpfer, Martin P. J.

    2018-05-01

    We investigate episodic soft-sediment deformation structures cross-cut by normal faults preserved in unlithified finely laminated calcite rich sediments in the Hirlatz cave in the Northern Calcareous Alps (Austria). These sediments comprise varve-like alternations of brighter carbonate/quartz rich layers, and darker clay mineral rich layers. The deformed sediments contain abundant millimeter to centimeter-scale soft-sediment structures (load casts, ball-and-pillow structures), sheet slumps (thrust faults and folds), erosive channels filled with slides and chaotic slumps. After deposition and soft-sediment deformation normal faults developed within the entire sedimentary succession, an event that probably correlates with an offset of c. 10 cm of the passage wall above the outcrop. Our major conclusions are: (i) The sediments have a glacial origin and were deposited in the Hirlatz cave under phreatic fluvio-lacustrine conditions. The deposition and the soft-sediment deformation occurred most likely during the last glaciation (i.e. around 25 ka ago); (ii) The liquefaction and formation of the soft-sediment structures in water-saturated stratified layers was triggered by episodic seismic events; (iii) The internally deformed sediments were later displaced by normal faults; (iv) A possible source for the seismic events is the active sinistral Salzach-Ennstal-Mariazeller-Puchberger (SEMP) strike-slip fault which is located about 10 km south of the outcrop and plays a major role in accommodating the extrusion of the Eastern Alps towards the Pannonian Basin. To our knowledge, the described structures are the first report of liquefaction and seismically induced soft-sediment deformations in Quaternary sediments in the Eastern Alps.

  16. Temperature and composition of carbonate cements record early structural control on cementation in a nascent deformation band fault zone: Moab Fault, Utah, USA

    Science.gov (United States)

    Hodson, Keith R.; Crider, Juliet G.; Huntington, Katharine W.

    2016-10-01

    Fluid-driven cementation and diagenesis within fault zones can influence host rock permeability and rheology, affecting subsequent fluid migration and rock strength. However, there are few constraints on the feedbacks between diagenetic conditions and structural deformation. We investigate the cementation history of a fault-intersection zone on the Moab Fault, a well-studied fault system within the exhumed reservoir rocks of the Paradox Basin, Utah, USA. The fault zone hosts brittle structures recording different stages of deformation, including joints and two types of deformation bands. Using stable isotopes of carbon and oxygen, clumped isotope thermometry, and cathodoluminescence, we identify distinct source fluid compositions for the carbonate cements within the fault damage zone. Each source fluid is associated with different carbonate precipitation temperatures, luminescence characteristics, and styles of structural deformation. Luminescent carbonates appear to be derived from meteoric waters mixing with an organic-rich or magmatic carbon source. These cements have warm precipitation temperatures and are closely associated with jointing, capitalizing on increases in permeability associated with fracturing during faulting and subsequent exhumation. Earlier-formed non-luminescent carbonates have source fluid compositions similar to marine waters, low precipitation temperatures, and are closely associated with deformation bands. The deformation bands formed at shallow depths very early in the burial history, preconditioning the rock for fracturing and associated increases in permeability. Carbonate clumped isotope temperatures allow us to associate structural and diagenetic features with burial history, revealing that structural controls on fluid distribution are established early in the evolution of the host rock and fault zone, before the onset of major displacement.

  17. ANALYSIS OF ELASTIC DEFORMATION OF BRAIDED TUBULAR STRUCTURES FOR MEDICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Mehmet Emin YÜKSEKKAYA

    2001-02-01

    Full Text Available In this study, self-expanding stents were fabricated and analyzed. These stents are in the form of 3-D tubular braided structures made of polymeric materials. This type of structures is used in medicine to open clogged artheries and veins by exerting radial force. The amount of radial force exerted into the membrane should not give any damage to the veins. Therefore, the geometry of the three dimensional tubular braided fabric is analyzed to give an optimum radial force for medical applications.

  18. Microscopical structure of the states of deformed nuclei in the neighborhood of the yrast line

    International Nuclear Information System (INIS)

    Janssen, D.; Mikhailov, I.N.

    1979-01-01

    A simple model is derived which allows one to study the structure of the nuclear states in the neighborhood of the 'yrast' band. In the present scheme the precession motion plays a role of one of the normal modes of oscillations. (The structure of the dispersion equation for this mode corresponds to the well known classical formula.) Vibrational states associated with quadrupole oscillations of the nuclear shape are determined from a general equation. At slow rotation this equation breaks up into the known equations for β-, Δ- and γ-vibrations and non-collectivized Ksup(π)=1 + excitations. (Auth.)

  19. Tooth axis and skeletal structures in mandibular molar vertical sections in jaw deformity with facial asymmetry using MPR images

    International Nuclear Information System (INIS)

    Nojima, Kunihiko; Yokose, Taishi; Ishii, Takenobu; Kobayashi, Makoto; Nishii, Yasushi

    2007-01-01

    The objective of the present study was to investigate frontal morphological asymmetry in the mandibular molar region in terms of tooth axis and skeletal structures using vertical MPR sections in jaw deformity accompanied by facial asymmetry. Subjects consisted of 15 patients with jaw deformity accompanied by facial asymmetry aged 17.4 years to 37.8 years. There were four men and eleven women. Based on X-ray computed tomography (CT) scans, Digital Imaging and Communications in Medicine (DICOM) viewer software was used to prepare multiplanar reconstruction (MPR) sections. The mandible was then positioned on a reference plane based on the menton and left and right gonions, and a vertical MPR section passing through the mesial root of the first mandibular molar was prepared. The following measurements were made on both the shifted and non-shifted sides: maximum buccolingual width of the mandibular body; height of the mandibular body; inclination angle of the mandibular body; degree of buccal protrusion of the mandibular body; and inclination angle of the buccolingual tooth axis of the first molar. Furthermore, degree of median deviation in the menton was measured using frontal cephalograms. Differences in morphological parameters between the shifted and non-shifted sides were assessed. Furthermore, the relationship between median deviation and asymmetry were statistically analyzed. There was no significant asymmetry in the maximum buccolingual width of the mandibular body, the height of the mandibular body or the degree of buccal protrusion of the mandibular body. However, when compared to the shifted side, the inclination angle of the buccolingual tooth axis of the first molar for the non-shifted side was significantly greater. There was a relatively strong correlation between median deviation and inclination angle of the mandibular body. The above findings clarified that, in orthognathic surgery for jaw deformity accompanied by facial asymmetry, actively improving

  20. A biomechanical analysis of the vertebral and rib deformities in structural scoliosis

    NARCIS (Netherlands)

    Veldhuizen, AG; Klein, JP; Webb, PJ; Nijenbanning, G; Cool, JC; von Horn, [No Value

    Although the structural changes occurring in the scoliotic spine have been reported as early as the 19th century, the descriptions and biomechanical explanations have not always been complete and consistent. In this study, three-dimensionally rendered CT images of two human skeletons with a

  1. Deformation and fracture of Cu alloy-stainless steel layered structures under dynamic loading

    International Nuclear Information System (INIS)

    McCoy, J.H.; Kumar, A.S.

    1998-01-01

    Fracture resistance of the current ITER first wall configuration, a copper alloy-stainless steel layered structure, is a major design issue. The question of dynamic crack propagation into and through the first wall structure is examined using dynamic finite element modeling (FEM). Several layered configurations that incorporate both strain and frictional energy dissipation during the fracture process are considered. With fixed overall specimen geometry, the energy required to extend a precrack is examined as a function of material properties, and the layer structure. It is found that the crack extension energies vary dramatically with the fracture strain of materials, and to a much lesser extent with the number of layers. In addition, it is found that crack propagation through the lower ductility copper alloy layer may be deflected at the stainless steel-copper interface and not result in total fracture of the structure. Although the total energy required is affected only to a small degree by the interface properties, the time to extend the precrack is strongly affected. By making proper selections of the interface and the layered material, crack propagation rates and the possibility of full fracture can be substantially reduced. (orig.)

  2. Fabrication, Characterization, And Deformation of 3D Structural Meta-Materials

    Science.gov (United States)

    Montemayor, Lauren C.

    Current technological advances in fabrication methods have provided pathways to creating architected structural meta-materials similar to those found in natural organisms that are structurally robust and lightweight, such as diatoms. Structural meta-materials are materials with mechanical properties that are determined by material properties at various length scales, which range from the material microstructure (nm) to the macro-scale architecture (mum -- mm). It is now possible to exploit material size effect, which emerge at the nanometer length scale, as well as structural effects to tune the material properties and failure mechanisms of small-scale cellular solids, such as nanolattices. This work demonstrates the fabrication and mechanical properties of 3-dimensional hollow nanolattices in both tension and compression. Hollow gold nanolattices loaded in uniaxial compression demonstrate that strength and stiffness vary as a function of geometry and tube wall thickness. Structural effects were explored by increasing the unit cell angle from 30° to 60° while keeping all other parameters constant; material size effects were probed by varying the tube wall thickness, t, from 200nm to 635nm, at a constant relative density and grain size. In-situ uniaxial compression experiments reveal an order-of-magnitude increase in yield stress and modulus in nanolattices with greater lattice angles, and a 150% increase in the yield strength without a concomitant change in modulus in thicker-walled nanolattices for fixed lattice angles. These results imply that independent control of structural and material size effects enables tunability of mechanical properties of 3-dimensional architected meta-materials and highlight the importance of material, geometric, and microstructural effects in small-scale mechanics. This work also explores the flaw tolerance of 3D hollow-tube alumina kagome nanolattices with and without pre-fabricated notches, both in experiment and simulation

  3. Modal analysis of graphene-based structures for large deformations, contact and material nonlinearities

    Science.gov (United States)

    Ghaffari, Reza; Sauer, Roger A.

    2018-06-01

    The nonlinear frequencies of pre-stressed graphene-based structures, such as flat graphene sheets and carbon nanotubes, are calculated. These structures are modeled with a nonlinear hyperelastic shell model. The model is calibrated with quantum mechanics data and is valid for high strains. Analytical solutions of the natural frequencies of various plates are obtained for the Canham bending model by assuming infinitesimal strains. These solutions are used for the verification of the numerical results. The performance of the model is illustrated by means of several examples. Modal analysis is performed for square plates under pure dilatation or uniaxial stretch, circular plates under pure dilatation or under the effects of an adhesive substrate, and carbon nanotubes under uniaxial compression or stretch. The adhesive substrate is modeled with van der Waals interaction (based on the Lennard-Jones potential) and a coarse grained contact model. It is shown that the analytical natural frequencies underestimate the real ones, and this should be considered in the design of devices based on graphene structures.

  4. Structure-phase transformations in 36NXTYu highly deformed alloy during aging

    International Nuclear Information System (INIS)

    Plotnikov, S.V.; Radashin, M.V.; Alontseva, D.L.

    2001-01-01

    The 36NXTYu alloy - containing 35.39% Ni, 12.43% Cr, 3.08% Ti, 1.22% Al, 0.93% Mn, 0.36% Si, 0.09% Cu , 0.03% C, 0.12% P, 0.09% S and the rest iron - has been examined. Under aging beginning in the alloy the Ni 3 (Al,Yi) type metastable γ'-phase release of with L12 structure is taking place, and then the stable η-phase (Ni 3 Ti, DO 24 ) is occurring. The thin foils structure and micro-diffraction analysis were observed with help of the electron microscope. Fractography has been watched on the scanning electron microscope. For study both phase content and samples texture the DRON-3 diffractometer was applied. The mechanical testing include one-axis static expansion with measurement of a strength limit, conventional fluidity limit, relational extension up to sample breakage. It is shown, that rolling deep levels in the 36NXTYu alloy, in the common case, do not change the structure-phase transformation morphology, but instead of γ'-phase the η-phase is discretely releasing

  5. A novel approach to modeling plate deformations in fluid–structure interactions

    Energy Technology Data Exchange (ETDEWEB)

    Howard, T.K., E-mail: howartre@onid.oregonstate.edu [Oregon State University, Department of Nuclear Engineering & Radiation Health Physics, 116 Radiation Center, Corvallis, OR 97331 (United States); Marcum, W.R., E-mail: marcumw@engr.orst.edu [Oregon State University, Department of Nuclear Engineering & Radiation Health Physics, 116 Radiation Center, Corvallis, OR 97331 (United States); Jones, W.F. [Idaho National Laboratory, Nuclear Fuels & Materials Department, 2525 Fremont Ave., Idaho Falls, ID 83415 (United States)

    2015-11-15

    Highlights: • A new method for computing fluid structure interactions of flat plates is presented herein. • The method is validated through consideration of a single plate subject to hydraulic loading. • The model is compared against solution forms computed via ABAQUS and experimental data. • The model compares well against experimental data and the commercial computational code. - Abstract: As computational power increases, so does the desire to use computational simulations while designing fuel plates. The downside is multi-physics simulations – or more specifically, fluid–structure interactions (FSI) as addressed herein – require a larger amount of computational resources. Current simulations of a single plate can take weeks on a desktop computer, thus requiring the use of multiple servers or a cluster for FSI simulations. While computational fluid dynamic (CFD) codes coupled to computational structural mechanics (CSM) codes can provide a wealth of information regarding flow patterns, there should be some skepticism in whether or not they are the only means of achieving the desired solution. When the parameters of interest are the onset of plate collapse and the associated fluid channel velocities, coupled CFD–CSM simulations provide superfluous information. The paper provides an alternative approach to solving FSI problems using a 1-D, semi-analytical model derived from first principles. The results are compared and contrasted to the numerical and experimental work performed by Kennedy et al. (2014. Experimental Investigation of Deflection of Flat Aluminium Plates Under Variable Velocity Parallel Flow, Columbia: University of Missouri TherMec Research Group).

  6. A novel approach to modeling plate deformations in fluid–structure interactions

    International Nuclear Information System (INIS)

    Howard, T.K.; Marcum, W.R.; Jones, W.F.

    2015-01-01

    Highlights: • A new method for computing fluid structure interactions of flat plates is presented herein. • The method is validated through consideration of a single plate subject to hydraulic loading. • The model is compared against solution forms computed via ABAQUS and experimental data. • The model compares well against experimental data and the commercial computational code. - Abstract: As computational power increases, so does the desire to use computational simulations while designing fuel plates. The downside is multi-physics simulations – or more specifically, fluid–structure interactions (FSI) as addressed herein – require a larger amount of computational resources. Current simulations of a single plate can take weeks on a desktop computer, thus requiring the use of multiple servers or a cluster for FSI simulations. While computational fluid dynamic (CFD) codes coupled to computational structural mechanics (CSM) codes can provide a wealth of information regarding flow patterns, there should be some skepticism in whether or not they are the only means of achieving the desired solution. When the parameters of interest are the onset of plate collapse and the associated fluid channel velocities, coupled CFD–CSM simulations provide superfluous information. The paper provides an alternative approach to solving FSI problems using a 1-D, semi-analytical model derived from first principles. The results are compared and contrasted to the numerical and experimental work performed by Kennedy et al. (2014. Experimental Investigation of Deflection of Flat Aluminium Plates Under Variable Velocity Parallel Flow, Columbia: University of Missouri TherMec Research Group).

  7. Large-Deformation Curling Actuators Based on Carbon Nanotube Composite: Advanced-Structure Design and Biomimetic Application.

    Science.gov (United States)

    Chen, Luzhuo; Weng, Mingcen; Zhou, Zhiwei; Zhou, Yi; Zhang, Lingling; Li, Jiaxin; Huang, Zhigao; Zhang, Wei; Liu, Changhong; Fan, Shoushan

    2015-12-22

    In recent years, electroactive polymers have been developed as actuator materials. As an important branch of electroactive polymers, electrothermal actuators (ETAs) demonstrate potential applications in the fields of artificial muscles, biomimetic devices, robotics, and so on. Large-shape deformation, low-voltage-driven actuation, and ultrafast fabrication are critical to the development of ETA. However, a simultaneous optimization of all of these advantages has not been realized yet. Practical biomimetic applications are also rare. In this work, we introduce an ultrafast approach to fabricate a curling actuator based on a newly designed carbon nanotube and polymer composite, which completely realizes all of the above required advantages. The actuator shows an ultralarge curling actuation with a curvature greater than 1.0 cm(-1) and bending angle larger than 360°, even curling into a tubular structure. The driving voltage is down to a low voltage of 5 V. The remarkable actuation is attributed not only to the mismatch in the coefficients of thermal expansion but also to the mechanical property changes of materials during temperature change. We also construct an S-shape actuator to show the possibility of building advanced-structure actuators. A weightlifting walking robot is further designed that exhibits a fast-moving motion while lifting a sample heavier than itself, demonstrating promising biomimetic applications.

  8. Optically induced lattice deformations, electronic structure changes, and enhanced superconductivity in YBa2Cu3O6.48

    Directory of Open Access Journals (Sweden)

    R. Mankowsky

    2017-07-01

    Full Text Available Resonant optical excitation of apical oxygen vibrational modes in the normal state of underdoped YBa2Cu3O6+x induces a transient state with optical properties similar to those of the equilibrium superconducting state. Amongst these, a divergent imaginary conductivity and a plasma edge are transiently observed in the photo-stimulated state. Femtosecond hard x-ray diffraction experiments have been used in the past to identify the transient crystal structure in this non-equilibrium state. Here, we start from these crystallographic features and theoretically predict the corresponding electronic rearrangements that accompany these structural deformations. Using density functional theory, we predict enhanced hole-doping of the CuO2 planes. The empty chain Cu dy2-z2 orbital is calculated to strongly reduce in energy, which would increase c-axis transport and potentially enhance the interlayer Josephson coupling as observed in the THz-frequency response. From these results, we calculate changes in the soft x-ray absorption spectra at the Cu L-edge. Femtosecond x-ray pulses from a free electron laser are used to probe changes in absorption at two photon energies along this spectrum and provide data consistent with these predictions.

  9. Serviceability limit state related to excessive lateral deformations to account for infill walls in the structural model

    Directory of Open Access Journals (Sweden)

    G. M. S. ALVA

    Full Text Available Brazilian Codes NBR 6118 and NBR 15575 provide practical values for interstory drift limits applied to conventional modeling in order to prevent negative effects in masonry infill walls caused by excessive lateral deformability, however these codes do not account for infill walls in the structural model. The inclusion of infill walls in the proposed model allows for a quantitative evaluation of structural stresses in these walls and an assessment of cracking in these elements (sliding shear diagonal tension and diagonal compression cracking. This paper presents the results of simulations of single-story one-bay infilled R/C frames. The main objective is to show how to check the serviceability limit states under lateral loads when the infill walls are included in the modeling. The results of numerical simulations allowed for an evaluation of stresses and the probable cracking pattern in infill walls. The results also allowed an identification of some advantages and limitations of the NBR 6118 practical procedure based on interstory drift limits.

  10. Crustal Structure and Deformation of the Sichuan-Yunnan Region Revealed by receiver Function Data

    Science.gov (United States)

    Zeng, S.; Zheng, Y.

    2017-12-01

    Sichuan-Yunnan and its surrounding areas locates in the southeast side to the Tibetan Plateau, due to the intrusion of the Indian Plate under the Tibetan Plateau, materials escape from the Tibetan Plateau and flow southward to southeastward. Because of such tectonic environment, the Sichuan-Yunnan region is experiencing high tectonic movement, and is capable of highly diffused seismicity. Based on dynamic simulation and field survey investigations, tectonic and geological studies proposed a decoupling model in this region and lower crustal flow may inflate in the crust. However, this idea needs more evidences, especially anisotropic structures to support it, since the anisotropic structures are usually directly related to the movement of materials, or to the tectonic distributions. In the past several years, a number of works have been done on the anisotropic structures in the Tibetan Plateau and its surroundings. In usually, previous studies were mainly carried out by two kinds of methods. First, the shear wave splitting of SKS, which mainly reflects the accumulation effect of the anisotropy of the crust to the mantle; the other way is use surface wave to investigate the anisotropic features at different azimuths and depths. In the recent years, receiver function is used to determine the inclination and anisotropy of the subsurface structure, comparing with the other two methods, receiver functions can provide higher resolution and reliable anisotropic features in the crust. Following the method of Liu and Niu(2012), we collected teleseismic data from the Himalayan first term network, and picked out high quality data based on the waveform SNR ratio, as well as the azimuthal distributions. Comparing with previous work (e.g., Sun et al.,2012), our work can provide more receiver functions results with higher reliability. We find that the crust beneath the Sichuan-Yunnan region has a thickness of 30-60 km and Vp/Vs ratio of 1.70-1.80. The Moho depth from northwest to

  11. Spatial organization of plastic deformation in single crystals with different structure of slip dislocation

    Energy Technology Data Exchange (ETDEWEB)

    Kunitsyna, T. S.; Teplyakova, L. A., E-mail: lat168@mail.ru; Koneva, N. A. [Tomsk State University of Architecture and Building, Tomsk, 634003 (Russian Federation); Poltaranin, M. A. [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2015-10-27

    It is established that different structure of slip dislocation at the end of the linear hardening stage results in different distribution of dislocation charges in the volume of a single crystal. In the alloy with a near atomic order the slip of single dislocations leads to formation of planar structures—layers with the excess density of dislocations. In the alloy with long-range atomic order the slip of superdislocations brings the formation of the system of parallel rod-like charged dislocation linking.

  12. Seismically-induced soft-sediment deformation structures associated with the Magallanes-Fagnano Fault System (Isla Grande de Tierra del Fuego, Argentina)

    Science.gov (United States)

    Onorato, M. Romina; Perucca, Laura; Coronato, Andrea; Rabassa, Jorge; López, Ramiro

    2016-10-01

    In this paper, evidence of paleoearthquake-induced soft-sediment deformation structures associated with the Magallanes-Fagnano Fault System in the Isla Grande de Tierra del Fuego, southern Argentina, has been identified. Well-preserved soft-sediment deformation structures were found in a Holocene sequence of the Udaeta pond. These structures were analyzed in terms of their geometrical characteristics, deformation mechanism, driving force system and possible trigger agent. They were also grouped in different morphological types: sand dykes, convolute lamination, load structures and faulted soft-sediment deformation features. Udaeta, a small pond in Argentina Tierra del Fuego, is considered a Quaternary pull-apart basin related to the Magallanes-Fagnano Fault System. The recognition of these seismically-induced features is an essential tool for paleoseismic studies. Since the three main urban centers in the Tierra del Fuego province of Argentina (Ushuaia, Río Grande and Tolhuin) have undergone an explosive growth in recent years, the results of this study will hopefully contribute to future analyses of the seismic risk of the region.

  13. Types of soft-sediment deformation structures in a lacustrine Ploužnice member (Stephanian, Gzhelian, Pennsylvanian, Bohemian Massif), their timing, and possible trigger mechanism

    Czech Academy of Sciences Publication Activity Database

    Stárková, M.; Martínek, K.; Mikuláš, Radek; Rosenau, N.

    2015-01-01

    Roč. 104, č. 5 (2015), s. 1277-1298 ISSN 1437-3254 Institutional support: RVO:67985831 Keywords : soft-sediment deformation structures * bioturbation * early diagenetic carbonate * lacustrine facies * Bohemian Massif * Stephanian C * Krkonoše Piedmont Basin Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.133, year: 2015

  14. Low energy dislocation structures due to unidirectional deformation at low temperatures

    DEFF Research Database (Denmark)

    Hansen, Niels; Kuhlmann-Wilsdorf, D.

    1986-01-01

    The line energy of dislocations is {Gb2f(v)/4π} 1n(R/b) with R range of the dislocation stress field from the axis. This equation implies that quasi-uniform distributions are unstable relative to dislocation clusters in which neighboring dislocations mutually screen their stress fields, correspon......The line energy of dislocations is {Gb2f(v)/4π} 1n(R/b) with R range of the dislocation stress field from the axis. This equation implies that quasi-uniform distributions are unstable relative to dislocation clusters in which neighboring dislocations mutually screen their stress fields......, correspondingly leaving the major fraction of the volume free of dislocations. The value of R decreases in the following order: pile-ups to dipolar mats, Taylor lattices, tilt and dipolar walls to dislocation cell structures. This is the same order in which dislocation structures tend to develop with increasing...... dislocation density and hence increased dislocation interactions, leading to the corresponding energy decrease per unit length of dislocation line. Taking into consideration also the longer-range “termination stresses” of finite dislocation boundaries, and minimizing the total energy, explains the size...

  15. Deformation and structure evolution of glassy poly(lactic acid) below the glass transition temperature

    DEFF Research Database (Denmark)

    Zhou, Chengbo; Li, Hongfei; Zhang, Yao

    2015-01-01

    , the onset of the mesocrystal formation is delayed to a higher strain value, whereas corresponding to the same critical orientation degree of amorphous chains (f(am) approximate to 0.45). The DSC results indicated that the post-T-g endothermic peak corresponding to the melting of mesocrystal appears...... and shifts to a higher temperature with increasing stretching temperature, followed by the down-shifts (to a lower temperature) of the exothermic peak of cold crystallization of PLA. The appearance of a small exothermic peak just before the melting peak related to the transition of the alpha' to alpha...... crystal implies the formation of an alpha' crystal during cold crystallization in the drawn PLA samples. The structure evolution of glassy PLA stretched below T-g was discussed in details....

  16. Effect of microstructure on the elasto-viscoplastic deformation of dual phase titanium structures

    Science.gov (United States)

    Ozturk, Tugce; Rollett, Anthony D.

    2018-02-01

    The present study is devoted to the creation of a process-structure-property database for dual phase titanium alloys, through a synthetic microstructure generation method and a mesh-free fast Fourier transform based micromechanical model that operates on a discretized image of the microstructure. A sensitivity analysis is performed as a precursor to determine the statistically representative volume element size for creating 3D synthetic microstructures based on additively manufactured Ti-6Al-4V characteristics, which are further modified to expand the database for features of interest, e.g., lath thickness. Sets of titanium hardening parameters are extracted from literature, and The relative effect of the chosen microstructural features is quantified through comparisons of average and local field distributions.

  17. Crystallite size effect on the monoclinic deformation of the bcc crystal structure of chromium

    Science.gov (United States)

    Przeniosło, R.; Fabrykiewicz, P.; Sosnowska, I.; Wardecki, D.; Sławiński, W. A.; Playford, H. Y.; Hempelmann, R.; Bukowski, M.

    2018-02-01

    The modulated spin density wave magnetic orderings observed in chromium suggests that the crystal structure of chromium cannot be described by the cubic space group Im 3 bar m. Our experimental studies of polycrystalline and nanocrystalline chromium by synchrotron radiation (SR) and neutron powder diffraction show a hkl-dependent Bragg peak broadening which can be interpreted by the low-symmetry monoclinic space group P21 / n instead of the high symmetry cubic space group Im 3 bar m. The monoclinic angle is βm = 90.05(1)° and 90.29(1)° for polycrystalline Cr and nanocrystalline Cr, respectively. The relative monoclinic distortion observed in chromium is 5 times larger than those reported for several oxides: BiFeO3, α-Fe2O3, Cr2O3 and calcite. The symmetry of the magnetic transverse spin density wave (TSDW) and the longitudinal spin density wave (LSDW) observed in Cr are described by using the superspace groups P21 / n(0 β 0) 00 and P 21‧ /n‧(0 β 0) 00, respectively. These superspace groups describe both the magnetic modulations and the atomic position modulations reported in the literature. The monoclinic symmetry of chromium is a robust effect which is observed in the paramagnetic as well as in the TSDW and LSDW phases.

  18. Deformation structure of water atomised and extruded Cu-Cr-Zr alloys

    International Nuclear Information System (INIS)

    Correia, J.B.; Davies, H.A.; Sellars, C.M.

    1994-01-01

    Copper alloy powders containing Cr and/or Zr were produced via water atomisation and consolidated by extrusion. The crystallographic orientations relative to the extrusion axis, both in the as-extruded condition and after heat treatment were assessed by an inverse pole figure texture determination method using X-ray diffraction. Transmission electron microscopy (TEM) was also used for microstructural observations. The as-extruded materials showed a clear double fibre texture ( left angle 111 right angle + left angle 100 right angle ), the left angle 111 right angle component being the stronger. After isochronal 1 hour heat treatments in the temperature range 400-700 C, a clear trend of a decreasing left angle 111 right angle component with increasing temperatures was seen. For the highest heat treatment temperature used (700 C), the alloys approached a random crystallographic distribution. The microstructure of the as-extruded material showed a banded structure with sharp boundaries parallel to the extrusion direction. Also, the left angle 111 right angle or left angle 100 right angle directions were generally parallel to the extrusion direction. TEM observation of longitudinal sections after exposure to increasingly high temperature, notably above 500 C, indicated that boundaries started to lose their sharpness and to spread sideways. When the same materials were observed in transverse sections, the competitive growth of some subgrains was clearly seen. (orig.)

  19. Crustal Structure of Active Deformation Zones in Africa: Implications for Global Crustal Processes

    Science.gov (United States)

    Ebinger, C. J.; Keir, D.; Bastow, I. D.; Whaler, K.; Hammond, J. O. S.; Ayele, A.; Miller, M. S.; Tiberi, C.; Hautot, S.

    2017-12-01

    The Cenozoic East African rift (EAR), Cameroon Volcanic Line (CVL), and Atlas Mountains formed on the slow-moving African continent, which last experienced orogeny during the Pan-African. We synthesize primarily geophysical data to evaluate the role of magmatism in shaping Africa's crust. In young magmatic rift zones, melt and volatiles migrate from the asthenosphere to gas-rich magma reservoirs at the Moho, altering crustal composition and reducing strength. Within the southernmost Eastern rift, the crust comprises 20% new magmatic material ponded in the lower crust and intruded as sills and dikes at shallower depths. In the Main Ethiopian Rift, intrusions comprise 30% of the crust below axial zones of dike-dominated extension. In the incipient rupture zones of the Afar rift, magma intrusions fed from crustal magma chambers beneath segment centers create new columns of mafic crust, as along slow-spreading ridges. Our comparisons suggest that transitional crust, including seaward dipping sequences, is created as progressively smaller screens of continental crust are heated and weakened by magma intrusion into 15-20 km thick crust. In the 30 Ma Recent CVL, which lacks a hot spot age progression, extensional forces are small, inhibiting the creation and rise of magma into the crust. In the Atlas orogen, localized magmatism follows the strike of the Atlas Mountains from the Canary Islands hot spot toward the Alboran Sea. CVL and Atlas magmatism has had minimal impact on crustal structure. Our syntheses show that magma and volatiles are migrating from the asthenosphere through the plates, modifying rheology, and contributing significantly to global carbon and water fluxes.

