Energy Technology Data Exchange (ETDEWEB)
Oekland, R H
1996-01-01
The conference paper relates to a project on investigating the effects of long-range transported pollutants in Norway. The paper gives a brief description of the more important results obtained in the project. The aim of the project was to investigate the pollution load in vegetation, soils and trees in Norwegian forest areas of the coniferous type. The project included the collection of samples from 200 test areas in a period of five years. 11 refs.
Alkali-aggregate reactivity (AAR) facts book.
2013-03-01
This document provides detailed information on alkali-aggregate reactivity (AAR). It primarily discusses alkali-silica reaction (ASR), covering the chemistry, symptoms, test methods, prevention, specifications, diagnosis and prognosis, and mitigation...
Aare Toikka näidend tuli lavale Budapestis
2011-01-01
Budapestis Kolibri teatris esietendus noortelavastus "Help", mille kirjutasid VAT teatri kunstiline juht Aare Toikka ja Ungari lavastja, proosa- ja näitekirjanik Peter Horvath. VAT teatri lavale jõuab "Help" 9. mail, lavastajaiks Margo Teder ja Aare Toikka
"Aarøes Strejfkorps - en dansk specialenhed i 1864"
DEFF Research Database (Denmark)
Papousek, Simon
2014-01-01
Boganmeldelse af genudgivelse af to artikler tidligere bragt i Militært Tidsskrift i slutningen af 1800-tallet, omhandlende oprettelsen, operationerne og historien om den danske specialenhed "Aarøes Strejfkorps" under Anden Slesvgiske Krig...
The Automated Aircraft Rework System (AARS): A system integration approach
Benoit, Michael J.
1994-01-01
The Mercer Engineering Research Center (MERC), under contract to the United States Air Force (USAF) since 1989, has been actively involved in providing the Warner Robins Air Logistics Center (WR-ALC) with a robotic workcell designed to perform rework automated defastening and hole location/transfer operations on F-15 wings. This paper describes the activities required to develop and implement this workcell, known as the Automated Aircraft Rework System (AARS). AARS is scheduled to be completely installed and in operation at WR-ALC by September 1994.
Parametric FEM for geometric biomembranes
Bonito, Andrea; Nochetto, Ricardo H.; Sebastian Pauletti, M.
2010-05-01
We consider geometric biomembranes governed by an L2-gradient flow for bending energy subject to area and volume constraints (Helfrich model). We give a concise derivation of a novel vector formulation, based on shape differential calculus, and corresponding discretization via parametric FEM using quadratic isoparametric elements and a semi-implicit Euler method. We document the performance of the new parametric FEM with a number of simulations leading to dumbbell, red blood cell and toroidal equilibrium shapes while exhibiting large deformations.
Unconventional material part FEM analysis
Directory of Open Access Journals (Sweden)
Michal TROPP
2016-12-01
Full Text Available The article covers the usability of alternative materials in vehicles construction. The paper elaborates upon the setup of the process and analysis of the results of carbon composite component FEM model. The 3D model, used for the examination, is a part of axle from alternative small electric vehicle. The analysis was conducted with the help of MSC Adams and Ansys Workbench software. Color maps of von Mises stress in material and total deformations of the component are the results of calculation.
Animation Augmented Reality Book Model (AAR Book Model) to Enhance Teamwork
Chujitarom, Wannaporn; Piriyasurawong, Pallop
2017-01-01
This study aims to synthesize an Animation Augmented Reality Book Model (AAR Book Model) to enhance teamwork and to assess the AAR Book Model to enhance teamwork. Samples are five specialists that consist of one animation specialist, two communication and information technology specialists, and two teaching model design specialists, selected by…
Parametric analysis of AAR influent factors on thin-walled columns
Directory of Open Access Journals (Sweden)
E. L. Madureira
Full Text Available ABSTRACTThe chemical reaction involving the alkalis of the cement and some minerals of the concrete aggregates, the Alkali-Aggregate Reaction or, simply, the AAR, promotes swelling and material damages. Despite the development stage of the researches on this pathology effects, its solution modeling still lacks refinement. The numerical simulation is an important resource for the structural damages evaluation due to AAR, and their repairs. The aim of this work is the numerical simulation of concrete thin-walled columns, affected by the AAR, from the finite element approximation on an orthotropic nonlinear framework, and a thermodynamic model designed to the assessment of the AAR swelling, with highlight on the compressive stress, the reinforcement and the temperature influences on the phenomenon. The obtained results revealed that the AAR induced the concrete strength decrease and the consequent reduction in preventive safety margin to the material failure, being more precocious at higher temperatures.
Adult Attachment Ratings (AAR): an item response theory analysis.
Pilkonis, Paul A; Kim, Yookyung; Yu, Lan; Morse, Jennifer Q
2014-01-01
The Adult Attachment Ratings (AAR) include 3 scales for anxious, ambivalent attachment (excessive dependency, interpersonal ambivalence, and compulsive care-giving), 3 for avoidant attachment (rigid self-control, defensive separation, and emotional detachment), and 1 for secure attachment. The scales include items (ranging from 6-16 in their original form) scored by raters using a 3-point format (0 = absent, 1 = present, and 2 = strongly present) and summed to produce a total score. Item response theory (IRT) analyses were conducted with data from 414 participants recruited from psychiatric outpatient, medical, and community settings to identify the most informative items from each scale. The IRT results allowed us to shorten the scales to 5-item versions that are more precise and easier to rate because of their brevity. In general, the effective range of measurement for the scales was 0 to +2 SDs for each of the attachment constructs; that is, from average to high levels of attachment problems. Evidence for convergent and discriminant validity of the scales was investigated by comparing them with the Experiences of Close Relationships-Revised (ECR-R) scale and the Kobak Attachment Q-sort. The best consensus among self-reports on the ECR-R, informant ratings on the ECR-R, and expert judgments on the Q-sort and the AAR emerged for anxious, ambivalent attachment. Given the good psychometric characteristics of the scale for secure attachment, however, this measure alone might provide a simple alternative to more elaborate procedures for some measurement purposes. Conversion tables are provided for the 7 scales to facilitate transformation from raw scores to IRT-calibrated (theta) scores.
Energy Technology Data Exchange (ETDEWEB)
Eichenberger, P.
2007-07-15
This preliminary project for the Swiss Federal Office of Energy (SFOE) presents a project which proposes the construction of a new small hydro plant in Niedergoesgen/Gretzenbach, Switzerland, that is to make use of the waters of the old river Aare. The project proposes the construction of a new, 350 kW plant at the site of an existing sill across the old river that originally formed part of a water-power installation given up in 1917. The existing parts of the old installation are described and the legal situation concerning water rights and land ownership are examined. Three variants for a new installation are described. Technical figures and energy-production estimates for a new installation are discussed. Ecological aspects are examined, as are the recreational aspects of the river at this location. Cost estimates and economic viability are discussed.
FEM-2D - Input description and performance
International Nuclear Information System (INIS)
Schmidt, F.A.R.
1975-03-01
FEM-2D solves the 2d diffusion equation by the Finite Element Method. This version of the code was written for x-y geometry, triangular elements with first and second order flux approximations, and has a solution routine which is based on a modified Cholesky procedure. FEM-2D is fully integrated into the modular system RSYST. However, we have developed a simulation program RSIMK which simulates some of the functions of RSYST and allows to run FEM-2D independently. (orig.) [de
Aare Tool. Piiratud transponeeritavusega heliread ja vorm Eduard Oja muusikas / Mart Jaanson
Jaanson, Mart, 1966-
2017-01-01
Arvustus: Aare Tool. Piiratud transponeeritavusega heliread ja vorm Eduard Oja muusikas. Doktoritöö, Eesti Muusika- ja Teatriakadeemia Väitekirjad 7, Tallinn: Eesti Muusika- ja Teatriakadeemia, 2016, 125 lk.
Teletorn muutub magnetiks / Oliver Õunmaa ; kommenteerinud Aare Siimon, Raili Paling
Õunmaa, Oliver
2010-01-01
Aprillis algab aasta aega kestev Tallinna teletorni remont, mille käigus tehtavate muudatuste kohta jagavad selgitusi torni haldava ettevõtte Levira finantsdirektor Aare Siimon ja Arhitektuuribüroo Koko arhitekt Raili Paling
Guide to diagnosis and appraisal of AAR damage to concrete in structures
Rooij, Mario; Wood, Jonathan
2013-01-01
This book describes procedures and methodologies used predominantly to obtain a diagnosis of damaged concrete possibly caused by Alkali-Aggregate Reaction (AAR). It has two primary objectives, namely firstly to identify the presence of AAR reaction, and whether or not the reaction is the primary or contributory cause of damage in the concrete; and secondly, to establish its intensity (severity) in various members of a structure. It includes aspects such as field inspection of the structure, sampling, petrographic examination of core samples, and supplementary tests and analyses on cores, such as mechanical tests and chemical analysis. Evaluation of test data for prognosis, consequences and appraisal will be more fully set out in AAR-6.2.
Simulation of HMA compaction by using FEM
ter Huerne, H.L.; van Maarseveen, M.F.A.M.; Molenaar, A.A.A.; van de Ven, M.F.C.
2008-01-01
This paper introduces a simulation tool for the compaction process of Hot Mix Asphalt (HMA) using a roller under varying external conditions. The focus is on the use of the Finite Element Model (FEM) with code DiekA, on its necessary requirements and on the presentation of simulation results. The
FEM growth and yield data monocultures - Poplar
Mohren, G.M.J.; Goudzwaard, L.; Jansen, J.J.; Oosterbaan, A.; Oldenburger, J.F.; Ouden, den J.
2016-01-01
The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species, with only a few plots,
The timing of the maximum extent of the Rhone Glacier at Wangen a.d. Aare
Energy Technology Data Exchange (ETDEWEB)
Ivy-Ochs, S.; Schluechter, C. [Bern Univ. (Switzerland); Kubik, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Beer, J. [EAWAG, Duebendorf (Switzerland)
1997-09-01
Erratic blocks found in the region of Wangen a.d. Aare delineate the maximum position of the Solothurn lobe of the Rhone Glacier. {sup 10}Be and {sup 26}Al exposure ages of three of these blocks show that the glacier withdraw from its maximum position at or slightly before 20,000{+-}1800 years ago. (author) 1 fig., 5 refs.
Piimatööstused kukkusid kahjumisse / Aare Annus ; interv. Silja Lättemäe
Annus, Aare
2005-01-01
Tallinna Piimatööstuse AS-i nõukogu esimees Aare Annus Eesti piimatööstuste raskest olukorrast seoses toorpiima kõrge kokkuostuhinnaga. Vt. ka: Kas saite piimahinnast kõva kasumit? Küsimusele vastavad Järvamaa talunik Arvo Kuutok ja Põlva Agro OÜ nõukogu esimees Jaak Hinrikus
Estonia : a European tax paradise? / Aare Kurist, Madis Müller
Kurist, Aare, 1974-
2003-01-01
PricewaterhouseCoopersi maksuosakonna juhataja Aare Kurist ja peaministri majandusnõunik Madis Müller analüüsivad 2000. aastal toimunud maksureformi eesmärke ja nende täitmist, prognoosivad EL-i liitumisläbirääkimiste võimalikku mõju Eesti maksupoliitikale ja võimalikku vajadust tulevikus Eesti maksukorralduse muutmiseks
Aare Sosaar nõuab sisse ERA Panga halbu laene / Tiit Elner
Elner, Tiit
2000-01-01
Ekspankur Aare Sosaare juhitav teadmata omanikega ERA Liising ostis pankrotis ERA Pangalt probleemseid laene, suurem nõuete ostja oli ka Krediidipank. Kokku on müüdud laenude lepingujärgne väärtus kuni 100 mln. kr.
The program FEM3D users manual
International Nuclear Information System (INIS)
Misfeldt, I.
1977-11-01
A short description of the program FEM3D that solves the three-dimensional, multigroup, neutron diffusion equation by the finite element method. The elements are box-formed Lagrange type elements of order 1, 2, or 3. The program gives very reliable results within reasonable calculation times, but it is not a fast program and should therefore mostly be used where high precision is needed. (author/BP)
Ribeiro, Maria; Broekmans, Maarten; Sims, Ian
2016-01-01
This RILEM AAR 1.2 Atlas is complementary to the petrographic method described in RILEM AAR 1.1. It is designed and intended to assist in the identification of alkali-reactive rock types in concrete aggregate by thin-section petrography. Additional issues include: • optical thin-section petrography conforming to RILEM AAR 1.1 is considered the prime assessment method for aggregate materials, being effective regarding cost and time. Unequivocal identification of minerals in very-fine grained rock types may however require use of supplementary methods. • the atlas adheres to internationally adopted schemes for rock classification and nomenclature, as recommended in AAR 1.1. Thus, rock types are classified as igneous, sedimentary or metamorphic based upon mineral content, microstructure and texture/fabric. • in addition, the atlas identifies known alkali-reactive silica types in each rock type presented. It also identifies consistent coincidence between certain lithologies and silica types; however, it ref...
Spacetime Discontinuous Galerkin FEM: Spectral Response
International Nuclear Information System (INIS)
Abedi, R; Omidi, O; Clarke, P L
2014-01-01
Materials in nature demonstrate certain spectral shapes in terms of their material properties. Since successful experimental demonstrations in 2000, metamaterials have provided a means to engineer materials with desired spectral shapes for their material properties. Computational tools are employed in two different aspects for metamaterial modeling: 1. Mircoscale unit cell analysis to derive and possibly optimize material's spectral response; 2. macroscale to analyze their interaction with conventional material. We compare two different approaches of Time-Domain (TD) and Frequency Domain (FD) methods for metamaterial applications. Finally, we discuss advantages of the TD method of Spacetime Discontinuous Galerkin finite element method (FEM) for spectral analysis of metamaterials
Energy Technology Data Exchange (ETDEWEB)
Sasaki, Y [Kyushu University, Fukuoka (Japan). Faculty of Engineering
1996-10-01
Analytical methods considering 3-D resistivity distribution, in particular, finite element method (FEM) were studied to improve the reliability of electromagnetic exploration. Integral equation, difference calculus, FEM and hybrid method are generally used as computational 3-D modeling method. FEM is widely used in various fields because FEM can easily handle complicated shapes and boundaries. However, in electromagnetic method, the assumption of continuous electric field is pointed out as important problem. The normal (orthogonal) component of current density should be continuous at the boundary between media with different conductivities, while this means that the normal component of electric field is discontinuous. In FEM, this means that current channeling is not properly considered, resulting in poor accuracy. Unless this problem is solved, FEM modeling is not practical. As one of the solutions, it is promising to specifically incorporate interior boundary conditions into element equation. 4 refs., 11 figs.
Financial security for women -- Fem Consult congress.
1996-01-01
The nongovernmental organization "Fem Consult," which seeks to strengthen the socioeconomic position of women by applying a gender perspective to programs and projects in developing countries, celebrated its 10th anniversary in 1996 by holding a conference in the Netherlands on financial security for women in the developing world. During the conference, the President of the WWF (Working Women's Forum) described her agency's 17 years of experience in lending to impoverished rural and urban women in India. By extending microcredit assistance through a network of cooperatives, the WWF has been the catalyst for lasting improvements in the economic and social status of impoverished women. Representatives of the Grameen Bank, Women's World Banking, the Ecumenical Development Cooperative Society, and other organizations also addressed the conference.
Stress And Strain Analysis of The Hip Joint Using FEM
Czech Academy of Sciences Publication Activity Database
Vaverka, M.; Návrat, Tomáš; Vrbka, M.; Florian, Z.; Fuis, Vladimír
2006-01-01
Roč. 14, 4-5 (2006), s. 271-279 ISSN 0928-7329 R&D Projects: GA ČR GA101/05/0136 Institutional research plan: CEZ:AV0Z20760514 Keywords : hip FEM surgace replacement pathological contact pressure stress * hip FEM surgace replacement pathological contact pressure stress Subject RIV: BO - Biophysics
Advanced HVAC modeling with FemLab/Simulink/MatLab
Schijndel, van A.W.M.
2003-01-01
The combined MatLab toolboxes FemLab and Simulink are evaluated as solvers for HVAC problems based on partial differential equations (PDEs). The FemLab software is designed to simulate systems of coupled PDEs, 1-D, 2-D or 3-D, nonlinear and time dependent. In order to show how the program works, a
Chemoinformatics Profiling of the Chromone Nucleus as a MAO-B/A2AAR Dual Binding Scaffold.