  20. Ionic conductivity, structural deformation, and programmable anisotropy of DNA origami in electric field.

    Science.gov (United States)

    Li, Chen-Yu; Hemmig, Elisa A; Kong, Jinglin; Yoo, Jejoong; Hernández-Ainsa, Silvia; Keyser, Ulrich F; Aksimentiev, Aleksei

    2015-02-24

    The DNA origami technique can enable functionalization of inorganic structures for single-molecule electric current recordings. Experiments have shown that several layers of DNA molecules, a DNA origami plate, placed on top of a solid-state nanopore is permeable to ions. Here, we report a comprehensive characterization of the ionic conductivity of DNA origami plates by means of all-atom molecular dynamics (MD) simulations and nanocapillary electric current recordings. Using the MD method, we characterize the ionic conductivity of several origami constructs, revealing the local distribution of ions, the distribution of the electrostatic potential and contribution of different molecular species to the current. The simulations determine the dependence of the ionic conductivity on the applied voltage, the number of DNA layers, the nucleotide content and the lattice type of the plates. We demonstrate that increasing the concentration of Mg(2+) ions makes the origami plates more compact, reducing their conductivity. The conductance of a DNA origami plate on top of a solid-state nanopore is determined by the two competing effects: bending of the DNA origami plate that reduces the current and separation of the DNA origami layers that increases the current. The latter is produced by the electro-osmotic flow and is reversible at the time scale of a hundred nanoseconds. The conductance of a DNA origami object is found to depend on its orientation, reaching maximum when the electric field aligns with the direction of the DNA helices. Our work demonstrates feasibility of programming the electrical properties of a self-assembled nanoscale object using DNA.

  1. Protein structural deformation induced lifetime shortening of photosynthetic bacteria light-harvesting complex LH2 excited state.

    Science.gov (United States)

    Chen, Xing-Hai; Zhang, Lei; Weng, Yu-Xiang; Du, Lu-Chao; Ye, Man-Ping; Yang, Guo-Zhen; Fujii, Ritsuko; Rondonuwu, Ferdy S; Koyama, Yasushi; Wu, Yi-Shi; Zhang, J P

    2005-06-01

    Photosynthetic bacterial light-harvesting antenna complex LH2 was immobilized on the surface of TiO(2) nanoparticles in the colloidal solution. The LH2/TiO(2) assembly was investigated by the time-resolved spectroscopic methods. The excited-state lifetimes for carotenoid-containing and carotenoidless LH2 have been measured, showing a decrease in the excited-state lifetime of B850 when LH2 was immobilized on TiO(2). The possibility that the decrease of the LH2 excited-state lifetime being caused by an interfacial electron transfer reaction between B850 and the TiO(2) nanoparticle was precluded experimentally. We proposed that the observed change in the photophysical properties of LH2 when assembled onto TiO(2) nanoparticles is arising from the interfacial-interaction-induced structural deformation of the LH2 complex deviating from an ellipse of less eccentric to a more eccentric ellipse, and the observed phenomenon can be accounted by an elliptical exciton model. Experiment by using photoinactive SiO(2) nanoparticle in place of TiO(2) and core complex LH1 instead of LH2 provide further evidence to the proposed mechanism.

  2. Structurally Deformed MoS2 for Electrochemically Stable, Thermally Resistant, and Highly Efficient Hydrogen Evolution Reaction

    KAUST Repository

    Chen, Yen-Chang; Lu, Ang-Yu; Lu, Ping; Yang, Xiulin; Jiang, Chang-Ming; Mariano, Marina; Kaehr, Brian; Lin, Oliver; Taylor, André ; Sharp, Ian D.; Li, Lain-Jong; Chou, Stanley S.; Tung, Vincent

    2017-01-01

    The emerging molybdenum disulfide (MoS2) offers intriguing possibilities for realizing a transformative new catalyst for driving the hydrogen evolution reaction (HER). However, the trade-off between catalytic activity and long-term stability represents a formidable challenge and has not been extensively addressed. This study reports that metastable and temperature-sensitive chemically exfoliated MoS2 (ce-MoS2) can be made into electrochemically stable (5000 cycles), and thermally robust (300 °C) while maintaining synthetic scalability and excellent catalytic activity through physical-transformation into 3D structurally deformed nanostructures. The dimensional transition enabled by a high throughput electrohydrodynamic process provides highly accessible, and electrochemically active surface area and facilitates efficient transport across various interfaces. Meanwhile, the hierarchically strained morphology is found to improve electronic coupling between active sites and current collecting substrates without the need for selective engineering the electronically heterogeneous interfaces. Specifically, the synergistic combination of high strain load stemmed from capillarity-induced-self-crumpling and sulfur (S) vacancies intrinsic to chemical exfoliation enables simultaneous modulation of active site density and intrinsic HER activity regardless of continuous operation or elevated temperature. These results provide new insights into how catalytic activity, electrochemical-, and thermal stability can be concurrently enhanced through the physical transformation that is reminiscent of nature, in which properties of biological materials emerge from evolved dimensional transitions.

  3. Structurally Deformed MoS2 for Electrochemically Stable, Thermally Resistant, and Highly Efficient Hydrogen Evolution Reaction

    KAUST Repository

    Chen, Yen-Chang

    2017-10-12

    The emerging molybdenum disulfide (MoS2) offers intriguing possibilities for realizing a transformative new catalyst for driving the hydrogen evolution reaction (HER). However, the trade-off between catalytic activity and long-term stability represents a formidable challenge and has not been extensively addressed. This study reports that metastable and temperature-sensitive chemically exfoliated MoS2 (ce-MoS2) can be made into electrochemically stable (5000 cycles), and thermally robust (300 °C) while maintaining synthetic scalability and excellent catalytic activity through physical-transformation into 3D structurally deformed nanostructures. The dimensional transition enabled by a high throughput electrohydrodynamic process provides highly accessible, and electrochemically active surface area and facilitates efficient transport across various interfaces. Meanwhile, the hierarchically strained morphology is found to improve electronic coupling between active sites and current collecting substrates without the need for selective engineering the electronically heterogeneous interfaces. Specifically, the synergistic combination of high strain load stemmed from capillarity-induced-self-crumpling and sulfur (S) vacancies intrinsic to chemical exfoliation enables simultaneous modulation of active site density and intrinsic HER activity regardless of continuous operation or elevated temperature. These results provide new insights into how catalytic activity, electrochemical-, and thermal stability can be concurrently enhanced through the physical transformation that is reminiscent of nature, in which properties of biological materials emerge from evolved dimensional transitions.

  4. Structural and K/Ar Illite geochronological constraints on the brittle deformation history of the Olkiluoto Region, Southwest Finland

    International Nuclear Information System (INIS)

    Viola, G.; Zwingmann, H.; Todd, A.; Raven, M.

    2011-07-01

    This study has generated a new conceptual scheme for the > 1.5 Gyr long brittle evolution of southwestern Finland and the Olkiluoto Island. Based on the study of a number of chosen outcrops containing key structural relationships and the analysis of almost two thousands striated fault planes, seven robust paleo stress tensors have been defined. By comparing and contrasting them with known paleostates of stress derived from southeast Sweden and by using absolute and relative geochronological criteria, it was possible to assign them to a number of specific tectonic events that have affected southwest Finland. Uniaxial compression of late Svecofennian age with a regional NNWSSE σ 1 axis was active soon after 1.75 Ga ago, when environmental conditions leading to brittle deformation were first attained in the region. A younger paleostress field with a NE-SW σ 1 axis, transpressive in character, is inferred to have been active soon after and to have caused significant reactivation of some of the structures formed during the first shortening event. A phase of ESE-WNW extension is constrained by a number of stress tensors and direct field evidence and is here tentatively assigned to the Gothian event and the time of rapakivi magmatism. Further NE-SW extension is taken as the last increment of crustal extension in southwestern Finland and is interpreted as having accommodated upper crustal stretching and the formation and infill of the NWSE- elongated Satakunta graben between 1.6 and 1.3 Ga. A significant and wellconstrained phase of c. NE-SW shortening post dated the rapakivi granites as well as the abundant c. 1260 Ma olivine diabase sills in southwestern Finland. A shortening direction of similar age is not described elsewhere in Fennoscandia. We propose that this phase might be the expression of an hitherto unreported phase of compression that caused inversion of the Satakunta graben. Later E-W compression is assigned to the early stages of the Mesoproterozoic

  5. Plastic deformation

    NARCIS (Netherlands)

    Sitter, de L.U.

    1937-01-01

    § 1. Plastic deformation of solid matter under high confining pressures has been insufficiently studied. Jeffreys 1) devotes a few paragraphs to deformation of solid matter as a preface to his chapter on the isostasy problem. He distinguishes two properties of solid matter with regard to its

  6. Towards the determination of deformation rates - pinch-and-swell structures as a natural and simulated paleo-strain rate gage

    Science.gov (United States)

    Peters, Max; Poulet, Thomas; Karrech, Ali; Regenauer-Lieb, Klaus; Herwegh, Marco

    2014-05-01

    Layered rocks deformed under viscous deformation conditions frequently show boudinage, a phenomenon that results from differences in effective viscosity between the involved layers. In the case of continuous necking of a mechanically stiffer layer embedded in a weaker matrix, symmetric boudins are interpreted as the result of dominant visco-plastic deformation (Goscombe et al., 2004). However, information on the physical conditions, material properties and deformation processes are yet unknown. Natural samples deformed under low-grade (TAustin and Evans (2007) combined with the thermodynamic approach of Regenauer-Lieb and Yuen (2004). Depending on the dissipated energy, grain sizes in these domains vary substantially in space and time. While low strain rates (low stresses) in the swells favor grain growth and GSI dominated deformation, high strain rates in the pinches provoke dramatic grain size reduction with an increasing contribution of GSS as a function of decreasing grain size. The development of symmetric necks observed in nature thus seems to coincide with the transition from dislocation to diffusion creep dominated flow with continuous grain size reduction and growth from swell to neck at relatively high extensional strains. REFERENCES Austin, N. and Evans, B. (2007). Paleowattmeters: A scaling relation for dynamically recrystallized grain size. Geology, 35. Goscombe, B.D., Passchier, C.W. and Hand, M. (2004). Boudinage classification: End-member boudin types and modified boudin structures, Journal of Structural Geology, 26. Herwegh, M., Poulet, T., Karrech, A. and Regenauer-Lieb, K. (in press). From transient to steady state deformation and grain size: A thermodynamic approach using elasto-visco-plastic numerical modeling. Journal of Geophysical Research. Karrech, A., Regenauer-Lieb, K. and Poulet, T. (2011a). A Damaged visco-plasticity model for pressure and temperature sensitive geomaterials. Journal of Engineering Science 49. Regenauer-Lieb, K. and Yuen

  7. Influence of grain structure on the deformation mechanism in martensitic shear reversion-induced Fe-16Cr-10Ni model austenitic alloy with low interstitial content: Coarse-grained versus nano-grained/ultrafine-grained structure

    Energy Technology Data Exchange (ETDEWEB)

    Challa, V.S.A. [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials Engineering, and Biomedical Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Misra, R.D.K., E-mail: dmisra2@utep.edu [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials Engineering, and Biomedical Engineering, University of Texas at El Paso, El Paso, TX 79968 (United States); Somani, M.C. [Center for Advanced Steels Research, The University of Oulu, P.O. Box 4200, 90014 Oulu (Finland); Wang, Z.D. [State Key Laboratory for Rolling and Automation, Northeastern University, 3-11 Wenhua Road, Shenyang 110819 (China)

    2016-04-20

    Nanograined/ultrafine-grained (NG/UFG) materials characterized by high strength-high ductility combination are excellent vehicles to obtain an unambiguous understanding of deformation mechanisms vis-à-vis their coarse-grained counterparts. In this context, the innovative concept of phase reversion-induced NG/UFG structure enabled achieving high strength besides comparable ductility, for instance, in metastable austenitic stainless steels. In the phase reversion process, severe deformation of austenite at room temperature (typically ~60–80%) transforms face-centered cubic austenite (γ) to body centered cubic martensite (α′). Upon annealing, martensite reverts to austenite leading to extensive grain refinement. The objective of the present study to fundamentally understand the deformation mechanisms in NG/UFG structure in relation to that of the coarse-grained (CG) structure was accomplished by combining depth-sensing nanoscale experiments on an Fe-16Cr-10Ni model austenitic alloy conducted at different strain rates, followed by the study of structural evolution in the deformed zone using transmission electron microscopy (TEM). In the high strength NG/UFG steel (YS~585 MPa), stacking faults and nanotwins contributed to the enhanced ductility (El~35%), while in the case of low strength (YS~260 MPa) coarse-grained (CG) counterpart, ductility was also high (El~40%), but chiefly due to strain-induced martensite, which points to a clear case of grain size effect (and the corresponding level of strength). The distinct change in the deformation mechanism from stacking faults and twinning-induced plasticity (TWIP) in the NG structure to transformation-induced plasticity (TRIP) in the CG structure is elucidated in terms of austenite stability-strain energy relationship. The insights on the relationship between grain structure (and strength) and deformation mechanisms are envisaged to be important in providing a new direction for the futuristic design of high strength

  8. Eocene to Miocene Out-of-Sequence Deformation in the Eastern Tibetan Plateau: Insights From Shortening Structures in the Sichuan Basin

    Science.gov (United States)

    Tian, Yuntao; Kohn, Barry P.; Qiu, Nansheng; Yuan, Yusong; Hu, Shengbiao; Gleadow, Andrew J. W.; Zhang, Peizhen

    2018-02-01

    A distinctive NNE trending belt of shortening structures dominates the topography and deformation of the eastern Sichuan Basin, 300 km east of the Tibetan Plateau. Debate continues as to whether the structures resulted from Cenozoic eastward growth of the Tibetan Plateau. A low-temperature thermochronology (AFT and AHe) data set from four deep boreholes and adjacent outcrops intersecting a branch of the shortening structures indicates distinctive differential cooling at 35-28 Ma across the structure, where stratigraphy has been offset vertically by 0.8-1.3 km. This result forms the first quantitative evidence for the existence of a late Eocene-Oligocene phase of shortening in the eastern Sichuan Basin, synchronous with the early phase of eastward growth and extrusion of the Tibetan Plateau. Further, a compilation of regional Cenozoic structures reveals a Miocene retreat of deformation from the foreland basin to the hinterland areas. Such a tectonic reorganization indicates that Eocene to Miocene deformation in the eastern Tibetan Plateau is out-of-sequence and was probably triggered by enhanced erosion in the eastern Tibetan Plateau.

  9. Using Fourier and Taylor series expansion in semi-analytical deformation analysis of thick-walled isotropic and wound composite structures

    Directory of Open Access Journals (Sweden)

    Jiran L.

    2016-06-01

    Full Text Available Thick-walled tubes made from isotropic and anisotropic materials are subjected to an internal pressure while the semi-analytical method is employed to investigate their elastic deformations. The contribution and novelty of this method is that it works universally for different loads, different boundary conditions, and different geometry of analyzed structures. Moreover, even when composite material is considered, the method requires no simplistic assumptions. The method uses a curvilinear tensor calculus and it works with the analytical expression of the total potential energy while the unknown displacement functions are approximated by using appropriate series expansion. Fourier and Taylor series expansion are involved into analysis in which they are tested and compared. The main potential of the proposed method is in analyses of wound composite structures when a simple description of the geometry is made in a curvilinear coordinate system while material properties are described in their inherent Cartesian coordinate system. Validations of the introduced semi-analytical method are performed by comparing results with those obtained from three-dimensional finite element analysis (FEA. Calculations with Fourier series expansion show noticeable disagreement with results from the finite element model because Fourier series expansion is not able to capture the course of radial deformation. Therefore, it can be used only for rough estimations of a shape after deformation. On the other hand, the semi-analytical method with Fourier Taylor series expansion works very well for both types of material. Its predictions of deformations are reliable and widely exploitable.

  10. Influence of preliminary deformation on structure and properties of Fe-Ni-V-C alloy after reverse α → γ transformation

    International Nuclear Information System (INIS)

    Izotov, V.I.; Kozlov, A.P.

    1979-01-01

    Using transmission electron microscopy, the Fe-25 Ni-1.5 V-0.3 C alloy structure was investigated after the γ → α → γ transformation and the effect of the preliminary deformation upon it in the range from 16 to 33% at the temperature of +200 and -196 deg C. Characteristic of nondeformed specimens is the lath morphology of the reverse austenite. Deformation prior to the α → γ transformation is conducive to the appearance of areas of fine-grained austenite With a low density of dislocations, probably forming through a partial recrystallization of the lath austenite. It was found that the reverse austenite inherits the misorientation zones which are a structure particularity of slippage-deformed (259) martensite crystals (7). The maximum strength of the alloy after the α → γ transformation is achieved through a preliminary deformation at-196 deg C leading to a decrease in the amount of austenite that failed to undergo the γ → α → γ transformation

  11. Structure and tectonic evolution of the southwestern Trinidad dome, Escambray complex, Central Cuba: Insights into deformation in an accretionary wedge

    Science.gov (United States)

    Despaigne-Díaz, Ana Ibis; García Casco, Antonio; Cáceres Govea, Dámaso; Wilde, Simon A.; Millán Trujillo, Guillermo

    2017-10-01

    The Trinidad dome, Escambray complex, Cuba, forms part of an accretionary wedge built during intra-oceanic subduction in the Caribbean from the Late Cretaceous to Cenozoic. The structure reflects syn-subduction exhumation during thickening of the wedge, followed by extension. Field mapping, metamorphic and structural analysis constrain the tectonic evolution into five stages. Three ductile deformation events (D1, D2 and D3) are related to metamorphism in a compressional setting and formation of several nappes. D1 subduction fabrics are only preserved as relict S1 foliation and rootless isoclinal folds strongly overprinted by the main S2 foliation. The S2 foliation is parallel to sheared serpentinised lenses that define tectonic contacts, suggesting thrust stacks and underthrusting at mantle depths. Thrusting caused an inverted metamorphic structure with higher-grade on top of lower-grade nappes. Exhumation started during D2 when the units were incorporated into the growing accretionary wedge along NNE-directed thrust faults and was accompanied by substantial decompression and cooling. Folding and thrusting continued during D3 and marks the transition from ductile to brittle-ductile conditions at shallower crustal levels. The D4-5 events are related to extension and contributed to the final exhumation (likely as a core complex). D4 is associated with a regional spaced S4 cleavage, late open folds, and numerous extension veins, whereas D5 is recorded by normal and strike-slip faults affecting all nappes. The P-t path shows rapid exhumation during D2 and slower rates during D3 when the units were progressively incorporated into the accretionary prism. The domal shape formed in response to tectonic denudation assisted by normal faulting and erosion at the surface during the final stages of structural development. These results support tectonic models of SW subduction of the Proto-Caribbean crust under the Caribbean plate during the latest Cretaceous and provide

  12. Structural petrology of undeformed and experimentally deformed halite samples from USERDA site No. 7 and No. 9

    International Nuclear Information System (INIS)

    Callender, J.; Ingwell, T.

    1977-01-01

    Preliminary data from USERDA test holes No. 7 and No. 9 in the Salado Formation of southeastern New Mexico are presented. Cores consist primarily of halite (> 80 modal percent), clay, polyhalite, anhydrite, celestite, iron oxide, and magnesite. Macroscopic features of undeformed core include moderately tight grain boundaries, large cavities (less than or equal to 8 mm 2 ), fluid inclusions, rare intragranular dislocations, and coarse and bimodal textures. Petrographic examination reveals numerous secondary fluid inclusions of variable size, blebby halite and transected hopper crystals, all of which suggest mobility and recrystallization of the primary evaporite assemblages. Deformed core shows a complex group of fabric elements, including tight grain boundaries, intercrystalline lattice rotation, cavity deformation and closure, distortion of hopper crystals, polygonization, irregular lattice dislocations, glide dislocations, and climb dislocations. Grain boundaries become tight or locked with deformation, forming pinned and bulged grains. Intercrystalline lattice rotation causes grains to rotate as much as 17 0 to develop preferred orientation. Polygonization yields fabrics analogous to prophyroclasts in cataclastic rocks. Irregular dislocations are relatively abundant. Glide dislocations are also abundant in many deformed specimens. Individual mineral components within deformed halite also exhibit deformational fabrics. Folded layers of clay and anhydrite, and bent and broken single crystals of anhydrite are present in some samples. Secondary fluid inclusions apparently migrate in response to differential stress and form along dislocations in halite, healing the dislocations by secondary crystallization and forming discontinuous or completely healed dislocation fabrics. 67 figures, 9 tables

  13. q-deformed Minkowski space

    International Nuclear Information System (INIS)

    Ogievetsky, O.; Pillin, M.; Schmidke, W.B.; Wess, J.; Zumino, B.

    1993-01-01

    In this lecture I discuss the algebraic structure of a q-deformed four-vector space. It serves as a good example of quantizing Minkowski space. To give a physical interpretation of such a quantized Minkowski space we construct the Hilbert space representation and find that the relevant time and space operators have a discrete spectrum. Thus the q-deformed Minkowski space has a lattice structure. Nevertheless this lattice structure is compatible with the operation of q-deformed Lorentz transformations. The generators of the q-deformed Lorentz group can be represented as linear operators in the same Hilbert space. (orig.)

  14. Effect of basement structure and salt tectonics on deformation styles along strike: An example from the Kuqa fold-thrust belt, West China

    Science.gov (United States)

    Neng, Yuan; Xie, Huiwen; Yin, Hongwei; Li, Yong; Wang, Wei

    2018-04-01

    The Kuqa fold-thrust belt (KFTB) has a complex thrust-system geometry and comprises basement-involved thrusts, décollement thrusts, triangle zones, strike-slip faults, transpressional faults, and pop-up structures. These structures, combined with the effects of Paleogene salt tectonics and Paleozoic basement uplift form a complex structural zone trending E-W. Interpretation and comprehensive analysis of recent high-quality seismic data, field observations, boreholes, and gravity data covering the KFTB has been performed to understand the characteristics and mechanisms of the deformation styles along strike. Regional sections, fold-thrust system maps of the surface and the sub-salt layer, salt and basement structure distribution maps have been created, and a comprehensive analysis of thrust systems performed. The results indicate that the thrust-fold system in Paleogene salt range can be divided into five segments from east to west: the Kela-3, Keshen, Dabei, Bozi, and Awate segments. In the easternmost and westernmost parts of the Paleogene salt range, strike-slip faulting and basement-involved thrusting are the dominant deformation styles, as basement uplift and the limits of the Cenozoic evaporite deposit are the main controls on deformation. Salt-core detachment fold-thrust systems coincide with areas of salt tectonics, and pop-up, imbricate, and duplex structures are associated with the main thrust faults in the sub-salt layer. Distribution maps of thrust systems, basement structures, and salt tectonics show that Paleozoic basement uplift controlled the Paleozoic foreland basin morphology and the distribution of Cenozoic salt in the KFTB, and thus had a strong influence on the segmented structural deformation and evolution of the fold-thrust belt. Three types of transfer zone are identified, based on the characteristics of the salt layer and basement uplift, and the effects of these zones on the fault systems are evaluated. Basement uplift and the boundary of

  15. Associative and Lie deformations of Poisson algebras

    OpenAIRE

    Remm, Elisabeth

    2011-01-01

    Considering a Poisson algebra as a non associative algebra satisfying the Markl-Remm identity, we study deformations of Poisson algebras as deformations of this non associative algebra. This gives a natural interpretation of deformations which preserves the underlying associative structure and we study deformations which preserve the underlying Lie algebra.

  16. Is nucleon deformed?

    International Nuclear Information System (INIS)

    Abbas, Afsar

    1992-01-01

    The surprising answer to this question Is nucleon deformed? is : Yes. The evidence comes from a study of the quark model of the single nucleon and when it is found in a nucleus. It turns out that many of the long standing problems of the Naive Quark Model are taken care of if the nucleon is assumed to be deformed. Only one value of the parameter P D ∼1/4 (which specifies deformation) fits g A (the axial vector coupling constant) for all the semileptonic decay of baryons, the F/D ratio, the pion-nucleon-delta coupling constant fsub(πNΔ), the double delta coupling constant 1 fsub(πΔΔ), the Ml transition moment μΔN and g 1 p the spin structure function of proton 2 . All this gives strong hint that both neutron and proton are deformed. It is important to look for further signatures of this deformation. When this deformed nucleon finds itself in a nuclear medium its deformation decreases. So much that in a heavy nucleus the nucleons are actually spherical. We look into the Gamow-Teller strengths, magnetic moments and magnetic transition strengths in nuclei to study this property. (author). 15 refs

  17. A probabilistic approach using deformable organ models for automatic definition of normal anatomical structures for 3D treatment planning

    International Nuclear Information System (INIS)

    Fritsch, Daniel; Yu Liyun; Johnson, Valen; McAuliffe, Matthew; Pizer, Stephen; Chaney, Edward

    1996-01-01

    Purpose/Objective : Current clinical methods for defining normal anatomical structures on tomographic images are time consuming and subject to intra- and inter-user variability. With the widespread implementation of 3D RTP, conformal radiotherapy, and dose escalation the implications of imprecise object definition have assumed a much higher level of importance. Object definition and volume-weighted metrics for normal anatomy, such as DVHs and NTCPs, play critical roles in aiming, shaping, and weighting beams. Improvements in object definition, including computer automation, are essential to yield reliable volume-weighted metrics and gains in human efficiency. The purpose of this study was to investigate a probabilistic approach using deformable models to automatically recognize and extract normal anatomy in tomographic images. Materials and Methods: Object models were created from normal organs that were segmented by an interactive method which involved placing a cursor near the center of the object on a slice and clicking a mouse button to initiate computation of structures called cores. Cores describe the skeletal and boundary shape of image objects in a manner that, in 2D, associates a location on the skeleton with the width of the object at that location. A significant advantage of cores is stability against image disturbances such as noise and blur. The model was composed of a relatively small set of extracted points on the skeleton and boundary. The points were carefully chosen to summarize the shape information captured by the cores. Neighborhood relationships between points were represented mathematically by energy functions that penalize, due to warping of the model, the ''goodness'' of match between the model and the image data at any stage during the segmentation process. The model was matched against the image data using a probabilistic approach based on Bayes theorem, which provides a means for computing a posteriori (posterior) probability from 1) a

  18. The Long-term deformation of the Longmen Shan (Sichuan, China), a key to understand the present structure of the eastern Tibet

    Science.gov (United States)

    Airaghi, Laura; de Sigoyer, Julia; Guillot, Stéphane; Lanari, Pierre; Warren, Clare J.; Robert, Alexandra

    2017-04-01

    The Longmen Shan thrust belt, at the eastern border of Tibetan plateau, is a tectonically active region as demonstrated by the Mw 7.9 Wenchuan (2008) and Mw 6.6 Lushan (2013) earthquakes. The Moho discontinuity deepens across the Longmen Shan (below the along-strike Wenchuan fault) from ˜40 km beneath the Sichuan basin to more than 60 km beneath the Songpan-Ganze block. Such a thickness is not compatible with the only ˜35 km of shortening estimated at the front of the belt during the Cenozoic-Quaternary compressive reactivation. The geological inheritance may thus play a key role in the present structure of the Longmen Shan. However the long-term history of the belt is still poorly documented. The major Wenchuan fault separates medium-grade metamorphic rocks to the West (internal domain of the Longmen Shan) to the greenschist metamorphic rocks to the East (external domain). In the hanging and footwall of the fault the South China basement also crops out. Metamorphic rocks, exhumed from depth, offer the opportunity to investigate the deep processes occurred in the Longmen Shan. We have characterized and dated the metamorphism in the central part of the belt by combining structural and microstructural observations with high-resolution X-ray mapping and chemical analyses of metamorphic minerals related to the different stages of deformation. In situ 40Ar/39Ar dating on mica and in situ U-Pb/Th dating on allanite (REE-rich epidote) allowed the different phases of metamorphism and deformation to be dated. Our results show that the Longmen Shan underwent a complex Mesozoic tectono-metamorphic history, articulated in a succession of pulses of deformation (burial or uplifting) and periods of quiescence. A first phase of rapid thin-skinned deformation occurred about 200 Ma ago. Internal sedimentary units were strongly deformed and buried down to 11±1 kbar, 550±30˚ C. This phase was followed by a period of slow exhumation between 200 and 170 Ma. A second pulse of

  19. Analysis of soft-sediment deformation structures in Neogene fluvio-lacustrine deposits of Çaybağı Formation, Eastern Turkey

    Science.gov (United States)

    Koç Taşgin, Calibe; Türkmen, İbrahim

    2009-06-01

    During the Neogene, both strike-slip and extensional regimes coexisted in eastern Turkey and, a number of fault-bounded basins associated with the East Anatolian Fault System developed. The Çaybağı Formation (Late Miocene-Early Pliocene) deposited in one of these basins consists of fluvio-lacustrine deposits. Numerous soft-sediment deformation structures are encountered in this formation, particularly in conglomerates, medium- to coarse-grained tuffaceous sandstones and claystones: folded structures (slumps, convolute laminations, and simple recumbent folds), water-escape structures (intruded sands, internal cusps, interpenetrative cusps and sand volcanoes), and load structures (load casts, pseudonodules, flame structures, and pillow structures). These structures are produced by liquefaction and/or fluidization of the unconsolidated sediments during a seismic shock. Consequently, the existence of seismically-induced deformation structures in the Çaybağı Formation and the association with a Neogene intraformational unconformity, growth faults, and reverse faults in the Çaybağı basin attest to the tectonic activity in this area during the Late Miocene and Early Pliocene. The East Anatolian Fault System, in particular the Uluova fault zone, is the most probable seismogenic source. Earthquakes with a magnitude of over 5 in the Richter scale can be postulated.

  20. Correlation of substructure with mechanical properties of plastically deformed reactor structural materials. Progress report, January 1, 1974--December 31, 1975

    International Nuclear Information System (INIS)

    Moteff, J.

    1976-01-01

    Ratio of the subgrain boundary dislocations to those contributing to creep deformation was found to be independent of applied stress and creep strain after the steady-state creep stage is reached. The observed cell or subgrain sizes are correlated with flow stress in Type 304 ss, and the deformation rate-stress relation obeys the equation epsilon =β lambda 3 (sigma/sub T//E)/sub n/ exp (-Q/sub c//RT), where lambda = subgrain size, sigma/sub T/ = effective true stress, E = Young modulus, and Q/sub c/ = 85 kcal/mole. Well-developed subgrains were observed in TEM on 304 ss tested in creep at 704 0 C. Role of twin boundary-grain boundary intersections in microcracking behavior of 304 ss deformed in slow tension and creep at 650 0 C was investigated. Grain shape analysis show that intragranular deformation becomes more predominant in the grains with the larger intercept distances, and that grain boundary sliding becomes important as the strain rate decreases. RT mechanical properties of austenitic ss are enhanced by subgrains formed during high-temperature deformation. The substructural development during high-temperature low-cycle fatigue of 304 ss was studied using TEM. Fatigue properties of Incoloy 800 tested in bend and push-pull modes are being compared. Effects of hold time on fatigue substructure and fracture of 304 ss are being studied. 31 figures, 53 references

  1. Lithological history and ductile deformation: the lessons for long-term stability of large-scales structures in the olkiluoto

    International Nuclear Information System (INIS)

    Wikstrom, L.; Aaltonen, I.; Mattila, J.

    2009-01-01

    The Olkiluoto site has been chosen as a repository site for the high-level nuclear waste in 2001. Investigations in the site have been ongoing since 1987. The basic idea in the crystalline nuclear waste site still is that the solid repository block surrounded by deformation zones can host a safe repository. It is impossible to say that neither the major ductile nor large-scale brittle deformation zones are stable, but it is possible to say that the tectonic processes have been active in a stable way for billions of years by reactivating the old features time after time and there are no signs of new large features formed in the vicinity of the site during the present time including post-glacial period. Understanding the geological history, especially the ductile deformation and over thrusting, begins from the understanding of the lithological features, mainly rock types, in the island. Vice versa, the occurrence and location of the lithological features are interpreted according to ductile deformation. In addition, you cannot study only present brittle deformation but you need to understand also older ductile and lithological features to be able to understand why these brittle features are where they are and to be able to predict them. (authors)

  2. Structure and magnetic properties of hot deformed Nd2Fe14B magnets doped with DyHx nanoparticles

    Science.gov (United States)

    Wang, C. G.; Yue, M.; Zhang, D. T.; Liu, W. Q.; Zhang, J. X.

    2016-04-01

    Commercial NdFeB powders mixed with DyHx nanoparticles are hot pressed and hot deformed into anisotropic magnets by Spark Plasma Sintering (SPS). The hot deformed magnet exhibits strong c-axis crystallographic texture. The coercivity of the magnet doped with 1.0 wt% DyHx is increased by 66.7%, compared with the magnet without DyHx, while the remanence decreases only by 3%. TEM observation shows that there exists a continuous (Nd,Dy)2Fe14B layer between Nd-rich phase and NdFeB main phase.

  3. Structure and Deformation in the Transpressive Zone of Southern California Inferred from Seismicity, Velocity, and Qp Models

    Science.gov (United States)

    Hauksson, E.; Shearer, P.

    2004-12-01

    We synthesize relocated regional seismicity and 3D velocity and Qp models to infer structure and deformation in the transpressive zone of southern California. These models provide a comprehensive synthesis of the tectonic fabric of the upper to middle crust, and the brittle ductile transition zone that in some cases extends into the lower crust. The regional seismicity patterns in southern California are brought into focus when the hypocenters are relocated using the double difference method. In detail, often the spatial correlation between background seismicity and late Quaternary faults is improved as the hypocenters become more clustered, and the spatial patterns are more sharply defined. Along some of the strike-slip faults the seismicity clusters decrease in width and form alignments implying that in many cases the clusters are associated with a single fault. In contrast, the Los Angeles Basin seismicity remains mostly scattered, reflecting a 3D distribution of the tectonic compression. We present the results of relocating 327,000 southern California earthquakes that occurred between 1984 and 2002. In particular, the depth distribution is improved and less affected by layer boundaries in velocity models or other similar artifacts, and thus improves the definition of the brittle ductile transition zone. The 3D VP and VP/VS models confirm existing tectonic interpretations and provide new insights into the configuration of the geological structures in southern California. The models extend from the US-Mexico border in the south to the Coast Ranges and Sierra Nevada in the north, and have 15 km horizontal grid spacing and an average vertical grid spacing of 4 km, down to 22 km depth. The heterogeneity of the crustal structure as imaged in both the VP and VP/VS models is larger within the Pacific than the North America plate, reflecting regional asymmetric variations in the crustal composition and past tectonic processes. Similarly, the relocated seismicity is

  4. Cenozoic structural evolution of the southwestern Bükk Mts. and the southern part of the Darnó Deformation Belt (NE Hungary

    Directory of Open Access Journals (Sweden)

    Petrik Attila

    2016-02-01

    Full Text Available Extensive structural field observations and seismic interpretation allowed us to delineate 7 deformation phases in the study area for the Cenozoic period. Phase D1 indicates NW–SE compression and perpendicular extension in the Late Oligocene–early Eggenburgian and it was responsible for the development of a wedge-shaped Paleogene sequence in front of north-westward propagating blind reverse faults. D2 is represented by E–W compression and perpendicular extension in the middle Eggenburgian–early Ottnangian. The D1 and D2 phases resulted in the erosion of Paleogene suites on elevated highs. Phase D2 was followed by a counterclockwise rotation, described in earlier publications. When considering the age of sediments deformed by the syn-sedimentary D3 deformation and preliminary geochronological ages of deformed volcanites the time of the first CCW rotation can be shifted slightly younger (~17–16.5 Ma than previously thought (18.5–17.5 Ma. Another consequence of our new timing is that the extrusional tectonics of the ALCAPA unit, the D2 local phase, could also terminate somewhat later by 1 Myr. D4 shows NE–SW extension in the late Karpatian–Early Badenian creating NW–SE trending normal faults which connected the major NNE–SSW trending sinistral faults. The D5 and D6 phases are late syn-rift deformations indicating E–W extension and NW–SE extension, respectively. D5 indicates syn-sedimentary deformation in the Middle Badenian–early Sarmatian and caused the synsedimentary thickening of mid-Miocene suites along NNE–SSW trending transtensional faults. D5 postdates the second CCW rotation which can be bracketed between ~16–15 Ma. This timing is somewhat older than previously considered and is based on new geochronological dates of pyroclastite rocks which were not deformed by this phase. D6 was responsible for further deepening of half-grabens during the Sarmatian. D7 is post-tilt NNW–SSE extension and induced the

  5. Syndepositional tectonics recorded by soft-sediment deformation and liquefaction structures (continental Lower Permian sediments, Southern Alps, Northern Italy): Stratigraphic significance

    Science.gov (United States)

    Berra, F.; Felletti, F.

    2011-04-01

    The Lower Permian succession of the Central Southern Alps (Lombardy, Northern Italy) was deposited in fault-controlled continental basins, probably related to transtensional tectonics. We focussed our study on the stratigraphic record of the Lower Permian Orobic Basin, which consists of a 1000 m thick succession of prevailing continental clastics with intercalations of ignimbritic flows and tuffs (Pizzo del Diavolo Formation, PDV) resting on the underlying prevailing pyroclastic flows of the Cabianca Volcanite. The PDV consists of a lower part (composed of conglomerates passing laterally to sandstones and distally to silt and shales), a middle part (pelitic, with carbonates) and an upper part (alternating sandstone, silt and volcanic flows). Syndepositional tectonics during the deposition of the PDV is recorded by facies distribution, thickness changes and by the presence of deformation and liquefaction structures interpreted as seismites. Deformation is recorded by both ductile structures (ball-and-pillow, plastic intrusion, disturbed lamination, convolute stratification and slumps) and brittle structures (sand dykes and autoclastic breccias). Both the sedimentological features and the geodynamic setting of the depositional basin confidently support the interpretation of the described deformation features as related to seismic shocks. The most significant seismically-induced deformation is represented by a slumped horizon (about 4 m thick on average) which can be followed laterally for more than 5 km. The slumped bed consists of playa-lake deposits (alternating pelites and microbial carbonates, associated with mud cracks and vertebrate tracks). The lateral continuity and the evidence of deposition on a very low-angle surface along with the deformation/liquefaction of the sediments suggest that the slump was triggered by a high-magnitude earthquake. The stratigraphic distribution of the seismites allows us to identify time intervals of intense seismic activity

  6. Soft-sediment deformation in New Zealand: Structures resulting from the 2010/11 Christchurch earthquakes and comparison with Pleistocene sediments of the Taupo Volcanic Zone (TVZ)

    Science.gov (United States)

    Scholz, C.; Downs, D. T.; Gravley, D.; Quigley, M.; Rowland, J. V.

    2011-12-01

    The distinction between seismites and other event-related soft-sediment deformation is a challenging problem. Recognition and interpretation is aided by comparison of recent examples produced during known seismic events and those generated experimentally. Seismites are important features, once recognized in a rock, for interpretations of paleotectonic environment, tectonic relationships of sediments in basins, sedimentary facies analysis, evaluation of earthquake frequency and hazard and consequent land managment. Two examples of soft-sediment deformation, potentially generated through ground shaking and associated liquefaction, are described from within the TVZ: 1) Near Matata on the western margin of the Whakatane Graben. This location has a complicated en-echelon fault history and large earthquakes occur from time to time (e.g., 1987 ML6.3 Edgecumbe event). The structures occur in ~550 ka volcanic sediments, and represent soft-sediment deformation within stratigraphically-bounded layers. Based on paleoenvironment, appearance, and diagnostic criteria described by other authors (Sims 1975; Hempton and Dewey 1983), we interpret these features to have formed by ground shaking related to an earthquake and/or possibly accompanying large volcanic eruptions, rather than by slope failure. 2) Near Taupo, 3 km from the active Kaiapo fault. Lakeward dipping, nearly horizontal lacustrine sediments overlay Taupo Ignimbrite (1.8 ka). At one outcrop the lake beds have subsided into the underlying substrate resulting in kidney-shaped features. These structures formed as a result of liquefaction of the underlying substrate, which may have been caused by ground shaking related to either seismic or volcanic activity. However, inferred time relationships are more consistent with seismic-induced ground shaking. We compare and contrast the form and geometry of the above structures with seismites generated during the recent Christchurch earthquakes (Sep. 2010 and Feb. 2011). Hempton, M

  7. Parameter Identification of Piecewise Linear Plasticity Metal Models Used in Numerical Modeling of Structures Under Plastic Deformation and Failure

    Directory of Open Access Journals (Sweden)

    A. V. Shmeliov

    2016-01-01

    Full Text Available The article describes the models of metallic materials used in the calculation of deformation and destruction of engineering structures. The reliability of material models can adequately assess the strength characteristics of the designs of new technology in its designing and certification.The article deals with contingencies and true mechanical properties of materials and presents equations of their relationship. It notes that in the software systems mechanical characteristics of materials are given in the true sense.The paper considers the linear and exponential models of materials, their characteristics, and methods to implement them. It considers the models of Johnson-Cook Steinberg-Guinan, Zerilli-Armstrong, Cowper-Symonds, Gurson-Tvergaard that take into account the strain rate and temperature of the material. Describes their applications, advantages and disadvantages. Considers single- and multi-parameter criteria of materials fracture, the prospects for their use. Gives a rational justification for using a piecewise linear plasticity material model *MAT_PIECEWISE_LINEAR_PLASTICITY (024, LS-DYNA software package for the engineering industry, and presents its main parameters.A technique to identify parameters of piecewise linear plasticity metal material models has been developed. The technique consists of the stages, based on the equations of transition from the conventional stress and strain values to the true ones. Taking into consideration the stressstrain state in the neck of the sample is a distinctive feature of the technique.Tensile tests of the round material samples have been conducted. To test the developed technique in the software package ANSYS LS-DYNA PC have been made tensile sample modeling and results comparison to show high convergence.Further improvement of the technique can be achieved through the development of a statistical approach to the analysis of the results of a series of tests. This will allow a kind of

  8. A multi-electrode and pre-deformed bilayer spring structure electrostatic attractive MEMS actuator with large stroke at low actuation voltage

    International Nuclear Information System (INIS)

    Hu, Fangrong; Li, Zhi; Xiong, Xianming; Niu, Junhao; Peng, Zhiyong; Qian, Yixian; Yao, Jun

    2012-01-01

    This paper presents a multi-electrode and pre-deformed bilayer spring structure electrostatic attractive microelectromechanical systems (MEMS) actuator; it has large stroke at relatively low actuation voltage. Generally, electrostatic-attractive-force-based actuators have small stroke due to the instability resulted from the electrostatic ‘pull-in’ phenomenon. However, in many applications, the electrostatic micro-actuator with large stroke at low voltage is more preferred. By introducing a multi-electrode and a pre-deformed bilayer spring structure, an electrostatic attractive MEMS actuator with large stroke at very low actuation voltage has been successfully demonstrated in this paper. The actuator contains a central plate with a size of 300 µm × 300 µm × 1.5 µm and it is supported by four L-shaped bilayer springs which are pre-deformed due to residual stresses. Each bilayer spring is simultaneously attracted by three adjacent fixed electrodes, and the factors affecting the electrostatic attractive force are analyzed by a finite element analysis method. The prototype of the actuator is fabricated by poly-multi-user-MEMS-process (PolyMUMP) and the static performance is tested using a white light interferometer. The measured stroke of the actuator reaches 2 µm at 13 V dc, and it shows a good agreement with the simulation. (paper)

  9. Investigation of deformation of elements of three-dimensional reinforced concrete structures located in the soil, interacting with each other through rubber gaskets

    Science.gov (United States)

    Berezhnoi, D. V.; Balafendieva, I. S.; Sachenkov, A. A.; Sekaeva, L. R.

    2017-06-01

    In work the technique of calculation of elements of three-dimensional reinforced concrete substructures located in a soil, interacting with each other through rubber linings is realized. To describe the interaction of deformable structures with the ground, special “semi-infinite” finite elements are used. A technique has been implemented that allows one to describe the contact interaction of three-dimensional structures by means of a special contact finite element with specific properties. The obtained numerical results are compared with the experimental data, their good agreement is noted.

  10. STRUCTURE OF THE LITHOSPHERE AND SEISMOTECTONIC DEFORMATIONS IN CONTACT ZONE OF LITHOSPHERIC PLATES IN THE SUMATRA ISLAND REGION

    Directory of Open Access Journals (Sweden)

    O. A. Kuchay

    2015-01-01

    Full Text Available The inversion seismic tomography algorithm (ITS was used to calculate 3D seismic anomalies models for velocities of P- and S-waves in the zone of the Sunda arc, Indonesia. In the area under study, strong earthquakes (M>4.8 are clustered in the zone of high P-wave velocities. Earthquake hypocenters are located in zones of both high and low velocity anomalies of S-waves. The giant Sumatra earthquake (December 26, 2004, Mw=9.0 ruptured the greatest fault length of any recorded earthquake, and the rupture started in the area wherein the sign of P-wave velo­city anomalies is abruptly changed. We calculated seismotectonic deformations (STD from data on mechanisms of 2227 earthquakes recorded from 1977 to 2013, and our calculations show that the STD component, that controls vertical extension of rocks, is most stable through all the depth levels. In the marginal regions at the western and eastern sides of the Sunda arc, the crustal areas (depths from 0 to 35 km are subject to deformations which sign is opposite to that of deformations in the central part. Besides, at depths from 70 to 150 km beneath the Sumatra earthquake epicentre area, the zone is subject to deformations which sign is opposite to that of deformations in the studied part of the Sunda arc. For earthquakes that may occur in the crust in the Sunda arc in the contact zone of the plates, maximum magnitudes depend on the direction of pressure imposed by the actively subducting plate, which is an additional criteria for determining the limit magnitude for the region under study. 

  11. Soft sediment deformation structures in a lacustrine sedimentary succession induced by volcano-tectonic activities: An example from the Cretaceous Beolgeumri Formation, Wido Volcanics, Korea

    Science.gov (United States)

    Ko, Kyoungtae; Kim, Sung Won; Lee, Hong-Jin; Hwang, In Gul; Kim, Bok Chul; Kee, Won-Seo; Kim, Young-Seog; Gihm, Yong Sik

    2017-08-01

    The Cretaceous Beolgeumri Formation is composed of laminated mudstones intercalated with sandstones, chert, and a bed of lapilli tuff that were deposited in a lacustrine environment at the terminal part of a regional strike-slip fault systems on the southwestern Korean Peninsula. The Beolgeumri Formation contains various types of soft sediment deformation (SSD) structures that are characterized by a wide extent (features and deformation styles: 1) fold structures, 2) load structures, 3) water-escape structures, 4) rip-down structures, 5) boudin structures, and 6) synsedimentary fault structures. Field examination of SSD structures together with an analysis of the sedimentological records of the Beolgeumri Formation indicate that the SSD structures formed largely by liquefaction and/or fluidization triggered by ground shaking during earthquakes. To constrain the timing of the development of SSD structures in the Beolgeumri Formation, we conducted sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon age dating of block sized lithic clasts bearing volcaniclastic deposits that conformably underlie (the Mangryeongbong Tuff) and overlie (the Ttandallae Tuff) the Beolgeumri Formation. The Mangryeongbong and Ttandallae Tuffs have ages of 86.63 ± 0.83 Ma and 87.24 ± 0.36 Ma, respectively, indicating that the Beolgeumri Formation was deposited during a short interval between major volcanic eruptions. The large lithic clasts of volcaniclastic deposits suggest that the Beolgeumri Formation was deposited adjacent to an active volcanic edifice(s). Syndepositional magmatic activities are suggested by the occurrence of a lapilli tuff bed in the Beolgeumri Formation and an igneous intrusion (intermediate sill) that is crosscut by a sand dike, as well as the similar age results of the underlying and overlying volcaniclastic deposits. Thus, we infer that the earthquakes that caused the development of SSD structures in the study area were closely related to syndepositional

  12. q-deformed Brownian motion

    CERN Document Server

    Man'ko, V I

    1993-01-01

    Brownian motion may be embedded in the Fock space of bosonic free field in one dimension.Extending this correspondence to a family of creation and annihilation operators satisfying a q-deformed algebra, the notion of q-deformation is carried from the algebra to the domain of stochastic processes.The properties of q-deformed Brownian motion, in particular its non-Gaussian nature and cumulant structure,are established.

  13. Effect of structural factors on mechanical properties of the magnesium alloy Ma2-1 under quasi-static and high strain rate deformation conditions

    Science.gov (United States)

    Garkushin, G. V.; Razorenov, S. V.; Krasnoveikin, V. A.; Kozulin, A. A.; Skripnyak, V. A.

    2015-02-01

    The elastic limit and tensile strength of deformed magnesium alloys Ma2-1 with different structures and textures were measured with the aim of finding a correlation between the spectrum of defects in the material and the resistance to deformation and fracture under quasi-static and dynamic loading conditions. The studies were performed using specimens in the as-received state after high-temperature annealing and specimens subjected to equal-channel angular pressing at a temperature of 250°C. The anisotropy of strength characteristics of the material after shock compression with respect to the direction of rolling of the original alloy was investigated. It was shown that, in contrast to the quasi-static loading conditions, under the shock wave loading conditions, the elastic limit and tensile strength of the magnesium alloy Ma2-1 after equal-channel angular pressing decrease as compared to the specimens in the as-received state.

  14. High-energy X-ray measurements of structural anisotropy and excess free volume in a homogenously deformed Zr-based metallic glass

    International Nuclear Information System (INIS)

    Ott, R.T.; Kramer, M.J.; Besser, M.F.; Sordelet, D.J.

    2006-01-01

    We have used high-energy X-ray scattering to measure the structural anisotropy and excess free volume in a homogeneously deformed Zr-based metallic glass alloy. The scattering results show that bond length anisotropy is present in the samples following isothermal tensile creep deformation. The average atomic bond length in the direction parallel to the tensile loading axis is larger than that in the direction normal to the loading axis. The magnitude of the bond length anisotropy is found to be dependent on the gradient of macroscopic plastic strain along the gauge length. Furthermore, the scattering results show that the excess free volume also increases with increasing macroscopic plastic strain. Results from differential scanning calorimetry analysis of free volume variations along the gauge length of the creep samples are consistent with results from the X-ray scattering experiments

  15. A one-parameter family of hamiltonian structures for the KP hierarchy and a continuous deformation of the nonlinear WKP algebra

    International Nuclear Information System (INIS)

    Figueroa-O'Farrill, J.M.; Mas, J.; Ramos, E.

    1993-01-01

    The KP hierarchy is hamiltonian relative to a one-parameter family of Poisson structures obtained from a generalized Adler map in the space of formal pseudodifferential symbols with noninteger powers. The resulting W-algebra is a one-parameter deformation of W KP admitting a central extension for generic values of the parameter, reducing naturally to W n for special values of the parameter, and contracting to the centrally extended W 1+∞ , W ∞ and further truncations. In the classical limit, all algebras in the one-parameter family are equivalent and isomorphic to W KP . The reduction induced by setting the spin-one field to zero yields a one-parameter deformation of W ∞ which contracts to a new nonlinear algebra of the W ∞ -type. (orig.)

  16. Soft-sediment deformation structures interpreted as seismites in the uppermost Aptian to lowermost Albian transgressive deposits of the Chihuahua basin (Mexico)

    Science.gov (United States)

    Blanc, E.J.-P.; Blanc-Aletru, M. -C.; Mojon, P.-O.

    1998-01-01

    Several levels of soft-sediment deformation structures (s.-s.d.s.) cut by synsedimentary normal faults have been observed in the transition beds between the "Las Vigas" and "La Virgen" formations (Cretaceous) in the northeastern part of the Chihuahua basin in Mexico. These structures consisted of four kinds of motifs (floating breccias, flame-like structures, large pillow structures, and wavy structures). They are restricted to five "stratigraphie" levels (Z1-Z5) and surrounded by undeformed beds in fluvio-lacustrine and tidal deposits and can be traced over a distance of several hundred meters. This deformation is interpreted to have resulted from the combined effects of liquidization and shear stress in soft-sediments due to local earthquakes in the area which could have been generated during the rifting stage of the Chihuahua basin. New constraints placed on the age of the "Las Vigas" Formation (bracketed by Late Aptian charophytes at the bottom and colomiellids of late Aptian to earliest Albian age at the top) suggest that this synrift tectonism lasted at least until the end of the Aptian. ?? Springer-Verlag 1998.

  17. On the formation of an ultrafine-duplex structure facilitated by severe shear deformation in a Ti–20Mo β-type titanium alloy

    International Nuclear Information System (INIS)

    Xu, W.; Wu, X.; Stoica, M.; Calin, M.; Kühn, U.; Eckert, J.; Xia, K.

    2012-01-01

    Severe plastic deformation in the form of equal channel angular pressing (ECAP) has been adopted to introduce severe shear strain into a Ti–20 wt.% Mo β-type titanium alloy to elucidate the aging response of the severely deformed β matrix. Upon isothermal aging in the (α + β) phase field, selective heterogeneous α nucleation and growth resulted in a mixed precipitation microstructure. An ultrafine-duplex (α + β) structure composed of equiaxed α precipitates formed inside the shear bands (SBs) created during ECAP, whereas acicular α precipitates were favoured outside the SBs. This distinct precipitation structure has been correlated to the structural characteristics of the SBs: high disorder with dislocation cells characteristic of low-angle boundaries and enhanced atomic diffusivity. The highly disordered structure results in a weak variant selection and thereby promotes randomly orientated α precipitation without obeying the Burgers orientation relationship. Furthermore, the enhanced atomic diffusivity facilitates rapid growth of the α nuclei to form the ultrafine-duplex (α + β) structure.

  18. Estimating 4D-CBCT from prior information and extremely limited angle projections using structural PCA and weighted free-form deformation for lung radiotherapy.

    Science.gov (United States)

    Harris, Wendy; Zhang, You; Yin, Fang-Fang; Ren, Lei

    2017-03-01

    To investigate the feasibility of using structural-based principal component analysis (PCA) motion-modeling and weighted free-form deformation to estimate on-board 4D-CBCT using prior information and extremely limited angle projections for potential 4D target verification of lung radiotherapy. A technique for lung 4D-CBCT reconstruction has been previously developed using a deformation field map (DFM)-based strategy. In the previous method, each phase of the 4D-CBCT was generated by deforming a prior CT volume. The DFM was solved by a motion model extracted by a global PCA and free-form deformation (GMM-FD) technique, using a data fidelity constraint and deformation energy minimization. In this study, a new structural PCA method was developed to build a structural motion model (SMM) by accounting for potential relative motion pattern changes between different anatomical structures from simulation to treatment. The motion model extracted from planning 4DCT was divided into two structures: tumor and body excluding tumor, and the parameters of both structures were optimized together. Weighted free-form deformation (WFD) was employed afterwards to introduce flexibility in adjusting the weightings of different structures in the data fidelity constraint based on clinical interests. XCAT (computerized patient model) simulation with a 30 mm diameter lesion was simulated with various anatomical and respiratory changes from planning 4D-CT to on-board volume to evaluate the method. The estimation accuracy was evaluated by the volume percent difference (VPD)/center-of-mass-shift (COMS) between lesions in the estimated and "ground-truth" on-board 4D-CBCT. Different on-board projection acquisition scenarios and projection noise levels were simulated to investigate their effects on the estimation accuracy. The method was also evaluated against three lung patients. The SMM-WFD method achieved substantially better accuracy than the GMM-FD method for CBCT estimation using extremely

  19. Deformation behaviour of turbine foundations

    International Nuclear Information System (INIS)

    Koch, W.; Klitzing, R.; Pietzonka, R.; Wehr, J.

    1979-01-01

    The effects of foundation deformation on alignment in turbine generator sets have gained significance with the transition to modern units at the limit of design possibilities. It is therefore necessary to obtain clarification about the remaining operational variations of turbine foundations. Static measurement programmes, which cover both deformation processes as well as individual conditions of deformation are described in the paper. In order to explain the deformations measured structural engineering model calculations are being undertaken which indicate the effect of limiting factors. (orig.) [de

  20. Fraktalnist deformational relief polycrystalline aluminum

    Directory of Open Access Journals (Sweden)

    М.В. Карускевич

    2006-02-01

    Full Text Available  The possibility of the fractal geometry method application for the analisys of surface deformation structures under cyclic loading is presented.It is shown, that deformation relief of the alclad aluminium alloyes meets the criteria of the fractality. For the fractal demention estimation the method of  “box-counting”can be applied.

  1. Structural Analysis of Shipping Casks, Vol. 9. Energy Absorption Capabilities of Plastically Deformed Struts Under Specified Impact Loading Conditions (Thesis)

    International Nuclear Information System (INIS)

    Davis, F.C.

    2001-01-01

    The purpose of this investigation was to determine the energy absorption characteristics of plastically deformed inclined struts under impact loading. This information is needed to provide a usable method by which designers and analysts of shipping casks for radioactive or fissile materials can determine the energy absorption capabilities of external longitudinal fins on cylindrical casks under specified impact conditions. A survey of technical literature related to experimental determination of the dynamic plastic behavior of struts revealed no information directly applicable to the immediate problem, especially in the impact velocity ranges desired, and an experimental program was conducted to obtain the needed data. Mild-steel struts with rectangular cross sections were impacted by free-falling weights dropped from known heights. These struts or fin specimens were inclined at five different angles to simulate different angles of impact that fins on a shipping cask could experience under certain accident conditions. The resisting force of the deforming strut was measured and recorded as a function of time by using load cells instrumented with resistance strain gage bridges, signal conditioning equipment, an oscilloscope, and a Polaroid camera. The acceleration of the impacting weight was measured and recorded as a function of time during the latter portion of the testing program by using an accelerometer attached to the drop hammer, appropriate signal conditioning equipment, the oscilloscope, and the camera. A digital computer program was prepared to numerically integrate the force-time and acceleration-time data recorded during the tests to obtain deformation-time data. The force-displacement relationships were then integrated to obtain values of absorbed energy with respect to deformation or time. The results for various fin specimen geometries and impact angles are presented graphically, and these curves may be used to compute the energy absorption capacity of

  2. Pyrite deformation and connections to gold mobility: Insight from micro-structural analysis and trace element mapping

    Science.gov (United States)

    Dubosq, R.; Lawley, C. J. M.; Rogowitz, A.; Schneider, D. A.; Jackson, S.

    2018-06-01

    The metamorphic transition of pyrite to pyrrhotite results in the liberation of lattice-bound and nano-particulate metals initially hosted within early sulphide minerals. This process forms the basis for the metamorphic-driven Au-upgrading model applied to many orogenic Au deposits, however the role of syn-metamorphic pyrite deformation in controlling the retention and release of Au and related pathfinder elements is poorly understood. The lower amphibolite facies metamorphic mineral assemblage (Act-Bt-Pl-Ep-Alm ± Cal ± Qz ± Ilm; 550 °C) of Canada's giant Detour Lake deposit falls within the range of pressure-temperature conditions (450 °C) for crystal plastic deformation of pyrite. We have applied a complementary approach of electron backscatter diffraction (EBSD) mapping and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) 2D element mapping on pyrite from the Detour Lake deposit. Chemical element maps document an early generation of Au-rich sieve textured pyrite domains and a later stage of syn-metamorphic oscillatory-zoned Au-poor pyrite. Both pyrite types are cut by Au-rich fractures as a consequence of remobilization of Au with trace element enrichment of first-row transition elements, post-transition metals, chalcogens and metalloids during a late brittle deformation stage. However, similar enrichment in trace elements and Au can be observed along low-angle grain boundaries within otherwise Au-poor pyrite, indicating that heterogeneous microstructural misorientation patterns and higher strain domains are also relatively Au-rich. We therefore propose that the close spatial relationship between pyrite and Au at the microscale, features typical of orogenic Au deposits, reflects the entrapment of Au within deformation-induced microstructures in pyrite rather than the release of Au during the metamorphic transition from pyrite to pyrrhotite. Moreover, mass balance calculations at the deposit scale suggest that only a small percentage

  3. Meso- and microscale structures related to post-magmatic deformation of the outer Izu-Bonin-Mariana fore arc system: preliminary results from IODP Expedition 352

    Science.gov (United States)

    Micheuz, P.; Kurz, W.; Ferre, E. C.