Cruz-Monteagudo, Maykel; Borges, Fernanda; Cordeiro, M Natalia D S; Helguera, Aliuska Morales; Tejera, Eduardo; Paz-Y-Mino, Cesar; Sanchez-Rodriguez, Aminael; Perera-Sardina, Yunier; Perez-Castillo, Yunierkis
2017-11-14
In the context of the current drug discovery efforts to find disease modifying therapies for Parkinson's disease (PD) the current single target strategy has proved inefficient. Consequently, the search for multi-potent agents is attracting more and more attention due to the multiple pathogenetic factors implicated in PD. Multiple evidences points to the dual inhibition of the monoamine oxidase B (MAO-B), as well as adenosine A2A receptor (A2AAR) blockade, as a promising approach to prevent the neurodegeneration involved in PD. Currently, only two chemical scaffolds has been proposed as potential dual MAO-B inhibitors/A2AAR antagonists (caffeine derivatives and benzothiazinones). In this study, we conduct a series of chemoinformatics analysis in order to evaluate and advance the potential of the chromone nucleus as a MAO-B/A2AAR dual binding scaffold. The information provided by SAR data mining analysis based on network similarity graphs and molecular docking studies support the suitability of the chromone nucleus as a potential MAOB/ A2AAR dual binding scaffold. Additionally, a virtual screening tool based on a group fusion similarity search approach was developed for the prioritization of potential MAO-B/A2AAR dual binder candidates. Among several data fusion schemes evaluated, the MEAN-SIM and MIN-RANK GFSS approaches demonstrated to be efficient virtual screening tools. Then, a combinatorial library potentially enriched with MAO-B/A2AAR dual binding chromone derivatives was assembled and sorted by using the MIN-RANK and then the MEAN-SIM GFSS VS approaches. The information and tools provided in this work represent valuable decision making elements in the search of novel chromone derivatives with a favorable dual binding profile as MAOB inhibitors and A2AAR antagonists with the potential to act as a disease-modifying therapeutic for Parkinson's disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
AAR at Hydro-Quebec : a review of field cases and intervention strategies
Energy Technology Data Exchange (ETDEWEB)
Durand, B. [Hydro-Quebec, Varennes, PQ (Canada). IREQ
2006-07-01
Hydro-Quebec owns and operates more than 560 dams, including 200 dams that are classified as large dams. By 2010, approximately 150 of the concrete dams will be at least 50 years old, and nearly 100 of the dams will be 70 years old. The current condition of these structures reflects the influence of several factors that have promoted aging, such as initial shrinkage causing latent microcracking; expansion and contraction related to temperature cycles; larger infiltration entailing increased uplift; leaching and deposition of calcium salts that clog joints and drains; hydric swelling; freezing and thawing cycles; erosion; sulfation; and, alkali-aggregate reactions (AAR). This paper focused on the swelling due to AAR, since more than 20 dams have been affected by this condition. Hydro-Quebec's approach to prevent AAR was described. In response to Canadian Standards Association (CSA) concrete expansion tests, Hydro-Quebec no longer allows admixtures for its concrete structures. Rather, non-reactive aggregates are used in the concrete. This paper also discussed the evaluation of residual expansion time caused by the alkali-silica reaction (ASR), which has affected the dam at La Tuque in the Mauricie Region. Results of laboratory expansion tests have been compared with the average expansion rate measured at the La Tuque dam. It was estimated that the concrete should continue to swell for at least 20 years at the same rate as measured since 1979. After that, expansion may possibly slow down due to self-confinement in the concrete. However, if confinement increases in 2 directions, it is probable that the expansion accelerates in the third direction. 26 refs., 3 tabs., 8 figs.
International Nuclear Information System (INIS)
Pelloni, S.; Stepanek, J.; Vontobel, P.
1989-01-01
The capability of the advanced analysis of reactor engineering (AARE) modular code system and JEF-1-based nuclear data libraries to analyze light water high converter reactor (LWHCR) lattices is investigated by calculating the wet and dry cells of the PROTEUS-LWHCR phase II experiment. The results are compared to those obtained using several cell codes. Main features of the AARE code system, such as the self-shielding of resonance cross sections in the whole energy range, the generation of adequate fission source spectra, and the efficiency of the elastic removal correction,are investigated. In particular, it is shown that AARE results for the k ∞ void coefficient agree very well with the experiment, whereas other codes give larger deviations
Lu, Jun; Xiao, Jun; Gao, Dong Jun; Zong, Shu Yu; Li, Zhu
2018-03-01
In the production of the Association of American Railroads (AAR) locomotive wheel-set, the press-fit curve is the most important basis for the reliability of wheel-set assembly. In the past, Most of production enterprises mainly use artificial detection methods to determine the quality of assembly. There are cases of miscarriage of justice appear. For this reason, the research on the standard is carried out. And the automatic judgment of press-fit curve is analysed and designed, so as to provide guidance for the locomotive wheel-set production based on AAR standard.
User's Manual for FEM-BEM Method. 1.0
Butler, Theresa; Deshpande, M. D. (Technical Monitor)
2002-01-01
A user's manual for using FORTRAN code to perform electromagnetic analysis of arbitrarily shaped material cylinders using a hybrid method that combines the finite element method (FEM) and the boundary element method (BEM). In this method, the material cylinder is enclosed by a fictitious boundary and the Maxwell's equations are solved by FEM inside the boundary and by BEM outside the boundary. The electromagnetic scattering on several arbitrarily shaped material cylinders using this FORTRAN code is computed to as examples.
Gomez, Sandra; Adalid-Peralta, Laura; Palafox-Fonseca, Hector; Cantu-Robles, Vito Adrian; Soberón, Xavier; Sciutto, Edda; Fragoso, Gladis; Bobes, Raúl J; Laclette, Juan P; Yauner, Luis del Pozo; Ochoa-Leyva, Adrián
2015-05-19
Excretory/Secretory (ES) proteins play an important role in the host-parasite interactions. Experimental identification of ES proteins is time-consuming and expensive. Alternative bioinformatics approaches are cost-effective and can be used to prioritize the experimental analysis of therapeutic targets for parasitic diseases. Here we predicted and functionally annotated the ES proteins in T. solium genome using an integration of bioinformatics tools. Additionally, we developed a novel measurement to evaluate the potential antigenicity of T. solium secretome using sequence length and number of antigenic regions of ES proteins. This measurement was formalized as the Abundance of Antigenic Regions (AAR) value. AAR value for secretome showed a similar value to that obtained for a set of experimentally determined antigenic proteins and was different to the calculated value for the non-ES proteins of T. solium genome. Furthermore, we calculated the AAR values for known helminth secretomes and they were similar to that obtained for T. solium. The results reveal the utility of AAR value as a novel genomic measurement to evaluate the potential antigenicity of secretomes. This comprehensive analysis of T. solium secretome provides functional information for future experimental studies, including the identification of novel ES proteins of therapeutic, diagnosis and immunological interest.
Fabbri, S. C.; Buechi, M. W.; Horstmeyer, H.; Hilbe, M.; Hübscher, C.; Schmelzbach, C.; Weiss, B.; Anselmetti, F. S.
2018-05-01
To investigate the history of the Aare Glacier and its overdeepened valley, a high-resolution multibeam bathymetric dataset and a 2D multi-channel reflection seismic dataset were acquired on perialpine Lake Thun (Switzerland). The overdeepened basin was formed by a combination of tectonically predefined weak zones and glacial erosion during several glacial cycles. In the deepest region of the basin, top of bedrock lies at ∼200 m below sea level, implying more than 750 m of overdeepening with respect to the current fluvial base level (i.e. lake level). Seismic stratigraphic analysis reveals the evolution of the basin and indicates a subaquatic moraine complex marked by high-amplitude reflections below the outermost edge of a morphologically distinct platform in the southeastern part of the lake. This stack of seven subaquatic terminal moraine crests was created by a fluctuating, "quasi-stagnant" grounded Aare Glacier during its overall recessional phase. Single packages of overridden moraine crests are seismically distuinguishable, which show a transition downstream into prograding clinoforms with foresets at the ice-distal slope. The succession of subaquatic glacial sequences (foresets and adjacent bottomsets) represent one fifth of the entire sedimentary thickness. Exact time constraints concerning the deglacial history of the Aare Glacier are very sparse. However, existing 10Be exposure ages from the accumulation area of the Aare Glacier and radiocarbon ages from a Late-Glacial lake close to the outlet of Lake Thun indicate that the formation of the subaquatic moraine complex and the associated sedimentary infill must have occurred in less than 1000 years, implying high sedimentation rates and rapid disintegration of the glacier. These new data improve our comprehension of the landforms associated with the ice-contact zone in water, the facies architecture of the sub- to proglacial units, the related depositional processes, and thus the retreat mechanisms of
Directory of Open Access Journals (Sweden)
L. Sanchez
Full Text Available There are many test methods used in the laboratory to detect potential alkali-aggregate reactions (AAR. However, up to now, there is no consensus if they are reliable and efficient. This work presents the development of a new and accelerated concrete prism test called ABCPT (accelerate Brazilian concrete prism test as an attempt to create a reliable and fast test that can analyze and classify the potential reactivity of aggregates in the laboratory. For this research, six aggregates from different lithotypes were used. The methods CPT, ACPT and ABCPT were carried out with all the aggregates and a comparative analysis among all tests was performed. ABCPT seems to have a great potential to analyze and classify aggregates in the laboratory, although it needs further testing with other lithotypes to be confirmed as feasible.
The small hydropower plant in the old river Aare in Niedergoesgen, Switzerland
International Nuclear Information System (INIS)
Eichenberger, P.
2007-07-01
This preliminary project for the Swiss Federal Office of Energy (SFOE) presents a project which proposes the construction of a new small hydro plant in Niedergoesgen/Gretzenbach, Switzerland, that is to make use of the waters of the old river Aare. The project proposes the construction of a new, 350 kW plant at the site of an existing sill across the old river that originally formed part of a water-power installation given up in 1917. The existing parts of the old installation are described and the legal situation concerning water rights and land ownership are examined. Three variants for a new installation are described. Technical figures and energy-production estimates for a new installation are discussed. Ecological aspects are examined, as are the recreational aspects of the river at this location. Cost estimates and economic viability are discussed.
FEM analysis of impact of external objects to pipelines
Energy Technology Data Exchange (ETDEWEB)
Gracie, Robert; Konuk, Ibrahim [Geological Survey of Canada, Ottawa, ON (Canada)]. E-mail: ikonuk@NRCan.gc.ca; Fredj, Abdelfettah [BMT Fleet Technology Limited, Ottawa, ON (Canada)
2003-07-01
One of the most common hazards to pipelines is impact of external objects. Earth moving machinery, farm equipment or bullets can dent or fail land pipelines. External objects such as anchors, fishing gear, ice can damage offshore pipelines. This paper develops an FEM model to simulate the impact process and presents investigations using the FEM model to determine the influence of the geometry and velocity of the impacting object and also will study the influence of the pipe diameter, wall thickness, and concrete thickness along with internal pressure. The FEM model is developed by using LS-DYNA explicit FEM software utilizing shell and solid elements. The model allows damage and removal of the concrete and corrosion coating elements during impact. Parametric studies will be presented relating the dent size to pipe diameter, wall thickness and concrete thickness, internal pipe pressure, and impacting object geometry. The primary objective of this paper is to develop and present the FEM model. The model can be applied to both offshore and land pipeline problems. Some examples are used to illustrate how the model can be applied to real life problems. A future paper will present more detailed parametric studies. (author)
Rapid Structural Design Change Evaluation with AN Experiment Based FEM
Chu, C.-H.; Trethewey, M. W.
1998-04-01
The work in this paper proposes a dynamic structural design model that can be developed in a rapid fashion. The approach endeavours to produce a simplified FEM developed in conjunction with an experimental modal database. The FEM is formulated directly from the geometry and connectivity used in an experimental modal test using beam/frame elements. The model sacrifices fine detail for a rapid development time. The FEM is updated at the element level so the dynamic response replicates the experimental results closely. The physical attributes of the model are retained, making it well suited to evaluate the effect of potential design changes. The capabilities are evaluated in a series of computational and laboratory tests. First, a study is performed with a simulated cantilever beam with a variable mass and stiffness distribution. The modal characteristics serve as the updating target with random noise added to simulate experimental uncertainty. A uniformly distributed FEM is developed and updated. The results show excellent results, all natural frequencies are within 0·001% with MAC values above 0·99. Next, the method is applied to predict the dynamic changes of a hardware portal frame structure for a radical design change. Natural frequency predictions from the original FEM differ by as much as almost 18% with reasonable MAC values. The results predicted from the updated model produce excellent results when compared to the actual hardware changes, the first five modal natural frequency difference is around 5% and the corresponding mode shapes producing MAC values above 0·98.
Energy Technology Data Exchange (ETDEWEB)
Higuchi, M; Ando, K; Shimada, S; Umetani, H [Toyota Motor Corp., Aichi (Japan)
1990-04-25
In order to apply FEM (finite element method) flow analysis to environmental engineering, the two-dimensional analysis system was developed, and applied to the design of plant ventilation and improvement of an enviromental control equipment. Furthermore, the three-dimensional analysis system was developed to extend its application. Since in a large scale model, no enhancement of a processing capacity was expected even by a supercomputer because of longer I/O times between internal and external memories caused by a small internal memory space, the parallel processing system with multiple external memories was introduced to analyze such models. To achieve more efficient processing, multiple series of renumbering codes were also prepared to optimize the processing order of solvers, elements and nodes. As examples, the improvement of a thermal oxidizer and the ventilation design for a forging plant, and as an example of a three-dimensional large scale model, the flow analysis around a plant were presented. 8 refs., 17 figs., 1 tab.
On a Weak Discrete Maximum Principle for hp-FEM
Czech Academy of Sciences Publication Activity Database
Šolín, Pavel; Vejchodský, Tomáš
-, č. 209 (2007), s. 54-65 ISSN 0377-0427 R&D Projects: GA ČR(CZ) GA102/05/0629 Institutional research plan: CEZ:AV0Z20570509; CEZ:AV0Z10190503 Keywords : discrete maximum principle * hp-FEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.943, year: 2007
The concepts and functions of a FEM workstation
International Nuclear Information System (INIS)
Brown, R.R.; Gloudeman, J.F.
1982-01-01
Recent advances in microprocessor-based computer hardware and associated software provide a basis for the development of a FEM workstation. The key requirements for such a workstation are reviewed and the recent hardware and software developments are discussed that make such a workstation both technically and economically feasible at this time. (orig.)
Initial experiments with the FOM-Fusion-FEM
International Nuclear Information System (INIS)
Verhoeven, A.G.A.; Bongers, W.A.; Caplan, M.; Dijk, G. van; Elzendoorn, B.S.Q.
1995-01-01
A Free Electron Maser is being built for ECRH applications on future fusion research devices such as ITER. A unique feature of the Dutch FOM-Fusion-FEM is the possibility to tune the frequency over the entire range from 130 to 260 GHz while the output power exceeds 1 MW
Evaluating DEM results with FEM perspectives of load : soil interaction
Tadesse, D.
2004-01-01
Keywords: Load - soil interaction, soil structure, soil mechanical properties, FEM (Finite Element Method), Plaxis (Finite Element Code), granular particles, shear stress, DEM (Distinct Element Method),
FEM growth and yield data monocultures - White willow
Jansen, J.J.; Oosterbaan, A.; Goudzwaard, L.; Oldenburger, J.F.; Mohren, G.M.J.; Ouden, den J.
2016-01-01
The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species, with only a few plots,
FEM growth and yield data Monocultures - Poplar (revised version)
Mohren, G.M.J.; Goudzwaard, L.; Jansen, J.J.; Schmidt, P.; Oosterbaan, A.; Oldenburger, J.; Ouden, den J.
2017-01-01
The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species with only a few plots,
FEM simulation of multi step forming of thick sheet
Wisselink, H.H.; Huetink, Han
2004-01-01
A case study has been performed on the forming of an industrial product. This product, a bracket, is made of 5mm thick sheet in multiple steps. The process exists of a bending step followed by a drawing and a flanging step. FEM simulations have been used to investigate this forming process. First,
FEM simulation of static loading test of the Omega beam
Bílý, Petr; Kohoutková, Alena; Jedlinský, Petr
2017-09-01
The paper deals with a FEM simulation of static loading test of the Omega beam. Omega beam is a precast prestressed high-performance concrete element with the shape of Greek letter omega. Omega beam was designed as a self-supporting permanent formwork member for construction of girder bridges. FEM program ATENA Science was exploited for simulation of load-bearing test of the beam. The numerical model was calibrated using the data from both static loading test and tests of material properties. Comparison of load-displacement diagrams obtained from the experiment and the model was conducted. Development of cracks and crack patterns were compared. Very good agreement of experimental data and the FEM model was reached. The calibrated model can be used for design of optimized Omega beams in the future without the need of expensive loading tests. The calibrated material model can be also exploited in other types of FEM analyses of bridges constructed with the use of Omega beams, such as limit state analysis, optimization of shear connectors, prediction of long-term deflections or prediction of crack development.
Modification of the FEM3 model to ensure mass conservation
International Nuclear Information System (INIS)
Gresho, P.M.
1987-01-01
The problem of global mass conservation (lack thereof) in the current anelastic equations solved by FEM3 is described and its cause explained. The additional equations necessary to solve the problem are presented and methods for their incorporation into the current code are suggested. 14 refs
FEM growth and yield data monocultures - other species
Goudzwaard, L.; Jansen, J.J.; Oosterbaan, A.; Oldenburger, J.F.; Mohren, G.M.J.; Ouden, den J.
2016-01-01
The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species, with only a few plots,
Utilization of FEM model for steel microstructure determination
Kešner, A.; Chotěborský, R.; Linda, M.; Hromasová, M.
2018-02-01
Agricultural tools which are used in soil processing, they are worn by abrasive wear mechanism cases by hard minerals particles in the soil. The wear rate is influenced by mechanical characterization of tools material and wear rate is influenced also by soil mineral particle contents. Mechanical properties of steel can be affected by a technology of heat treatment that it leads to a different microstructures. Experimental work how to do it is very expensive and thanks to numerical methods like FEM we can assumed microstructure at low cost but each of numerical model is necessary to be verified. The aim of this work has shown a procedure of prediction microstructure of steel for agricultural tools. The material characterizations of 51CrV4 grade steel were used for numerical simulation like TTT diagram, heat capacity, heat conduction and other physical properties of material. A relationship between predicted microstructure by FEM and real microstructure after heat treatment shows a good correlation.