    2015-12-01

    IODP Expedition 352 aimed to drill through the entire volcanic sequence of the Bonin fore arc. Four sites were drilled, two on the outer fore arc and two on the upper trench slope. Analysis of structures within drill cores, combined with borehole and site survey seismic data, indicates that tectonic deformation in the outer Izu-Bonin-Mariana fore arc is mainly post-magmatic, associated with the development of syn-tectonic sedimentary basins. Within the magmatic basement, deformation was accommodated by shear along cataclastic fault zones, and the formation of tension fractures, hybrid (tension and shear) fractures, and shear fractures. Veins commonly form by mineral filling of tension or hybrid fractures and, generally, show no or limited observable macroscale displacement along the fracture plane. The vein filling generally consists of (Low Mg-) calcite and/or various types of zeolite as well as clay. Vein frequency varies with depth but does not seem to correlate with the proximity of faults. This may indicate that these veins are genetically related to hydrothermal activity taking place shortly after magma cooling. Host-rock fragments are commonly embedded within precipitated vein material pointing to a high fluid pressure. Vein thickness varies from < 1 mm up to 15 mm. The wider veins appear to have formed in incremental steps of extension. Calcite veins tend to be purely dilational at shallow depths, but gradually evolve towards oblique tensional veins at depth, as shown by the growth of stretched calcite and/or zeolites (idiomorphic and/or stretched) with respect to vein margins. With increasing depth, the calcite grains exhibit deformation microstructures more frequently than at shallower core intervals. These microstructures include thin twinning (type I twins), increasing in width with depth (type I and type II twins), curved twins, and subgrain boundaries indicative of incipient plastic deformation.

  4. Field Monitoring of Deformations and Internal Forces of Surrounding Rocks and Lining Structures in the Construction of the Gangkou Double-Arched Tunnel—A Case Study

    Directory of Open Access Journals (Sweden)

    Qixiang Yan

    2017-02-01

    Full Text Available Double-arched tunnel is a special and complex underground structure which needs to be monitored carefully during construction. Taking the Gangkou tunnel as the engineering background, this paper presents a case study of field monitoring of a representative double-arched tunnel. Typical cross sections were chosen in each class of surrounding rock masses in the tunnel area and different types of sensors were embedded in designed locations, and the deformations and forces of both surrounding rocks and lining structures were monitored systematically. The dynamic evolution as well as the spatial distribution characteristics of the monitoring data including the internal displacements of surrounding rocks and the contact pressures between surrounding rocks and primary linings, the axial forces in rock bolts and the internal forces in both steel arches and secondary linings were analyzed. The monitoring and analysis results show that the deformations and forces of both surrounding rocks and lining structures are directly related to the construction procedures, geological conditions and locations in the double-arched tunnel. According to the results, some reasonable suggestions were provided for the improvement of the tunnel construction. This study will provide useful reference and guidance for the design, construction and monitoring of similar engineering projects in future.

  5. Neoproterozoic Evolution and Najd‒Related Transpressive Shear Deformations Along Nugrus Shear Zone, South Eastern Desert, Egypt (Implications from Field‒Structural Data and AMS‒Technique)

    Science.gov (United States)

    Hagag, W.; Moustafa, R.; Hamimi, Z.

    2018-01-01

    The tectonometamorphic evolution of Nugrus Shear Zone (NSZ) in the south Eastern Desert of Egypt was reevaluated through an integrated study including field-structural work and magnetofabric analysis using Anisotropy of Magnetic Susceptibility (AMS) technique, complemented by detailed microstructural investigation. Several lines of evidence indicate that the Neoproterozoic juvenile crust within this high strain zone suffered an impressive tectonic event of left-lateral transpressional regime, transposed the majority of the earlier formed structures into a NNW to NW-directed wrench corridor depicts the northwestern extension of the Najd Shear System (NSS) along the Eastern Desert of Egypt. The core of the southern Hafafit dome underwent a high metamorphic event ( M 1) developed during the end of the main collisional orogeny in the Arabian-Nubian Shield (ANS). The subsequent M 2 metamorphic event was retrogressive and depicts the tectonic evolution and exhumation of the Nugrus-Hafafit area including the Hafafit gneissic domes, during the origination of the left-lateral transpressive wrench corridor of the NSS. The early tectonic fabric within the NSZ and associated highly deformed rocks was successfully detected by the integration of AMS-technique and microstructural observations. Such fabric grain was checked through a field-structural work. The outcomes of the present contribution advocate a complex tectonic evolution with successive and overlapped deformation events for the NSZ.

  6. Observation of states beyond band termination in 156,157,158Er and strongly deformed structures in 173,174,175Hf

    International Nuclear Information System (INIS)

    Riley, M A; Djongolov, M K; Evans, A O

    2006-01-01

    High-spin terminating bands in heavy nuclei were first identified in nuclei around 158 Er 90 . While examples of terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work, the high-spin structure of 156,157,158 Er has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently four strongly or superdeformed (SD) sequences have been observed in 174 Hf, and cranking calculations using the Ultimate Cranker code predict that such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment took place to search for linking transitions between the SD bands, possible wobbling modes, and new SD band structures

  7. Progressive deformation of ultramafic rocks accompanied with deflection of layered structure and mylonitization culminating into a pseudotachylyte-bearing seismogenic fault - a field evidence of plastic instability

    Science.gov (United States)

    Ueda, T.; Obata, M.

    2011-12-01

    Plastic instability leading to rupture nucleation and propagetion (e.g. Hobbs et al.1986, Kelemen and Hirth, 2007) is an attractive hypothesis for deep earthquakes but lacked clear field evidences. 1D across-fault shear localization observed in some places (e.g. Jin et al.1998) is not clear if the deformation is directly related with seismicity. We present a clear field evidence of plastic instability as guided by pyroxenite/peridotite layering deflection structure (hereafter called LD structure, see figure) accompanied with mylonitization in spinel(Sp)-peridotite facies (P>~1GPa) in Balmuccia peridotite, Ivrea-Verbano Zone, Italy. The studied area contains abundant PST-bearing faults and N-S trending primary pyroxenite layers. Many faults in the area cut pyroxenite layers, but LD structure is found only in one place presented here. Many PSTs in the area have been (re)crystallized in Sp-peridotite facies, and have typically ultramylonitic texture (Ueda et al., 2008) with some injection veins. The fault with LD structure is situated in a fault system, which has two dominant attitudes with regional N-S extension. The shear strain of LD structure measured on outcrop surface is ~2.0. Near the fault, elongated Opx porphyroclasts (ellipses in figure) oblique to local layering are visible in peridotite. The dominant deformation textures are dynamic recrystallization in peridotite and kinking or undulatory extinction in pyroxenite. The mineral assemblages of the mylonite neoblast in the peridotite and the pyroxenite are Ol+Opx+Cpx+Sp+hornblende(Hbl), Cpx+Opx+Sp, respectively. Hbl typically occur only in neoblast. In the vicinity (several hundreds of micron) of the fault, dolomite(Dol) also occur in equilibrium with the assemblage above. The recrystallized grain sizes are 20-50 microns in peridotite and 10-30 microns in pyroxenite. The rarity of LD structure is consistent with general conception that deformation processes which lead to dynamic rupture initiation ought to be

  8. ANALYSIS OF DEFORMED STATE STRUCTURES OF THE KYIV METRO RUNNING TUNNELS ON A TRANSITION ZONE FROM SPONDYLOV’S CLAY TO BUCHATSKIY SANDS

    Directory of Open Access Journals (Sweden)

    V. D. Petrenko

    2014-07-01

    Full Text Available Purpose. In the section of changes geotechnical conditions of spondylov’s clay to buchatskiy sands may have significant structural deformation of running tunnels. It is necessary to identify the cause of deformities develop ways to minimize and based modeling and calculations to prove the effectiveness of measures to reduce deformation.Methodology. To solve the analysis problem of the stress-strain state (SSS of the system «structure array» it was conducted the numerical simulation using the finite element method (FEM. On the basis of the obtained results the graphs were constructed and the dependencies were determined. Findings. The presence of weak water-saturated soils in tray of the tunnel on an area of transition from spondylov’s clay to buchatskiy sand causes significant increasing in strain construction of tunnels and general vibration liquefaction in soil basis. Also change the physical and mechanical characteristics of soils within the frames of tunnels influences on the level of strain state of most frames. Improved strain state settings of tunnels in areas of change soil characteristics of the array (especially at the bottom of casing can be achieved by chemical consolidation of weak soils. Composition of solutions for fixing the weak soils should be determined based on the study of grain size, porosity, and other parameters of physical and mechanical and physical and chemical characteristics of soils.Originality.The basic cause significant strain on transition zone from spondylov’s clay to buchatskiy sands is found, that is explained by saturated phenomenon vibration liquefaction basis under the tunnel.Practical value.The approaches to reduce the strain in the construction of running tunnels in the transition zone from spondylov’s clay to buchatskiy sands are developed, as well as in the area ofthe station «Glybochytska»the Kyiv Metro.

  9. Deformations of the Almheiri-Polchinski model

    Energy Technology Data Exchange (ETDEWEB)

    Kyono, Hideki; Okumura, Suguru; Yoshida, Kentaroh [Department of Physics, Kyoto University, Kitashirakawa Oiwake-cho, Kyoto 606-8502 (Japan)

    2017-03-31

    We study deformations of the Almheiri-Polchinski (AP) model by employing the Yang-Baxter deformation technique. The general deformed AdS{sub 2} metric becomes a solution of a deformed AP model. In particular, the dilaton potential is deformed from a simple quadratic form to a hyperbolic function-type potential similarly to integrable deformations. A specific solution is a deformed black hole solution. Because the deformation makes the spacetime structure around the boundary change drastically and a new naked singularity appears, the holographic interpretation is far from trivial. The Hawking temperature is the same as the undeformed case but the Bekenstein-Hawking entropy is modified due to the deformation. This entropy can also be reproduced by evaluating the renormalized stress tensor with an appropriate counter-term on the regularized screen close to the singularity.

  10. The Impacts of 3-D Earth Structure on GIA-Induced Crustal Deformation and Future Sea-Level Change in the Antarctic

    Science.gov (United States)

    Powell, E. M.; Hay, C.; Latychev, K.; Gomez, N. A.; Mitrovica, J. X.

    2017-12-01

    Glacial Isostatic Adjustment (GIA) models used to constrain the extent of past ice sheets and viscoelastic Earth structure, or to correct geodetic and geological observables for ice age effects, generally only consider depth-dependent variations in Earth viscosity and lithospheric structure. A et al. [2013] argued that 3-D Earth structure could impact GIA observables in Antarctica, but concluded that the presence of such structure contributes less to GIA uncertainty than do differences in Antarctic deglaciation histories. New seismic and geological evidence, however, indicates the Antarctic is underlain by complex, high amplitude variability in viscoelastic structure, including a low viscosity zone (LVZ) under West Antarctica. Hay et al. [2016] showed that sea-level fingerprints of modern melting calculated using such Earth models differ from those based on elastic or 1-D viscoelastic Earth models within decades of melting. Our investigation is motivated by two questions: (1) How does 3-D Earth structure, especially this LVZ, impact observations of GIA-induced crustal deformation associated with the last deglaciation? (2) How will 3-D Earth structure affect predictions of future sea-level rise in Antarctica? We compute the gravitationally self-consistent sea level, uplift, and gravity changes using the finite volume treatment of Latychev et al. [2005]. We consider four viscoelastic Earth models: a global 1-D model; a regional, West Antarctic-like 1-D model; a 3-D model where the lithospheric thickness varies laterally; and a 3-D model where both viscosity and lithospheric thickness vary laterally. For our Last Glacial Maximum to present investigations we employ ICE6g [Peltier et al., 2015]. For our present-future investigations we consider a melt scenario consistent with GRACE satellite gravity derived solutions [Harig et al., 2015]. Our calculations indicate that predictions of crustal deformations due to both GIA and ongoing melting are strongly influenced by 3-D

  11. Lithospheric structure of northwest Africa: Insights into the tectonic history and influence of mantle flow on large-scale deformation

    Science.gov (United States)

    Miller, Meghan S.; Becker, Thorsten

    2014-05-01

    Northwest Africa is affected by late stage convergence of Africa with Eurasia, the Canary Island hotspot, and bounded by the Proterozoic-age West African craton. We present seismological evidence from receiver functions and shear-wave splitting along with geodynamic modeling to show how the interactions of these tectonic features resulted in dramatic deformation of the lithosphere. We interpret seismic discontinuities from the receiver functions and find evidence for localized, near vertical-offset deformation of both crust-mantle and lithosphere-asthenosphere interfaces at the flanks of the High Atlas. These offsets coincide with the locations of Jurassic-aged normal faults that have been reactivated during the Cenozoic, further suggesting that inherited, lithospheric-scale zones of weakness were involved in the formation of the Atlas. Another significant step in lithospheric thickness is inferred within the Middle Atlas. Its location corresponds to the source of regional Quaternary alkali volcanism, where the influx of melt induced by the shallow asthenosphere appears restricted to a lithospheric-scale fault on the northern side of the mountain belt. Inferred stretching axes from shear-wave splitting are aligned with the topographic grain in the High Atlas, suggesting along-strike asthenospheric shearing in a mantle channel guided by the lithospheric topography. Isostatic modeling based on our improved lithospheric constraints indicates that lithospheric thinning alone does not explain the anomalous Atlas topography. Instead, an mantle upwelling induced by a hot asthenospheric anomaly appears required, likely guided by the West African craton and perhaps sucked northward by subducted lithosphere beneath the Alboran. This dynamic support scenario for the Atlas also suggests that the timing of uplift is contemporaneous with the recent volcanismin the Middle Atlas.

  12. Magnetic structure of deformation-induced shear bands in amorphous Fe{sub 80}B{sub 16}Si{sub 4} observed by magnetic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, G.W. [Center for Materials Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hawley, M.E. [Materials Science and Technology Division, (MST-8), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Markiewicz, D.J. [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States); Spaepen, F.; Barth, E.P. [Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States)

    1999-04-01

    Processing-induced magnetic structures in amorphous metallic alloys are of interest because of their impact on the performance of materials used in electric device applications. Plastic deformation associated with cutting or bending the material to the desired shape occurs through the formation of shear bands. The stress associated with these shear bands induces magnetic domains that can lead to power losses through interaction with the fields and currents involved in normal device operation. These domains have been studied previously using a variety of techniques capable of imaging magnetic domain structures. In an effort to better characterize and understand these issues, we have applied atomic and magnetic force microscopy to these materials to provide three-dimensional nanometer-scale topographic resolution and micrometer-scale magnetic resolution. {copyright} {ital 1999 American Institute of Physics.}

  13. Record of continental to marine transition from the Mesoproterozoic Ampani basin, Central India: An exercise of process-based sedimentology in a structurally deformed basin

    Science.gov (United States)

    Chakraborty, Partha Pratim; Saha, Subhojit; Das, Kaushik

    2017-08-01

    The Mesoproterozoic Ampani Group of rocks, a structurally deformed sedimentary package hosted within the Bastar Craton in central India, was studied for process-based facies and paleoenvironmental analyses. Outcrop mapping on 1:1500 scale, deconvolution of deformation pattern, and process-based facies analyses have led to the identification of fifteen facies types, clubbed under four facies associations. A range of paleoenvironmental settings varying from continental fluvial to distal marine shelf is inferred. Deductive paleohydrology revealed poorly-efficient 'dirty river' character for the Ampani River system with low water discharge. However, at times of catastrophic sheet floods release of sediments trapped at the river mouth in form of hyperpycnal underflows triggered formation of river mouth delta. Reworking of delta front sediment in wave-dominated coastline resulted development of beach-foreshore and shoreface (proximal to distal). Variation in the relative proportion of bar and interbar products within the shoreface successions exposed at different studied sections is interpreted as signature of relative bathymetric variation. The pro-deltaic Ampani shelf was storm infested. Tectonic perturbance in the basin hinterland in course of Ampani sedimentation is inferred from occurrence of a disparately thick lobate high-density flow deposit towards the top of shoreface succession and increase in feldspar content upward within the shoreface succession. Addition of detritus from a ∼1600 Ma Mesoproterozoic provenance in upper part of shoreface also strengthen the contention. Deconvolution of deformation pattern and delineation of environmental products ranging between continental and deep marine allowed us to infer the Ampani sediment package as fining-upward in character evolved in a transgressive mode.

  14. Fiber optic monitoring methods for composite steel-concrete structures based on determination of neutral axis and deformed shape.

    Science.gov (United States)

    2014-01-01

    Structural Health Monitoring has great potential to provide valuable information about the actual structural condition and can help optimize the management activities. However, few effective and robust monitoring methods exist which hinders a nationw...

  15. Determination of scattering character and structural parameters of a surface layer according to X-ray data for a film with variable deformation gradient

    International Nuclear Information System (INIS)

    Dyshekov, A.A.; Khapachev, Yu.P.

    1997-01-01

    The problem of the dynamic X-ray diffraction for a crystal with the exponential variation of the deformation is considered. The qualitative criteria of the deformation is considered. The qualitative criteria of the degree of the solvability of the problem of determination of the deformation amplitude and the deformed range thickness on X-ray diffraction results are established. The unambiguous solvability of this problem, is connected with two alternative cases: the slowness condition for the ratio of the surface crystal deformation to the deformed layer thickness or, vice versa, the high value of this ratio. The estimation expressions for the deformed surface layer thickness and the deformation amplitude on the data of angular shifts of the main diffraction maximum and oscillations are obtained for two limit cases [ru

  16. Lithospheric Structure and Active Deformation in the Salton Trough from Coseismic and Postseismic Models of the 2010 Mw 7.2 El Mayor-Cucapah Earthquake

    Science.gov (United States)

    Fielding, E. J.; Huang, M. H.; Dickinson, H.; Freed, A. M.; Burgmann, R.; Gonzalez-Ortega, J. A.; Andronicos, C.

    2016-12-01

    The 4 April 2010 Mw 7.2 El Mayor-Cucapah (EMC) Earthquake ruptured about 120 km along several NW-striking faults to the west of the Cerro Prieto Fault in the Salton Trough of Baja California, Mexico. We analyzed interferometric synthetic aperture radar (SAR), SAR and optical pixel offsets, and continuous and campaign GPS data to optimize an EMC coseismic rupture model with 9 fault segments, which fits the complex structure of the faults. Coseismic slip inversion with a layered elastic model shows that largely right-lateral slip is confined to upper 10 km with strong variations along strike. Near-field GPS measures slip on a north-striking normal fault that ruptured at the beginning of the earthquake, previously inferred from seismic waveforms. EMC Earthquake postseismic deformation shows the Earth's response to the large coseismic stress changes. InSAR shows rapid shallow afterslip at the north and south ends of the main ruptures. Continuous GPS from the Plate Boundary Observatory operated by UNAVCO measures the first six years of postseismic deformation, extremely rapid near the rupture. Afterslip on faults beneath the coseismic rupture cannot explain far-field displacements that are best explained by viscoelastic relaxation of the lower crust and upper mantle. We built a viscoelastic 3D finite element model of the lithosphere and asthenosphere based on available data for the region with the EMC coseismic faults embedded inside. Coseismic slip was imposed on the model, allowed to relax for 5 years, and then compared to the observed surface deformation. Systematic exploration of the viscoelastic parameters shows that horizontal and vertical heterogeneity is required to fit the postseismic deformation. Our preferred viscoelastic model has weaker viscosity layers beneath the Salton Trough than adjacent blocks that are consistent with the inferred differences in the geotherms. Defining mechanical lithosphere as rocks that have viscosities greater than 10^19 Pa s (able

  17. Bunionette deformity.

    Science.gov (United States)

    Cohen, Bruce E; Nicholson, Christopher W

    2007-05-01

    The bunionette, or tailor's bunion, is a lateral prominence of the fifth metatarsal head. Most commonly, bunionettes are the result of a widened 4-5 intermetatarsal angle with associated varus of the metatarsophalangeal joint. When symptomatic, these deformities often respond to nonsurgical treatment methods, such as wider shoes and padding techniques. When these methods are unsuccessful, surgical treatment is based on preoperative radiographs and associated lesions, such as hyperkeratoses. In rare situations, a simple lateral eminence resection is appropriate; however, the risk of recurrence or overresection is high with this technique. Patients with a lateral bow to the fifth metatarsal are treated with a distal chevron-type osteotomy. A widened 4-5 intermetatarsal angle often requires a diaphyseal osteotomy for correction.

  18. Correlation of substructure with mechanical properties of plastically deformed reactor structural materials. Progress report, January 1, 1976--June 30, 1977

    International Nuclear Information System (INIS)

    Moteff, J.

    1977-01-01

    Transmission electron microscopy used to evaluate the deformation (creep, fatigue and tensile) induced microstructure of 304 SS, Incoloy 800, 330 SS and three of the experimental alloys (E19, E23 and E36) obtained from the National Alloy Program clearly shows that the relationship between the subgrain size (lambda) and the applied stress (sigma) obeys the equation lambda = Ab (sigma/E) -1 where A is a constant of the order of 4, b the Burgers rector and E is Young's modulus. Hot-hardness studies on 304 SS, 316 SS, Incoloy 800, 2 1 / 4 Cr-1 Mo steels, 330 SS, Inconel 718, PE-16, Inconel 706, M-813 and the above three experimental alloys suggests that reasonable effective activation energies for creep may be obtained through the use of the hardness test as a strength microprobe tool. The ordering of the strength levels obtained through hot-hardness follows quite closely that obtained in tensile tests when those data are available

  19. Plastic Deformation of Metal Surfaces

    DEFF Research Database (Denmark)

    Hansen, Niels; Zhang, Xiaodan; Huang, Xiaoxu

    2013-01-01

    of metal components. An optimization of processes and material parameters must be based on a quantification of stress and strain gradients at the surface and in near surface layer where the structural scale can reach few tens of nanometers. For such fine structures it is suggested to quantify structural...... parameters by TEM and EBSD and apply strength-structural relationships established for the bulk metal deformed to high strains. This technique has been applied to steel deformed by high energy shot peening and a calculated stress gradient at or near the surface has been successfully validated by hardness...

  20. Anisotropic Ripple Deformation in Phosphorene.

    Science.gov (United States)

    Kou, Liangzhi; Ma, Yandong; Smith, Sean C; Chen, Changfeng

    2015-05-07

    Two-dimensional materials tend to become crumpled according to the Mermin-Wagner theorem, and the resulting ripple deformation may significantly influence electronic properties as observed in graphene and MoS2. Here, we unveil by first-principles calculations a new, highly anisotropic ripple pattern in phosphorene, a monolayer black phosphorus, where compression-induced ripple deformation occurs only along the zigzag direction in the strain range up to 10%, but not the armchair direction. This direction-selective ripple deformation mode in phosphorene stems from its puckered structure with coupled hinge-like bonding configurations and the resulting anisotropic Poisson ratio. We also construct an analytical model using classical elasticity theory for ripple deformation in phosphorene under arbitrary strain. The present results offer new insights into the mechanisms governing the structural and electronic properties of phosphorene crucial to its device applications.

  1. The shallow sedimentary and structural deformation in the southern Longmen Shan: constraints on the seismotectonics of the 2013 Lushan Mw6.7 Earthquake

    Science.gov (United States)

    Lu, R.; Xu, X.; He, D.; Suppe, J.

    2017-12-01

    On April 20, 2013, an unexpected Mw 6.7 earthquake occurred in Lushan County at the southern Longmen Shan, the eastern margin of the Tibetan Plateau. After this Lushan earthquake, whether the seismogenic fault is a high-angle or low-angle fault? The structural characteristics, attribution, and the seismotectonic model of this earthquake have many debates and problems. In this study, a high-resolution seismic reflection profile was combined with near-surface geological data, earthquake relocation and geodetic measurements, and a recent deep artificial seismic reflection profile to identify the active fault and seismotectonics of this earthquake. Three-dimensional imaging of the aftershocks was used to identify two planar faults that together form a y-shape (f1 and f2). Seismic interpretations suggest that the seismogenic fault f1 is a typical basement blind fault that did not penetrate into the overlying Mesozoic and Cenozoic units, and it is not a Shuangshi-Dachuan fault (F4) or the frontal Dayi buried fault (F6). Geodetic measurements suggest that the coseismic deformation is consistent with the geometry and kinematics of shear fault-bend folding (FBF). The history of tectonic evolution since the Paleozoic in Longmen Shan area also referred. There are three major detachments control the structural deformation of the upper crust in the Longmen Shan and Western Sichuan Basin, resulting in multiple superimposed deformation events. Deep seismic data indicate the syndepositional nature of fault f1 a preexisting normal fault older than the Triassic, which underwent positive inversion tectonics during the Late Cenozoic. A thrust fault f3 converges with f1 at a depth of approximately12 km with an accumulated slip 3.6 km. This 2013 Lushan earthquake triggered by blind faults is a hidden earthquake. Since the Late Cenozoic, with the strong and on-going compression of the Qinghai-Tibet Plateau to the Sichuan Basin, the early-period normal faults were activated after

  2. Thorax deformity, joint hypermobility and anxiety disorder

    International Nuclear Information System (INIS)

    Gulsun, M.; Dumlu, K.; Erbas, M.; Yilmaz, Mehmet B.; Pinar, M.; Tonbul, M.; Celik, C.; Ozdemir, B.

    2007-01-01

    Objective was to evaluate the association between thorax deformities, panic disorder and joint hypermobility. The study includes 52 males diagnosed with thorax deformity, and 40 healthy male controls without thorax deformity, in Tatvan Bitlis and Isparta, Turkey. The study was carried out from 2004 to 2006. The teleradiographic and thoracic lateral images of the subjects were evaluated to obtain the Beighton scores; subjects psychiatric conditions were evaluated using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-1), and the Hamilton Anxiety Scale (HAM-A) was applied in order to determine the anxiety levels. Both the subjects and controls were compared in sociodemographic, anxiety levels and joint mobility levels. In addition, males with joint hypermobility and thorax deformity were compared to the group with thorax deformity without joint hypermobility. A significant difference in HAM-A scores was found between the groups with thorax deformity and without. In addition, 21 subjects with thorax deformity met the joint hypermobility criteria in the group with thorax deformity and 7 subjects without thorax deformity met the joint hypermobility criteria in the group without thorax deformity, according to Beighton scoring. The Beighton score of subjects with thorax deformity were significantly different from those of the group without deformity. Additionally, anxiety scores of the males with thorax deformity and joint hypermobility were found higher than males with thorax deformity without joint hypermobility. Anxiety disorders, particularly panic disorder, have a significantly higher distribution in males subjects with thorax deformity compared to the healthy control group. In addition, the anxiety level of males with thorax deformity and joint hypermobility is higher than males with thorax deformity without joint hypermobility. (author)

  3. Characteristic analysis on the deformation behaviour of shell-like lattice structures subjected to follower forces; Judo kaju wo ukeru kosa arch kozo no daihenkei kyodo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Fukuchi, N.; Okada, K. [Kyushu University, Fukuoka (Japan); Fujii, M. [Namura Shipbuilding Co. Ltd., Osaka (Japan); Shiraki, M. [Toyota Motor Corp., Aichi (Japan)

    1998-09-04

    The deformation mechanisms of submerged shell-like lattice structures with membrane are in principle of a non-conservative nature since the follower type hydrostatic pressure. In the region of large deformations, especially in the case of geometrically deep shell-like lattice structures, the system could be much more accurately defined in a mono-clinically convected coordinate description than the conventional spatial description. Also, a complete analysis of a non-conservative system requires a criterion since the system can have multiple ranges of stability and instability involving buckling and snapping. This paper presents the development of the governing equations for the finite deformations of shell-like lattices defined in a mono-clincally convected coordinate description and applies the same to different cases of lattice deformations. The validity of the formulations is verified for finite deformation. The examples of some geometrically special shell-like lattice structures are presented as well to show the feasibility of the present formulation. 5 refs., 11 figs.

  4. [Preliminary evaluation on 3-demension changes of facial soft tissue with structure light scanning technique before and after orthognathic surgery of Class III deformities].

    Science.gov (United States)

    Peng, Ju-xiang; Jiang, Jiu-hui; Zhao, Yi-jiao; Wang, Yong; Li, Ze; Wang, Ning-ning; Feng, Zhi-min

    2015-02-18

    To evaluate facial soft tissue 3-deminsion changes of skeletal Class III malocclusion patients after orthognathic surgery using structure light scanning technique. Eight patients [3 males and 5 females, aged (27.08 ± 4.42) years] with Class III dentoskeletal relationship who underwent a bimaxillary orthognathic surgical procedure involving advancement of the maxilla by Le Fort I osteotomy and mandibular setback by bilateral sagittal split ramus osteotomy (BSSO) and genioplasty to correct deformity were included. 3D facial images were obtained by structure light scanner for all the patients 2 weeks preoperatively and 6 months postoperatively. The facial soft tissue changes were evaluated in 3-dimension. The linear distances and angulation changes for facial soft tissue landmarks were analyzed. The soft tissue volumetric changes were assessed too. There were significant differences in the sagittal and vertical changes of soft tissue landmarks. The greatest amount of soft tissue change was close to lips. There were more volumetric changes in the chin than in the maxilla, and fewer in the forehead. After biomaxillary surgery, there were significant facial soft tissue differences mainly in the sagittal and vertical dimension for skeletal Class III patients. The structure light 3D scanning technique can be accurately used to estimate the soft tissue changes in patients who undergo orthognathic surgery.

  5. Effect of heat treatment and plastic deformation on the structure and the mechanical properties of nitrogen-bearing 04N9Kh2A steel

    Science.gov (United States)

    Blinov, V. M.; Bannykh, O. A.; Lukin, E. I.; Kostina, M. V.; Blinov, E. V.

    2014-11-01

    The effect of the conditions of heat treatment and plastic deformation on the structure and the mechanical properties of low-carbon martensitic nickel steel (9 wt % Ni) with an overequilibrium nitrogen content is studied. The limiting strain to failure of 04N9Kh2A steel is found to be 40% at a rolling temperature of 20°C and 80% at a rolling temperature of 900°C. Significant strengthening of the steel (σ0.2 = 1089 MPa) is obtained after rolling at a reduction of 40% at 20°C. The start and final temperatures of the α → γ transformation on heating and those of the γ → α transformation on cooling are determined by dilatometry. The specific features of the formation of the steel structure have been revealed as functions of the annealing and tempering temperatures. Electron-microscopic studies show that, after quenching from 850°C and tempering at 600°C for 1 h, the structure contains packet martensite with thin interlayers of retained austenite between martensite crystals. The strength of the nitrogen-bearing 04N9Kh2A steel after quenching from 850 and 900°C, cooling in water, and subsequent tempering at 500°C for 1 h is significantly higher than that of carboncontaining 0H9 steel used in cryogenic engineering.