An Integrated NDE and FEM Characterization of Composite Rotors
Abdul-Aziz, Ali; Baaklini, George Y.; Trudell, Jeffrey J.
2000-01-01
A structural assessment by integrating finite-element methods (FEM) and a nondestructive evaluation (NDE) of two flywheel rotor assemblies is presented. Composite rotor A is pancake like with a solid hub design, and composite rotor B is cylindrical with a hollow hub design. Detailed analyses under combined centrifugal and interference-fit loading are performed. Two- and three-dimensional stress analyses and two-dimensional fracture mechanics analyses are conducted. A comparison of the structural analysis results obtained with those extracted via NDE findings is reported. Contact effects due to press-fit conditions are evaluated. Stress results generated from the finite-element analyses were corroborated with the analytical solution. Cracks due to rotational loading up to 49 000 rpm for rotor A and 34 000 rpm for rotor B were successfully imaged with NDE and predicted with FEM and fracture mechanics analyses. A procedure that extends current structural analysis to a life prediction tool is also defined.
Construction of compact FEM using solenoid-induced helical wiggler
International Nuclear Information System (INIS)
Ohigashi, N.; Tsunawaki, Y.; Fujita, M.; Imasaki, K.; Mima, K.; Nakai, S.
2003-01-01
A prototype of compact Free-Electron Maser (FEM) has been designed for the operation in a usual small laboratory which does not have electric source capacity available enough. The electron energy is 60-120 keV. As it is lower, stronger guiding magnetic field is necessary in addition to wiggler field. To fulfil this condition a solenoid-induced helical wiggler is applied from the viewpoint of saving the electric power of restricted source capacity. The wiggler, for example, with the period of 12 mm creates the field of 92 G in the guiding field of 3.2 kG. The whole system of FEM has been just constructed in a small-scale laboratory. It is so small to occupy the area of 0.7x2.9 m 2
Comparative FEM-based Analysis of Multiphase Induction Motor
Directory of Open Access Journals (Sweden)
Leonard Livadaru
2014-09-01
Full Text Available This paper presents a comparative study of multiphase induction motor, which has alternately three-, five- and six-phase stator winding. The machine has been designed particularly for this purpose and has individual ring coils placed in each stator slot. The study consists in FEM analyses and mainly looks for the particularities of magnetic quantities such as air-gap flux density and electromagnetic torque.
Effect of Cervical Lessions on the Tooth FEM Study
Gabriela Bereşescu; Ligia Brezeanu; Claudia Şoaita
2010-01-01
The approach used until recently concerning the phenomena of dental abfraction points to the conclusion that the cervical area of the tooth, were this type of lesion usually occur, concentrates the stress resulted from the action of the forces applied on various areas on the crown. Moreover, any lesion in the cervical area facilitates the possibility of its advance into the tooth, ultimately fracturing it. Our paper presents a FEM (finite element method) study on the results of a mechanical a...
Mode splitting effect in FEMs with oversized Bragg resonators
Energy Technology Data Exchange (ETDEWEB)
Peskov, N. Yu.; Sergeev, A. S. [Institute of Applied Physics Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Kaminsky, A. K.; Perelstein, E. A.; Sedykh, S. N. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kuzikov, S. V. [Institute of Applied Physics Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Nizhegorodsky State University, Nizhny Novgorod (Russian Federation)
2016-07-15
Splitting of the fundamental mode in an oversized Bragg resonator with a step of the corrugation phase, which operates over the feedback loop involving the waveguide waves of different transverse structures, was found to be the result of mutual influence of the neighboring zones of the Bragg scattering. Theoretical description of this effect was developed within the framework of the advanced (four-wave) coupled-wave approach. It is shown that mode splitting reduces the selective properties, restricts the output power, and decreases the stability of the narrow-band operating regime in the free-electron maser (FEM) oscillators based on such resonators. The results of the theoretical analysis were confirmed by 3D simulations and “cold” microwave tests. Experimental data on Bragg resonators with different parameters in a 30-GHz FEM are presented. The possibility of reducing the mode splitting by profiling the corrugation parameters is shown. The use of the mode splitting effect for the output power enhancement by passive compression of the double-frequency pulse generated in the FEM with such a resonator is discussed.
RF Wave Simulation Using the MFEM Open Source FEM Package
Stillerman, J.; Shiraiwa, S.; Bonoli, P. T.; Wright, J. C.; Green, D. L.; Kolev, T.
2016-10-01
A new plasma wave simulation environment based on the finite element method is presented. MFEM, a scalable open-source FEM library, is used as the basis for this capability. MFEM allows for assembling an FEM matrix of arbitrarily high order in a parallel computing environment. A 3D frequency domain RF physics layer was implemented using a python wrapper for MFEM and a cold collisional plasma model was ported. This physics layer allows for defining the plasma RF wave simulation model without user knowledge of the FEM weak-form formulation. A graphical user interface is built on πScope, a python-based scientific workbench, such that a user can build a model definition file interactively. Benchmark cases have been ported to this new environment, with results being consistent with those obtained using COMSOL multiphysics, GENRAY, and TORIC/TORLH spectral solvers. This work is a first step in bringing to bear the sophisticated computational tool suite that MFEM provides (e.g., adaptive mesh refinement, solver suite, element types) to the linear plasma-wave interaction problem, and within more complicated integrated workflows, such as coupling with core spectral solver, or incorporating additional physics such as an RF sheath potential model or kinetic effects. USDoE Awards DE-FC02-99ER54512, DE-FC02-01ER54648.
3D FEM Simulation of Flank Wear in Turning
Attanasio, Aldo; Ceretti, Elisabetta; Giardini, Claudio
2011-05-01
This work deals with tool wear simulation. Studying the influence of tool wear on tool life, tool substitution policy and influence on final part quality, surface integrity, cutting forces and power consumption it is important to reduce the global process costs. Adhesion, abrasion, erosion, diffusion, corrosion and fracture are some of the phenomena responsible of the tool wear depending on the selected cutting parameters: cutting velocity, feed rate, depth of cut, …. In some cases these wear mechanisms are described by analytical models as a function of process variables (temperature, pressure and sliding velocity along the cutting surface). These analytical models are suitable to be implemented in FEM codes and they can be utilized to simulate the tool wear. In the present paper a commercial 3D FEM software has been customized to simulate the tool wear during turning operations when cutting AISI 1045 carbon steel with uncoated tungsten carbide tip. The FEM software was improved by means of a suitable subroutine able to modify the tool geometry on the basis of the estimated tool wear as the simulation goes on. Since for the considered couple of tool-workpiece material the main phenomena generating wear are the abrasive and the diffusive ones, the tool wear model implemented into the subroutine was obtained as combination between the Usui's and the Takeyama and Murata's models. A comparison between experimental and simulated flank tool wear curves is reported demonstrating that it is possible to simulate the tool wear development.
Energy Technology Data Exchange (ETDEWEB)
Beltzig, C.; Schlageter, G.
1996-12-31
For the first barrage weir after the confluence of the Rhine and Aare rivers, a maximum storage level is determined and set that constitutes an operating optimum and takes the different inflow and outfall volumes as well as existing retention capacities into account. Moreover, the process control system ensures automatic operation of the three engine units of the power station including process control of the barrage weir and the external systems belonging to the Albbruck-Doggern hydroelectric power station on the Rhine (RADAG). (orig./RHM)
Bansagi, Boglarka; Antoniadi, Thalia; Burton-Jones, Sarah; Murphy, Sinead M; McHugh, John; Alexander, Michael; Wells, Richard; Davies, Joanna; Hilton-Jones, David; Lochmüller, Hanns; Chinnery, Patrick; Horvath, Rita
2015-08-01
Charcot-Marie-Tooth disease (CMT) is the most common inherited neuropathy with heterogeneous clinical presentation and genetic background. The axonal form (CMT2) is characterised by decreased action potentials indicating primary axonal damage. The underlying pathology involves axonal degeneration which is supposed to be related to axonal protein dysfunction caused by various gene mutations. The overlapping clinical manifestation of CMT2 with distal hereditary motor neuropathy (dHMN) and intermediate CMT causes further diagnostic difficulties. Aminoacyl-tRNA synthetases have been implicated in the pathomechanism of CMT2. They have an essential role in protein translation by attaching amino acids to their cognate tRNAs. To date six families have been reported worldwide with dominant missense alanyl-tRNA synthetase (AARS) mutations leading to clinically heterogeneous axonal neuropathies. The pathomechanism of some variants could be explained by impaired amino acylation activity while other variants implicating an editing defect need to be further investigated. Here, we report a cohort of six additional families originating from the United Kingdom and Ireland with dominant AARS-related neuropathies. The phenotypic manifestation was distal lower limb predominant sensorimotor neuropathy but upper limb impairment with split hand deformity occasionally associated. Nerve conduction studies revealed significant demyelination accompanying the axonal lesion in motor and sensory nerves. Five families have the c.986G>A, p.(Arg329His) variant, further supporting that this is a recurrent loss of function variant. The sixth family, of Irish origin, had a novel missense variant, c.2063A>G, p.(Glu688Gly). We discuss our findings and the associated phenotypic heterogeneity in these families, which expands the clinical spectrum of AARS-related neuropathies.
Herwegh, Marco; Baumberger, Roland; Wehrens, Philip; Schubert, Raphael; Berger, Alfons; Maeder, Urs; Spillmann, Thomas
2014-05-01
The successful use of deep geothermal energy requires 3D flow paths, which allow an efficient heat exchange between the surrounding host rocks and the circulating fluids. Recent attempts to exploit this energy resource clearly demonstrate that the new technology is facing sever problems. Some major problems are related to the prediction of permeability, the 3D structure of the flow paths and the mechanical responses during elevated fluid pressures at depths of several kilometers. Although seemingly new in a technical perspective, nature is facing and solving similar problems since the beginning of the Alpine orogeny. Based on detailed studies in the Hasli Valley (Aar Massif) we can demonstrate that deformation and fluid flow are strongly localized along mechanical anisotropies (e.g. lithological variations, brittle and ductile faults). Some of them already evolved during Variscan and post-Variscan times. Interestingly, these inherited structures are reactivated over and over again during the Alpine orogeny. Their reactivation occurred at depths of ~13-15 km with elevated temperatures (400-475°C) and involved both ductile and brittle deformation processes. Brittle deformation in form of hydrofracking was always present due to the circulating fluids. It is this process, which was and still is responsible for seismic activity. With progressive uplift and exhumation of the Aar Massif, ductile deformation structures became replaced by brittle cataclasites and fault gouges during fault activity at shallower crustal levels. Existing hydrotest data from the Grimsel Test Site (Nagra's underground research laboratory) indicate that these brittle successors of the ductile shear zones are domains of enhanced recent fluid percolation. Note that although being exposed today, the continuation of these fault structures are still active at depth in both brittle and ductile deformation modes, a fact that can be inferred from recent uplift rates and the active seismicity. On the
In vitro toxicity of FemOn, FemOn-SiO2 composite, and SiO2-FemOn core-shell magnetic nanoparticles
Directory of Open Access Journals (Sweden)
Toropova YG
2017-01-01
of uncoated, FemOn-SiO2 composite flake-like, and SiO2-FemOn core-shell IONPs on cell viability, function, and morphology were tested 48 h postincubation in human umbilical vein endothelial cell culture. Cell viability and apoptosis/necrosis rate were determined using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay and annexin V-phycoerythrin kit, respectively. Cell morphology was evaluated using bright-field microscopy and forward and lateral light scattering profiles obtained with flow cytometry analysis. All tested IONP types were used at three different doses, that is, 0.7, 7.0, and 70.0 µg. Dose-dependent changes in cell morphology, viability, and apoptosis rate were shown. At higher doses, all types of IONPs caused formation of binucleated cells suggesting impaired cytokinesis. FemOn-SiO2 composite flake-like and SiO2-FemOn core-shell IONPs were characterized by similar profile of cytotoxicity, whereas bare IONPs were shown to be less toxic. The presence of either silica core or silica nanoflakes in composite IONPs can promote cytotoxic effects. Keywords: iron oxide nanoparticles, composite nanoparticles, silica coating, silica nanoflakes, cytotoxicity
Effect of Cervical Lessions on the Tooth FEM Study
Directory of Open Access Journals (Sweden)
Gabriela Bereşescu
2010-12-01
Full Text Available The approach used until recently concerning the phenomena of dental abfraction points to the conclusion that the cervical area of the tooth, were this type of lesion usually occur, concentrates the stress resulted from the action of the forces applied on various areas on the crown. Moreover, any lesion in the cervical area facilitates the possibility of its advance into the tooth, ultimately fracturing it. Our paper presents a FEM (finite element method study on the results of a mechanical analysis of the phenomena involving the tooth damaged by cervical lesions.
Simulation of ultrasonic and EMAT arrays using FEM and FDTD.
Xie, Yuedong; Yin, Wuliang; Liu, Zenghua; Peyton, Anthony
2016-03-01
This paper presents a method which combines electromagnetic simulation and ultrasonic simulation to build EMAT array models. For a specific sensor configuration, Lorentz forces are calculated using the finite element method (FEM), which then can feed through to ultrasonic simulations. The propagation of ultrasound waves is numerically simulated using finite-difference time-domain (FDTD) method to describe their propagation within homogenous medium and their scattering phenomenon by cracks. Radiation pattern obtained with Hilbert transform on time domain waveforms is proposed to characterise the sensor in terms of its beam directivity and field distribution along the steering angle. Copyright © 2015 Elsevier B.V. All rights reserved.
Numerical Modelling of the Special Light Source with Novel R-FEM Method
Directory of Open Access Journals (Sweden)
Pavel Fiala
2008-01-01
Full Text Available This paper presents information about new directions in the modelling of lighting systems, and an overview of methods for the modelling of lighting systems. The novel R-FEM method is described, which is a combination of the Radiosity method and the Finite Elements Method (FEM. The paper contains modelling results and their verification by experimental measurements and by the Matlab simulation for this R-FEM method.
A Hybrid FEM-ANN Approach for Slope Instability Prediction
Verma, A. K.; Singh, T. N.; Chauhan, Nikhil Kumar; Sarkar, K.
2016-09-01
Assessment of slope stability is one of the most critical aspects for the life of a slope. In any slope vulnerability appraisal, Factor Of Safety (FOS) is the widely accepted index to understand, how close or far a slope from the failure. In this work, an attempt has been made to simulate a road cut slope in a landslide prone area in Rudrapryag, Uttarakhand, India which lies near Himalayan geodynamic mountain belt. A combination of Finite Element Method (FEM) and Artificial Neural Network (ANN) has been adopted to predict FOS of the slope. In ANN, a three layer, feed- forward back-propagation neural network with one input layer and one hidden layer with three neurons and one output layer has been considered and trained using datasets generated from numerical analysis of the slope and validated with new set of field slope data. Mean absolute percentage error estimated as 1.04 with coefficient of correlation between the FOS of FEM and ANN as 0.973, which indicates that the system is very vigorous and fast to predict FOS for any slope.
CFD-FEM coupling for accurate prediction of thermal fatigue
International Nuclear Information System (INIS)
Hannink, M.H.C.; Kuczaj, A.K.; Blom, F.J.; Church, J.M.; Komen, E.M.J.
2009-01-01
Thermal fatigue is a safety related issue in primary pipework systems of nuclear power plants. Life extension of current reactors and the design of a next generation of new reactors lead to growing importance of research in this direction. The thermal fatigue degradation mechanism is induced by temperature fluctuations in a fluid, which arise from mixing of hot and cold flows. Accompanied physical phenomena include thermal stratification, thermal striping, and turbulence [1]. Current plant instrumentation systems allow monitoring of possible causes as stratification and temperature gradients at fatigue susceptible locations [1]. However, high-cycle temperature fluctuations associated with turbulent mixing cannot be adequately detected by common thermocouple instrumentations. For a proper evaluation of thermal fatigue, therefore, numerical simulations are necessary that couple instantaneous fluid and solid interactions. In this work, a strategy for the numerical prediction of thermal fatigue is presented. The approach couples Computational Fluid Dynamics (CFD) and the Finite Element Method (FEM). For the development of the computational approach, a classical test case for the investigation of thermal fatigue problems is studied, i.e. mixing in a T-junction. Due to turbulent mixing of hot and cold fluids in two perpendicularly connected pipes, temperature fluctuations arise in the mixing zone downstream in the flow. Subsequently, these temperature fluctuations are also induced in the pipes. The stresses that arise due to the fluctuations may eventually lead to thermal fatigue. In the first step of the applied procedure, the temperature fluctuations in both fluid and structure are calculated using the CFD method. Subsequently, the temperature fluctuations in the structure are imposed as thermal loads in a FEM model of the pipes. A mechanical analysis is then performed to determine the thermal stresses, which are used to predict the fatigue lifetime of the structure
FEM simulation of TBC failure in a model system
Energy Technology Data Exchange (ETDEWEB)
Seiler, P; Baeker, M; Roesier, J [Institut fuer Werkstoffe (IfW), Technische Universitaet Braunschweig (Germany); Beck, T; Schweda, M, E-mail: p.seiler@tu-bs.d [Institut fuer Energieforschung/ Werkstoffstruktur und -Eigenschaften (IEF 2), Forschungszentrum Juelich (Germany)
2010-07-01
In order to study the behavior of the complex failure mechanisms in thermal barrier coatings on turbine blades, a simplified model system is used to reduce the number of system parameters. The artificial system consists of a bond-coat material (fast creeping Fecralloy or slow creeping MA956) as the substrate with a Y{sub 2}O{sub 3} partially stabilized plasma sprayed zircon oxide TBC on top and a TGO between the two layers. A 2-dimensional FEM simulation was developed to calculate the growth stress inside the simplified coating system. The simulation permits the study of failure mechanisms by identifying compression and tension areas which are established by the growth of the oxide layer. This provides an insight into the possible crack paths in the coating and it allows to draw conclusions for optimizing real thermal barrier coating systems.