  6. Structure of a Wear-Resistant Medium-Carbon Steel After Hot Deformation in Hammer Dies and Heat Treatment

    Science.gov (United States)

    Knyazyuk, T. V.; Petrov, S. N.; Ryabov, V. V.; Khlusova, E. I.

    2018-01-01

    The structure of model specimens and articles fabricated from medium-carbon high-strength steels is studied for developing modes of forming of working members of tilling machines with cutting edges thinned without the expensive operation of electromachining. The effect of the temperature of heating of billets on the grain size of austenite is determined. The kinetics of recrystallization is studied in the temperature, rate and strain ranges typical for hot forming. A quantitative crystallographic analysis of the microstructure is performed by the EBSD technique. The degrees of distortion of the crystal lattices of structural components and the mean sizes of martensite blocks are determined.

  7. Perceptual transparency from image deformation.

    Science.gov (United States)

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin'ya

    2015-08-18

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid's surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of "invisible" transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation.

  8. 3D printed, bio-inspired prototypes and analytical models for structured suture interfaces with geometrically-tuned deformation and failure behavior

    Science.gov (United States)

    Lin, Erica; Li, Yaning; Ortiz, Christine; Boyce, Mary C.

    2014-12-01

    Geometrically structured interfaces in nature possess enhanced, and often surprising, mechanical properties, and provide inspiration for materials design. This paper investigates the mechanics of deformation and failure mechanisms of suture interface designs through analytical models and experiments on 3D printed polymer physical prototypes. Suture waveforms with generalized trapezoidal geometries (trapezoidal, rectangular, anti-trapezoidal, and triangular) are studied and characterized by several important geometric parameters: the presence or absence of a bonded tip region, the tip angle, and the geometry. It is shown that a wide range (in some cases as great as an order of magnitude) in stiffness, strength, and toughness is achievable dependent on tip bonding, tip angle, and geometry. Suture interfaces with a bonded tip region exhibit a higher initial stiffness due to the greater load bearing by the skeletal teeth, a double peak in the stress-strain curve corresponding to the failure of the bonded tip and the failure of the slanted interface region or tooth, respectively, and an additional failure and toughening mechanism due to the failure of the bonded tip. Anti-trapezoidal geometries promote the greatest amplification of properties for suture interfaces with a bonded tip due the large tip interface area. The tip angle and geometry govern the stress distributions in the teeth and the ratio of normal to shear stresses in the interfacial layers, which together determine the failure mechanism of the interface and/or the teeth. Rectangular suture interfaces fail by simple shearing of the interfaces. Trapezoidal and triangular suture interfaces fail by a combination of shear and tensile normal stresses in the interface, leading to plastic deformation, cavitation events, and subsequent stretching of interface ligaments with mostly elastic deformation in the teeth. Anti-trapezoidal suture interfaces with small tip angles have high stress concentrations in the teeth

  9. Quaternionic and Poisson-Lie structures in three-dimensional gravity: The cosmological constant as deformation parameter

    International Nuclear Information System (INIS)

    Meusburger, C.; Schroers, B. J.

    2008-01-01

    Each of the local isometry groups arising in three-dimensional (3d) gravity can be viewed as a group of unit (split) quaternions over a ring which depends on the cosmological constant. In this paper we explain and prove this statement and use it as a unifying framework for studying Poisson structures associated with the local isometry groups. We show that, in all cases except for the case of Euclidean signature with positive cosmological constant, the local isometry groups are equipped with the Poisson-Lie structure of a classical double. We calculate the dressing action of the factor groups on each other and find, among others, a simple and unified description of the symplectic leaves of SU(2) and SL(2,R). We also compute the Poisson structure on the dual Poisson-Lie groups of the local isometry groups and on their Heisenberg doubles; together, they determine the Poisson structure of the phase space of 3d gravity in the so-called combinatorial description

  10. Experimental studies on local damage of reinforced concrete structures by the impact deformable missiles-Part 2

    International Nuclear Information System (INIS)

    Esashi, Y.; Ohnuma, H.; Ito, C.; Shirai, K.

    1989-01-01

    In order to establish a rational method of determining the local damage to reinforced concrete structures due to the impact of aircraft engine missiles, three types of impact tests with different scales have been planned and executed. In this paper, results and discussion of the intermediate-scale tests are presented

  11. A method for enabling real-time structural deformation in remote handling control system by utilizing offline simulation results and 3D model morphing

    International Nuclear Information System (INIS)

    Kiviranta, Sauli; Saarinen, Hannu; Maekinen, Harri; Krassi, Boris

    2011-01-01

    A full scale physical test facility, DTP2 (Divertor Test Platform 2) has been established in Finland for demonstrating and refining the Remote Handling (RH) equipment designs for ITER. The first prototype RH equipment at DTP2 is the Cassette Multifunctional Mover (CMM) equipped with Second Cassette End Effector (SCEE) delivered to DTP2 in October 2008. The purpose is to prove that CMM/SCEE prototype can be used successfully for the 2nd cassette RH operations. At the end of F4E grant 'DTP2 test facility operation and upgrade preparation', the RH operations of the 2nd cassette were successfully demonstrated to the representatives of Fusion For Energy (F4E). Due to its design, the CMM/SCEE robot has relatively large mechanical flexibilities when the robot carries the nine-ton-weighting 2nd Cassette on the 3.6-m long lever. This leads into a poor absolute accuracy and into the situation where the 3D model, which is used in the control system, does not reflect the actual deformed state of the CMM/SCEE robot. To improve the accuracy, the new method has been developed in order to handle the flexibilities within the control system's virtual environment. The effect of the load on the CMM/SCEE has been measured and minimized in the load compensation model, which is implemented in the control system software. The proposed method accounts for the structural deformations of the robot in the control system through the 3D model morphing by utilizing the finite element method (FEM) analysis for morph targets. This resulted in a considerable improvement of the CMM/SCEE absolute accuracy and the adequacy of the 3D model, which is crucially important in the RH applications, where the visual information of the controlled device in the surrounding environment is limited.

  12. SEM observation of grain boundary structures in quartz-iron oxide rocks deformed at intermediate metamorphic conditions

    Directory of Open Access Journals (Sweden)

    Leonardo Lagoeiro

    2011-09-01

    Full Text Available Several studies have demonstrated the effect of a second phase on the distribution of fluid phase and dissolution of quartz grains. However, as most observations came from aggregates deformed under hydrostatic stress conditions and mica-bearing quartz rocks, 3-D distribution of pores on quartz-quartz (QQB and quartz-hematite boundaries (QHB has been studied. Several fracture surfaces oriented according to finite strain ellipsoid were analyzed. The pore distribution characterizes the porosity and grain shape as highly anisotropic, which results from the nature and orientation of boundaries. QHB have physical/chemical properties very different from QQB, once the hematite plates have strong effect on wetting behavior of fluid, likewise micas in quartzites. They are pore-free flat surfaces, normal to compression direction, suggesting that they were once wetted with a continuous fluid film acting as faster diffusion pathway. At QQB, the pores are faceted, isolated, close to its edges reflecting the crystallographic control and an interconnected network of fluid along grain junctions. The QQB facing the extension direction are sites of fluid concentration. As consequence, the anisotropic dissolution and grain growth were responsible for the formation of hematite plates and tabular quartz grains significantly contributing for the generation of the foliation observed in the studied rocks.Muitos estudos têm demonstrado o efeito de uma segunda fase sobre a distribuição de fase fluida e dissolução de grãos de quartzo. Entretanto, como a maioria das observações vêm de agregados deformados sob condições de tensão hidrostática e em rochas quartzosas ricas em mica, a distribuição 3D de poros e bordas quartzo-quartzo (BQQ e quartzo-hematita (BQH tem sido estudada. Várias superfícies de fraturas orientadas segundo o elipsóide de deformação finita foram analisadas. A distribuição dos poros caracteriza a porosidade e a forma dos grãos como

  13. Orbita - Anatomy, development and deformities

    International Nuclear Information System (INIS)

    Hartmann, K.M.; Reith, W.; Golinski, M.; Schroeder, A.C.

    2008-01-01

    The development of the structures of the human orbita is very complex, but understanding the development makes it easier to understand normal anatomy and dysplasia. The following article first discusses the embryonic development of the eye structures and then presents the ''normal'' radiological anatomy using different investigation techniques and the most common deformities. (orig.) [de

  14. Numerical simulation of deformation and fracture of space protective shell structures from concrete and fiber concrete under pulse loading

    International Nuclear Information System (INIS)

    Radchenko, P A; Batuev, S P; Radchenko, A V; Plevkov, V S

    2015-01-01

    This paper presents results of numerical simulation of interaction between aircraft Boeing 747-400 and protective shell of nuclear power plant. The shell is presented as complex multilayered cellular structure comprising layers of concrete and fiber concrete bonded with steel trusses. Numerical simulation was held three-dimensionally using the author's algorithm and software taking into account algorithms for building grids of complex geometric objects and parallel computations. The dynamics of stress-strain state and fracture of structure were studied. Destruction is described using two-stage model that allows taking into account anisotropy of elastic and strength properties of concrete and fiber concrete. It is shown that wave processes initiate destruction of shell cellular structure—cells start to destruct in unloading wave, originating after output of compression wave to the free surfaces of cells. (paper)

  15. Structural changes in a clay-containing nanocomposite with a different moisture content caused by its deformation

    International Nuclear Information System (INIS)

    Fajtel'son, E.A.; Glaskova, T.I.; Korkhovm, V.P.; Aniskevich, A.N.

    2010-01-01

    This paper presents the results of an investigation of the properties of a clay-containing nanocomposite with an epoxy binder under moisture-temperature and mechanical action. It has been established that whatever the moisture content, the nanocomposite crystallizes under the thermomechanical action (upon reaching the glasstransition temperature). When the nanocomposite is heated to 70 C, the restructuring process is reversible, and its heating to above 150 C leads to its amorphization. The presence of clay nanoparticles (up to 6 mass percent) does not influence the temperature of structural transitions of the nanocomposite and does not cause a substantial strengthening effect. The sorbed moisture plasticizes the nanocomposite and decreases its glasstransition temperature by 10 C. The specific features of the thermomechanical behavior of nanocomposites upon their tensile prestrain or creep are due to the formation of an oriented structure. Their crystallization begins at lower temperatures and with a higher degree of crystallinity than that of unloaded nanostructures. (authors)

  16. A novel deformation mechanism for superplastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Muto, H.; Sakai, M. (Toyohashi Univ. of Technology (Japan). Dept. of Materials Science)

    1999-01-01

    Uniaxial compressive creep tests with strain value up to -0.1 for a [beta]-spodumene glass ceramic are conducted at 1060 C. From the observation of microstructural changes between before and after the creep deformations, it is shown that the grain-boundary sliding takes place via cooperative movement of groups of grains rather than individual grains under the large-scale-deformation. The deformation process and the surface technique used in this work are not only applicable to explain the deformation and flow of two-phase ceramics but also the superplastic deformation. (orig.) 12 refs.

  17. Weak solutions for the motion of a self-propelled deformable structure in a viscous incompressible fluid

    Czech Academy of Sciences Publication Activity Database

    Nečasová, Šárka; Takahashi, T.; Tucsnak, M.

    2011-01-01

    Roč. 116, č. 3 (2011), s. 329-352 ISSN 0167-8019 R&D Projects: GA ČR(CZ) GAP201/11/1304 Institutional research plan: CEZ:AV0Z10190503 Keywords : Navier-Stokes equations * fluid-structure integration * weak solutions * free boundary Subject RIV: BA - General Mathematics Impact factor: 0.899, year: 2011 http://rd.springer.com/article/10.1007/s10440-011-9646-2#

  18. Refined Modeling of Flexural Deformation of Layered Plates with a Regular Structure Made from Nonlinear Hereditary Materials

    Science.gov (United States)

    Yankovskii, A. P.

    2018-01-01

    On the basis of constitutive equations of the Rabotnov nonlinear hereditary theory of creep, the problem on the rheonomic flexural behavior of layered plates with a regular structure is formu-lated. Equations allowing one to describe, with different degrees of accuracy, the stress-strain state of such plates with account of their weakened resistance to transverse shear were ob-tained. From them, the relations of the nonclassical Reissner- and Reddytype theories can be found. For axially loaded annular plates clamped at one edge and loaded quasistatically on the other edge, a simplified version of the refined theory, whose complexity is comparable to that of the Reissner and Reddy theories, is developed. The flexural strains of such metal-composite annular plates in shortterm and long-term loadings at different levels of heat action are calcu-lated. It is shown that, for plates with a relative thickness of order of 1/10, neither the classical theory, nor the traditional nonclassical Reissner and Reddy theories guarantee reliable results for deflections even with the rough 10% accuracy. The accuracy of these theories decreases at elevated temperatures and with time under long-term loadings of structures. On the basic of relations of the refined theory, it is revealed that, in bending of layered metal-composite heat-sensitive plates under elevated temperatures, marked edge effects arise in the neighborhood of the supported edge, which characterize the shear of these structures in the transverse direction

  19. Arabian Plate Deformation: The role of inherited structures in the localization of strain in the Red Sea extensional system

    Science.gov (United States)

    Aldaajani, T.; Furlong, K.; Malservisi, R.

    2017-12-01

    The Red Sea rift structural architecture changes dramatically along strike from narrow localized spreading (with creation of new oceanic crust) in the south to asymmetrical diffuse extension north of 21 ° latitude. The region of diffuse extension falls within a triangle that is bounded to the east by the Sarhan graben, (a Cenozoic failed rift), to the west by the northern Red Sea Rift, and to the south by the Makkah-Madinah-Nafud (MMN) volcanic line. Geological observations appear to show that tectonic stresses acting on inherited structures within the NW Arabian margin are associated with the region of diffuse extension. In contrast, in the southern Red Sea, a single strong block within the SW Arabian margin led to localize the extension there. Using current velocities from more than 30 GNSS stations distributed within the Arabian plate, we are able to map its rigidity and the distribution of strain along the plate margin. The data show that the transition between the two styles of extension within the Red Sea (crustal accretion vs crustal extension) corresponds with a transition between rigid behavior and diffuse extension within the Arabian Plate. This suggests that the preexisting structures within the Arabian plate play a significant role in the style of extension along the Red Sea margin.

  20. Nonlinear Deformable-body Dynamics

    CERN Document Server

    Luo, Albert C J

    2010-01-01

    "Nonlinear Deformable-body Dynamics" mainly consists in a mathematical treatise of approximate theories for thin deformable bodies, including cables, beams, rods, webs, membranes, plates, and shells. The intent of the book is to stimulate more research in the area of nonlinear deformable-body dynamics not only because of the unsolved theoretical puzzles it presents but also because of its wide spectrum of applications. For instance, the theories for soft webs and rod-reinforced soft structures can be applied to biomechanics for DNA and living tissues, and the nonlinear theory of deformable bodies, based on the Kirchhoff assumptions, is a special case discussed. This book can serve as a reference work for researchers and a textbook for senior and postgraduate students in physics, mathematics, engineering and biophysics. Dr. Albert C.J. Luo is a Professor of Mechanical Engineering at Southern Illinois University, Edwardsville, IL, USA. Professor Luo is an internationally recognized scientist in the field of non...

  1. Molecular and genetic characterization of a radiation-induced structural rearrangement in mouse chromosome 2 causing mutations at the limb deformity and agouti loci

    International Nuclear Information System (INIS)

    Woychik, R.P.; Generoso, W.M.; Russell, L.B.; Cain, K.T.; Cacheiro, N.L.; Bultman, S.J.; Selby, P.B.; Dickinson, M.E.; Hogan, B.L.

    1990-01-01

    Molecular characterization of mutations in the mouse, particularly those involving agent-induced major structural alterations, is proving to be useful for correlating the structure and expression of individual genes with their function in the whole organism. Here we present the characterization of a radiation-induced mutation that simultaneously generated distinct alleles of both the limb deformity (ld) and agouti (a) loci, two developmentally important regions of chromosome 2 normally separated by 20 centimorgans. Cytogenetic analysis revealed that an interstitial segment of chromosome 17 (17B- 17C; or, possibly, 17A2-17B) had been translocated into the distal end of chromosome 2, resulting in a smaller-than-normal chromosome 17 (designated 17del) and a larger form of chromosome 2 designated 2(17). Additionally, a large interstitial segment of the 2(17) chromosome, immediately adjacent and proximal to the insertion site, did not match bands 2E4-2H1 at corresponding positions on a normal chromosome 2. Molecular analysis detected a DNA rearrangement in which a portion of the ld locus was joined to sequences normally tightly linked to the a locus. This result, along with the genetic and cytogenetic data, suggests that the alleles of ld and a in this radiation-induced mutation, designated ldIn2 and ajIn2, were associated with DNA breaks caused by an inversion of an interstitial segment in the 2(17) chromosome

  2. 2-(2-Chlorobenzoylimino)-1,3-thiazolidine: structure refinement from neutron diffraction data at 113 K and charge density deformation maps

    International Nuclear Information System (INIS)

    Cohen-Addad, C.; Savariault, J.-M.; Lehmann, M.S.

    1981-01-01

    The structure of 2-(2-chlorobenzoylimino)-1,3-thiazolidine, C 10 H 9 ClN 2 OS, has been redetermined by neutron diffraction at 113 K. The space group is P2 1 /c with lattice parameters a = 19.950 (4), b = 7.420 (2), c = 11.566 (3) A, β = 109.10 (3) 0 , Z = 4, Msub(r) = 240.7 and dsub(calc) = 1.52 Mg m -3 . The final R(F 2 ) was 0.045 for 1768 reflections. The structural results show unambiguously that the molecule is found in the imino form with an H atom located near the endocyclic N atom of the thiazolidine group. Based on deformation electron density maps and the interatomic distances it is speculated that the difference in geometry between the two tautomeric forms (imino and amino) is small and that the occurrence of one or the other is strongly dependent on the substituents. A short intramolecular S-O contact of 2.68 A is found and is believed to constitute a very weak bond. (Auth.)

  3. Foam rheology at large deformation

    Science.gov (United States)

    Géminard, J.-C.; Pastenes, J. C.; Melo, F.

    2018-04-01

    Large deformations are prone to cause irreversible changes in materials structure, generally leading to either material hardening or softening. Aqueous foam is a metastable disordered structure of densely packed gas bubbles. We report on the mechanical response of a foam layer subjected to quasistatic periodic shear at large amplitude. We observe that, upon increasing shear, the shear stress follows a universal curve that is nearly exponential and tends to an asymptotic stress value interpreted as the critical yield stress at which the foam structure is completely remodeled. Relevant trends of the foam mechanical response to cycling are mathematically reproduced through a simple law accounting for the amount of plastic deformation upon increasing stress. This view provides a natural interpretation to stress hardening in foams, demonstrating that plastic effects are present in this material even for minute deformation.

  4. Structural analysis within the Rožná and Olší uranium deposits (Strážek Moldanubicum) for the estimation of deformation and stress conditions of underground gas storage

    Czech Academy of Sciences Publication Activity Database

    Ptáček, Jiří; Melichar, R.; Hájek, Antonín; Koníček, Petr; Souček, Kamil; Staš, Lubomír; Kříž, P.; Lazárek, J.

    2013-01-01

    Roč. 10, č. 2 (2013), s. 237-246 ISSN 1214-9705 Institutional support: RVO:68145535 Keywords : structural analysis * deformation * stress * underground gas storage Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 0.667, year: 2013 http://www.irsm.cas.cz/materialy/acta_content/2013_02/acta_170_13_Ptacek_237-246.pdf

  5. AISI/DOE Technology Roadmap Program: TRP 9732Steel Processing Properties and Their Effect on Impact Deformation of Lightweight Structures

    Energy Technology Data Exchange (ETDEWEB)

    Srdan Simunovic; Gustavo Aramayo

    2002-01-31

    The objective of the research was to perform a comprehensive computational analysis of the effects of material and process modeling approaches on performance of Ultra Light Steel Auto Body (ULSAB) vehicle models. The research addressed numerous material related effects, impact conditions as well as analyzed the performance of the ULSAB vehicles in crashes against designs representing the current US vehicle fleet. Crash modeling simulations show a clear effect of strain-rate sensitivity on high strength steel (HSS) intensive vehicle. The influence of a strain-rate model can be an incremental sensitivity due to the increased flow stress when similar structure collapse modes are predicted. However, significant differences in crash energy management capacity can be predicted if the change in loading on members alters the predicted collapse mode of the structure. From the material substitution study it can be concluded that HSS material substitution cannot be performed on the basis of the material yield point only and that, especially for advanced HSS vehicle designs, the entire region of material plastic response has to be considered. However, the problem of modeling of the overall dynamic crush process still remains open and requires further experimental and theoretical investigation. Crash modeling simulations show a moderate effect of forming on overall crash performance. The design is the determining factor on the vehicle performance and, therefore, the results of this research cannot provide measures that can be used in a general case. However, it has been shown that for materials that have modest strain hardening, the forming effect is observable and that when more complex forming operations are used, especially in combination with rapid strain hardening materials, forming effects should be taken in the consideration in the computational crash models. crash compatibility study between ULSAB and cars of similar geometric characteristics have shown that the U LSAB

  6. Neotectonics and structure of the Himalayan deformation front in the Kashmir Himalaya, India: Implication in defining what controls a blind thrust front in an active fold-thrust belt

    Science.gov (United States)

    Gavillot, Y. G.; Meigs, A.; Yule, J. D.; Rittenour, T. M.; Malik, M. O. A.

    2014-12-01

    Active tectonics of a deformation front constrains the kinematic evolution and structural interaction between the fold-thrust belt and most-recently accreted foreland basin. In Kashmir, the Himalayan Frontal thrust (HFT) is blind, characterized by a broad fold, the Suruin-Mastargh anticline (SMA), and displays no emergent faults cutting either limb. A lack of knowledge of the rate of shortening and structural framework of the SMA hampers quantifying the earthquake potential for the deformation front. Our study utilized the geomorphic expression of dated deformed terraces on the Ujh River in Kashmir. Six terraces are recognized, and three yield OSL ages of 53 ka, 33 ka, and 0.4 ka. Vector fold restoration of long terrace profiles indicates a deformation pattern characterized by regional uplift across the anticlinal axis and back-limb, and by fold limb rotation on the forelimb. Differential uplift across the fold trace suggests localized deformation. Dip data and stratigraphic thicknesses suggest that a duplex structure is emplaced at depth along the basal décollement, folding the overlying roof thrust and Siwalik-Muree strata into a detachment-like fold. Localized faulting at the fold axis explains the asymmetrical fold geometry. Folding of the oldest dated terrace, suggest that rock uplift rates across the SMA range between 2.0-1.8 mm/yr. Assuming a 25° dipping ramp for the blind structure on the basis of dip data constraints, the shortening rate across the SMA ranges between 4.4-3.8 mm/yr since ~53 ka. Of that rate, ~1 mm/yr is likely absorbed by minor faulting in the near field of the fold axis. Given that Himalaya-India convergence is ~18.8-11 mm/yr, internal faults north of the deformation front, such as the Riasi thrust absorbs more of the Himalayan shortening than does the HFT in Kashmir. We attribute a non-emergent thrust at the deformation front to reflect deformation controlled by pre-existing basin architecture in Kashmir, in which the thick succession

  7. Nanodisturbances in deformed Gum Metal

    International Nuclear Information System (INIS)

    Gutkin, Mikhail Yu.; Ishizaki, Toshitaka; Kuramoto, Shigeru; Ovid'ko, Ilya A.

    2006-01-01

    Systematic experiments have been performed to characterize defect structures in deformed Gum Metal, a special titanium alloy with high strength, low Young's modulus, excellent cold workability and low resistance to shear in certain crystallographic planes. Results from high-resolution transmission electron microscopy characterization reveal nanodisturbances (planar nanoscopic areas of local shear) as typical elements of defect structures in deformed Gum Metal. A theoretical model is suggested describing nanodisturbances as nanoscale dipoles of non-conventional partial dislocations with arbitrary, non-quantized Burgers vectors. It is shown theoretically that the homogeneous generation of nanodisturbances is energetically favorable in Gum Metal, where they effectively carry plastic flow

  8. Low-energy structure studies of odd-odd deformed nuclei and the coriolis and residual interactions

    Energy Technology Data Exchange (ETDEWEB)

    Dewberry, R.A.

    1980-08-01

    The nuclear level structure of /sup 176/Lu, /sup 170/Tm, /sup 166/Ho, and /sup 160/Tb have been studied by means of the /sup 177/Hf(t,..cap alpha..)/sup 176/Lu, /sup 171/Yb(t,..cap alpha..)/sup 170/Tm, /sup 167/Er(t,..cap alpha..)/sup 166/Ho, and /sup 161/Dy(t,..cap alpha..)/sup 160/Tb reactions and with the use of previously published (d,p) spectroscopy and gamma transitions from the (n,..gamma..) reactions. The (t,..cap alpha..) reactions have been performed and analyzed with 17 MeV tritons and the Los Alamos Q3D spectrometer. Eighty-one new rotational states in excited proton configurations or vibrational excited states are proposed. An independent parameterization of the Coriolis interaction is presented, which leads to satisfactory results in reproducing experimental single-particle transfer reaction cross-sections by theoretical calculations. The anomalous population of the excited neutron configurations (404 reduces to -624 up arrow) in /sup 176/Lu and (411 reduces to +- 512 up arrow) in /sup 170/Tm, and the anomalously low (t,..cap alpha..) cross-sections of the (411 up arrow +- 633 up arrow) configuration in /sup 166/Ho are observed. Qualitative explanation of the anomalies is presented in terms of the mixing of states which satisfy the requirement delta/sub I'/,/sub I/delta/sub K'/,/sub K/. Off-diagonal H/sub INT/ matrix elements are calculated, which show that the residual interaction cannot be used to account for the magnitude of the cross-sections observed.

  9. Study of deformation behavior, structure and mechanical properties of the AlSiMnFe alloy during ECAP-PBP.

    Science.gov (United States)

    Naizabekov, A B; Andreyachshenko, V A; Kocich, Radim

    2013-01-01

    The presented article deals with the effects of equal channel angular pressing (ECAP) with a newly adjusted die geometry on the microstructure and mechanical properties of the Al-Si-Mn-Fe alloy. This alloy was subjected to two modes of heat treatment followed by the ECAP process, which led to partial back pressure (ECAP-PBP). Ultra-fine grained (UFG) structure formed through ECAP-PBP process has been studied by methods of optical as well as electron microscopy. The obtained results indicate that quenched alloys, in comparison to slowly cooled alloys, do not contain large brittle particles which subsequently initiate a premature creation of cracks. It was shown that the mechanical properties of these alloys after such processing depend first and foremost on the selected type of heat treatment and on the number of performed passes. The maximum of ultimate tensile strength (417 MPa) was obtained for quenched alloy after 3 passes. On the other hand, maximum ductility was found in slowly cooled alloy after second pass. Further passes reduced strength due to the brittle behavior of excluded particles. One of the partial findings is that there is only a small dependency of the resulting size of grains on previously applied thermal processing. The minimum grain sizes were obtained after 3 passages, where their size ranged between 0.4 and 0.8 μm. The application of quick cooling after heat processing due to the occurrence of finer precipitates in the matrix seems to produce better results. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Inferred rheological structure and mantle conditions from postseismic deformation following the 2010 Mw 7.2 El Mayor-Cucapah Earthquake

    Science.gov (United States)

    Dickinson-Lovell, Haylee; Huang, Mong-Han; Freed, Andrew M.; Fielding, Eric; Bürgmann, Roland; Andronicos, Christopher

    2018-06-01

    The 2010 Mw7.2 El Mayor-Cucapah earthquake provides a unique target of postseismic study as deformation extends across several distinct geological provinces, including the cold Mesozoic arc crust of the Peninsular Ranges and newly formed, hot, extending lithosphere within the Salton Trough. We use five years of global positioning system measurements to invert for afterslip and constrain a 3-D finite-element model that simulates viscoelastic relaxation. We find that afterslip cannot readily explain far-field displacements (more than 50 km from the epicentre). These displacements are best explained by viscoelastic relaxation of a horizontally and vertically heterogeneous lower crust and upper mantle. Lower viscosities beneath the Salton Trough compared to the Peninsular Ranges and other surrounding regions are consistent with inferred differences in the respective geotherms. Our inferred viscosity structure suggests that the depth of the Lithosphere/Asthenosphere Boundary (LAB) is ˜65 km below the Peninsular Ranges and ˜32 km beneath the Salton Trough. These depths are shallower than the corresponding seismic LAB. This suggests that the onset of partial melting in peridotite may control the depth to the base of the mechanical lithosphere. In contrast, the seismic LAB may correspond to an increase in the partial melt percentage associated with the change from a conductive to an adiabatic geotherm.

  11. The Influence of Deformation on the Surface Structure of Silicon Under Irradiation by $^{86}$Kr Ions with Energy 253 MeV

    CERN Document Server

    Vlasukova, L A; Hofmann, A; Komarov, F F; Semina, V K; Yuvchenko, V N

    2006-01-01

    The influence of the previously produced deformation in silicon structure by means of macro-scratch surface covering on the sputtering processes under following irradiation by swift $^{86}$Kr ions is studied. The significant leveling of surface relief of irradiated silicon was observed using atomic force microscopy method (AFM), in particular it takes place for smoothing of micro-scratches produced by mechanical polishing of silicon initial plates. The experimental studies of irradiated surface allowed one to conclude that it is impossible to explain the surface changes only by elastic cascade mechanism as it was calculated using the computer code TRIM-98, because the calculated sputtered layers of silicon at ion fluence $\\Phi_{\\rm Kr} = 1{.}3\\cdot10^{14}$ ion/cm$^{2}$ should be $\\Delta H_{\\rm Sputtering}^{\\rm Kr} = 5{.}5\\cdot10^{-3 }${\\AA}. Correspondingly, the surface changes should be explained by one of mechanisms of inelastic sputtering. The macro-cracks on the surface were observed near the scratches. I...

  12. SU-G-JeP3-04: Estimating 4D CBCT from Prior Information and Extremely Limited Angle Projections Using Structural PCA and Weighted Free-Form Deformation

    International Nuclear Information System (INIS)

    Harris, W; Yin, F; Zhang, Y; Ren, L

    2016-01-01

    Purpose: To investigate the feasibility of using structure-based principal component analysis (PCA) motion-modeling and weighted free-form deformation to estimate on-board 4D-CBCT using prior information and extremely limited angle projections for potential 4D target verification of lung radiotherapy. Methods: A technique for lung 4D-CBCT reconstruction has been previously developed using a deformation field map (DFM)-based strategy. In the previous method, each phase of the 4D-CBCT was generated by deforming a prior CT volume. The DFM was solved by a motion-model extracted by global PCA and a free-form deformation (GMM-FD) technique, using data fidelity constraint and the deformation energy minimization. In this study, a new structural-PCA method was developed to build a structural motion-model (SMM) by accounting for potential relative motion pattern changes between different anatomical structures from simulation to treatment. The motion model extracted from planning 4DCT was divided into two structures: tumor and body excluding tumor, and the parameters of both structures were optimized together. Weighted free-form deformation (WFD) was employed afterwards to introduce flexibility in adjusting the weightings of different structures in the data fidelity constraint based on clinical interests. XCAT (computerized patient model) simulation with a 30 mm diameter lesion was simulated with various anatomical and respirational changes from planning 4D-CT to onboard volume. The estimation accuracy was evaluated by the Volume-Percent-Difference (VPD)/Center-of-Mass-Shift (COMS) between lesions in the estimated and “ground-truth” on board 4D-CBCT. Results: Among 6 different XCAT scenarios corresponding to respirational and anatomical changes from planning CT to on-board using single 30° on-board projections, the VPD/COMS for SMM-WFD was reduced to 10.64±3.04%/1.20±0.45mm from 21.72±9.24%/1.80±0.53mm for GMM-FD. Using 15° orthogonal projections, the VPD/COMS was

  13. SU-G-JeP3-04: Estimating 4D CBCT from Prior Information and Extremely Limited Angle Projections Using Structural PCA and Weighted Free-Form Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Harris, W; Yin, F; Zhang, Y; Ren, L [Duke University Medical Center, Durham, NC (United States)

    2016-06-15

    Purpose: To investigate the feasibility of using structure-based principal component analysis (PCA) motion-modeling and weighted free-form deformation to estimate on-board 4D-CBCT using prior information and extremely limited angle projections for potential 4D target verification of lung radiotherapy. Methods: A technique for lung 4D-CBCT reconstruction has been previously developed using a deformation field map (DFM)-based strategy. In the previous method, each phase of the 4D-CBCT was generated by deforming a prior CT volume. The DFM was solved by a motion-model extracted by global PCA and a free-form deformation (GMM-FD) technique, using data fidelity constraint and the deformation energy minimization. In this study, a new structural-PCA method was developed to build a structural motion-model (SMM) by accounting for potential relative motion pattern changes between different anatomical structures from simulation to treatment. The motion model extracted from planning 4DCT was divided into two structures: tumor and body excluding tumor, and the parameters of both structures were optimized together. Weighted free-form deformation (WFD) was employed afterwards to introduce flexibility in adjusting the weightings of different structures in the data fidelity constraint based on clinical interests. XCAT (computerized patient model) simulation with a 30 mm diameter lesion was simulated with various anatomical and respirational changes from planning 4D-CT to onboard volume. The estimation accuracy was evaluated by the Volume-Percent-Difference (VPD)/Center-of-Mass-Shift (COMS) between lesions in the estimated and “ground-truth” on board 4D-CBCT. Results: Among 6 different XCAT scenarios corresponding to respirational and anatomical changes from planning CT to on-board using single 30° on-board projections, the VPD/COMS for SMM-WFD was reduced to 10.64±3.04%/1.20±0.45mm from 21.72±9.24%/1.80±0.53mm for GMM-FD. Using 15° orthogonal projections, the VPD/COMS was

  14. Molecular dynamics simulation of deformation twin in rocksalt vanadium nitride

    International Nuclear Information System (INIS)

    Fu, Tao; Peng, Xianghe; Zhao, Yinbo; Li, Tengfei; Li, Qibin; Wang, Zhongchang

    2016-01-01

    We perform molecular dynamics simulation of nano-indentation with a cylindrical indenter to investigate the formation mechanism of deformation twin in vanadium nitride (VN) with a rocksalt structure. We find that the deformation twins occur during the loading stage, and subsequently conduct a systematic analysis of nucleation, propagation and thickening of a deformation twin. We find that the nucleation of a partial dislocation and its propagation to form a stacking fault are premise of deformation twin formation. The sequential nucleation and propagation of partial dislocation on adjacent parallel {111} planes are found to cause the thickening of the deformation twin. Moreover, the deformation twins can exist in VN at room temperature. - Highlights: • MD simulations of indentation are performed to study the deformation twin in VN. • The deformation twins can occur in VN during the loading stage. • The nucleation, propagation and thickening of a deformation twin are analyzed. • The deformation twins can exist in VN at room temperature.

  15. Clustering and triaxial deformations of 40Ca

    International Nuclear Information System (INIS)

    Taniguchi, Yasutaka; Kimura, Masaaki; Kanada-En'yo, Yoshiko; Horiuchi, Hisashi

    2007-01-01

    We have studied the positive-parity states of 40 Ca using antisymmetrized molecular dynamics (AMD) and the generator coordinate method (GCM). Imposing two different kinds of constraints on the variational calculation, we have found various kinds of 40 Ca structures such as a deformed-shell structure, as well as α- 36 Ar and 12 C- 28 Si cluster structures. After the GCM calculation, we obtained a normal-deformed band and a superdeformed band together with their side bands associated with triaxial deformation. The calculated B(E2) values agreed well with empirical data. It was also found that the normal-deformed and superdeformed bands have non-negligible α- 36 Ar cluster and 12 C- 28 Si cluster components, respectively. This leads to the presence of an α- 36 Ar higher nodal band occurring above the normal-deformed band

  16. Thermodynamic analysis of elastic-plastic deformation

    International Nuclear Information System (INIS)

    Lubarda, V.

    1981-01-01

    The complete set of constitutive equations which fully describes the behaviour of material in elastic-plastic deformation is derived on the basis of thermodynamic analysis of the deformation process. The analysis is done after the matrix decomposition of the deformation gradient is introduced into the structure of thermodynamics with internal state variables. The free energy function, is decomposed. Derive the expressions for the stress response, entropy and heat flux, and establish the evolution equation. Finally, we establish the thermodynamic restrictions of the deformation process. (Author) [pt

  17. Deformations of topological open strings

    NARCIS (Netherlands)

    Hofman, C.; Ma, Whee Ky

    Deformations of topological open string theories are described, with an emphasis on their algebraic structure. They are encoded in the mixed bulk-boundary correlators. They constitute the Hochschild complex of the open string algebra - the complex of multilinear maps on the boundary Hilbert space.

  18. IBA in deformed nuclei

    International Nuclear Information System (INIS)

    Casten, R.F.; Warner, D.D.

    1982-01-01

    The structure and characteristic properties and predictions of the IBA in deformed nuclei are reviewed, and compared with experiment, in particular for 168 Er. Overall, excellent agreement, with a minimum of free parameters (in effect, two, neglecting scale factors on energy differences), was obtained. A particularly surprising, and unavoidable, prediction is that of strong β → γ transitions, a feature characteristically absent in the geometrical model, but manifest empirically. Some discrepancies were also noted, principally for the K=4 excitation, and the detailed magnitudes of some specific B(E2) values. Considerable attention is paid to analyzing the structure of the IBA states and their relation to geometric models. The bandmixing formalism was studied to interpret both the aforementioned discrepancies and the origin of the β → γ transitions. The IBA states, extremely complex in the usual SU(5) basis, are transformed to the SU(3) basis, as is the interaction Hamiltonian. The IBA wave functions appear with much simplified structure in this way as does the structure of the associated B(E2) values. The nature of the symmetry breaking of SU(3) for actual deformed nuclei is seen to be predominantly ΔK=0 mixing. A modified, and more consistent, formalism for the IBA-1 is introduced which is simpler, has fewer free parameters (in effect, one, neglecting scale factors on energy differences), is in at least as good agreement with experiment as the earlier formalism, contains a special case of the 0(6) limit which corresponds to that known empirically, and appears to have a close relationship to the IBA-2. The new formalism facilitates the construction of contour plots of various observables (e.g., energy or B(E2) ratios) as functions of N and chi/sub Q/ which allow the parameter-free discussion of qualitative trajectories or systematics

  19. A technique for recording polycrystalline structure and orientation during in situ deformation cycles of rock analogues using an automated fabric analyser.

    Science.gov (United States)

    Peternell, M; Russell-Head, D S; Wilson, C J L

    2011-05-01

    Two in situ plane-strain deformation experiments on norcamphor and natural ice using synchronous recording of crystal c-axis orientations have been performed with an automated fabric analyser and a newly developed sample press and deformation stage. Without interrupting the deformation experiment, c-axis orientations are determined for each pixel in a 5 × 5 mm sample area at a spatial resolution of 5 μm/pixel. In the case of norcamphor, changes in microstructures and associated crystallographic information, at a strain rate of ∼2 × 10(-5) s(-1), were recorded for the first time during a complete in situ deformation-cycle experiment that consisted of an annealing, deformation and post-deformation annealing path. In the case of natural ice, slower external strain rates (∼1 × 10(-6) s(-1)) enabled the investigation of small changes in the polycrystal aggregate's crystallography and microstructure for small amounts of strain. The technical setup and first results from the experiments are presented. © 2010 The Authors Journal of Microscopy © 2010 Royal Microscopical Society.

  20. Modeling of Ground Deformation and Shallow Surface Waves Generated by Martian Dust Devils and Perspectives for Near-Surface Structure Inversion

    Science.gov (United States)

    Kenda, Balthasar; Lognonné, Philippe; Spiga, Aymeric; Kawamura, Taichi; Kedar, Sharon; Banerdt, William Bruce; Lorenz, Ralph; Banfield, Don; Golombek, Matthew

    2017-10-01

    We investigated the possible seismic signatures of dust devils on Mars, both at long and short period, based on the analysis of Earth data and on forward modeling for Mars. Seismic and meteorological data collected in the Mojave Desert, California, recorded the signals generated by dust devils. In the 10-100 s band, the quasi-static surface deformation triggered by pressure fluctuations resulted in detectable ground-tilt effects: these are in good agreement with our modeling based on Sorrells' theory. In addition, high-frequency records also exhibit a significant excitation in correspondence to dust devil episodes. Besides wind noise, this signal includes shallow surface waves due to the atmosphere-surface coupling and is used for a preliminary inversion of the near-surface S-wave profile down to 50 m depth. In the case of Mars, we modeled the long-period signals generated by the pressure field resulting from turbulence-resolving Large-Eddy Simulations. For typical dust-devil-like vortices with pressure drops of a couple Pascals, the corresponding horizontal acceleration is of a few nm/s2 for rocky subsurface models and reaches 10-20 nm/s2 for weak regolith models. In both cases, this signal can be detected by the Very-Broad Band seismometers of the InSight/SEIS experiment up to a distance of a few hundred meters from the vortex, the amplitude of the signal decreasing as the inverse of the distance. Atmospheric vortices are thus expected to be detected at the InSight landing site; the analysis of their seismic and atmospheric signals could lead to additional constraints on the near-surface structure, more precisely on the ground compliance and possibly on the seismic velocities.

  1. Static response of deformable microchannels

    Science.gov (United States)

    Christov, Ivan C.; Sidhore, Tanmay C.

    2017-11-01

    Microfluidic channels manufactured from PDMS are a key component of lab-on-a-chip devices. Experimentally, rectangular microchannels are found to deform into a non-rectangular cross-section due to fluid-structure interactions. Deformation affects the flow profile, which results in a nonlinear relationship between the volumetric flow rate and the pressure drop. We develop a framework, within the lubrication approximation (l >> w >> h), to self-consistently derive flow rate-pressure drop relations. Emphasis is placed on handling different types of elastic response: from pure plate-bending, to half-space deformation, to membrane stretching. The ``simplest'' model (Stokes flow in a 3D rectangular channel capped with a linearly elastic Kirchhoff-Love plate) agrees well with recent experiments. We also simulate the static response of such microfluidic channels under laminar flow conditions using ANSYSWorkbench. Simulations are calibrated using experimental flow rate-pressure drop data from the literature. The simulations provide highly resolved deformation profiles, which are difficult to measure experimentally. By comparing simulations, experiments and our theoretical models, we show good agreement in many flow/deformation regimes, without any fitting parameters.

  2. MAPPING FLOW LOCALIZATION PROCESSES IN DEFORMATION OF IRRADIATED REACTOR STRUCTURAL ALLOYS - FINAL REPORT. Nuclear Energy Research Initiative Program No. MSF99-0072. Period: August 1999 through September 2002. (ORNL/TM-2003/63)

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, K.

    2003-09-26

    Metals that can sustain plastic deformation homogeneously throughout their bulk tend to be tough and malleable. Often, however, if a metal has been hardened it will no longer deform uniformly. Instead, the deformation occurs in narrow bands on a microscopic scale wherein stresses and strains become concentrated in localized zones. This strain localization degrades the mechanical properties of the metal by causing premature plastic instability failure or by inducing the formation of cracks. Irradiation with neutrons hardens a metal and makes it more prone to deformation by strain localization. Although this has been known since the earliest days of radiation damage studies, a full measure of the connection between neutron irradiation hardening and strain localization is wanting, particularly in commercial alloys used in the construction of nuclear reactors. Therefore, the goal of this project is to systematically map the extent of involvement of strain localization processes in plastic deformation of three reactor alloys that have been neutron irradiated. The deformation processes are to be identified and related to changes in the tensile properties of the alloys as functions of neutron fluence (dose) and degree of plastic strain. The intent is to define the role of strain localization in radiation embrittlement phenomena. The three test materials are a tempered bainitic A533B steel, representing reactor pressure vessel steel, an annealed 316 stainless steel and annealed Zircaloy-4 representing reactor internal components. These three alloys cover the range of crystal structures usually encountered in structural alloys, i.e. body-centered cubic (bcc), face-centered cubic (fcc), and close-packed hexagonal (cph), respectively. The experiments were conducted in three Phases, corresponding to the three years duration of the project. Phases 1 and 2 addressed irradiations and tensile tests made at near-ambient temperatures, and covered a wide range of neutron fluences

  3. Highly deformable bones: unusual deformation mechanisms of seahorse armor.

    Science.gov (United States)

    Porter, Michael M; Novitskaya, Ekaterina; Castro-Ceseña, Ana Bertha; Meyers, Marc A; McKittrick, Joanna

    2013-06-01

    Multifunctional materials and devices found in nature serve as inspiration for advanced synthetic materials, structures and robotics. Here, we elucidate the architecture and unusual deformation mechanisms of seahorse tails that provide prehension as well as protection against predators. The seahorse tail is composed of subdermal bony plates arranged in articulating ring-like segments that overlap for controlled ventral bending and twisting. The bony plates are highly deformable materials designed to slide past one another and buckle when compressed. This complex plate and segment motion, along with the unique hardness distribution and structural hierarchy of each plate, provide seahorses with joint flexibility while shielding them against impact and crushing. Mimicking seahorse armor may lead to novel bio-inspired technologies, such as flexible armor, fracture-resistant structures or prehensile robotics. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  4. Structure and magnetic properties of hot deformed Nd{sub 2}Fe{sub 14}B magnets doped with DyH{sub x} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.G.; Yue, M., E-mail: yueming@bjut.edu.cn; Zhang, D.T.; Liu, W.Q.; Zhang, J.X.

    2016-04-15

    Commercial NdFeB powders mixed with DyH{sub x} nanoparticles are hot pressed and hot deformed into anisotropic magnets by Spark Plasma Sintering (SPS). The hot deformed magnet exhibits strong c-axis crystallographic texture. The coercivity of the magnet doped with 1.0 wt% DyH{sub x} is increased by 66.7%, compared with the magnet without DyH{sub x}, while the remanence decreases only by 3%. TEM observation shows that there exists a continuous (Nd,Dy){sub 2}Fe{sub 14}B layer between Nd-rich phase and NdFeB main phase. - Highlights: • The hot deformed magnet exhibits strong c-axis crystallographic texture. • The coercivity of the magnet significantly improved, and the remanence decreases slight. • TEM observation shows that there exists a continuous (Nd,Dy){sub 2}Fe{sub 14}B layer.

  5. Deformation twinning: Influence of strain rate

    Energy Technology Data Exchange (ETDEWEB)

    Gray, G.T. III

    1993-11-01

    Twins in most crystal structures, including advanced materials such as intermetallics, form more readily as the temperature of deformation is decreased or the rate of deformation is increased. Both parameters lead to the suppression of thermally-activated dislocation processes which can result in stresses high enough to nucleate and grow deformation twins. Under high-strain rate or shock-loading/impact conditions deformation twinning is observed to be promoted even in high stacking fault energy FCC metals and alloys, composites, and ordered intermetallics which normally do not readily deform via twinning. Under such conditions and in particular under the extreme loading rates typical of shock wave deformation the competition between slip and deformation twinning can be examined in detail. In this paper, examples of deformation twinning in the intermetallics TiAl, Ti-48Al-lV and Ni{sub 3}A as well in the cermet Al-B{sub 4}C as a function of strain rate will be presented. Discussion includes: (1) the microstructural and experimental variables influencing twin formation in these systems and twinning topics related to high-strain-rate loading, (2) the high velocity of twin formation, and (3) the influence of deformation twinning on the constitutive response of advanced materials.

  6. Physics-based deformable organisms for medical image analysis

    Science.gov (United States)

    Hamarneh, Ghassan; McIntosh, Chris

    2005-04-01

    Previously, "Deformable organisms" were introduced as a novel paradigm for medical image analysis that uses artificial life modelling concepts. Deformable organisms were designed to complement the classical bottom-up deformable models methodologies (geometrical and physical layers), with top-down intelligent deformation control mechanisms (behavioral and cognitive layers). However, a true physical layer was absent and in order to complete medical image segmentation tasks, deformable organisms relied on pure geometry-based shape deformations guided by sensory data, prior structural knowledge, and expert-generated schedules of behaviors. In this paper we introduce the use of physics-based shape deformations within the deformable organisms framework yielding additional robustness by allowing intuitive real-time user guidance and interaction when necessary. We present the results of applying our physics-based deformable organisms, with an underlying dynamic spring-mass mesh model, to segmenting and labelling the corpus callosum in 2D midsagittal magnetic resonance images.

  7. Quantum deformation of the affine transformation algebra

    International Nuclear Information System (INIS)

    Aizawa, N.; Sato, Haru-Tada

    1994-01-01

    We discuss a quantum deformation of the affine transformation algebra in one-dimensional space. It is shown that the quantum algebra has a non-cocommutative Hopf algebra structure, simple realizations and quantum tensor operators. (orig.)

  8. Mosaic dislocation structures in aluminium crystals deformed in multiple slip at 0.5 to 0.8TM

    DEFF Research Database (Denmark)

    Theyssier, M.C.; Chenal, B.; Driver, J.H.

    1995-01-01

    corresponding to the stable rolling texture components of polycrystalline f.c.c. metals, C {112} [111], S {421} [112] and B {110} [112] and one recrystallisation component {001} [250]. The deformation microstructures are investigated by different techniques over a wide range of scales and the local orientations...... have been measured by EBSD (electron back scattered diffraction) and by CBED (convergent beam electron diffraction). The deformation microstructures are subdivided by dislocation boundaries which bound cell blocks oriented at +/- 30 degrees to +/- 55 degrees with respect to the rolling direction...

  9. Developing a Virtual Rock Deformation Laboratory

    Science.gov (United States)

    Zhu, W.; Ougier-simonin, A.; Lisabeth, H. P.; Banker, J. S.

    2012-12-01

    Experimental rock physics plays an important role in advancing earthquake research. Despite its importance in geophysics, reservoir engineering, waste deposits and energy resources, most geology departments in U.S. universities don't have rock deformation facilities. A virtual deformation laboratory can serve as an efficient tool to help geology students naturally and internationally learn about rock deformation. Working with computer science engineers, we built a virtual deformation laboratory that aims at fostering user interaction to facilitate classroom and outreach teaching and learning. The virtual lab is built to center around a triaxial deformation apparatus in which laboratory measurements of mechanical and transport properties such as stress, axial and radial strains, acoustic emission activities, wave velocities, and permeability are demonstrated. A student user can create her avatar to enter the virtual lab. In the virtual lab, the avatar can browse and choose among various rock samples, determine the testing conditions (pressure, temperature, strain rate, loading paths), then operate the virtual deformation machine to observe how deformation changes physical properties of rocks. Actual experimental results on the mechanical, frictional, sonic, acoustic and transport properties of different rocks at different conditions are compiled. The data acquisition system in the virtual lab is linked to the complied experimental data. Structural and microstructural images of deformed rocks are up-loaded and linked to different deformation tests. The integration of the microstructural image and the deformation data allows the student to visualize how forces reshape the structure of the rock and change the physical properties. The virtual lab is built using the Game Engine. The geological background, outstanding questions related to the geological environment, and physical and mechanical concepts associated with the problem will be illustrated on the web portal. In

  10. Simulation of rock deformation behavior

    Directory of Open Access Journals (Sweden)

    Я. И. Рудаев

    2016-12-01

    Full Text Available A task of simulating the deformation behavior of geomaterials under compression with account of over-extreme branch has been addressed. The physical nature of rock properties variability as initially inhomogeneous material is explained by superposition of deformation and structural transformations of evolutionary type within open nonequilibrium systems. Due to this the description of deformation and failure of rock is related to hierarchy of instabilities within the system being far from thermodynamic equilibrium. It is generally recognized, that the energy function of the current stress-strain state is a superposition of potential component and disturbance, which includes the imperfection parameter accounting for defects not only existing in the initial state, but also appearing under load. The equation of state has been obtained by minimizing the energy function by the order parameter. The imperfection parameter is expressed through the strength deterioration, which is viewed as the internal parameter of state. The evolution of strength deterioration has been studied with the help of Fokker – Planck equation, which steady form corresponds to rock statical stressing. Here the diffusion coefficient is assumed to be constant, while the function reflecting internal sliding and loosening of the geomaterials is assumed as an antigradient of elementary integration catastrophe. Thus the equation of state is supplemented with a correlation establishing relationship between parameters of imperfection and strength deterioration. While deformation process is identified with the change of dissipative media, coupled with irreversible structural fluctuations. Theoretical studies are proven with experimental data obtained by subjecting certain rock specimens to compression.

  11. {kappa}-deformed realization of D=4 conformal algebra

    Energy Technology Data Exchange (ETDEWEB)

    Klimek, M. [Technical Univ. of Czestochowa, Inst. of Mathematics and Computer Science, Czestochowa (Poland); Lukierski, J. [Universite de Geneve, Department de Physique Theorique, Geneve (Switzerland)

    1995-07-01

    We describe the generators of {kappa}-conformal transformations, leaving invariant the {kappa}-deformed d`Alembert equation. In such a way one obtains the conformal extension of-shell spin spin zero realization of {kappa}-deformed Poincare algebra. Finally the algebraic structure of {kappa}-deformed conformal algebra is discussed. (author). 23 refs.

  12. An experimental study of plastic deformation of materials

    DEFF Research Database (Denmark)

    Knudsen, Tine

    The thesis falls in three parts, focusing on different aspects of plastic deformation of metals. Part I investigates the dislocation structures induced by hot deformation and compares these with the structures after cold deformation. In particular, it is shown that the dislocation structures...... after cold deformation by calorimetry and by analysis of the dislocation structure. The stored energy measured by calorimetry is found to be larger than that determined from the dislocation structure by a factor between 1.9 and 2.7, and this factor decreases with the plastic strain. Part III aimed...

  13. Ground Deformation and Sources geometry of the 2016 Central Italy Earthquake Sequence Investigated through Analytical and Numerical Modeling of DInSAR Measurements and Structural-Geological Data

    Science.gov (United States)

    Solaro, G.; Bonano, M.; Boncio, P.; Brozzetti, F.; Castaldo, R.; Casu, F.; Cirillo, D.; Cheloni, D.; De Luca, C.; De Nardis, R.; De Novellis, V.; Ferrarini, F.; Lanari, R.; Lavecchia, G.; Manunta, M.; Manzo, M.; Pepe, A.; Pepe, S.; Tizzani, P.; Zinno, I.

    2017-12-01

    The 2016 Central Italy seismic sequence started on 24th August with a MW 6.1 event, where the intra-Apennine WSW-dipping Vettore-Gorzano extensional fault system released a destructive earthquake, causing 300 casualties and extensive damage to the town of Amatrice and surroundings. We generated several interferograms by using ALOS and Sentinel 1-A and B constellation data acquired on both ascending and descending orbits to show that most displacement is characterized by two main subsiding lobes of about 20 cm on the fault hanging-wall. By inverting the generated interferograms, following the Okada analytical approach, the modelling results account for two sources related to main shock and more energetic aftershock. Through Finite Element numerical modelling that jointly exploits DInSAR deformation measurements and structural-geological data, we reconstruct the 3D source of the Amatrice 2016 normal fault earthquake which well fit the main shock. The inversion shows that the co-seismic displacement area was partitioned on two distinct en echelon fault planes, which at the main event hypocentral depth (8 km) merge in one single WSW-dipping surface. Slip peaks were higher along the southern half of the Vettore fault, lower along the northern half of Gorzano fault and null in the relay zone between the two faults; field evidence of co-seismic surface rupture are coherent with the reconstructed scenario. The following seismic sequence was characterized by numerous aftershocks located southeast and northwest of the epicenter which decreased in frequency and magnitude until the end of October, when a MW 5.9 event occurred on 26th October about 25 km to the NW of the previous mainshock. Then, on 30th October, a third large event of magnitude MW 6.5 nucleated below the town of Norcia, striking the area between the two preceding events and filling the gap between the previous ruptures. Also in this case, we exploit a large dataset of DInSAR and GPS measurements to investigate

  14. From labyrinthine aplasia to otocyst deformity.

    Science.gov (United States)

    Giesemann, Anja Maria; Goetz, Friedrich; Neuburger, Jürgen; Lenarz, Thomas; Lanfermann, Heinrich

    2010-02-01

    Inner ear malformations (IEMs) are rare and it is unusual to encounter the rarest of them, namely labyrinthine aplasia (LA) and otocyst deformity. They do, however, provide useful pointers as to the early embryonic development of the ear. LA is characterised as a complete absence of inner ear structures. While some common findings do emerge, a clear definition of the otocyst deformity does not exist. It is often confused with the common cavity first described by Edward Cock. Our purpose was to radiologically characterise LA and otocyst deformity. Retrospective analysis of CT and MRI data from four patients with LA or otocyst deformity. Middle and inner ear findings were categorised by two neuroradiologists. The bony carotid canal was found to be absent in all patients. Posterior located cystic structures were found in association with LA and otocyst deformity. In the most severe cases, only soft tissue was present at the medial border of the middle ear cavity. The individuals with otocyst deformity also had hypoplasia of the petrous apex bone. These cases demonstrate gradual changes in the two most severe IEMs. Clarification of terms was necessary and, based on these findings, we propose defining otocyst deformity as a cystic structure in place of the inner ear, with the cochlea, IAC and carotid canal absent. This condition needs to be differentiated from the common cavity described by Edward Cook. A clear definition of inner ear malformations is essential if outcomes following cochlear implantation are to be compared.

  15. From labyrinthine aplasia to otocyst deformity

    International Nuclear Information System (INIS)

    Giesemann, Anja Maria; Goetz, Friedrich; Lanfermann, Heinrich; Neuburger, Juergen; Lenarz, Thomas

    2010-01-01

    Inner ear malformations (IEMs) are rare and it is unusual to encounter the rarest of them, namely labyrinthine aplasia (LA) and otocyst deformity. They do, however, provide useful pointers as to the early embryonic development of the ear. LA is characterised as a complete absence of inner ear structures. While some common findings do emerge, a clear definition of the otocyst deformity does not exist. It is often confused with the common cavity first described by Edward Cock. Our purpose was to radiologically characterise LA and otocyst deformity. Retrospective analysis of CT and MRI data from four patients with LA or otocyst deformity. Middle and inner ear findings were categorised by two neuroradiologists. The bony carotid canal was found to be absent in all patients. Posterior located cystic structures were found in association with LA and otocyst deformity. In the most severe cases, only soft tissue was present at the medial border of the middle ear cavity. The individuals with otocyst deformity also had hypoplasia of the petrous apex bone. These cases demonstrate gradual changes in the two most severe IEMs. Clarification of terms was necessary and, based on these findings, we propose defining otocyst deformity as a cystic structure in place of the inner ear, with the cochlea, IAC and carotid canal absent. This condition needs to be differentiated from the common cavity described by Edward Cook. A clear definition of inner ear malformations is essential if outcomes following cochlear implantation are to be compared. (orig.)

  16. Deformations of superconformal theories

    Energy Technology Data Exchange (ETDEWEB)

    Córdova, Clay [School of Natural Sciences, Institute for Advanced Study,1 Einstein Drive, Princeton, NJ 08540 (United States); Dumitrescu, Thomas T. [Department of Physics, Harvard University,17 Oxford Street, Cambridge, MA 02138 (United States); Intriligator, Kenneth [Department of Physics, University of California,9500 Gilman Drive, San Diego, La Jolla, CA 92093 (United States)

    2016-11-22

    We classify possible supersymmetry-preserving relevant, marginal, and irrelevant deformations of unitary superconformal theories in d≥3 dimensions. Our method only relies on symmetries and unitarity. Hence, the results are model independent and do not require a Lagrangian description. Two unifying themes emerge: first, many theories admit deformations that reside in multiplets together with conserved currents. Such deformations can lead to modifications of the supersymmetry algebra by central and non-central charges. Second, many theories with a sufficient amount of supersymmetry do not admit relevant or marginal deformations, and some admit neither. The classification is complicated by the fact that short superconformal multiplets display a rich variety of sporadic phenomena, including supersymmetric deformations that reside in the middle of a multiplet. We illustrate our results with examples in diverse dimensions. In particular, we explain how the classification of irrelevant supersymmetric deformations can be used to derive known and new constraints on moduli-space effective actions.