FEM Techniques for High Stress Detection in Accelerated Fatigue Simulation
Veltri, M.
2016-09-01
This work presents the theory and a numerical validation study in support to a novel method for a priori identification of fatigue critical regions, with the aim to accelerate durability design in large FEM problems. The investigation is placed in the context of modern full-body structural durability analysis, where a computationally intensive dynamic solution could be required to identify areas with potential for fatigue damage initiation. The early detection of fatigue critical areas can drive a simplification of the problem size, leading to sensible improvement in solution time and model handling while allowing processing of the critical areas in higher detail. The proposed technique is applied to a real life industrial case in a comparative assessment with established practices. Synthetic damage prediction quantification and visualization techniques allow for a quick and efficient comparison between methods, outlining potential application benefits and boundaries.
Generalized multiscale finite element methods (GMsFEM)
Efendiev, Yalchin R.; Galvis, Juan; Hou, Thomasyizhao
2013-01-01
In this paper, we propose a general approach called Generalized Multiscale Finite Element Method (GMsFEM) for performing multiscale simulations for problems without scale separation over a complex input space. As in multiscale finite element methods (MsFEMs), the main idea of the proposed approach is to construct a small dimensional local solution space that can be used to generate an efficient and accurate approximation to the multiscale solution with a potentially high dimensional input parameter space. In the proposed approach, we present a general procedure to construct the offline space that is used for a systematic enrichment of the coarse solution space in the online stage. The enrichment in the online stage is performed based on a spectral decomposition of the offline space. In the online stage, for any input parameter, a multiscale space is constructed to solve the global problem on a coarse grid. The online space is constructed via a spectral decomposition of the offline space and by choosing the eigenvectors corresponding to the largest eigenvalues. The computational saving is due to the fact that the construction of the online multiscale space for any input parameter is fast and this space can be re-used for solving the forward problem with any forcing and boundary condition. Compared with the other approaches where global snapshots are used, the local approach that we present in this paper allows us to eliminate unnecessary degrees of freedom on a coarse-grid level. We present various examples in the paper and some numerical results to demonstrate the effectiveness of our method. © 2013 Elsevier Inc.
Generalized multiscale finite element methods (GMsFEM)
Efendiev, Yalchin R.
2013-10-01
In this paper, we propose a general approach called Generalized Multiscale Finite Element Method (GMsFEM) for performing multiscale simulations for problems without scale separation over a complex input space. As in multiscale finite element methods (MsFEMs), the main idea of the proposed approach is to construct a small dimensional local solution space that can be used to generate an efficient and accurate approximation to the multiscale solution with a potentially high dimensional input parameter space. In the proposed approach, we present a general procedure to construct the offline space that is used for a systematic enrichment of the coarse solution space in the online stage. The enrichment in the online stage is performed based on a spectral decomposition of the offline space. In the online stage, for any input parameter, a multiscale space is constructed to solve the global problem on a coarse grid. The online space is constructed via a spectral decomposition of the offline space and by choosing the eigenvectors corresponding to the largest eigenvalues. The computational saving is due to the fact that the construction of the online multiscale space for any input parameter is fast and this space can be re-used for solving the forward problem with any forcing and boundary condition. Compared with the other approaches where global snapshots are used, the local approach that we present in this paper allows us to eliminate unnecessary degrees of freedom on a coarse-grid level. We present various examples in the paper and some numerical results to demonstrate the effectiveness of our method. © 2013 Elsevier Inc.
A FEM based methodology to simulate multiple crack propagation in friction stir welds
DEFF Research Database (Denmark)
Lepore, Marcello; Carlone, Pierpaolo; Berto, Filippo
2017-01-01
. The residual stress field was inferred by a thermo-mechanical FEM simulation of the process, considering temperature dependent elastic-plastic material properties, material softening and isotropic hardening. Afterwards, cracks introduced in the selected location of FEM computational domain allow stress...
Uncertainty assessment of a dike with an anchored sheet pile wall using FEM
Rippi, Aikaterini; Nuttall, Jonathan; Teixeira, Ana; Schweckendiek, T.; Lang, M.; Klijn, F.; Samuels, P.
2016-01-01
The Dutch design codes for the dikes with retaining walls rely on Finite Element Analysis (FEM) in combination with partial safety factors. However, this can lead to conservative designs. For this reason, in this study, a reliability analysis is carried out with FEM calculations aiming to
Simulations of e-beam emittance effects on the performance of the fusion-FEM
Tulupov, A. V.; Caplan, M.; Urbanus, W. H.
1996-01-01
At the FOM-Institute for Plasma Physics, The Netherlands, the construction of the Fusion Free-Electron Maser (FEM) is nearing completion. The design objective of the FEM is to generate 1 MW of microwave power during long pulses in the frequency range of 130 to 260 GHz [1,2]. Applications are in the
Prediction of the FOM FEM experimental results using multi-mode time-dependent simulations
Caplan, M.; Bongers, W. A.; Verhoeven, A. G. A.; van der Geer, C. A. J.; Valentini, M.; Urbanus, W. H.
1998-01-01
The Free Electron Maser (FEM) constructed at the FOM Institute, Netherlands is now ready to undergo the first set of short pulse (< 20 mu s) experiments to demonstrate the capability of generating 1 MW of microwave power in the range 130-250 GHz. Predictions of the FEM performance requires a
Nonlinear observer design for a nonlinear string/cable FEM model using contraction theory
DEFF Research Database (Denmark)
Turkyilmaz, Yilmaz; Jouffroy, Jerome; Egeland, Olav
model is presented in the form of partial differential equations (PDE). Galerkin's method is then applied to obtain a set of ordinary differential equations such that the cable model is approximated by a FEM model. Based on the FEM model, a nonlinear observer is designed to estimate the cable...
Directory of Open Access Journals (Sweden)
Liliya eEuro
2015-02-01
Full Text Available The accuracy of mitochondrial protein synthesis is dependent on the coordinated action of nuclear-encoded mitochondrial aminoacyl-tRNA synthetases (mtARSs and the mitochondrial DNA-encoded tRNAs. The recent advances in whole-exome sequencing have revealed the importance of the mtARS proteins for mitochondrial pathophysiology since nearly every nuclear gene for mtARS (out of 19 is now recognized as a disease gene for mitochondrial disease. Typically, defects in each mtARS have been identified in one tissue-specific disease, most commonly affecting the brain, or in one syndrome. However, mutations in the AARS2 gene for mitochondrial alanyl-tRNA synthetase (mtAlaRS have been reported both in patients with infantile-onset cardiomyopathy and in patients with childhood to adulthood-onset leukoencephalopathy. We present here an investigation of the effects of the described mutations on the structure of the synthetase, in an effort to understand the tissue-specific outcomes of the different mutations.The mtAlaRS differs from the other mtARSs because in addition to the aminoacylation domain, it has a conserved editing domain for deacylating tRNAs that have been mischarged with incorrect amino acids. We show that the cardiomyopathy phenotype results from a single allele, causing an amino acid change p.R592W in the editing domain of AARS2, whereas the leukodystrophy mutations are located in other domains of the synthetase. Nevertheless, our structural analysis predicts that all mutations reduce the aminoacylation activity of the synthetase, because all mtAlaRS domains contribute to tRNA binding for aminoacylation. According to our model, the cardiomyopathy mutations severely compromise aminoacylation whereas partial activity is retained by the mutation combinations found in the leukodystrophy patients. These predictions provide a hypothesis for the molecular basis of the distinct tissue-specific phenotypic outcomes.
Report on first masing and single mode locking in a prebunched beam FEM oscillator
Energy Technology Data Exchange (ETDEWEB)
Cohen, M.; Eichenbaum, A.; Kleinman, H. [Tel-Aviv Univ., Ramat-Aviv (Israel)] [and others
1995-12-31
Radiation characteristics of a table-top free electron maser (FEM) are described in this paper. The FEM employs a prebunched electron beam and is operated as an oscillator in the low-gain collective (Raman) regime. Using electron beam prebunching single mode locking at any one of the possible oscillation modes was obtained. The electron beam is prebunched by a microwave tube section before it is injected into the wiggler. By tuning the electron beam bunching frequency, the FEM oscillation frequency can be locked to any eigen frequency of the resonant waveguide cavity which is within the frequency band of net gain of the FEM. The oscillation build up process is sped up, when the FEM operates with a prebunched electron beam, and the build-up time of radiation is shortened significantly. First measurements of masing with and without prebunching and characterization of the emitted radiation are reported.
Modelling Sawing of Metal Tubes Through FEM Simulation
International Nuclear Information System (INIS)
Bort, C. M. Giorgio; Bosetti, P.; Bruschi, S.
2011-01-01
The paper presents the development of a numerical model of the sawing process of AISI 304 thin tubes, which is cut through a circular blade with alternating roughing and finishing teeth. The numerical simulation environment is the three-dimensional FEM software Deform v.10.1. The teeth actual trajectories were determined by a blade kinematics analysis developed in Matlab. Due to the manufacturing rolling steps and subsequent welding stage, the tube material is characterized by a gradient of properties along its thickness. Consequently, a simplified cutting test was set up and carried out in order to identify the values of relevant material parameters to be used in the numerical model. The dedicated test was the Orthogonal Tube Cutting test (OTC), which was performed on an instrumented lathe. The proposed numerical model was validated by comparing numerical results and experimental data obtained from sawing tests carried out on an industrial machine. The following outputs were compared: the cutting force, the chip thickness, and the chip contact area.
Modelling Sawing of Metal Tubes Through FEM Simulation
Bort, C. M. Giorgio; Bosetti, P.; Bruschi, S.
2011-05-01
The paper presents the development of a numerical model of the sawing process of AISI 304 thin tubes, which is cut through a circular blade with alternating roughing and finishing teeth. The numerical simulation environment is the three-dimensional FEM software Deform™ v.10.1. The teeth actual trajectories were determined by a blade kinematics analysis developed in Matlab™. Due to the manufacturing rolling steps and subsequent welding stage, the tube material is characterized by a gradient of properties along its thickness. Consequently, a simplified cutting test was set up and carried out in order to identify the values of relevant material parameters to be used in the numerical model. The dedicated test was the Orthogonal Tube Cutting test (OTC), which was performed on an instrumented lathe. The proposed numerical model was validated by comparing numerical results and experimental data obtained from sawing tests carried out on an industrial machine. The following outputs were compared: the cutting force, the chip thickness, and the chip contact area.
Charge-conserving FEM-PIC schemes on general grids
International Nuclear Information System (INIS)
Campos Pinto, M.; Jund, S.; Salmon, S.; Sonnendruecker, E.
2014-01-01
Particle-In-Cell (PIC) solvers are a major tool for the understanding of the complex behavior of a plasma or a particle beam in many situations. An important issue for electromagnetic PIC solvers, where the fields are computed using Maxwell's equations, is the problem of discrete charge conservation. In this article, we aim at proposing a general mathematical formulation for charge-conserving finite-element Maxwell solvers coupled with particle schemes. In particular, we identify the finite-element continuity equations that must be satisfied by the discrete current sources for several classes of time-domain Vlasov-Maxwell simulations to preserve the Gauss law at each time step, and propose a generic algorithm for computing such consistent sources. Since our results cover a wide range of schemes (namely curl-conforming finite element methods of arbitrary degree, general meshes in two or three dimensions, several classes of time discretization schemes, particles with arbitrary shape factors and piecewise polynomial trajectories of arbitrary degree), we believe that they provide a useful roadmap in the design of high-order charge-conserving FEM-PIC numerical schemes. (authors)
Adaptive stochastic Galerkin FEM with hierarchical tensor representations
Eigel, Martin
2016-01-08
PDE with stochastic data usually lead to very high-dimensional algebraic problems which easily become unfeasible for numerical computations because of the dense coupling structure of the discretised stochastic operator. Recently, an adaptive stochastic Galerkin FEM based on a residual a posteriori error estimator was presented and the convergence of the adaptive algorithm was shown. While this approach leads to a drastic reduction of the complexity of the problem due to the iterative discovery of the sparsity of the solution, the problem size and structure is still rather limited. To allow for larger and more general problems, we exploit the tensor structure of the parametric problem by representing operator and solution iterates in the tensor train (TT) format. The (successive) compression carried out with these representations can be seen as a generalisation of some other model reduction techniques, e.g. the reduced basis method. We show that this approach facilitates the efficient computation of different error indicators related to the computational mesh, the active polynomial chaos index set, and the TT rank. In particular, the curse of dimension is avoided.
Applications of ATILA FEM software to smart materials case studies in designing devices
Uchino, Kenji
2013-01-01
ATILA Finite Element Method (FEM) software facilitates the modelling and analysis of applications using piezoelectric, magnetostrictor and shape memory materials. It allows entire designs to be constructed, refined and optimized before production begins. Through a range of instructive case studies, Applications of ATILA FEM software to smart materials provides an indispensable guide to the use of this software in the design of effective products.Part one provides an introduction to ATILA FEM software, beginning with an overview of the software code. New capabilities and loss integratio
Development of an artificial neural network model integrated with constitutive and FEM models
International Nuclear Information System (INIS)
Kong, L.X.; Hodgson, P.D.
2000-01-01
Although the standard error of IPANN model developed by Kong and Hodgson is lower than the constitutive model, it is found that the prediction of reaction force and torque during rolling with FEM is less accurate for IPANN model in some deformation regions. It is the summation of the product of the strain and stress in the deformation range, which contributes most to the precise prediction. An ANN model is therefore, developed in this work by integrating both the IPANN and FEM models. It is found that the integrated IPANN and FEM model is the most accurate model. (author)
Coupled FEM-DBEM method to assess crack growth in magnet system of Wendelstein 7-X
Directory of Open Access Journals (Sweden)
R. Citarella
2013-10-01
Full Text Available The fivefold symmetric modular stellarator Wendelstein 7-X (W7-X is currently under construction in Greifswald, Germany. The superconducting coils of the magnet system are bolted onto a central support ring and interconnected with five so-called lateral support elements (LSEs per half module. After welding of the LSE hollow boxes to the coil cases, cracks were found in the vicinity of the welds that could potentially limit the allowed number N of electromagnetic (EM load cycles of the machine. In response to the appearance of first cracks during assembly, the Stress Intensity Factors (SIFs were calculated and corresponding crack growth rates of theoretical semi-circular cracks of measured sizes in potentially critical position and orientation were predicted using Paris’ law, whose parameters were calibrated in fatigue tests at cryogenic temperature. In this paper the Dual Boundary Element Method (DBEM is applied in a coupled FEM-DBEM approach to analyze the propagation of multiple cracks with different shapes. For this purpose, the crack path is assessed with the Minimum Strain Energy density criterion and SIFs are calculated by the J-integral approach. The Finite Element Method (FEM is adopted to model, using the commercial codes Ansys or Abaqus;, the overall component whereas the submodel analysis, in the volume surrounding the cracked area, is performed by FEM (“FEM-FEM approach” or alternatively by DBEM (“FEM-DBEM approach”. The “FEM-FEM approach” considers a FEM submodel, that is extracted from the FEM global model; the latter provide the boundary conditions for the submodel. Such approach is affected by some restrictions in the crack propagation phase, whereas, with the “FEM-DBEM approach”, the crack propagation simulation is straightforward. In this case the submodel is created in a DBEM environment with boundary conditions provided by the global FEM analysis; then the crack is introduced and a crack propagation analysis
A FEM Modeling of the Concrete Pavement Made of the Recycling Material
Directory of Open Access Journals (Sweden)
Šešlija Miloš
2016-01-01
Full Text Available Paper is a brief review of the research focused on formulation an numerical model for the concrete pavement which is made by the recycling material. For numerical modeling the finite element model (FEM and the 3D finite element model were applied. The software EverFE 2.25, was used. The results of FEM analysis is in a chapter shape showing move value change, strees and deflections for all layers a construction road model. In the next phase of the research was provided by FEM software with appropriate general purpose non-linear models, which allows the analysis of the real behavior of solid pavement under load.
Bolt-Grout Interactions in Elastoplastic Rock Mass Using Coupled FEM-FDM Techniques
Directory of Open Access Journals (Sweden)
Debasis Deb
2010-01-01
Full Text Available Numerical procedure based on finite element method (FEM and finite difference method (FDM for the analysis of bolt-grout interactions are introduced in this paper. The finite element procedure incorporates elasto-plastic concepts with Hoek and Brown yield criterion and has been applied for rock mass. Bolt-grout interactions are evaluated based on finite difference method and are embedded in the elasto-plastic procedures of FEM. The experimental validation of the proposed FEM-FDM procedures and numerical examples of a bolted tunnel are provided to demonstrate the efficacy of the proposed method for practical applications.