  17. Rock types and ductile structures on a rock domain basis, and fracture orientation and mineralogy on a deformation zone basis. Preliminary site description. Forsmark area - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Michael [Geological Survey of Sweden, Uppsala (Sweden); Forssberg, Ola [Golder Associates AB, Uppsala (Sweden)

    2006-09-15

    This report presents the results of the analysis of base geological data in order to establish the dominant rock type, the subordinate rock types and the orientation of ductile mineral fabrics within each rock domain included in the regional geological model, version 1.2. An assessment of the degree of homogeneity of each domain is also provided. The analytical work has utilised the presentation of data in the form of histograms and stereographic projections. Fisher means and K values or best-fit great circles and corresponding pole values have been calculated for the ductile structural data. These values have been used in the geometric modelling of rock domains in the regional model, version 1.2. Furthermore, all analytical results have been used in the assignment of properties to rock domains in this model. A second analytical component reported here addresses the orientation and mineralogy of fractures in the deterministic deformation zones that are included in the regional geological model, version 1.2. The analytical work has once again utilised the presentation of data in the form of histograms and stereographic projections. Fisher means and K values are presented for the orientation of fracture sets in the deterministic deformation zones that have been identified with the help of new borehole data. The frequencies of occurrence of different minerals along the fractures in these deformation zones as well as the orientation of fractures in the zones, along which different minerals occur, are also presented. The results of the analyses have been used in the establishment of a conceptual structural model for the Forsmark site and in the assignment of properties to deterministic deformation zones in model version 1.2.

  18. Quantum deformed magnon kinematics

    OpenAIRE

    Gómez, César; Hernández Redondo, Rafael

    2007-01-01

    The dispersion relation for planar N=4 supersymmetric Yang-Mills is identified with the Casimir of a quantum deformed two-dimensional kinematical symmetry, E_q(1,1). The quantum deformed symmetry algebra is generated by the momentum, energy and boost, with deformation parameter q=e^{2\\pi i/\\lambda}. Representing the boost as the infinitesimal generator for translations on the rapidity space leads to an elliptic uniformization with crossing transformations implemented through translations by t...

  19. Mechanics of deformable bodies

    CERN Document Server

    Sommerfeld, Arnold Johannes Wilhelm

    1950-01-01

    Mechanics of Deformable Bodies: Lectures on Theoretical Physics, Volume II covers topics on the mechanics of deformable bodies. The book discusses the kinematics, statics, and dynamics of deformable bodies; the vortex theory; as well as the theory of waves. The text also describes the flow with given boundaries. Supplementary notes on selected hydrodynamic problems and supplements to the theory of elasticity are provided. Physicists, mathematicians, and students taking related courses will find the book useful.

  20. Exactly marginal deformations from exceptional generalised geometry

    Energy Technology Data Exchange (ETDEWEB)

    Ashmore, Anthony [Merton College, University of Oxford,Merton Street, Oxford, OX1 4JD (United Kingdom); Mathematical Institute, University of Oxford,Andrew Wiles Building, Woodstock Road, Oxford, OX2 6GG (United Kingdom); Gabella, Maxime [Institute for Advanced Study,Einstein Drive, Princeton, NJ 08540 (United States); Graña, Mariana [Institut de Physique Théorique, CEA/Saclay,91191 Gif-sur-Yvette (France); Petrini, Michela [Sorbonne Université, UPMC Paris 05, UMR 7589, LPTHE,75005 Paris (France); Waldram, Daniel [Department of Physics, Imperial College London,Prince Consort Road, London, SW7 2AZ (United Kingdom)

    2017-01-27

    We apply exceptional generalised geometry to the study of exactly marginal deformations of N=1 SCFTs that are dual to generic AdS{sub 5} flux backgrounds in type IIB or eleven-dimensional supergravity. In the gauge theory, marginal deformations are parametrised by the space of chiral primary operators of conformal dimension three, while exactly marginal deformations correspond to quotienting this space by the complexified global symmetry group. We show how the supergravity analysis gives a geometric interpretation of the gauge theory results. The marginal deformations arise from deformations of generalised structures that solve moment maps for the generalised diffeomorphism group and have the correct charge under the generalised Reeb vector, generating the R-symmetry. If this is the only symmetry of the background, all marginal deformations are exactly marginal. If the background possesses extra isometries, there are obstructions that come from fixed points of the moment maps. The exactly marginal deformations are then given by a further quotient by these extra isometries. Our analysis holds for any N=2 AdS{sub 5} flux background. Focussing on the particular case of type IIB Sasaki-Einstein backgrounds we recover the result that marginal deformations correspond to perturbing the solution by three-form flux at first order. In various explicit examples, we show that our expression for the three-form flux matches those in the literature and the obstruction conditions match the one-loop beta functions of the dual SCFT.

  1. Quantification of abdominal aortic deformation after EVAR

    Science.gov (United States)

    Demirci, Stefanie; Manstad-Hulaas, Frode; Navab, Nassir

    2009-02-01

    Quantification of abdominal aortic deformation is an important requirement for the evaluation of endovascular stenting procedures and the further refinement of stent graft design. During endovascular aortic repair (EVAR) treatment, the aortic shape is subject to severe deformation that is imposed by medical instruments such as guide wires, catheters, and, the stent graft. This deformation can affect the flow characteristics and morphology of the aorta which have been shown to be elicitors for stent graft failures and be reason for reappearance of aneurysms. We present a method for quantifying the deformation of an aneurysmatic aorta imposed by an inserted stent graft device. The outline of the procedure includes initial rigid alignment of the two abdominal scans, segmentation of abdominal vessel trees, and automatic reduction of their centerline structures to one specified region of interest around the aorta. This is accomplished by preprocessing and remodeling of the pre- and postoperative aortic shapes before performing a non-rigid registration. We further narrow the resulting displacement fields to only include local non-rigid deformation and therefore, eliminate all remaining global rigid transformations. Finally, deformations for specified locations can be calculated from the resulting displacement fields. In order to evaluate our method, experiments for the extraction of aortic deformation fields are conducted on 15 patient datasets from endovascular aortic repair (EVAR) treatment. A visual assessment of the registration results and evaluation of the usage of deformation quantification were performed by two vascular surgeons and one interventional radiologist who are all experts in EVAR procedures.

  2. Deformation Prediction Using Linear Polynomial Functions ...

    African Journals Online (AJOL)

    By Deformation, we mean change of shape of any structure from its original shape and by monitoring over time using Geodetic means, the change in shape, size and the overall structural dynamics behaviors of structure can be detected. Prediction is therefor based on the epochs measurement obtained during monitoring, ...

  3. Investigation of the three-dimensional thermoelastic deformation of the core structure of a fast breeder reactor under stationary working conditions

    International Nuclear Information System (INIS)

    Yong-Su, Hoang.

    1976-12-01

    In this study a method is described which has been developed in order to calculate three-dimensional deformation of the reactor core, taking into account thermal expansion. Two problem areas are of particular importance: 1) The spatial deflection of subassemblies in specified flexible supports and with specified clearances; 2) The investigation of the equilibrium configurations of the subassemblies in the planes of clamping (problem of clamping plane). - The elementary theory of beam deflection has been used to calculate the deformation of subassemblies. However, particular problems have been encountered as a result of flexibly designed support configurations having some spatial clearances. The problem has essentially been solved in two steps: a) Uniqueness analysis of the beam-support configuration; b) Calculation of the support loads and bending line for the unique beam-support configuration. - Basic difficulties currently prevent the problem of clamping plane being solved in a satisfactory manner. Therefore, a simplified clamping model was used for supports without spatial clearance and a parametric study was performed for supports having spatial clearance. The computation method developed is applied to the MARK I core of SNR 300. Core deformations are calculated under different support conditions for the subassemblies in the grid plate and in the upper clamping plane. (orig./HR) [de

  4. DISLOCATIONS STRUCTURE AND SCATTERING PHENOMENON IN CRYSTALLINE CELL SIZE OF 2024 AL ALLOY DEFORMED BY ONE PASS OF ECAP AT ROOM TEMPERATURE

    Directory of Open Access Journals (Sweden)

    M. H. Goodarzy

    2014-03-01

    Full Text Available Variation in microstructural features of 2024 aluminum alloy plastically deformed by equal channel angular pressing (ECAP at room temperature, was investigated by X-Ray diffraction in this work. These include dislocation density dislocation characteristic and the cell size of crystalline domains. Dislocations contrast factor was calculated using elastic constants of the alloy such as C 11, C 22 and C 44 . The effect of dislocations contrast factor on the anisotropic strain broadening of diffraction profiles was considered for measuring the microstructural features on the base of the modified Williamson-Hall and Warren-Averbach methods. Results showed that the dislocations density of the solution annealed sample increased from 4.28×10 12m-2 to 2.41×10 14m-2 after one pass of cold ECAP and the fraction of edge dislocations in the solution annealed sample increased from 43% to 74% after deformation. This means that deformation changed the overall dislocations characteristic more to edge dislocations. Also the crystalline cell size of the solution annealed sample decreased from 0.83μm to about 210nm after one pass of ECAP process at room temperature

  5. Twist deformations of the supersymmetric quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Castro, P.G.; Chakraborty, B.; Toppan, F., E-mail: pgcastro@cbpf.b, E-mail: biswajit@bose.res.i, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Kuznetsova, Z., E-mail: zhanna.kuznetsova@ufabc.edu.b [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

    2009-07-01

    The N-extended supersymmetric quantum mechanics is deformed via an abelian twist which preserves the super-Hopf algebra structure of its universal enveloping superalgebra. Two constructions are possible. For even N one can identify the 1D N-extended superalgebra with the fermionic Heisenberg algebra. Alternatively, supersymmetry generators can be realized as operators belonging to the Universal Enveloping Superalgebra of one bosonic and several fermionic oscillators. The deformed system is described in terms of twisted operators satisfying twist deformed (anti)commutators. The main differences between an abelian twist defined in terms of fermionic operators and an abelian twist defined in terms of bosonic operators are discussed. (author)

  6. Deformation relaxation in heavy-ion collisions

    International Nuclear Information System (INIS)

    Yu, L.; Gan, Z.G.; Zhang, Z.Y.; Zhang, H.F.; Li, J.Q.

    2014-01-01

    In deeply inelastic heavy-ion collisions, the quadrupole deformations of both fragments are taken as stochastic independent dynamical variables governed by the Fokker–Planck equation (FPE) under the corresponding driving potential. The mean values, variances and covariance of the fragments are analytically expressed by solving the FPE in head on collisions. The characteristics and mechanism of the deformation are discussed. It is found that both the internal structures and interactions of the colliding partners are critical for the deformation relaxation in deeply inelastic collisions.

  7. Intracrystalline deformation of calcite

    NARCIS (Netherlands)

    Bresser, J.H.P. de

    1991-01-01

    It is well established from observations on natural calcite tectonites that intracrystalline plastic mechanisms are important during the deformation of calcite rocks in nature. In this thesis, new data are presented on fundamental aspects of deformation behaviour of calcite under conditions where

  8. The Spherical Deformation Model

    DEFF Research Database (Denmark)

    Hobolth, Asgar

    2003-01-01

    Miller et al. (1994) describe a model for representing spatial objects with no obvious landmarks. Each object is represented by a global translation and a normal deformation of a sphere. The normal deformation is defined via the orthonormal spherical-harmonic basis. In this paper we analyse the s...

  9. On the Dequantization of Fedosov's Deformation Quantization

    Science.gov (United States)

    Karabegov, Alexander V.

    2003-08-01

    To each natural deformation quantization on a Poisson manifold M we associate a Poisson morphism from the formal neighborhood of the zero section of the cotangent bundle to M to the formal neighborhood of the diagonal of the product M x M~, where M~ is a copy of M with the opposite Poisson structure. We call it dequantization of the natural deformation quantization. Then we "dequantize" Fedosov's quantization.

  10. q-deformed Poincare algebra

    International Nuclear Information System (INIS)

    Ogievetsky, O.; Schmidke, W.B.; Wess, J.; Muenchen Univ.; Zumino, B.; Lawrence Berkeley Lab., CA

    1992-01-01

    The q-differential calculus for the q-Minkowski space is developed. The algebra of the q-derivatives with the q-Lorentz generators is found giving the q-deformation of the Poincare algebra. The reality structure of the q-Poincare algebra is given. The reality structure of the q-differentials is also found. The real Laplaacian is constructed. Finally the comultiplication, counit and antipode for the q-Poincare algebra are obtained making it a Hopf algebra. (orig.)

  11. Plastic Deformation of Pressured Metallic Glass

    Directory of Open Access Journals (Sweden)

    Yun Cheng

    2017-11-01

    Full Text Available Although pressured metallic glass (MG has been reported in the literature; there are few studies focusing on pressure effects on the structure; dynamics and its plastic deformation. In this paper; we report on and characterize; via molecular dynamics simulation, the structure and dynamics heterogeneity of pressured MGs, and explore a causal link between local structures and plastic deformation mechanism of pressured glass. The results exhibit that the dynamical heterogeneity of metallic liquid is more pronounced at high pressure, while the MGs were less fragile after the release of external pressure, reflected by the non-Gaussian parameter (NGP. High pressure glass shows better plastic deformation; and the local strain zone distributed more uniformly than of in normal glass. Further research indicates that although the number of icosahedrons in pressured glass was much larger than that in normal glass, while the interpenetrating connections of icosahedra (ICOI exhibited spatial correlations were rather poor; In addition, the number of ‘fast’ atoms indexed by the atoms’ moving distance is larger than that in normal glass; leading to the sharp decreasing in number of icosahedrons during deformation. An uniform distribution of ‘fast’ atoms also contributed to better plastic deformation ability in the pressured glass. These findings may suggest a link between the deformation and destruction of icosahedra with short-range order.

  12. Deformations of super Riemann surfaces

    International Nuclear Information System (INIS)

    Ninnemann, H.

    1992-01-01

    Two different approaches to (Konstant-Leites-) super Riemann surfaces are investigated. In the local approach, i.e. glueing open superdomains by superconformal transition functions, deformations of the superconformal structure are discussed. On the other hand, the representation of compact super Riemann surfaces of genus greater than one as a fundamental domain in the Poincare upper half-plane provides a simple description of super Laplace operators acting on automorphic p-forms. Considering purely odd deformations of super Riemann surfaces, the number of linear independent holomorphic sections of arbitrary holomorphic line bundles will be shown to be independent of the odd moduli, leading to a simple proof of the Riemann-Roch theorem for compact super Riemann surfaces. As a further consequence, the explicit connections between determinants of super Laplacians and Selberg's super zeta functions can be determined, allowing to calculate at least the 2-loop contribution to the fermionic string partition function. (orig.)

  13. Deformations of super Riemann surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ninnemann, H [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    1992-11-01

    Two different approaches to (Konstant-Leites-) super Riemann surfaces are investigated. In the local approach, i.e. glueing open superdomains by superconformal transition functions, deformations of the superconformal structure are discussed. On the other hand, the representation of compact super Riemann surfaces of genus greater than one as a fundamental domain in the Poincare upper half-plane provides a simple description of super Laplace operators acting on automorphic p-forms. Considering purely odd deformations of super Riemann surfaces, the number of linear independent holomorphic sections of arbitrary holomorphic line bundles will be shown to be independent of the odd moduli, leading to a simple proof of the Riemann-Roch theorem for compact super Riemann surfaces. As a further consequence, the explicit connections between determinants of super Laplacians and Selberg's super zeta functions can be determined, allowing to calculate at least the 2-loop contribution to the fermionic string partition function. (orig.).

  14. Performance through Deformation and Instability

    Science.gov (United States)

    Bertoldi, Katia

    2015-03-01

    Materials capable of undergoing large deformations like elastomers and gels are ubiquitous in daily life and nature. An exciting field of engineering is emerging that uses these compliant materials to design active devices, such as actuators, adaptive optical systems and self-regulating fluidics. Compliant structures may significantly change their architecture in response to diverse stimuli. When excessive deformation is applied, they may eventually become unstable. Traditionally, mechanical instabilities have been viewed as an inconvenience, with research focusing on how to avoid them. Here, I will demonstrate that these instabilities can be exploited to design materials with novel, switchable functionalities. The abrupt changes introduced into the architecture of soft materials by instabilities will be used to change their shape in a sudden, but controlled manner. Possible and exciting applications include materials with unusual properties such negative Poisson's ratio, phononic crystals with tunable low-frequency acoustic band gaps and reversible encapsulation systems.

  15. κ-deformed Dirac oscillator in an external magnetic field

    Science.gov (United States)

    Chargui, Y.; Dhahbi, A.; Cherif, B.

    2018-04-01

    We study the solutions of the (2 + 1)-dimensional κ-deformed Dirac oscillator in the presence of a constant transverse magnetic field. We demonstrate how the deformation parameter affects the energy eigenvalues of the system and the corresponding eigenfunctions. Our findings suggest that this system could be used to detect experimentally the effect of the deformation. We also show that the hidden supersymmetry of the non-deformed system reduces to a hidden pseudo-supersymmetry having the same algebraic structure as a result of the κ-deformation.

  16. Plastic deformation of 2D crumpled wires

    International Nuclear Information System (INIS)

    Gomes, M A F; Donato, C C; Brito, V P; Coelho, A S O

    2008-01-01

    When a single long piece of elastic wire is injected through channels into a confining two-dimensional cavity, a complex structure of hierarchical loops is formed. In the limit of maximum packing density, these structures are described by several scaling laws. In this paper this packing process is investigated but using plastic wires which give rise to completely irreversible structures of different morphology. In particular, the plastic deformation from circular to oblate configurations of crumpled wires is experimentally studied, obtained by the application of an axial strain. Among other things, it is shown that in spite of plasticity, irreversibility and very large deformations, scaling is still observed.

  17. Frictional contact behaviour of the tyre: the effect of tread slip on the in-plane structural deformation and stress field development

    Science.gov (United States)

    Tsotras, Achillefs; Mavros, George

    2010-08-01

    The analysis of the in-plane deformation of the tyre in relation to the frictional contact between the road and the tread is a crucial first step in the understanding of its contribution to the longitudinal dynamics of a vehicle. In this work, the physical mechanism of the generation of the two-dimensional contact pressure distribution for a non-rolling tyre is studied. Towards this aim, a physical tyre model is constructed, consisting of an analytical ring under pretension, a non-linear sidewall foundation, and a discretised foundation of viscoelastic elements representing the tread. Tread behaviour is examined first, with focus on the development of shear micro-slip. The tread simulation is enhanced with the combination of radial and tangential tread elements and the benefits of such an approach are identified. Subsequently, the contact of the complete model is examined by implementing an algorithm for transient simulations in the time domain. The effects of the imposed vertical load and sidewall non-linearity on the contact stress and strain fields are identified. The modelling approach is validated by comparison with published experimental results. The physical mechanism that couples the torsional and horizontal/vertical deformations of the carcass with the frictional forces at the tread is identified and discussed in detail. The proposed modelling approach is found appropriate for the description of the development of the two-dimensional contact pressure field as a function of the frictional potential of the contact.

  18. Diffeomorphic Statistical Deformation Models

    DEFF Research Database (Denmark)

    Hansen, Michael Sass; Hansen, Mads/Fogtman; Larsen, Rasmus

    2007-01-01

    In this paper we present a new method for constructing diffeomorphic statistical deformation models in arbitrary dimensional images with a nonlinear generative model and a linear parameter space. Our deformation model is a modified version of the diffeomorphic model introduced by Cootes et al....... The modifications ensure that no boundary restriction has to be enforced on the parameter space to prevent folds or tears in the deformation field. For straightforward statistical analysis, principal component analysis and sparse methods, we assume that the parameters for a class of deformations lie on a linear...... with ground truth in form of manual expert annotations, and compared to Cootes's model. We anticipate applications in unconstrained diffeomorphic synthesis of images, e.g. for tracking, segmentation, registration or classification purposes....

  19. The Spherical Deformation Model

    DEFF Research Database (Denmark)

    Hobolth, Asgar

    2003-01-01

    Miller et al. (1994) describe a model for representing spatial objects with no obvious landmarks. Each object is represented by a global translation and a normal deformation of a sphere. The normal deformation is defined via the orthonormal spherical-harmonic basis. In this paper we analyse the s...... a single central section of the object. We use maximum-likelihood-based inference for this purpose and demonstrate the suggested methods on real data....

  20. The thermal and mechanical deformation study of up-stream pumping mechanical seal

    International Nuclear Information System (INIS)

    Chen, H L; Xu, C; Zuo, M Z; Wu, Q B

    2015-01-01

    Taking the viscosity-temperature relationship of the fluid film into consideration, a 3-D numerical model was established by ANSYS software which can simulate the heat transfer between the upstream pumping mechanical seal stationary and rotational rings and the fluid film between them as well as simulate the thermal deformation, structure deformation and the coupling deformation of them. According to the calculation result, thermal deformation causes the seal face expansion and the maximum thermal deformation appears at the inside of the seal ring. Pressure results in a mechanical deformation, the maximum deformation occurs at the top of the spiral groove and the overall trend is inward the mating face, opposite to the thermal deformation. The coupling deformation indicate that the thermal deformation can be partly counteracted by pressure deformation. Using this model, the relationship between deformation and shaft speed and the sealing liquid pressure was studied. It's found that the shaft speed will both enhance the thermal and structure deformation and the fluid pressure will enhance the structure deformation but has little to do with the thermal deformation. By changing the sealing material, it's found that material with low thermal expansion coefficient and low elastic modulus will suffer less thermal-pressure deformation

  1. The thermal and mechanical deformation study of up-stream pumping mechanical seal

    Science.gov (United States)

    Chen, H. L.; Xu, C.; Zuo, M. Z.; Wu, Q. B.

    2015-01-01

    Taking the viscosity-temperature relationship of the fluid film into consideration, a 3-D numerical model was established by ANSYS software which can simulate the heat transfer between the upstream pumping mechanical seal stationary and rotational rings and the fluid film between them as well as simulate the thermal deformation, structure deformation and the coupling deformation of them. According to the calculation result, thermal deformation causes the seal face expansion and the maximum thermal deformation appears at the inside of the seal ring. Pressure results in a mechanical deformation, the maximum deformation occurs at the top of the spiral groove and the overall trend is inward the mating face, opposite to the thermal deformation. The coupling deformation indicate that the thermal deformation can be partly counteracted by pressure deformation. Using this model, the relationship between deformation and shaft speed and the sealing liquid pressure was studied. It's found that the shaft speed will both enhance the thermal and structure deformation and the fluid pressure will enhance the structure deformation but has little to do with the thermal deformation. By changing the sealing material, it's found that material with low thermal expansion coefficient and low elastic modulus will suffer less thermal-pressure deformation.

  2. The effect of microstructure on the deformation modes and mechanical properties of Ti-6Al-2Nb-1Ta-0.8Mo: Part II. Equiaxed structures

    Science.gov (United States)

    Lin, Fu-Shiong; Starke, E. A.; Gysler, A.

    1984-10-01

    The Ti-6Al-2Nb-lTa-0.8Mo alloy was processed to develop both near-basal and transverse textures. Samples were annealed at different temperatures to vary the equiaxed alpha grain size and the thick-ness of the grain boundary beta, and subsequently quenched in order to transform the beta phase to either martensite, tempered martensite, or Widmanstätten alpha + beta. The effect of microstructure and texture on tensile properties and on fracture toughness was investigated. In addition, yield locus diagrams were constructed in order to study the texture strengthening effect. The yield strength was found to be strongly dependent on the thickness and Burgers relationship of the transformed beta phase surrounding the alpha grains. A texture hardening effect as large as 60 pct was found for the basal-texture material but only 15 pct for the transverse texture material. These variations are asso-ciated with differences in deformation behavior.

  3. Order and chaos in nuclear and metal cluster deformation

    International Nuclear Information System (INIS)

    Radu, S.

    1995-08-01

    The vast amount of nuclear and metal cluster data indicates that shell structure and deformation are two simultaneous properties. A conflicting situation is therefore encountered as the shell structure, a firm expression of order, is apparently not compatible with the non-integrable nature of the models incorporating deformation. The main issue covered in this thesis is the intricate connection between deformation and chaotic behaviour in deformation models pertinent to nuclear structure and metal cluster physics. It is shown that, at least in some cases, it is possible to reconcile the occurrence of shell structure with non-integrability. The coupling of an axially deformed harmonic oscillator to an axially symmetric octupole term renders the problem non-integrable. The chaotic character of the motion is strongly dependent on the type of deformation, in that a prolate shape shows virtually no chaos, while in an oblate case the motion exhibits fully developed chaos when the octupole term is switched on. Whereas the problem is non-integrable, the quantum mechanical spectrum nevertheless shows some shell structure in the prolate case for particular, yet fairly large octupole strengths; for spherical or oblate deformation the shell structure disappears. This result is explained in terms of classical periodic orbits which are found by employing the 'removal of resonances method'. Particular emphasis is put on the effect of the hexadecapole deformation which is important in fission processes. The combined effect of octupole and hexadecapole deformation leads to important conclusions for the experimental work as a high degree of ambiguity is signaled for the interpretation of data. The ambiguity results from the discovery of a mutual cancellation of the octupole and hexadecapole deformation in prolate superdeformed systems. The phenomenological Nilsson model is treated in a similar way. It is argued that while in nuclei it produces good results for the low-lying levels

  4. Structural and mineralogical studies of the Tso Morari Dome: Insight into the deformation kinematics of the eclogitic gneiss, Ladakh Himalaya, India

    Science.gov (United States)

    Dutta, D.; Mukherjee, S.

    2017-12-01

    Coesite-bearing eclogites from the Tso Morari Dome (TMD) and the Kaghan valley (Pakistan) are two examples from the Himalayan orogen that attained UHP conditions within 5 Ma, by subducting the frontal part of the advancing Indian plate through a subduction channel, and subsequently extruded rapidly ( 17 mm yr-1). This study focuses on the deformation of the gneissic rock that hosts the UHP eclogites. 25 rock samples were collected from two transects viz. (A) Sumdo-Karzok and (B) Sumdo-Debring. Preliminary thin-section studies reveal differences in microstructural characters between the rocks of A and B. Although dynamically recrystallised quartz grains are present in all these samples, grain boundary migration recyrstallisation ( 530-650 °C) are better preserved in the rocks of A. Similarly, intra-granular fractures in both quartz and feldspars, the latter being dominant, are more prominent in the samples along A. Chessboard extinction patterns (> 700 °C) in quartz, micro-faults in plagioclase grains and undulatory extinction in micas are also present. Samples close to the Zildat shear zone (ZSZ; N margin of the TMD) exhibit medium-sized, lenticular quartzo-feldspathic grains. Their abundance wanes away from the fault possibly due to decreasing deformation intensity. XRD studies reveal a decline in the ratio of modal percentage K-feldspar to that of muscovite towards the N margin: the fall being more gradual along B. Biotites are less abundant ( 14 % towards the ZSZ. Previous workers reported similar increase in micaceous minerals in ductile- and brittle shear zones from other terrains, and suggested higher fluid activity as the key factor. Subduction of the Indian continental crust and subsequent exhumation, along the subduction channel, followed Coutte- and Poiseuille flows, respectively. Hence, rocks near the ZSZ should exhibit opposing shear senses, which we encounter both at micro- and meso-scales. Besides, Google Earth images show geomorphologic features

  5. α-clustering and triaxial deformations in 40Ca

    International Nuclear Information System (INIS)

    Taniguchi, Yasutaka; Kimura, Masaaki; Kanada-En'yo, Yoshiko; Horiuchi, Hisashi

    2007-01-01

    We have studied the positive-parity states of 40 Ca using antisymmetrized molecular dynamics (AMD) and the generator coordinate method (GCM). Imposing two different kinds of constraints on the variational calculation, we have found various kinds of 40 Ca structures such as a deformed-shell structure, as well as α- 36 Ar and 12 C- 28 Si cluster structures. After the GCM calculation, we obtained a normal-deformed band and a superdeformed band together with their side bands associated with triaxial deformation. The calculated B(E2) values agreed well with empirical data. It was also found that the normal-deformed and superdeformed bands contain α- 36 Ar and 12 C- 28 Si cluster structure components, respectively. This leads to the presence of an α- 36 Ar higher-nodal band occurring above the normal-deformed band

  6. Austenite strengthening and softening during hot deformation

    International Nuclear Information System (INIS)

    Tushinskij, L.I.; Vlasov, V.S.; Kazimirova, I.E.; Tokarev, A.O.

    1981-01-01

    Processes of formation of austenite structure of 20 and 12Kh18N10T steels during hot deformation and postdeformation isothermal holdings have been investigated by the methods of analysis of curves of hot deformation, high-temperature metallography and light microscopy. Deformation has been exercised by extention in vacuum with average 4x10 -2 s -1 rate. Deformation temperatures of steel 20 are 930 and 1000 deg C, of steel 12Kh18N10T - 1100 deg C. It is stated that dynamic recrystallization takes place in both investigated steels during hot deformation. In the carbonic steel it is developed by shifting sections of high-angular boundaries, flow stress in this case remains constant. Recrystallization is developed by subgrain coalescence in austenite steel, that brings about preservation of increased defect density in recrystallized volumes. As a result strengthening of steel is continued up to fracture during the increase of the deformation degree. Postdeformation weakening of 12Kh18N10T steel is slowed down as compared with weakening of carbonic steel [ru

  7. Deformable Organic Nanowire Field-Effect Transistors.

    Science.gov (United States)

    Lee, Yeongjun; Oh, Jin Young; Kim, Taeho Roy; Gu, Xiaodan; Kim, Yeongin; Wang, Ging-Ji Nathan; Wu, Hung-Chin; Pfattner, Raphael; To, John W F; Katsumata, Toru; Son, Donghee; Kang, Jiheong; Matthews, James R; Niu, Weijun; He, Mingqian; Sinclair, Robert; Cui, Yi; Tok, Jeffery B-H; Lee, Tae-Woo; Bao, Zhenan

    2018-02-01

    Deformable electronic devices that are impervious to mechanical influence when mounted on surfaces of dynamically changing soft matters have great potential for next-generation implantable bioelectronic devices. Here, deformable field-effect transistors (FETs) composed of single organic nanowires (NWs) as the semiconductor are presented. The NWs are composed of fused thiophene diketopyrrolopyrrole based polymer semiconductor and high-molecular-weight polyethylene oxide as both the molecular binder and deformability enhancer. The obtained transistors show high field-effect mobility >8 cm 2 V -1 s -1 with poly(vinylidenefluoride-co-trifluoroethylene) polymer dielectric and can easily be deformed by applied strains (both 100% tensile and compressive strains). The electrical reliability and mechanical durability of the NWs can be significantly enhanced by forming serpentine-like structures of the NWs. Remarkably, the fully deformable NW FETs withstand 3D volume changes (>1700% and reverting back to original state) of a rubber balloon with constant current output, on the surface of which it is attached. The deformable transistors can robustly operate without noticeable degradation on a mechanically dynamic soft matter surface, e.g., a pulsating balloon (pulse rate: 40 min -1 (0.67 Hz) and 40% volume expansion) that mimics a beating heart, which underscores its potential for future biomedical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Searching for the effects of the May-June 2012 Emilia seismic sequence (northern Italy: medium-depth deformation structures at the periphery of the epicentral area

    Directory of Open Access Journals (Sweden)

    Lisa Borgatti

    2012-10-01

    Full Text Available In 2012, a seismic sequence occurred in the lowlands of the Emilia-Romagna Region (northern Italy, between the borders of the Modena, Ferrara and Bologna Provinces. It consisted of seven mainshocks (5.9 > Ml > 5 that were recorded between May 20 and 29, 2012 [INGV 2012a] and 2,200 minor earthquakes [INGV 2012b]. An interferometric analysis [Bignami et al. 2012, Salvi et al. 2012, this volume] highlighted three main deformation areas, each of which was 12 km wide (from S to N and 10 km to 20 km long in an ESE-WNW to E-W direction, thus affecting an area of about 600 km2 (Figure 1. Field and aerial geological surveys recorded numerous surficial effects, such as: (i sediment liquefaction [Crespellani et al. 2012]; (ii localized ground fissures resembling surficial faulting [Fioravante and Giretti 2012] (Figure 2; (iii groundwater levels rising up to 400 cm above the local ground level in phreatic wells during the mainshocks (lower values were observed in confined aquifers; and (iv dormancy of previously known sinkholes [Borgatti et al. 2010, Cremonini 2010a, and references therein]. Some of the observed surface phenomena were previously recorded as coseismic effects during the earthquakes of Ferrara (1570 and Argenta (1624 [Boschi et al. 1995, Galli 2000], together with the early rising of the water level of the Po River in the Stellata section. […

  9. Detection of time-varying structures by large deformation diffeomorphic metric mapping to aid reading of high-resolution CT images of the lung.

    Directory of Open Access Journals (Sweden)

    Ryo Sakamoto

    Full Text Available OBJECTIVES: To evaluate the accuracy of advanced non-linear registration of serial lung Computed Tomography (CT images using Large Deformation Diffeomorphic Metric Mapping (LDDMM. METHODS: FIFTEEN CASES OF LUNG CANCER WITH SERIAL LUNG CT IMAGES (INTERVAL: 62.2±26.9 days were used. After affine transformation, three dimensional, non-linear volume registration was conducted using LDDMM with or without cascading elasticity control. Registration accuracy was evaluated by measuring the displacement of landmarks placed on vessel bifurcations for each lung segment. Subtraction images and Jacobian color maps, calculated from the transformation matrix derived from image warping, were generated, which were used to evaluate time-course changes of the tumors. RESULTS: The average displacement of landmarks was 0.02±0.16 mm and 0.12±0.60 mm for proximal and distal landmarks after LDDMM transformation with cascading elasticity control, which was significantly smaller than 3.11±2.47 mm and 3.99±3.05 mm, respectively, after affine transformation. Emerged or vanished nodules were visualized on subtraction images, and enlarging or shrinking nodules were displayed on Jacobian maps enabled by highly accurate registration of the nodules using LDDMM. However, some residual misalignments were observed, even with non-linear transformation when substantial changes existed between the image pairs. CONCLUSIONS: LDDMM provides accurate registration of serial lung CT images, and temporal subtraction images with Jacobian maps help radiologists to find changes in pulmonary nodules.

  10. Autogenous Deformation of Concrete

    DEFF Research Database (Denmark)

    Autogenous deformation of concrete can be defined as the free deformation of sealed concrete at a constant temperature. A number of observed problems with early age cracking of high-performance concretes can be attributed to this phenomenon. During the last 10 years , this has led to an increased...... focus on autogenous deformation both within concrete practice and concrete research. Since 1996 the interest has been significant enough to hold international, yearly conferences entirely devoted to this subject. The papers in this publication were presented at two consecutive half-day sessions...... at the American Concrete Institute’s Fall Convention in Phoenix, Arizona, October 29, 2002. All papers have been reviewed according to ACI rules. This publication, as well as the sessions, was sponsored by ACI committee 236, Material Science of Concrete. The 12 presentations from 8 different countries indicate...

  11. Interfacial Bubble Deformations

    Science.gov (United States)

    Seymour, Brian; Shabane, Parvis; Cypull, Olivia; Cheng, Shengfeng; Feitosa, Klebert

    Soap bubbles floating at an air-water experience deformations as a result of surface tension and hydrostatic forces. In this experiment, we investigate the nature of such deformations by taking cross-sectional images of bubbles of different volumes. The results show that as their volume increases, bubbles transition from spherical to hemispherical shape. The deformation of the interface also changes with bubble volume with the capillary rise converging to the capillary length as volume increases. The profile of the top and bottom of the bubble and the capillary rise are completely determined by the volume and pressure differences. James Madison University Department of Physics and Astronomy, 4VA Consortium, Research Corporation for Advancement of Science.

  12. Joining by plastic deformation

    DEFF Research Database (Denmark)

    Mori, Ken-ichiro; Bay, Niels; Fratini, Livan

    2013-01-01

    As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating opportuni......As the scale and complexity of products such as aircraft and cars increase, demand for new functional processes to join mechanical parts grows. The use of plastic deformation for joining parts potentially offers improved accuracy, reliability and environmental safety as well as creating...

  13. Marginally Deformed Starobinsky Gravity

    DEFF Research Database (Denmark)

    Codello, A.; Joergensen, J.; Sannino, Francesco

    2015-01-01

    We show that quantum-induced marginal deformations of the Starobinsky gravitational action of the form $R^{2(1 -\\alpha)}$, with $R$ the Ricci scalar and $\\alpha$ a positive parameter, smaller than one half, can account for the recent experimental observations by BICEP2 of primordial tensor modes....

  14. Transfer involving deformed nuclei

    International Nuclear Information System (INIS)

    Rasmussen, J.O.; Guidry, M.W.; Canto, L.F.

    1985-03-01

    Results are reviewed of 1- and 2-neutron transfer reactions at near-barrier energies for deformed nuclei. Rotational angular momentum and excitation patterns are examined. A strong tendency to populating high spin states within a few MeV of the yrast line is noted, and it is interpreted as preferential transfer to rotation-aligned states. 16 refs., 12 figs

  15. Advanced Curvature Deformable Mirrors

    Science.gov (United States)

    2010-09-01

    ORGANIZATION NAME(S) AND ADDRESS(ES) University of Hawaii ,Institute for Astronomy,640 North A‘ohoku Place, #209 , Hilo ,HI,96720-2700 8. PERFORMING...Advanced Curvature Deformable Mirrors Christ Ftaclas1,2, Aglae Kellerer2 and Mark Chun2 Institute for Astronomy, University of Hawaii

  16. Simulation of Stamping Process of Automotive Panel Considering Die Deformation

    International Nuclear Information System (INIS)

    Keum, Y.T.; Ahn, I.H.; Lee, I.K.; Song, M.H.; Kwon, S.O.; Park, J.S.

    2005-01-01

    In order to see the effect of die deformation on the forming of sheet metals, the draw-ins, strains, and spring-backs of an automotive fender panels are numerically simulated considering the die deformation, which is found by the simultaneous structural analysis of press and dies. By coupling the forming analysis and the structural analysis, the die deformation is simultaneously taken into account in the forming process. Furthermore, for the consideration of load difference transferred among the upper die, punch, and blank holder due to the changes in sheet thickness, the gap elements are employed instead of the blank sheet in the structural analysis. The numerical simulation results of an automotive fender draw panel are compared with the measurements. The comparison of the forming and spring-back analysis results between the rigid die and the deformed die shows that the deformed tool provides more accurate forming and spring-back prediction

  17. Experimental deformation of a mafic rock - interplay between fracturing, reaction and viscous deformation

    Science.gov (United States)

    Marti, Sina; Stünitz, Holger; Heilbronner, Renée; Plümper, Oliver; Drury, Martyn

    2016-04-01

    Deformation experiments were performed on natural Maryland Diabase (˜ 55% Plg, 42% Px, 3% accessories, 0.18 wt.-% H2O added) in a Griggs-type deformation apparatus in order to explore the brittle-viscous transition and the interplay between deformation and mineral reactions. Shear experiments at strain rates of ˜ 2e-5 /s are performed, at T=600, 700 and 800°C and confining pressures Pc=1.0 and 1.5 GPa. Deformation localizes in all experiments. Below 700°C, the microstructure is dominated by brittle deformation with a foliation formed by cataclastic flow and high strain accommodated along 3-5 major ultracataclasite shear bands. At 700°C, the bulk of the material still exhibits abundant microfractures, however, deformation localizes into an anastomosing network of shear bands (SB) formed from a fine-grained (<< 1 μm) mixture of newly formed Plg and Amph. These reaction products occur almost exclusively along syn-kinematic structures such as fractures and SB. Experiments at 800°C show extensive mineral reactions, with the main reaction products Amph+Plg (+Zo). Deformation is localized in broad C' and C SB formed by a fine-grained (0.1 - 0.8 μm) mixture of Plg+Amph (+Zo). The onset of mineral reactions in the 700°C experiments shows that reaction kinetics and diffusional mass transport are fast enough to keep up with the short experimental timescales. While in the 700°C experiments brittle processes kinematically contribute to deformation, fracturing is largely absent at 800°C. Diffusive mass transfer dominates. The very small grain size within SB favours a grain size sensitive deformation mechanism. Due to the presence of water (and relatively high supported stresses), dissolution-precipitation creep is interpreted to be the dominant strain accommodating mechanism. From the change of Amph coronas around Px clasts with strain, we can determine that Amph is re-dissolved at high stress sites while growing in low stress sites, showing the ability of Amph to

  18. Deformable nematic droplets in a magnetic field

    NARCIS (Netherlands)

    Otten, R.H.J.; van der Schoot, P. P. A. M.

    2012-01-01

    We present a Frank-Oseen elasticity theory for the shape and structure of deformable nematic droplets with homeotropic surface anchoring in the presence of a magnetic field. Inspired by recent experimental observations, we focus on the case where the magnetic susceptibility is negative, and find

  19. Carbon distribution in bainitic steel subjected to deformation

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Yu. F., E-mail: yufi55@mail.ru [Institute of High Current Electronics SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation); Nikitina, E. N., E-mail: Nikitina-EN@mail.ru; Gromov, V. E., E-mail: gromov@physics.sibsiu.ru [Siberian State Industrial University, Novokuznetsk, 654007 (Russian Federation)

    2015-10-27

    Analysis of the formation and evolution of carbide phase in medium carbon steel with a bainitic structure during compressive deformation was performed by means of transmission electron diffraction microscopy. Qualitative transformations in carbide phase medium size particles, their density and volume concentration depended on the degree of deformation.

  20. Deformation bands in porous carbonate grainstones: Field and laboratory observations

    NARCIS (Netherlands)

    Cilona, A.; Baud, P.; Tondi, E.; Agosta, F.; Vinciguerra, S.; Rustichelli, A.; Spiers, C.J.

    2012-01-01

    Recent field-based studies documented deformation bands in porous carbonates; these structures accommodate volumetric and/or shear strain by means of pore collapse, grain rotation and/or sliding. Microstructural observations of natural deformation bands in carbonates showed that, at advanced stages

  1. Meso- and microscale vein structures in fore-arc basalts and boninites related to post-magmatic tectonic deformation in the outer Izu-Bonin-Mariana fore arc system: preliminary results from IODP Expedition 352

    Science.gov (United States)

    Quandt, Dennis; Micheuz, Peter; Kurz, Walter

    2016-04-01

    The International Ocean Discovery Program (IODP) Expedition 352 aimed to drill through the entire volcanic sequence of the Izu-Bonin-Mariana fore arc. Two drill sites are situated on the outer fore arc composed of fore arc basalts (FAB) whereas two more sites are located on the upper trench slope penetrating the younger boninites. First results from IODP Expedition 352 and preliminary post-cruise data suggest that FAB were generated by decompression melting during near-trench sea-floor spreading, and that fluids from the subducting slab were not involved in their genesis. Subduction zone fluids involved in boninite genesis appear to have been derived from progressively higher temperatures and pressures over time as the subducting slab thermally matured. Structures within the drill cores combined with borehole and site survey seismic data indicate that tectonic deformation in the outer Izu-Bonin-Mariana fore arc is mainly post-magmatic associated with the development of syn-tectonic sedimentary basins. Within the magmatic basement deformation was accommodated by shear along cataclastic fault zones and the formation of tension fractures, shear fractures and hybrid (tension and shear) fractures. Veins form by mineral filling of tension or hybrid fractures and show no or limited observable macroscale displacement along the fracture plane. (Low Mg-) Calcite and/or various types of zeolite are the major vein constituents, where the latter are considered to be alteration products of basaltic glass. Micrite contents vary significantly and are related to neptunian dikes. In boninites calcite develops mainly blocky shapes but veins with fibrous and stretched crystals also occur in places indicating antitaxial as well as ataxial growth, respectively. In FAB calcite forms consistently blocky crystals without any microscopic identifiable growth direction suggesting precipitation from a highly supersaturated fluid under dropping fluid pressure conditions. However, fluid pressure

  2. Computing the stresses and deformations of the human eye components due to a high explosive detonation using fluid-structure interaction model.

    Science.gov (United States)

    Karimi, Alireza; Razaghi, Reza; Navidbakhsh, Mahdi; Sera, Toshihiro; Kudo, Susumu

    2016-05-01

    In spite the fact that a very small human body surface area is comprised by the eye, its wounds due to detonation have recently been dramatically amplified. Although many efforts have been devoted to measure injury of the globe, there is still a lack of knowledge on the injury mechanism due to Primary Blast Wave (PBW). The goal of this study was to determine the stresses and deformations of the human eye components, including the cornea, aqueous, iris, ciliary body, lens, vitreous, retina, sclera, optic nerve, and muscles, attributed to PBW induced by trinitrotoluene (TNT) explosion via a Lagrangian-Eulerian computational coupling model. Magnetic Resonance Imaging (MRI) was employed to establish a Finite Element (FE) model of the human eye according to a normal human eye. The solid components of the eye were modelled as Lagrangian mesh, while an explosive TNT, air domain, and aqueous were modelled using Arbitrary Lagrangian-Eulerian (ALE) mesh. Nonlinear dynamic FE simulations were accomplished using the explicit FE code, namely LS-DYNA. In order to simulate the blast wave generation, propagation, and interaction with the eye, the ALE formulation with Jones-Wilkins-Lee (JWL) equation defining the explosive material were employed. The results revealed a peak stress of 135.70kPa brought about by detonation upsurge on the cornea at the distance of 25cm. The highest von Mises stresses were observed on the sclera (267.3kPa), whereas the lowest one was seen on the vitreous body (0.002kPa). The results also showed a relatively high resultant displacement for the macula as well as a high variation for the radius of curvature for the cornea and lens, which can result in both macular holes, optic nerve damage and, consequently, vision loss. These results may have implications not only for understanding the value of stresses and strains in the human eye components but also giving an outlook about the process of PBW triggers damage to the eye. Copyright © 2016 Elsevier Ltd

  3. Effect of alloy deformation on the average spacing parameters of non-deforming particles

    International Nuclear Information System (INIS)

    Fisher, J.; Gurland, J.

    1980-02-01

    It is shown on the basis of stereological definitions and a few simple experiments that the commonly used average dispersion parameters, area fraction (A/sub A/)/sub β/, areal particle density N/sub Aβ/ and mean free path lambda/sub α/, remain invariant during plastic deformation in the case of non-deforming equiaxed particles. Directional effects on the spacing parameters N/sub Aβ/ and lambda/sub α/ arise during uniaxial deformation by rotation and preferred orientation of nonequiaxed particles. Particle arrangement in stringered or layered structures and the effect of deformation on nearest neighbor distances of particles and voids are briefly discussed in relation to strength and fracture theories

  4. Variscan deformation along the Teisseyre-Tornquist Zone in SE Poland: Thick-skinned structural inheritance or thin-skinned thrusting?

    Science.gov (United States)

    Krzywiec, P.; Gągała, Ł.; Mazur, S.; Słonka, Ł.; Kufrasa, M.; Malinowski, M.; Pietsch, K.; Golonka, J.

    2017-10-01

    Recently acquired seismic reflection data provide better insight in the structural style of extensive sedimentary series overlying the SW slope of the East European Craton (EEC) in Poland. The two main seismic datasets - the POLCRUST-01 profile and PolandSPAN survey - yielded contrasting thick - and thin-skinned structural models for the same structural units in SE Poland. We reattempt an interpretation of the POLCRUST-01 profile using techniques of cross-section balancing and restoration aided by 2D forward seismic modelling. An outcome is the thin-skinned structural model is. This solution relies on a continuous top of the EEC crystalline basement well represented in the seismic data as well as on fragmentary, yet conclusive seismic geometries in shallow depth intervals proving the Ediacaran-Palaeozoic series to be thrust and folded. A Variscan (late Carboniferous) compressional regime is consequently invoked to explain thin-skinned structuring of the pre-Permian sedimentary pile and > 20 km of calculated shortening. We demonstrate an ambiguous nature of the top-basement irregularities previously used as indicators of basement-rooted vertical faulting. The tilt and abrupt increase of the top-basement taper under the thin-skinned belt are attributed to pre-Ordovician tectonic processes operating along the SW margin of the EEC. Post-rift subsidence and/or flexural loading giving rise to a broken foreland plate are invoked.

  5. Deformation associated with continental normal faults

    Science.gov (United States)

    Resor, Phillip G.

    Deformation associated with normal fault earthquakes and geologic structures provide insights into the seismic cycle as it unfolds over time scales from seconds to millions of years. Improved understanding of normal faulting will lead to more accurate seismic hazard assessments and prediction of associated structures. High-precision aftershock locations for the 1995 Kozani-Grevena earthquake (Mw 6.5), Greece image a segmented master fault and antithetic faults. This three-dimensional fault geometry is typical of normal fault systems mapped from outcrop or interpreted from reflection seismic data and illustrates the importance of incorporating three-dimensional fault geometry in mechanical models. Subsurface fault slip associated with the Kozani-Grevena and 1999 Hector Mine (Mw 7.1) earthquakes is modeled using a new method for slip inversion on three-dimensional fault surfaces. Incorporation of three-dimensional fault geometry improves the fit to the geodetic data while honoring aftershock distributions and surface ruptures. GPS Surveying of deformed bedding surfaces associated with normal faulting in the western Grand Canyon reveals patterns of deformation that are similar to those observed by interferometric satellite radar interferometry (InSAR) for the Kozani Grevena earthquake with a prominent down-warp in the hanging wall and a lesser up-warp in the footwall. However, deformation associated with the Kozani-Grevena earthquake extends ˜20 km from the fault surface trace, while the folds in the western Grand Canyon only extend 500 m into the footwall and 1500 m into the hanging wall. A comparison of mechanical and kinematic models illustrates advantages of mechanical models in exploring normal faulting processes including incorporation of both deformation and causative forces, and the opportunity to incorporate more complex fault geometry and constitutive properties. Elastic models with antithetic or synthetic faults or joints in association with a master

  6. The structure of an LIM-only protein 4 (LMO4 and Deformed epidermal autoregulatory factor-1 (DEAF1 complex reveals a common mode of binding to LMO4.

    Directory of Open Access Journals (Sweden)

    Soumya Joseph

    Full Text Available LIM-domain only protein 4 (LMO4 is a widely expressed protein with important roles in embryonic development and breast cancer. It has been reported to bind many partners, including the transcription factor Deformed epidermal autoregulatory factor-1 (DEAF1, with which LMO4 shares many biological parallels. We used yeast two-hybrid assays to show that DEAF1 binds both LIM domains of LMO4 and that DEAF1 binds the same face on LMO4 as two other LMO4-binding partners, namely LIM domain binding protein 1 (LDB1 and C-terminal binding protein interacting protein (CtIP/RBBP8. Mutagenic screening analysed by the same method, indicates that the key residues in the interaction lie in LMO4LIM2 and the N-terminal half of the LMO4-binding domain in DEAF1. We generated a stable LMO4LIM2-DEAF1 complex and determined the solution structure of that complex. Although the LMO4-binding domain from DEAF1 is intrinsically disordered, it becomes structured on binding. The structure confirms that LDB1, CtIP and DEAF1 all bind to the same face on LMO4. LMO4 appears to form a hub in protein-protein interaction networks, linking numerous pathways within cells. Competitive binding for LMO4 therefore most likely provides a level of regulation between those different pathways.

  7. q-Deformed nonlinear maps

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 64; Issue 3 ... Keywords. Nonlinear dynamics; logistic map; -deformation; Tsallis statistics. ... As a specific example, a -deformation procedure is applied to the logistic map. Compared ...

  8. Q-deformed systems and constrained dynamics

    International Nuclear Information System (INIS)

    Shabanov, S.V.

    1993-01-01

    It is shown that quantum theories of the q-deformed harmonic oscillator and one-dimensional free q-particle (a free particle on the 'quantum' line) can be obtained by the canonical quantization of classical Hamiltonian systems with commutative phase-space variables and a non-trivial symplectic structure. In the framework of this approach, classical dynamics of a particle on the q-line coincides with the one of a free particle with friction. It is argued that q-deformed systems can be treated as ordinary mechanical systems with the second-class constraints. In particular, second-class constrained systems corresponding to the q-oscillator and q-particle are given. A possibility of formulating q-deformed systems via gauge theories (first-class constrained systems) is briefly discussed. (orig.)

  9. q-Deformed Kink solutions

    International Nuclear Information System (INIS)

    Lima, A.F. de

    2003-01-01

    The q-deformed kink of the λφ 4 -model is obtained via the normalisable ground state eigenfunction of a fluctuation operator associated with the q-deformed hyperbolic functions. The kink mass, the bosonic zero-mode and the q-deformed potential in 1+1 dimensions are found. (author)

  10. Cosmetic and Functional Nasal Deformities

    Science.gov (United States)

    ... nasal complaints. Nasal deformity can be categorized as “cosmetic” or “functional.” Cosmetic deformity of the nose results in a less ... taste , nose bleeds and/or recurrent sinusitis . A cosmetic or functional nasal deformity may occur secondary to ...

  11. [Babies with cranial deformity].

    Science.gov (United States)

    Feijen, Michelle M W; Claessens, Edith A W M Habets; Dovens, Anke J Leenders; Vles, Johannes S; van der Hulst, Rene R W J

    2009-01-01

    Plagiocephaly was diagnosed in a baby aged 4 months and brachycephaly in a baby aged 5 months. Positional or deformational plagio- or brachycephaly is characterized by changes in shape and symmetry of the cranial vault. Treatment options are conservative and may include physiotherapy and helmet therapy. During the last two decades the incidence of positional plagiocephaly has increased in the Netherlands. This increase is due to the recommendation that babies be laid on their backs in order to reduce the risk of sudden infant death syndrome. We suggest the following: in cases of positional preference of the infant, referral to a physiotherapist is indicated. In cases of unacceptable deformity of the cranium at the age 5 months, moulding helmet therapy is a possible treatment option.

  12. Deformed supersymmetric mechanics

    International Nuclear Information System (INIS)

    Ivanov, E.; Sidorov, S.

    2013-01-01

    Motivated by a recent interest in curved rigid supersymmetries, we construct a new type of N = 4, d = 1 supersymmetric systems by employing superfields defined on the cosets of the supergroup SU(2|1). The relevant worldline supersymmetry is a deformation of the standard N = 4, d = 1 supersymmetry by a mass parameter m. As instructive examples we consider at the classical and quantum levels the models associated with the supermultiplets (1,4,3) and (2,4,2) and find out interesting interrelations with some previous works on nonstandard d = 1 supersymmetry. In particular, the d = 1 systems with 'weak supersymmetry' are naturally reproduced within our SU(2|1) superfield approach as a subclass of the (1,4,3) models. A generalization to the N = 8, d = 1 case implies the supergroup SU(2|2) as a candidate deformed worldline supersymmetry

  13. Deformation Theory ( Lecture Notes )

    Czech Academy of Sciences Publication Activity Database

    Doubek, M.; Markl, Martin; Zima, P.

    2007-01-01

    Roč. 43, č. 5 (2007), s. 333-371 ISSN 0044-8753. [Winter School Geometry and Physics/27./. Srní, 13.01.2007-20.01.2007] R&D Projects: GA ČR GA201/05/2117 Institutional research plan: CEZ:AV0Z10190503 Keywords : deformation * Mauerer-Cartan equation * strongly homotopy Lie algebra Subject RIV: BA - General Mathematics

  14. Deformations of fractured rock

    International Nuclear Information System (INIS)

    Stephansson, O.

    1977-09-01

    Results of the DBM and FEM analysis in this study indicate that a suitable rock mass for repository of radioactive waste should be moderately jointed (about 1 joint/m 2 ) and surrounded by shear zones of the first order. This allowes for a gentle and flexible deformation under tectonic stresses and prevent the development of large cross-cutting failures in the repository area. (author)

  15. Impact of the rate of the additive process of forming a heavy structure deforming in creep on the development of its technological stresses

    Science.gov (United States)

    Parshin, Dmitry A.

    2018-05-01

    The additive process of forming a semicircular arched structure by means of layer-by-layer addition of material to its inner surface is simulated. The impact of this process running mode on the development of the technological stresses fields in the structure being formed under the action of gravity under properties of the material creep and aging is examined. In the framework of the linear mechanics of accreted solids a mathematical model of the process under study is offered and numerical experiments are conducted. It is shown that the stress-strain state of the additively formed heavy objects decisively depends on their formation mode. Various practically important trends and features of this dependence are studied.

  16. Discrete integrable systems and deformations of associative algebras

    International Nuclear Information System (INIS)

    Konopelchenko, B G

    2009-01-01

    Interrelations between discrete deformations of the structure constants for associative algebras and discrete integrable systems are reviewed. Theory of deformations for associative algebras is presented. Closed left ideal generated by the elements representing the multiplication table plays a central role in this theory. Deformations of the structure constants are generated by the deformation driving algebra and governed by the central system of equations. It is demonstrated that many discrete equations such as discrete Boussinesq equation, discrete WDVV equation, discrete Schwarzian KP and BKP equations, discrete Hirota-Miwa equations for KP and BKP hierarchies are particular realizations of the central system. An interaction between the theories of discrete integrable systems and discrete deformations of associative algebras is reciprocal and fruitful. An interpretation of the Menelaus relation (discrete Schwarzian KP equation), discrete Hirota-Miwa equation for KP hierarchy, consistency around the cube as the associativity conditions and the concept of gauge equivalence, for instance, between the Menelaus and KP configurations are particular examples.

  17. An Overview of Prognosis Health Management Research at Glenn Research Center for Gas Turbine Engine Structures With Special Emphasis on Deformation and Damage Modeling

    Science.gov (United States)

    Arnold, Steven M.; Goldberg, Robert K.; Lerch, Bradley A.; Saleeb, Atef F.

    2009-01-01

    Herein a general, multimechanism, physics-based viscoelastoplastic model is presented in the context of an integrated diagnosis and prognosis methodology which is proposed for structural health monitoring, with particular applicability to gas turbine engine structures. In this methodology, diagnostics and prognostics will be linked through state awareness variable(s). Key technologies which comprise the proposed integrated approach include (1) diagnostic/detection methodology, (2) prognosis/lifing methodology, (3) diagnostic/prognosis linkage, (4) experimental validation, and (5) material data information management system. A specific prognosis lifing methodology, experimental characterization and validation and data information management are the focal point of current activities being pursued within this integrated approach. The prognostic lifing methodology is based on an advanced multimechanism viscoelastoplastic model which accounts for both stiffness and/or strength reduction damage variables. Methods to characterize both the reversible and irreversible portions of the model are discussed. Once the multiscale model is validated the intent is to link it to appropriate diagnostic methods to provide a full-featured structural health monitoring system.

  18. An Overview of Prognosis Health Management Research at GRC for Gas Turbine Engine Structures With Special Emphasis on Deformation and Damage Modeling

    Science.gov (United States)

    Arnold, Steven M.; Goldberg, Robert K.; Lerch, Bradley A.; Saleeb, Atef F.

    2009-01-01

    Herein a general, multimechanism, physics-based viscoelastoplastic model is presented in the context of an integrated diagnosis and prognosis methodology which is proposed for structural health monitoring, with particular applicability to gas turbine engine structures. In this methodology, diagnostics and prognostics will be linked through state awareness variable(s). Key technologies which comprise the proposed integrated approach include 1) diagnostic/detection methodology, 2) prognosis/lifing methodology, 3) diagnostic/prognosis linkage, 4) experimental validation and 5) material data information management system. A specific prognosis lifing methodology, experimental characterization and validation and data information management are the focal point of current activities being pursued within this integrated approach. The prognostic lifing methodology is based on an advanced multi-mechanism viscoelastoplastic model which accounts for both stiffness and/or strength reduction damage variables. Methods to characterize both the reversible and irreversible portions of the model are discussed. Once the multiscale model is validated the intent is to link it to appropriate diagnostic methods to provide a full-featured structural health monitoring system.

  19. Deformation-induced structural changes of amorphous Ni{sub 0.5}Zr{sub 0.5} in molecular-dynamic simulations; Verformungsinduzierte Strukturaenderungen bei amorphen Ni{sub 0.5}Zr{sub 0.5} in Molekulardynamik-Simulationen

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, K

    2006-10-31

    The present work investigates the plastic deformation of metallic glasses by the aid of molecular-dynamic simulations. The parameters for the model system are adapted to those for a NiZr-alloy. In particular, the composition Ni{sub 0.5}Zr{sub 0.5} is used. The analyzed deformation simulations are conducted for small systems with 5184 atoms and large systems with 17500 atoms in a periodic simulation cell. The deformation simulations of pre-deformed samples are carried out either at constant shear-rate or at constant load, the latter mode modeling a creep experiment. Stress-strain curves for pre-deformed samples show a less pronounced stress-overshoot phenomenon. Creep-simulations of samples deformed beyond the yield region indicate a drastically reduced viscosity in these systems when compared to samples pre-deformed only up to the linear regime of the stress-strain curve. From analyzing the local atomic topology it is found that the transition from the highly viscous, hard-to-deform state of the undeformed or only weakly strained system into the easy-to-deform flow-state, present if the system is strained far beyond the yielding regime of the stress-strain curve, is connected with the formation of a region containing atoms with massive changes in their topology which is oriented along a diagonal plane of the simulation cell. The degree of localization of these deformation bands is influenced by temperature and shear-rate. In subsequent deformations of pre-deformed sam