Subauste, M Cecilia; Ventura-Holman, Tereza; Du, Liqin; Subauste, Jose S; Chan, Shing-Leng; Yu, Victor C; Maher, Joseph F
2009-12-01
Evasion of apoptosis plays an important role in colon cancer progression. Following loss of the Apc tumor suppressor gene in mice, the gene encoding Fem1b is upregulated early in neoplastic intestinal epithelium. Fem1b is a pro-apoptotic protein that interacts with Fas, TNFR1 and Apaf-1, and increased expression of Fem1b induces apoptosis of cancer cells. Fem1b is a homolog of FEM-1, a protein in Caenorhabditis elegans that is negatively regulated by ubiquitination and proteasomal degradation. To study Fem1b regulation in colon cancer progression, we used apoptotis-sensitive SW480 cells, derived from a primary colon cancer, and their isogenic, apoptosis-resistant counterparts SW620 cells, derived from a subsequent metastatic lesion in the same patient. Treatment with proteasome inhibitor increased Fem1b protein levels in SW620 cells, but not in SW480 cells. In SW620 cells we found that endogenous Fem1b co-immunoprecipitates in complexes with RACK1, a protein known to mediate ubiquitination and proteasomal degradation of other pro-apoptotic proteins and to be upregulated in colon cancer. Full-length Fem1b, or the N-terminal region of Fem1b, associated with RACK1 when co-expressed in HEK293T cells, and RACK1 stimulated ubiquitination of Fem1b. RACK1 overexpression in SW620 cells led to downregulation of Fem1b protein levels. Conversely, downregulation of RACK1 led to upregulation of Fem1b protein levels, associated with induction of apoptosis, and this apoptosis was inhibited by blocking Fem1b protein upregulation. In conclusion, RACK1 downregulates levels of the pro-apoptotic protein Fem1b in metastatic, apoptosis-resistant colon cancer cells, which may promote apoptosis-resistance during progression of colon cancer.
Energy Technology Data Exchange (ETDEWEB)
Staat, M; Heitzer, M [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Sicherheitsforschung und Reaktortechnik
1998-11-01
Detailed, inelastic FEM analyses yield accurate information about the stresses and deformations in passive components. The local loading conditions, however, cannot be directly compared with a limit load in terms of structural mechanics. Concentration on the load carrying capacity is an approach simplifying the analysis. Based on the plasticity theory, limit and shakedown analyses calculate the load carrying capacities directly and exactly. The paper explains the implementation of the limit and shakedown data sets in a general FEM program and the direct calculation of the load carrying capacities of passive components. The concepts used are explained with respect to common structural analysis. Examples assuming high local stresses illustrate the application of FEM-based limit and shakedown analyses. The calculated interaction diagrams present a good insight into the applicable operational loads of individual passive components. The load carrying analysis also opens up a structure mechanics-based approach to assessing the load-to-collapse of cracked components made of highly ductile fracture-resistant material. (orig./CB) [Deutsch] Genaue Kenntnis der Spannungen und Verformungen in passiven Komponenten gewinnt man mit detailierten inelastischen FEM Analysen. Die lokale Beanspruchung laesst sich aber nicht direkt mit einer Beanspruchbarkeit im strukturmechanischen Sinne vergleichen. Konzentriert man sich auf die Frage nach der Tragfaehigkeit, dann vereinfacht sich die Analyse. Im Rahmen der Plastizitaetstheorie berechnen Traglast- und Einspielanalyse die tragbaren Lasten direkt und exakt. In diesem Beitrag wird eine Implementierung der Traglast- und Einspielsaetze in ein allgemeines FEM Programm vorgestellt, mit der die Tragfaehigkeit passiver Komponenten direkt berechnet wird. Die benutzten Konzepte werden in Bezug auf die uebliche Strukturanalyse erlaeutert. Beispiele mit lokal hoher Beanspruchung verdeutlichen die Anwendung der FEM basierten Traglast- und
Development of a 2-D Simplified P3 FEM Solver for Arbitrary Geometry Applications
Energy Technology Data Exchange (ETDEWEB)
Ryu, Eun Hyun; Joo, Han Gyu [Seoul National University, Seoul (Korea, Republic of)
2010-10-15
In the calculation of power distributions and multiplication factors in a nuclear reactor, the Finite Difference Method (FDM) and the nodal methods are primarily used. These methods are, however, limited to particular geometries and lack general application involving arbitrary geometries. The Finite Element Method (FEM) can be employed for arbitrary geometry application and there are numerous FEM codes to solve the neutron diffusion equation or the Sn transport equation. The diffusion based FEM codes have the drawback of inferior accuracy while the Sn based ones require a considerable computing time. This work here is to seek a compromise between these two by employing the simplified P3 (SP3) method for arbitrary geometry applications. Sufficient accuracy with affordable computing time and resources would be achieved with this choice of approximate transport solution when compared to full FEM based Pn or Sn solutions. For now only 2-D solver is considered
DVD. Aare Ermel tutvustab / Aare Ermel
Ermel, Aare, 1957-2013
2007-01-01
Eluloofilm "Lermontov" : režissöör Nikolai Burljajev : NSV Liit 1986 ja teleseriaal "Petshorin: meie aja kangelane" ("Petshorin: geroi nashego vremeni") : režissöör Aleksandr Kott : nimiosas Igor Petrenko : Venemaa 2006
FEM Modelling of Lateral-Torsional Buckling Using Shell and Solid Elements
DEFF Research Database (Denmark)
Valeš, Jan; Stan, Tudor-Cristian
2017-01-01
The paper describes two methods of FEM modelling of I-section beams loaded by bending moments. Series of random realizations with initial imperfections following the first eigenmode of lateral-torsional buckling were created. Two independent FEM software products were used for analyses of resista...... of resistance. At the end the difference and correlation between the results as well as advantages and disadvantages of both methods are discussed....
Motion Sensorless Control of BLDC PM Motor with Offline FEM Info Assisted State Observer
DEFF Research Database (Denmark)
Stirban, Alin; Boldea, Ion; Andreescu, Gheorghe-Daniel
2010-01-01
This paper describes a new offline FEM assisted position and speed observer, for brushless dc (BLDC) PM motor drive sensorless control, based on the line-to-line PM flux linkage estimation. The zero-crossing of the line-to-line PM flux linkage occurs right in the middle of two commutation points...... identification. Digital simulations and experimental results are shown, demonstrating the reliability of the FEM assisted position and speed observer for BLDC PM motor sensorless control operation....
A new 2D FEM analysis of a disc machine with offset rotor
Energy Technology Data Exchange (ETDEWEB)
Gair, S.; Canova, A. [Napier Univ., Edinburgh (United Kingdom). Dept. of Electrical, Electronic and Computer Engineering; Eastham, J.F.; Betzer, T. [Univ. of Bath (United Kingdom). School of Electronic and Electrical Engineering
1995-12-31
The paper presents a new 2-Dimensional Finite Element Method (2D FEM) analysis of a double sided axial field, permanent magnet excited brushless DC motor. The rotor of the machine is free to move in a direction perpendicular to the axis of the shaft. Computed 2D results are compared with 3D FEM analysis and the new analysis method is shown to give close agreement.
CVD diamond Brewster window: feasibility study by FEM analyses
Directory of Open Access Journals (Sweden)
Vaccaro A.
2012-09-01
Full Text Available Chemical vapor deposition (CVD diamond windows are a crucial component in heating and current drive (H&CD applications. In order to minimize the amount of reflected power from the diamond disc, its thickness must match the desired beam wavelength, thus proper targeting of the plasma requires movable beam reflectors. This is the case, for instance, of the ITER electron cyclotron H&CD system. However, looking at DEMO, the higher heat loads and neutron fluxes could make the use of movable parts close to the plasma difficult. The issue might be solved by using gyrotrons able to tune the beam frequency to the desired resonance, but this concept requires transmission windows that work in a given frequency range, such as the Brewster window. It consists of a CVD diamond disc brazed to two copper cuffs at the Brewster angle. The brazing process is carried out at about 800°C and then the temperature is decreased down to room temperature. Diamond and copper have very different thermal expansion coefficients, therefore high stresses build up during the cool down phase that might lead to failure of the disc. Considering also the complex geometry of the window with the skewed position of the disc, analyses are required in the first place to check its feasibility. The cool down phase was simulated by FEM structural analyses for several geometric and constraint configurations of the window. A study of indirect cooling of the window by water was also performed considering a HE11 mode beam. The results are here reported.
Subauste, M Cecilia; Sansom, Owen J; Porecha, Nehal; Raich, Natacha; Du, Liqin; Maher, Joseph F
2010-02-01
In the treatment of colon cancer, the development of resistance to apoptosis is a major factor in resistance to therapy. New molecular approaches to overcome apoptosis resistance, such as selectively upregulating proapoptotic proteins, are needed in colon cancer therapy. In a mouse model with inactivation of the adenomatous polyposis coli (Apc) tumor suppressor gene, reflecting the pathogenesis of most human colon cancers, the gene encoding feminization-1 homolog b (Fem1b) is upregulated in intestinal epithelium following Apc inactivation. Fem1b is a proapoptotic protein that interacts with apoptosis-inducing proteins Fas, tumor necrosis factor receptor-1 (TNFR1), and apoptotic protease activating factor-1 (Apaf-1). Increasing Fem1b expression induces apoptosis of cancer cells, but effects on colon cancer cells have not been reported. Fem1b is a homolog of feminization-1 (FEM-1), a protein in Caenorhabditis elegans that is regulated by proteasomal degradation, but whether Fem1b is likewise regulated by proteasomal degradation is unknown. Herein, we found that Fem1b protein is expressed in primary human colon cancer specimens, and in malignant SW620, HCT-116, and DLD-1 colon cancer cells. Increasing Fem1b expression, by transfection of a Fem1b expression construct, induced apoptosis of these cells. We found that proteasome inhibitor treatment of SW620, HCT-116, and DLD-1 cells caused upregulation of Fem1b protein levels, associated with induction of apoptosis. Blockade of Fem1b upregulation with morpholino antisense oligonucleotide suppressed the proteasome inhibitor-induced apoptosis of these cells. In conclusion, the proapoptotic protein Fem1b is downregulated by the proteasome in malignant colon cancer cells and mediates proteasome inhibitor-induced apoptosis of these cells. Therefore, Fem1b could represent a novel molecular target to overcome apoptosis resistance in therapy of colon cancer.
MODAL ANALYSIS FOR REVISION OF A FEM MODEL OF A STEEL TRUSS BEAM
Directory of Open Access Journals (Sweden)
Michal Venglar
2017-11-01
Full Text Available The paper deals with a preparation of a complex FEM model for a local damage detection. The initial verified and validated three-dimensional FEM model of a steel truss bridge in laboratory is revised step-by-step to achieve the accurate model according to the experimental model. The emphasis is on modelling of the joints with 4 rivets and modelling of correct boundary conditions, as well as mass parameters and cross-section dimensions.A modal analysis of the structure is performed in FEM software. Many experimental measurements were made to correctly revise the FEM model. The calculated natural frequencies are compared with the measured ones. In addition, mode-shapes from the calculation are validated with the measured mode-shapes. The difference between the prepared FEM model and the measured specimen is small enough after a few steps of tuning. The verified, validated and revised numerical model can be used in future for a local damage detection.
Three-dimensional FEM model of FBGs in PANDA fibers with experimentally determined model parameters
Lindner, Markus; Hopf, Barbara; Koch, Alexander W.; Roths, Johannes
2017-04-01
A 3D-FEM model has been developed to improve the understanding of multi-parameter sensing with Bragg gratings in attached or embedded polarization maintaining fibers. The material properties of the fiber, especially Young's modulus and Poisson's ratio of the fiber's stress applying parts, are crucial for accurate simulations, but are usually not provided by the manufacturers. A methodology is presented to determine the unknown parameters by using experimental characterizations of the fiber and iterative FEM simulations. The resulting 3D-Model is capable of describing the change in birefringence of the free fiber when exposed to longitudinal strain. In future studies the 3D-FEM model will be employed to study the interaction of PANDA fibers with the surrounding materials in which they are embedded.
Application of an enriched FEM technique in thermo-mechanical contact problems
Khoei, A. R.; Bahmani, B.
2018-02-01
In this paper, an enriched FEM technique is employed for thermo-mechanical contact problem based on the extended finite element method. A fully coupled thermo-mechanical contact formulation is presented in the framework of X-FEM technique that takes into account the deformable continuum mechanics and the transient heat transfer analysis. The Coulomb frictional law is applied for the mechanical contact problem and a pressure dependent thermal contact model is employed through an explicit formulation in the weak form of X-FEM method. The equilibrium equations are discretized by the Newmark time splitting method and the final set of non-linear equations are solved based on the Newton-Raphson method using a staggered algorithm. Finally, in order to illustrate the capability of the proposed computational model several numerical examples are solved and the results are compared with those reported in literature.
Investigation of Ice-PVC separation under Flexural Loading using FEM Analysis
Directory of Open Access Journals (Sweden)
H Xue
2016-08-01
Full Text Available This paper presents the FEM technique applied in the study of ice separation over a polyvinyl chloride (PVC surface. A two layer model of ice and PVC is analysed theoretically using Euler-Bernoulli beam theory and the rule of mixtures. The physical samples are prepared by freezing ice over the PVC surfaces. The samples are tested experimentally in a four-point loading setup. The experimental results contain strain data gathered through a data acquisition system using the LabView software. The data is collected at the rate of 1 kHz per load step. A model is also coded in MATLAB® and simulated using the finite element method (FEM in ANSYS® Multiphysics. The FEM model of the ice and PVC sample is built using solid elements. The mesh is tested for sensitively. A good agreement is found between the theoretical, experimental and numerical simulation results.
An adaptive singular ES-FEM for mechanics problems with singular field of arbitrary order
Nguyen-Xuan, H.; Liu, G. R.; Bordas, Stéphane; Natarajan, S.; Rabczuk, T.
2013-01-01
This paper presents a singular edge-based smoothed finite element method (sES-FEM) for mechanics problems with singular stress fields of arbitrary order. The sES-FEM uses a basic mesh of three-noded linear triangular (T3) elements and a special layer of five-noded singular triangular elements (sT5) connected to the singular-point of the stress field. The sT5 element has an additional node on each of the two edges connected to the singular-point. It allows us to represent simple and efficient ...
Zaidi, N. A.; Rosli, Muhamad Farizuan; Effendi, M. S. M.; Abdullah, Mohamad Hariri
2017-09-01
For almost all injection molding applications of Polyethylene Terephthalate (PET) plastic was analyzed the strength, durability and stiffness of properties by using Finite Element Method (FEM) for jointing system of wood furniture. The FEM was utilized for analyzing the PET jointing system for Oak and Pine as wood based material of furniture. The difference pattern design of PET as wood jointing furniture gives the difference value of strength furniture itself. The results show the wood specimen with grooves and eclipse pattern design PET jointing give lower global estimated error is 28.90%, compare to the rectangular and non-grooves wood specimen of global estimated error is 63.21%.
Directory of Open Access Journals (Sweden)
Stolz, Christian
2013-09-01
Full Text Available The distribution, thickness and composition of the floodplain sediments in the valleys of the Aar and its tributaries (Taunus Mountains were investigated by way of extensive fieldwork at 25 locations. In the entire catchment area, 48.8 million tons of loamy f loodplain fines could be assessed. Most of these were deposited since late medieval times due to extensive historical land use and forest clearing, especially in the mining region along the middle course of the Aar. In its lower course, the enhanced sedimentation of loamy f loodplain sediments started during the Bronze Age.
X-ray strain tensor imaging: FEM simulation and experiments with a micro-CT.
Kim, Jae G; Park, So E; Lee, Soo Y
2014-01-01
In tissue elasticity imaging, measuring the strain tensor components is necessary to solve the inverse problem. However, it is impractical to measure all the tensor components in ultrasound or MRI elastography because of their anisotropic spatial resolution. The objective of this study is to compute 3D strain tensor maps from the 3D CT images of a tissue-mimicking phantom. We took 3D micro-CT images of the phantom twice with applying two different mechanical compressions to it. Applying the 3D image correlation technique to the CT images under different compression, we computed 3D displacement vectors and strain tensors at every pixel. To evaluate the accuracy of the strain tensor maps, we made a 3D FEM model of the phantom, and we computed strain tensor maps through FEM simulation. Experimentally obtained strain tensor maps showed similar patterns to the FEM-simulated ones in visual inspection. The correlation between the strain tensor maps obtained from the experiment and the FEM simulation ranges from 0.03 to 0.93. Even though the strain tensor maps suffer from high level noise, we expect the x-ray strain tensor imaging may find some biomedical applications such as malignant tissue characterization and stress analysis inside the tissues.
Analysis of the deep rolling process on turbine blades using the FEM/BEM-coupling
International Nuclear Information System (INIS)
Baecker, V; Klocke, F; Wegner, H; Timmer, A; Grzhibovskis, R; Rjasanow, S
2010-01-01
Highly stressed components of aircraft engines, like turbine blades, have to satisfy stringent requirements regarding durability and reliability. The induction of compressive stresses and strain hardening in their surface layer has proven as a promising method to significantly increase their fatigue resistance. The required surface layer properties can be achieved by deep rolling. The determination of optimal process parameters still requires elaborate experimental set-up and subsequent time- and cost-extensive measurements. In previous works the application of the Finite Element Method (FEM) was proposed as an effective and cost reducing alternative to predict the surface layer state for given process parameters. However, FEM requires very fine mesh in the surface layer to resolve the high stress gradients with sufficient accuracy. The hereby caused high time and memory requirements render an efficient simulation of complete turbine components as impossible. In this article a solution is offered by coupling the FEM with the Boundary Elements Method (BEM). It enables the computing of large scale models at low computational cost and high result accuracy. Different approaches of the FEM/BEM-coupling for the simulation of deep rolling are examined with regard to their stability and required computing time.
An effective FEM-based approach for discrete 3D crack growth
DEFF Research Database (Denmark)
Nielsen, Morten Eggert; Lambertsen, Søren Heide; Pedersen, Erik B.
2015-01-01
A new geometric approach for discrete crack growth modeling is proposed and implemented in a commercial FEM software. The basic idea is to model the crack growth by removing volumes of material as the crack front advances. Thereby, adaptive meshing techniques, found in commercial software, is wel...
Fem Dewey-begreber til analyse af Facilitated Work Based Learning
DEFF Research Database (Denmark)
Thomassen, Anja Overgaard
teoretiske ramme er helt overvejende baseret på John Deweys (1859-1952) pragmatisme og herudfra er der udviklet modeller, som anvendes i analysen af de empiriske data. Det fremlægges i paperet, hvorledes disse modeller er blevet udviklet og anvendt i ph.d.-afhandlingen, og hvorledes de centrale fem begreber...
Mixed FEM for Second Order Elliptic Problems on Polygonal Meshes with BEM-Based Spaces
Efendiev, Yalchin; Galvis, Juan; Lazarov, Raytcho; Weiß er, Steffen
2014-01-01
We present a Boundary Element Method (BEM)-based FEM for mixed formulations of second order elliptic problems in two dimensions. The challenge, we would like to address, is a proper construction of H(div)-conforming vector valued trial functions
hp-FEM electromechanical transduction model of ionic polymer metal composites
Czech Academy of Sciences Publication Activity Database
Pugal, D.; Šolín, Pavel; Kim, K.; Aabloo, A.
2014-01-01
Roč. 260, April (2014), s. 135-148 ISSN 0377-0427 R&D Projects: GA ČR(CZ) GAP102/11/0498 Institutional support: RVO:61388998 Keywords : hp-FEM * Nernst-Planck * Poisson Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.266, year: 2014
International Nuclear Information System (INIS)
Kim, Kang Soo; Lee, Ho Jin; Woo, Wan Chuck; Seong, Baek Seok; Byeon, Jin Gwi; Park, Kwang Soo; Jung, In Chul
2010-01-01
Much research has been done to estimate the residual stress on a dissimilar metal weld. There are many methods to estimate the weld residual stress and FEM (Finite Element Method) is generally used due to the advantage of the parametric study. And the X-ray method and a Hole Drilling technique for an experimental method are also usually used. The aim of this paper is to develop the appropriate FEM model to estimate the residual stresses of the dissimilar overlay weld pipe. For this, firstly, the specimen of the dissimilar overlay weld pipe was manufactured. The SA 508 Gr3 nozzle, the SA 182 safe end and SA376 pipe were welded by the Alloy 182. And the overlay weld by the Alloy 52M was performed. The residual stress of this specimen was measured by using the Neutron Diffraction device in the HANARO (High-flux Advanced Neutron Application ReactOr) research reactor, KAERI (Korea Atomic Energy Research Institute). Secondly, FEM Model on the dissimilar overlay weld pipe was made and analyzed by the ABAQUS Code (ABAQUS, 2004). Thermal analysis and stress analysis were performed, and the residual stress was calculated. Thirdly, the results of the FEM analysis were compared with those of the experimental methods
Space-time adaptive hp-FEM for problems with traveling sharp fronts
Czech Academy of Sciences Publication Activity Database
Šolín, Pavel; Korous, L.
2013-01-01
Roč. 95, č. 1 (2013), S709-S722 ISSN 0010-485X Institutional support: RVO:61388998 Keywords : adaptive hp-FEM * transient problems * sharp fronts Subject RIV: BA - General Mathematics Impact factor: 1.055, year: 2013
Influence of seed layer moduli on FEM based modulus backcalculation results
CSIR Research Space (South Africa)
Matsui, K
2006-01-01
Full Text Available This paper presents recentupdates of DBALM (Dynamic Back Analysis for Layer Moduli) software whose solver is based on exi-symmetric FEM and was first developed in 1993. Examples of airfield pavement application are also presented. The results...
Efficient preconditioning of hphp-FEM matrix sequences with slowly-varying coefficients
DEFF Research Database (Denmark)
Gatto, P.; Hesthaven, J. S.; Christiansen, Rasmus Ellebæk
2017-01-01
We previously introduced a preconditioner that has proven effective for hphp-FEM discretizations of various challenging elliptic and hyperbolic problems. The construction is inspired by standard nested dissection, and relies on the assumption that the Schur complements can be approximated, to hig...
Prediction of the properties of PVD/CVD coatings with the use of FEM analysis
International Nuclear Information System (INIS)
Śliwa, Agata; Mikuła, Jarosław; Gołombek, Klaudiusz; Tański, Tomasz; Kwaśny, Waldemar; Bonek, Mirosław; Brytan, Zbigniew
2016-01-01
Highlights: • Prediction of the properties of PVD/CVD coatings with the use of (FEM) analysis. • Stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N coatings. • The experimental values of stresses were determined on X-ray diffraction patterns. • An FEM model was established for the purpose of building a computer simulation. - Abstract: The aim of this paper is to present the results of the prediction of the properties of PVD/CVD coatings with the use of finite element method (FEM) analysis. The possibility of employing the FEM in the evaluation of stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N, Ti/(Ti,Si)N/(Ti,Si)N, and Ti/DLC/DLC coatings by taking into account their deposition conditions on magnesium alloys has been discussed in the paper. The difference in internal stresses in the zone between the coating and the substrate is caused by, first of all, the difference between the mechanical and thermal properties of the substrate and the coating, and also by the structural changes that occur in these materials during the fabrication process, especially during the cooling process following PVD and CVD treatment. The experimental values of stresses were determined based on X-ray diffraction patterns that correspond to the modelled values, which in turn can be used to confirm the correctness of the accepted mathematical model for testing the problem. An FEM model was established for the purpose of building a computer simulation of the internal stresses in the coatings. The accuracy of the FEM model was verified by comparing the results of the computer simulation of the stresses with experimental results. A computer simulation of the stresses was carried out in the ANSYS environment using the FEM method. Structure observations, chemical composition measurements, and mechanical property characterisations of the investigated materials has been carried out to give a background for the discussion of the results that were
Prediction of the properties of PVD/CVD coatings with the use of FEM analysis
Energy Technology Data Exchange (ETDEWEB)
Śliwa, Agata; Mikuła, Jarosław; Gołombek, Klaudiusz; Tański, Tomasz; Kwaśny, Waldemar; Bonek, Mirosław, E-mail: miroslaw.bonek@polsl.pl; Brytan, Zbigniew
2016-12-01
Highlights: • Prediction of the properties of PVD/CVD coatings with the use of (FEM) analysis. • Stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N coatings. • The experimental values of stresses were determined on X-ray diffraction patterns. • An FEM model was established for the purpose of building a computer simulation. - Abstract: The aim of this paper is to present the results of the prediction of the properties of PVD/CVD coatings with the use of finite element method (FEM) analysis. The possibility of employing the FEM in the evaluation of stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N, Ti/(Ti,Si)N/(Ti,Si)N, and Ti/DLC/DLC coatings by taking into account their deposition conditions on magnesium alloys has been discussed in the paper. The difference in internal stresses in the zone between the coating and the substrate is caused by, first of all, the difference between the mechanical and thermal properties of the substrate and the coating, and also by the structural changes that occur in these materials during the fabrication process, especially during the cooling process following PVD and CVD treatment. The experimental values of stresses were determined based on X-ray diffraction patterns that correspond to the modelled values, which in turn can be used to confirm the correctness of the accepted mathematical model for testing the problem. An FEM model was established for the purpose of building a computer simulation of the internal stresses in the coatings. The accuracy of the FEM model was verified by comparing the results of the computer simulation of the stresses with experimental results. A computer simulation of the stresses was carried out in the ANSYS environment using the FEM method. Structure observations, chemical composition measurements, and mechanical property characterisations of the investigated materials has been carried out to give a background for the discussion of the results that were
Ermel, Aare, 1957-2013
2006-01-01
Kolmest iseseisvast armastusloost koosnev episoodfilm "Eros" : režissöörid Wong Kar-Wai ("Käsi"), Steven Soderbergh ("Tasakaal" / "Equilibrium"), Michelangelo Antonioni ("Asjade ohtlik käik") : Hongkong - Hiina - USA - Prantsuse - Itaalia 2004
Tavaline roomlane / Aare Ermel
Ermel, Aare, 1957-2013
2007-01-01
Iiri päritolu näitleja Ray Richardson, kes kehastab ajaloolises teleseriaalis "Rooma" (tootjad Ameerika HBO, inglaste BBC ja itaallaste RAI) Gaius Julius Caesari sõdurit Titus Pullot. Sama : Teleleht nr. 1, lk. 14 : ill
Ermel, Aare, 1957-2013
2005-01-01
Eesti Joonisfilm ja Nukufilm üllitasid firma V&K Holding kaudu kaks videokassetti "Armastuskolmnurgad" ja "Rebasenaine läheb taevasse" eesti noorte animaatorite Kaspar Jancise, Ülo Pikkovi ja Priit Tenderi loominguga
Ermel, Aare, 1957-2013
2009-01-01
Woody Alleni uusimatest filmiprojektidest. Ingmar Bergmanni kodusaare Fårö tulevikust kunstiinimeste puhke- ja loomekoduna. Lahkunud on Mikheil Kalatozišvili (19. 05. 1959 - 12. 10. 2009) ja Rosanna Schiaffino (25. 11. 1939 - 17. 10. 2009)
Ermel, Aare, 1957-2013
2010-01-01
Oliver Stone töödest. Charlie Chaplin virtuaalmaailmas. Lähiminevikus lahkunud: inglise-kanada filmiajaloolane ja -kriitik Robin Wood (23. II 1931 - 18. XII 2009), vene filmihelilooja Isaak Švarts (13. V 1923 - 27. XII 2009), prantsuse filmi- ja teatrilavastaja Eric Rohmer (4. IV 1920 - 11. I 2010)
Ermel, Aare, 1957-2013
2008-01-01
Lühisõnumid: Prantsuse kinodesse on jõudnud retrofilmid - "Couche, ühe inimese lugu" (koomik Michel Coluche'ist, rezh. Antoine de Gaunes; ), "Tapainstinkt" ja "Ühiskonna vaenlane nr 1" (mõlemad gangster Jacques Mesrine'ist, rezh. Jean-Francois Richet). Jean-Jacques Annaud' "Kashmir". Roomas triumfeeris "Resolution 819" (rezh. Giacomo Battiato). Humberto Solas (4. XII 1941 - 17. IX 2008)
Ermel, Aare, 1957-2013
2011-01-01
Lühisõnumeid filmimaailmast: Scorsesel valmib dokumentaalfilm George Harrisonist. Meirellesel uus mängufilm "360". Lähiminevikus lahkunuid: Gualtiero Jacopetti (4.09.1919 - 17. 08.2011), Raoul Ruiz (25.07.1941 - 19.08.2011), Ia Savvina (2.03.1938-27.08.2011)
Ermel, Aare, 1957-2013
2010-01-01
Lühisõnumeid filmimaailmast: Režissöör Terry Gilliami unistus ekraniseerida klassikateos "Don Quijote" nurjus. Ansambel Queenist hakatakse filmi tegema. "Kadunud paradiis" on tulekul. Lähiminevikus lahkunuid: Alain Corneau (7. aug. 1943 - 29. aug. 2010) ja Claude Chabrol (24. juuni 1930 - 12. sept. 2010)
Ermel, Aare, 1957-2013
2001-01-01
Austraalias oma filmikarjääri alustanud näitlejanna Frances O'Connor (1969), kes mängib nimiosa Inglismaa-USA seriaalis Gustave Flaubert'i romaani "Madame Bovary" ainetel. Ka : Nädal nr. 52, lk. 17
Ermel, Aare, 1957-2013
2009-01-01
Ameeriklase Rob Marshalli Fellini klassikafilmi "8 1/2" kaasajastatud versioon "Üheksa" ("Nine"). Nimekiri filmidest, millest võiks uusversioone luua. Lahkus vene filminäitleja Vjatšeslav Tihhonov
Ermel, Aare, 1957-2013
2009-01-01
Lühisõnumeid filmimaailmast: 21.- 30. augustini peetavast 20. rahvusvahelisest filmifestivalist "Espoo Cine"; Martin Scorsese hakkab tegema eluloofilmi Frank Sinatrast; Lahkus itaalia filmikriitik, dramaturg ja stsenarist Tullio Kezich (17. IX 1928 - 17. VIII 2009)
Ermel, Aare, 1957-2013
2010-01-01
Lühisõnumid filmimaailmast: Prantsusmaal käivitub keskkooliõpilastele mõeldud üleriigiline filmiõpe. James Nguyeni õudusfilm "Linnuepideemia: šokk ja terror" osutus keskpäraseks soperdiseks. Clint Eastwood ja mitmed tuntud filmiinimesed tähisatvad tänavu 80ndat sünnipäeva. Lahkus operaator William Lubtchansky
Prediction of the properties of PVD/CVD coatings with the use of FEM analysis
Śliwa, Agata; Mikuła, Jarosław; Gołombek, Klaudiusz; Tański, Tomasz; Kwaśny, Waldemar; Bonek, Mirosław; Brytan, Zbigniew
2016-12-01
The aim of this paper is to present the results of the prediction of the properties of PVD/CVD coatings with the use of finite element method (FEM) analysis. The possibility of employing the FEM in the evaluation of stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N, Ti/(Ti,Si)N/(Ti,Si)N, and Ti/DLC/DLC coatings by taking into account their deposition conditions on magnesium alloys has been discussed in the paper. The difference in internal stresses in the zone between the coating and the substrate is caused by, first of all, the difference between the mechanical and thermal properties of the substrate and the coating, and also by the structural changes that occur in these materials during the fabrication process, especially during the cooling process following PVD and CVD treatment. The experimental values of stresses were determined based on X-ray diffraction patterns that correspond to the modelled values, which in turn can be used to confirm the correctness of the accepted mathematical model for testing the problem. An FEM model was established for the purpose of building a computer simulation of the internal stresses in the coatings. The accuracy of the FEM model was verified by comparing the results of the computer simulation of the stresses with experimental results. A computer simulation of the stresses was carried out in the ANSYS environment using the FEM method. Structure observations, chemical composition measurements, and mechanical property characterisations of the investigated materials has been carried out to give a background for the discussion of the results that were recorded during the modelling process.
Traat, Mats, 1936-
1996-01-01
Orig.: Heldimus; Sajupäev; Jaanituli; Setumaa I-II; Ainult poeet. Harala elulood: Aire Valgus; Aare Valgus; Peeter Petrov; Vaike Metsleht; Valdur Laiapea; Hillar Aruda, ökonomist; Pärja Lumendi; Valjo Zeiger; Pavlo Moskalenko; Johannes Iva; Viljar Laanemägi; Olga Kaljusaar; Aimi Vaimets; Einard Kalm (1923-1984); Sonetid vaikimisest I; Kui
DEFF Research Database (Denmark)
Sonne, Mads Rostgaard; Carlone, P.; Citarella, R.
2015-01-01
This paper deals with a numerical and experimental investigation on the influence of residual stresses on fatigue crack growth in AA2024-T3 friction stir welded butt joints. An integrated FEM-DBEM procedure for the simulation of crack propagation is proposed and discussed. A numerical FEM model...... of the welding process of precipitation hardenable AA2024-T3 aluminum alloy is employed to infer the process induced residual stress field. The reliability of the FEM simulations with respect to the induced residual stresses is assessed comparing numerical outcomes with experimental data obtained by means...
International Nuclear Information System (INIS)
Castro, Nélia; Sorensen, Bjørn E.; Broekmans, Maarten A.T.M.
2012-01-01
The mineral content of 5 aggregate samples from 4 different countries, including reactive and non-reactive aggregate types, was assessed quantitatively by X-ray diffraction (XRD) using polished sections. Additionally, electron probe microanalyzer (EPMA) mapping and cathodoluminescence (CL) were used to characterize the opal-CT identified in one of the aggregate samples. Critical review of results from polished sections against traditionally powdered specimen has demonstrated that for fine-grained rocks without preferred orientation the assessment of mineral content by XRD using polished sections may represent an advantage over traditional powder specimens. Comparison of data on mineral content and silica speciation with expansion data from PARTNER project confirmed that the presence of opal-CT plays an important role in the reactivity of one of the studied aggregates. Used as a complementary tool to RILEM AAR-1, the methodology suggested in this paper has the potential to improve the strength of the petrographic method.
FEM-DEM coupling simulations of the tool wear characteristics in prestressed machining superalloy
Directory of Open Access Journals (Sweden)
Ruitao Peng
2016-01-01
Full Text Available Due to the complicated contact loading at the tool-chip interface, ceramic tool wear in prestressed machining superalloy is rare difficult to evaluate only by experimental approaches. This study aims to develop a methodology to predict the tool wear evolution by using combined FEM and DEM numerical simulations. Firstly, a finite element model for prestressed cutting is established, subsequently a discrete element model to describe the tool-chip behaviour is established based on the obtained boundary conditions by FEM simulations, finally, simulated results are experimentally validated. The predicted tool wear results show nice agreement with experiments, the simulation indicates that, within a certain range, higher cutting speed effectively results in slighter wear of Sialon ceramic tools, and deeper depth of cut leads to more serious tool wear.
First lasing of the Dutch Fusion-FEM: 730 kW, 200 GHz
Energy Technology Data Exchange (ETDEWEB)
Urbanus, W.H. E-mail: urbanus@rijnh.nl; Bongers, W.A.; Geer, C.A.J. van der; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Smeets, P.H.M.; Schueller, F.C.; Verhoeven, A.G.A.; Bratman, V.L.; Denisov, G.G.; Savilov, A.V.; Shmelyov, M.Yu.; Caplan, M.; Varfolomeev, A.A
1999-06-01
A high-power electrostatic free-electron maser is operated at various frequencies. An output power of 730 kW at 206 GHz is generated with a 7.2 A, 1.77 MeV electron beam, and 360 kW at 167 GHz is generated with a 7.0 A, 1.61 MeV electron beam. It is shown experimentally and by simulations that, depending on the electron beam energy, the FEM can operate in single-frequency regime. First experiments were done without electron beam energy recovery system, and the pulse length was limited to 12 {mu}s. Nevertheless, many aspects of generation of mm-wave power have been explored, such as the dependency on the electron beam energy and beam current and cavity settings such as the feedback coefficient. The achieved parameters and the FEM dynamics are in good accordance with simulations.
FEM × DEM: a new efficient multi-scale approach for geotechnical problems with strain localization
Directory of Open Access Journals (Sweden)
Nguyen Trung Kien
2017-01-01
Full Text Available The paper presents a multi-scale modeling of Boundary Value Problem (BVP approach involving cohesive-frictional granular materials in the FEM × DEM multi-scale framework. On the DEM side, a 3D model is defined based on the interactions of spherical particles. This DEM model is built through a numerical homogenization process applied to a Volume Element (VE. It is then paired with a Finite Element code. Using this numerical tool that combines two scales within the same framework, we conducted simulations of biaxial and pressuremeter tests on a cohesive-frictional granular medium. In these cases, it is known that strain localization does occur at the macroscopic level, but since FEMs suffer from severe mesh dependency as soon as shear band starts to develop, the second gradient regularization technique has been used. As a consequence, the objectivity of the computation with respect to mesh dependency is restored.
New progress of FEM simulation and AI application in rolling at RAL
International Nuclear Information System (INIS)
Liu Xianghua; Wang Guodong; Zhao Kun
2000-01-01
New progresses on FEM simulation and AI application in rolling have been achieved at RAL recently. The existence and uniqueness of the extreme point of total functional for rolling problem has been proved. Different rolling processes, such as H-beam rolling, ribbing strip rolling, slab sizing, have been solved by our in-house FEM software package. The simulation results have been put into production use to improve the precision of math models. The Artificial Neural Network has been used to predict rolling force, coiling temperature, microstructure and properties of the rolled products. An expert system for deviation diagnoses of strip thickness has been developed for industry use. Synergetic Artificial Intelligence has also been applied to rolling scheduling. We are making continuous efforts to develop AI applications for rolling line co-operating in China steel industry. (author)
Fluxball magnetic field analysis using a hybrid analytical/FEM/BEM with equivalent currents
International Nuclear Information System (INIS)
Fernandes, João F.P.; Camilo, Fernando M.; Machado, V. Maló
2016-01-01
In this paper, a fluxball electric machine is analyzed concerning the magnetic flux, force and torque. A novel method is proposed based in a special hybrid FEM/BEM (Finite Element Method/Boundary Element Method) with equivalent currents by using an analytical treatment for the source field determination. The method can be applied to evaluate the magnetic field in axisymmetric problems, in the presence of several magnetic materials. Same results obtained by a commercial Finite Element Analysis tool are presented for validation purposes with the proposed method. - Highlights: • The Fluxball machine magnetic field is analyzed by a new FEM/BEM/Analytical method. • The method is adequate for axisymmetric non homogeneous magnetic field problems. • The source magnetic field is evaluated considering a non-magnetic equivalent problem. • Material magnetization vectors are accounted by using equivalent currents. • A strong reduction of the finite element domain is achieved.
3D FEM Geometry and Material Flow Optimization of Porthole-Die Extrusion
International Nuclear Information System (INIS)
Ceretti, Elisabetta; Mazzoni, Luca; Giardini, Claudio
2007-01-01
The aim of this work is to design and to improve the geometry of a porthole-die for the production of aluminum components by means of 3D FEM simulations. In fact, the use of finite element models will allow to investigate the effects of the die geometry (webs, extrusion cavity) on the material flow and on the stresses acting on the die so to reduce the die wear and to improve the tool life. The software used to perform the simulations was a commercial FEM code, Deform 3D. The technological data introduced in the FE model have been furnished by METRA S.p.A. Company, partner in this research. The results obtained have been considered valid and helpful by the Company for building a new optimized extrusion porthole-die
AN APPROACH TO EFFICIENT FEM SIMULATIONS ON GRAPHICS PROCESSING UNITS USING CUDA
Directory of Open Access Journals (Sweden)
Björn Nutti
2014-04-01
Full Text Available The paper presents a highly efficient way of simulating the dynamic behavior of deformable objects by means of the finite element method (FEM with computations performed on Graphics Processing Units (GPU. The presented implementation reduces bottlenecks related to memory accesses by grouping the necessary data per node pairs, in contrast to the classical way done per element. This strategy reduces the memory access patterns that are not suitable for the GPU memory architecture. Furthermore, the presented implementation takes advantage of the underlying sparse-block-matrix structure, and it has been demonstrated how to avoid potential bottlenecks in the algorithm. To achieve plausible deformational behavior for large local rotations, the objects are modeled by means of a simplified co-rotational FEM formulation.
Energy Technology Data Exchange (ETDEWEB)
Baniassadi, Majid; Mortazavi, Behzad; Hamedani, Amani; Garmestani, Hamid; Ahzi, Said; Fathi-Torbaghan, Madjid; Ruch, David; Khaleel, Mohammad A.
2012-01-31
In this study, a previously developed reconstruction methodology is extended to three-dimensional reconstruction of a three-phase microstructure, based on two-point correlation functions and two-point cluster functions. The reconstruction process has been implemented based on hybrid stochastic methodology for simulating the virtual microstructure. While different phases of the heterogeneous medium are represented by different cells, growth of these cells is controlled by optimizing parameters such as rotation, shrinkage, translation, distribution and growth rates of the cells. Based on the reconstructed microstructure, finite element method (FEM) was used to compute the effective elastic modulus and effective thermal conductivity. A statistical approach, based on two-point correlation functions, was also used to directly estimate the effective properties of the developed microstructures. Good agreement between the predicted results from FEM analysis and statistical methods was found confirming the efficiency of the statistical methods for prediction of thermo-mechanical properties of three-phase composites.
Stress and fatigue analyses of primary circuit components of NPP using FEM
International Nuclear Information System (INIS)
Gal, P.
2015-01-01
This poster is a short illustration of the numerical assessment of the VVER-440 reactor pressure vessel (RPV) main flange. RPV main flange consists in free flange, pressure ring, flange bolts, nut and nickel gasket. Operating temperature transient modes, like heat up regime can lead to serious tension in bolts. So temperature fields have to be calculated. The fatigue assessment of the main flange bolt requires the determination of the coefficient of stress concentrators in bolt thread. Stress concentrators can be computed through FEM or given by norms (PNAEG). The most significant value of fatigue usage factor is in the first thread connection between bolt and nut. A finite element method (FEM) is used for calculation stress and temperature distribution in the reactor flange. The reassessment was performed according Czech normative document NTD-A.S.I. and VERLIFE
Energy Technology Data Exchange (ETDEWEB)
Barbeiro, A.R.; Ureba, A.; Baeza, J.A.; Jimenez-Ortega, E.; Plaza, A. Leal [Universidad de Sevilla, Departamento de Fisiologia Medica y Biofisica, Seville (Spain); Linares, R. [Hospital Infanta Luisa, Servicio de Radiofisica, Seville (Spain); Mateos, J.C.; Velazquez, S. [Hospital Universitario Virgen del Rocio, Servicio de Radiofisica, Seville (Spain)
2015-06-15
Purpose: VMAT involves two main sources of uncertainty: one related to the dose calculation accuracy, and the other linked to the continuous delivery of a discrete calculation. The purpose of this work is to present QuAArC, an alternative VMAT QA system to control and potentially reduce these uncertainties. Methods: An automated MC simulation of log files, recorded during VMAT treatment plans delivery, was implemented in order to simulate the actual treatment parameters. The linac head models and the phase-space data of each Control Point (CP) were simulated using the EGSnrc/BEAMnrc MC code, and the corresponding dose calculation was carried out by means of BEAMDOSE, a DOSXYZnrc code modification. A cylindrical phantom was specifically designed to host films rolled up at different radial distances from the isocenter, for a 3D and continuous dosimetric verification. It also allows axial and/or coronal films and point measurements with several types of ion chambers at different locations. Specific software was developed in MATLAB in order to process and evaluate the dosimetric measurements, which incorporates the analysis of dose distributions, profiles, dose difference maps, and 2D/3D gamma index. It is also possible to obtain the experimental DVH reconstructed on the patient CT, by an optimization method to find the individual contribution corresponding to each CP on the film, taking into account the total measured dose, and the corresponding CP dose calculated by MC. Results: The QuAArC system showed high reproducibility of measurements, and consistency with the results obtained with the commercial system implemented in the verification of the evaluated treatment plans. Conclusion: A VMAT QA system based on MC simulation and high resolution dosimetry with film has been developed for treatment verification. It shows to be useful for the study of the real VMAT capabilities, and also for linac commissioning and evaluation of other verification devices.
Deng, Han; Qi, Xingshun; Peng, Ying; Li, Jing; Li, Hongyu; Zhang, Yongguo; Liu, Xu; Sun, Xiaolin; Guo, Xiaozhong
2015-12-20
BACKGROUND Aspartate aminotransferase-to-platelet ratio index (APRI), aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), FIB-4, fibrosis index (FI), and King scores might be alternatives to the use of upper gastrointestinal endoscopy for the diagnosis of esophageal varices (EVs) in liver cirrhosis. This study aimed to evaluate their diagnostic accuracy in predicting the presence and severity of EVs in liver cirrhosis. MATERIAL AND METHODS All patients who were consecutively admitted to our hospital and underwent upper gastrointestinal endoscopy between January 2012 and June 2014 were eligible for this retrospective study. Areas under curve (AUCs) were calculated. Subgroup analyses were performed according to the history of upper gastrointestinal bleeding (UGIB) and splenectomy. RESULTS A total of 650 patients with liver cirrhosis were included, and 81.4% of them had moderate-severe EVs. In the overall analysis, the AUCs of these non-invasive scores for predicting moderate-severe EVs and presence of any EVs were 0.506-0.6 and 0.539-0.612, respectively. In the subgroup analysis of patients without UGIB, their AUCs for predicting moderate-severe varices and presence of any EVs were 0.601-0.664 and 0.596-0.662, respectively. In the subgroup analysis of patients without UGIB or splenectomy, their AUCs for predicting moderate-severe varices and presence of any EVs were 0.627-0.69 and 0.607-0.692, respectively. CONCLUSIONS APRI, AAR, FIB-4, FI, and King scores had modest diagnostic accuracy of EVs in liver cirrhosis. They might not be able to replace the utility of upper gastrointestinal endoscopy for the diagnosis of EVs in liver cirrhosis.
The application of NISA II FEM package in seismic qualification of small class IE electric motors
International Nuclear Information System (INIS)
Fancev, T.; Saban, I.; Grgic, D.
1995-01-01
According to the IEEE standards 323/1974 and 344/1975, seismic qualification of class IE equipment is appropriate combination of test and analysis methods. Complex equipment and assemblies are usually tested through seismic testing. The analysis is recommended for simple equipment that can be easily modeled to correctly predict its response. This article deals with the application of NISA II FEM package in 3D FE modeling and mode shape calculations of small power low voltage electric motors. (author)
Arbitrary-Level Hanging Nodes and Automatic Adaptivity in the hp-FEM
Czech Academy of Sciences Publication Activity Database
Šolín, Pavel; Červený, Jakub; Doležel, Ivo
2008-01-01
Roč. 77, č. 1 (2008), s. 117-132 ISSN 0378-4754 R&D Projects: GA ČR(CZ) GA102/07/0496; GA ČR GA102/05/0629; GA AV ČR IAA100760702 Institutional research plan: CEZ:AV0Z20570509 Keywords : constrained approximation * hanging nodes * hp-FEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.930, year: 2008
Discrete maximum principle for Poisson equation with mixed boundary conditions solved by hp-FEM
Czech Academy of Sciences Publication Activity Database
Vejchodský, Tomáš; Šolín, P.
2009-01-01
Roč. 1, č. 2 (2009), s. 201-214 ISSN 2070-0733 R&D Projects: GA AV ČR IAA100760702; GA ČR(CZ) GA102/07/0496; GA ČR GA102/05/0629 Institutional research plan: CEZ:AV0Z10190503 Keywords : discrete maximum principle * hp-FEM * Poisson equation * mixed boundary conditions Subject RIV: BA - General Mathematics
Discrete conservation of nonnegativity for elliptic problems solved by the hp-FEM
Czech Academy of Sciences Publication Activity Database
Šolín, P.; Vejchodský, Tomáš; Araiza, R.
2007-01-01
Roč. 76, 1-3 (2007), s. 205-210 ISSN 0378-4754 R&D Projects: GA ČR GP201/04/P021 Institutional research plan: CEZ:AV0Z10190503 Keywords : discrete nonnegativity conservation * discrete Green's function * elliptic problems * hp-FEM * higher-order finite element methods * Poisson equation * numerical experimetns Subject RIV: BA - General Mathematics Impact factor: 0.738, year: 2007
International Nuclear Information System (INIS)
Gu Fangyu; Zeng Xiao
1990-01-01
It is considered impossible to inspect flaw by using ordinary mechanical measuring methods. In this paper, it is found that the stree and strain distortions of pressure vessel with 2D linear shape crack in the deep location appear the 'cat effect' on the surface of stracture, and that the location and size of the crack can be determined with strain measuring and FEM according to 'cat effect' of strain distortion
Heat Generation Effects on U-Mo/Al through ABAQUS FEM Simulation
Energy Technology Data Exchange (ETDEWEB)
Cho, Taewon; Jeong, Gwan Yoon; Lee, Cheol Min; Sohn Dongseong [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)
2014-05-15
U-Mo/Al dispersion fuels have been considered a most promising candidate for a replacement of Highly Enriched Uranium (HEU) fuel in many research reactors. Coulson developed a FEM model which show the fuel meat realistically and compared the thermal conductivity results of two and three dimensional model. Williams also developed a FEM model which are different from the former in that it use regularly meshed unit cells. He showed a heat generation effects through FEM simulation and the effective thermal conductivity of the fuel with heat generated in the fuel particles is a little lower than that of the fuel with no heat generated. In the current work, the heat generation effects are analyzed and discussed in a wider range of volume fraction with more realistic models by using ABAQUS finite element package. The FEM model is used to determine the effective thermal conductivity of U-Mo/Al and to simulate the heat generation effects in the study. This model reflected the microscopic morphology of the fuel very well by making random distribution particles although the particle shape is considered as sphere. All simulation results show the heat generation effects although the effects are small when the volume fraction of fuels are high. When the particles are surrounded with interaction layers, the heat transfer from the particle to matrix is disturbed by interaction layers due to the low thermal conductivity of interaction layers. However this effects decreases when the sum of the volume fraction of fuels and interaction layers exceeds 40-50 vol% because a great portion of the heat must pass through fuels and interaction layers although the heat is applied on the surface. Therefore particle size and initial particle volume fractions will be the important factors for the heat generation effects when interaction layers grow during irradiations.
On Scientific Data and Image Compression Based on Adaptive Higher-Order FEM
Czech Academy of Sciences Publication Activity Database
Šolín, Pavel; Andrš, David
2009-01-01
Roč. 1, č. 1 (2009), s. 56-68 ISSN 2070-0733 R&D Projects: GA ČR(CZ) GA102/07/0496; GA AV ČR IAA100760702 Institutional research plan: CEZ:AV0Z20570509 Keywords : data compress ion * image compress ion * adaptive hp-FEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering http://www.global-sci.org/aamm
Modular hp-FEM system HERMES and its application to Maxwell´s equations
Czech Academy of Sciences Publication Activity Database
Vejchodský, Tomáš; Šolín, P.; Zítka, M.
2007-01-01
Roč. 76, č. 2 (2007), s. 223-228 ISSN 0378-4754. [MODELLING 2005. Plzeň, 04.06.2005-08.06.2005] R&D Projects: GA ČR GP201/04/P021 Institutional research plan: CEZ:AV0Z10190503 Keywords : hp-FEM * time-harmonic Maxwell´s equations * hierarchic higher-order edge elements Subject RIV: BA - General Mathematics Impact factor: 0.738, year: 2007
Investigation of load transfer efficiency in jointed plain concrete pavements (JPCP using FEM
Directory of Open Access Journals (Sweden)
Vahid Sadeghi
2018-05-01
Full Text Available Owing to heavy traffic loads, rigid pavements encounter various types of failures at transverse joints during their lifetime. Three-dimensional finite-element method (3D-FEM was used to assess the structural response of jointed concrete pavement under moving tandem axle loads. In this study, 3D FEM was verified using an existing numerical model and field measurement of the concrete slab traversed by a moving truck. This paper also investigated the effects of multiple parameters: material properties, slab geometry, load magnitude and frictional status of the slab and base layer on load transfer efficiency (LTE of the transverse joints. Further study has been done to investigate the slab performance without the dowel bars which occurs when parts of the pavement needed to be repaired using precast slabs. The aggregate interlock between the new slab and the existing slab is simulated by frictional interface. In 3D FEM model, the load transfer efficiency has been improved by increasing the elasticity modules of the concrete slab and the base layer or increasing the slab thickness. This can decrease the joints' deflections, reduces the damages on pavement joints. Removing dowel bars adversely affected the load transfer. Keywords: Concrete pavement, Load transfer, Finite-element method, Dowel bar, Structural behavior
International Nuclear Information System (INIS)
Manurung, Yupiter H.P.; Lidam, Robert Ngendang; Rahim, M. Ridzwan; Zakaria, M. Yusof; Redza, M. Ridhwan; Sulaiman, M. Shahar; Tham, Ghalib; Abas, Sunhaji K.
2013-01-01
This paper presents an investigation of the welding sequence effect on induced angular distortion using FEM and experiments. The specimen of a combined joint geometry was modeled and simulated using Multipass Welding Advisor (MWA) in SYSWELD 2010 based on the thermal-elastic-plastic approach with low manganese carbon steel S3355J2G3 as specimen material and Goldak's double ellipsoid as heat source model. To validate the simulation results, a series of experiments was conducted with two different welding sequences using automated welding process, low carbon steel as parent metal, digital GMAW power source with premixed shielding gas and both-sided clamping technique. Based on the results, it was established that the thermo-elastic-plastic 3D FEM analysis shows good agreement with experimental results and the welding sequence “from outside to inside” induced less angular distortion compared to “from inside to outside”. -- Highlights: • 3D FEM was used to analyze the welding distortion on two different sequences. • Simulation results were validated with experiments using automated welding system. • Simulation results and experiments showed acceptable accuracy. • Welding sequence “outside–inside” showed less distortion than “inside–outside”
Uncertainty assessment of a dike with an anchored sheet pile wall using FEM
Directory of Open Access Journals (Sweden)
Rippi Aikaterini
2016-01-01
Full Text Available The Dutch design codes for the dikes with retaining walls rely on Finite Element Analysis (FEM in combination with partial safety factors. However, this can lead to conservative designs. For this reason, in this study, a reliability analysis is carried out with FEM calculations aiming to demonstrate the feasibility of reliability analysis for a dike with an anchored sheet pile wall modelled in the 2D FEM, Plaxis. Sensitivity and reliability analyses were carried out and enabled by coupling the uncertainty package, OpenTURNS and Plaxis. The most relevant (ultimate limit states concern the anchor, the sheet pile wall, the soil body failure (global instability and finally the system. The case was used to investigate the applicability of the First Order Reliability Method (FORM and Directional Sampling (DS to analysing these limit states. The final goal is to estimate the probability of failure and identify the most important soil properties that affect the behaviour of each component and the system as a whole. The results of this research can be used to assess and optimize the current design procedure for dikes with retaining walls.
Crack growth analysis in a weld-heat-affected zone using S-version FEM
International Nuclear Information System (INIS)
Kikuchi, Masanori; Wada, Yoshitaka; Shimizu, Yuto; Li, Yulong
2012-01-01
The objective of this study is the prediction of crack propagation under thermal, residual stress fields using S-Version FEM (S-FEM). By using the S-FEM technique, only the local mesh should be re-meshed and it becomes easy to simulate crack growth. By combining with an auto-meshing technique, the local mesh is re-meshed automatically, and a curved crack path is modeled easily. Virtual crack closure integral method (VCCM) is used to evaluate energy release rate at the crack tip. For crack growth analyses, crack growth rate and growth direction are determined using criteria for mixed mode loading condition. In order to confirm the validity of this analysis, some comparisons with previously reported analyses were done, and good agreement obtained. In this study, residual stress data were provided by JAEA, Japan Atomic Energy Agency, based on their numerical simulation. Stress corrosion crack (SCC) growth analyses in a pipe are conducted in two-dimensional and three-dimensional fields. Two cases, for an axi-symmetric distribution of residual stress in the pipe wall and a non-axisymmetric one are assumed. Effects of residual stress distribution patterns on SCC cracking are evaluated and discussed.
Liu, Ying; Song, Huadong; Zhu, Panpan; Lu, Hao; Tang, Qi
2017-08-01
The elasticity of erythrocytes is an important criterion to evaluate the quality of blood. This paper presents a novel research on erythrocytes' elasticity with the application of optical tweezers and the finite element method (FEM) during blood storage. In this work, the erythrocytes with different in vitro times were linearly stretched by trapping force using optical tweezers and the time dependent elasticity of erythrocytes was investigated. The experimental results indicate that the membrane shear moduli of erythrocytes increased with the increasing in vitro time, namely the elasticity was decreasing. Simultaneously, an erythrocyte shell model with two parameters (membrane thickness h and membrane shear modulus H) was built to simulate the linear stretching states of erythrocytes by the FEM, and the simulations conform to the results obtained in the experiment. The evolution process was found that the erythrocytes membrane thicknesses were decreasing. The analysis assumes that the partial proteins and lipid bilayer of erythrocyte membrane were decomposed during the in vitro preservation of blood, which results in thin thickness, weak bending resistance, and losing elasticity of erythrocyte membrane. This study implies that the FEM can be employed to investigate the inward mechanical property changes of erythrocyte in different environments, which also can be a guideline for studying the erythrocyte mechanical state suffered from different diseases.
International Nuclear Information System (INIS)
Navardi, Mohammad Javad; Babaghorbani, Behnaz; Ketabi, Abbas
2014-01-01
Highlights: • This paper proposes a new method to optimize a Switched Reluctance Motor (SRM). • A combination of SOA and GA with Finite Element Method (FEM) analysis is employed to solve the SRM design optimization. • The results show that optimized SRM obtains higher average torque and higher efficiency. - Abstract: In this paper, performance optimization of Switched Reluctance Motor (SRM) was determined using Seeker Optimization Algorithm (SOA). The most efficient aim of the algorithm was found for maximum torque value at a minimum mass of the entire construction, following changing the geometric parameters. The optimization process was carried out using a combination of Seeker Optimization Algorithm and Finite Element Method (FEM). Fitness value was calculated by FEM analysis using COMSOL3.4, and the SOA was realized by MATLAB. The proposed method has been applied for a case study and it has been also compared with Genetic Algorithm (GA). The results show that the optimized motor using SOA had higher torque value and efficiency with lower mass and torque ripple, exhibiting the validity of this methodology for SRM design
Numerical calculation of acoustic radiation from band-vibrating structures via FEM/FAQP method
Directory of Open Access Journals (Sweden)
GAO Honglin
2017-08-01
Full Text Available The Finite Element Method (FEM combined with the Frequency Averaged Quadratic Pressure method (FAQP are used to calculate the acoustic radiation of structures excited in the frequency band. The surface particle velocity of stiffened cylindrical shells under frequency band excitation is calculated using finite element software, the normal vibration velocity is converted from the surface particle velocity to calculate the average energy source (frequency averaged across intensity, frequency averaged across pressure and frequency averaged across velocity, and the FAQP method is used to calculate the average sound pressure level within the bandwidth. The average sound pressure levels are then compared with the bandwidth using finite element and boundary element software, and the results show that FEM combined with FAQP is more suitable for high frequencies and can be used to calculate the average sound pressure level in the 1/3 octave band with good stability, presenting an alternative to applying frequency-by-frequency calculation and the average frequency process. The FEM/FAQP method can be used as a prediction method for calculating acoustic radiation while taking the randomness of vibration at medium and high frequencies into consideration.
International Nuclear Information System (INIS)
Stenvall, A; Tarhasaari, T
2010-01-01
Many people these days employ only commercial finite element method (FEM) software when solving for the hysteresis losses of superconductors. Thus, the knowledge of a modeller is in the capability of using the black boxes of software efficiently. This has led to a relatively superficial examination of different formulations while the discussion stays mainly on the usage of the user interfaces of these programs. Also, if we stay only at the mercy of commercial software producers, we end up having less and less knowledge on the details of solvers. Then, it becomes more and more difficult to conceptually solve new kinds of problem. This may prevent us finding new kinds of method to solve old problems more efficiently, or finding a solution for a problem that was considered almost impossible earlier. In our earlier research, we presented the background of a co-tree gauged T-ψ FEM solver for computing the hysteresis losses of superconductors. In this paper, we examine the feasibility of FEM and eddy current vector potential formulation in the same problem.
Rao, Chengping; Zhang, Youlin; Wan, Decheng
2017-12-01
Fluid-Structure Interaction (FSI) caused by fluid impacting onto a flexible structure commonly occurs in naval architecture and ocean engineering. Research on the problem of wave-structure interaction is important to ensure the safety of offshore structures. This paper presents the Moving Particle Semi-implicit and Finite Element Coupled Method (MPS-FEM) to simulate FSI problems. The Moving Particle Semi-implicit (MPS) method is used to calculate the fluid domain, while the Finite Element Method (FEM) is used to address the structure domain. The scheme for the coupling of MPS and FEM is introduced first. Then, numerical validation and convergent study are performed to verify the accuracy of the solver for solitary wave generation and FSI problems. The interaction between the solitary wave and an elastic structure is investigated by using the MPS-FEM coupled method.
Fischer, Bennet; Hopf, Barbara; Lindner, Markus; Koch, Alexander W.; Roths, Johannes
2017-04-01
A 3D FEM model of an FBG in a PANDA fiber with an extended fiber length of 25.4 mm is presented. Simulating long fiber lengths with limited computer power is achieved by using an iterative solver and by optimizing the FEM mesh. For verification purposes, the model is adapted to a configuration with transversal loads on the fiber. The 3D FEM model results correspond with experimental data and with the results of an additional 2D FEM plain strain model. In further studies, this 3D model shall be applied to more sophisticated situations, for example to study the temperature dependence of surface-glued or embedded FBGs in PANDA fibers that are used for strain-temperature decoupling.
DEFF Research Database (Denmark)
Barkmann, R; Dencks, S; Laugier, P
2010-01-01
has been introduced yet. We developed a QUS scanner for measurements at the femur (Femur Ultrasound Scanner, FemUS) and tested its in vivo performance. METHODS: Using the FemUS device, we obtained femoral QUS and DXA on 32 women with recent hip fractures and 30 controls. Fracture discrimination......A quantitative ultrasound (QUS) device for measurements at the proximal femur was developed and tested in vivo (Femur Ultrasound Scanner, FemUS). Hip fracture discrimination was as good as for DXA, and a high correlation with hip BMD was achieved. Our results show promise for enhanced QUS...... and the correlation with femur bone mineral density (BMD) were assessed. RESULTS: Hip fracture discrimination using the FemUS device was at least as good as with hip DXA and calcaneal QUS. Significant correlations with total hip bone mineral density were found with a correlation coefficient R (2) up to 0...
Experimental study of a high-current FEM with a broadband microwave system
Energy Technology Data Exchange (ETDEWEB)
Denisov, G.G.; Bratman, V.L.; Ginzburg, N.S. [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)] [and others
1995-12-31
One of the main features of FELs and FEMs is the possibility of fast and wideband tuning of the resonant frequency of active media, which can be provided by changing the particle energy. For a frequency adjustable FEM-oscillator, a broadband microwave system, which is simply combined with an electron-optical FEM system and consists of an oversized waveguide and reflectors based on the microwave beams multiplication effect has been proposed and studied successfully in {open_quotes}cold{close_quotes} measurements. Here, the operating ability of a cavity, that includes some key elements of the broadband microwave system, was tested in the presence of an electron beam. To provide large particle oscillation velocities in a moderate undulator field and the presence of a guide magnetic field, the FEM operating regime of double resonance was chosen. In this regime the cyclotron as well as undulator resonance conditions were satisfied. The FEM-oscillator was investigated experimentally on a high-current accelerator {open_quotes}Sinus-6{close_quotes} that forms an electron beam with particle energy 500keV and pulse duration 25ns. The aperture with a diameter 2.5mm at the center of the anode allows to pass through only the central fraction of the electron beam with a current about 100A and a small spread of longitudinal velocities of the particles. Operating transverse velocity was pumped into the electron beam in the pulse plane undulator of a 2.4cm period. The cavity with a frequency near 45GHz consists of a square waveguide and two reflectors. The broadband up-stream reflector based on the multiplication effect had the power reflectivity coefficient more than 90% in the frequency band 10% for the H{sup 10} wave of the square waveguide with the maximum about 100% at a frequency 45GHz. The down-stream narrow-band Bragg reflector had the power reflection coefficient approximately 80% in the frequency band of 4% near 45GHz for the operating mode.
Energy Technology Data Exchange (ETDEWEB)
Park, Sang-Jin; Kim, Hoe-Woong; Joo, Young-Sang; Kim, Sung-Kyun; Kim, Jong-Bum [KAERI, Daejeon (Korea, Republic of)
2016-05-15
This paper introduces the 2-D FEM simulation of the propagation and radiation of the leaky Lamb wave in and from a plate-type ultrasonic waveguide sensor conducted for the radiation beam profile analysis. The FEM simulations are performed with three different excitation frequencies and the radiation beam profiles obtained from FEM simulations are compared with those obtained from corresponding experiments. This paper deals with the 2-D FEM simulation of the propagation and radiation of the leaky Lamb wave in and from a plate-type ultrasonic waveguide sensor conducted to analyze the radiation beam profiles. The radiation beam profile results obtained from the FEM simulation show good agreement with the ones obtained from the experiment. This result will be utilized to improve the performance of the developed waveguide sensor. The quality of the visualized image is mainly affected by beam profile characteristics of the leaky wave radiated from the waveguide sensor. However, the relationships between the radiation beam profile and many parameters of the waveguide sensor are not fully revealed yet. Therefore, further parametric studies are necessary to improve the performance of the sensor and the finite element method (FEM) is one of the most effective tools for the parametric study.
Higher Order, Hybrid BEM/FEM Methods Applied to Antenna Modeling
Fink, P. W.; Wilton, D. R.; Dobbins, J. A.
2002-01-01
In this presentation, the authors address topics relevant to higher order modeling using hybrid BEM/FEM formulations. The first of these is the limitation on convergence rates imposed by geometric modeling errors in the analysis of scattering by a dielectric sphere. The second topic is the application of an Incomplete LU Threshold (ILUT) preconditioner to solve the linear system resulting from the BEM/FEM formulation. The final tOpic is the application of the higher order BEM/FEM formulation to antenna modeling problems. The authors have previously presented work on the benefits of higher order modeling. To achieve these benefits, special attention is required in the integration of singular and near-singular terms arising in the surface integral equation. Several methods for handling these terms have been presented. It is also well known that achieving he high rates of convergence afforded by higher order bases may als'o require the employment of higher order geometry models. A number of publications have described the use of quadratic elements to model curved surfaces. The authors have shown in an EFIE formulation, applied to scattering by a PEC .sphere, that quadratic order elements may be insufficient to prevent the domination of modeling errors. In fact, on a PEC sphere with radius r = 0.58 Lambda(sub 0), a quartic order geometry representation was required to obtain a convergence benefi.t from quadratic bases when compared to the convergence rate achieved with linear bases. Initial trials indicate that, for a dielectric sphere of the same radius, - requirements on the geometry model are not as severe as for the PEC sphere. The authors will present convergence results for higher order bases as a function of the geometry model order in the hybrid BEM/FEM formulation applied to dielectric spheres. It is well known that the system matrix resulting from the hybrid BEM/FEM formulation is ill -conditioned. For many real applications, a good preconditioner is required
Callari, C.; Federico, F.
2000-04-01
Laboratory consolidation of structured clayey soils is analysed in this paper. The research is carried out by two different methods. The first one treats the soil as an isotropic homogeneous equivalent Double Porosity (DP) medium. The second method rests on the extensive application of the Finite Element Method (FEM) to combinations of different soils, composing 2D or fully 3D ordered structured media that schematically discretize the complex material. Two reference problems, representing typical situations of 1D laboratory consolidation of structured soils, are considered. For each problem, solution is obtained through integration of the equations governing the consolidation of the DP medium as well as via FEM applied to the ordered schemes composed of different materials. The presence of conventional experimental devices to ensure the drainage of the sample is taken into account through appropriate boundary conditions. Comparison of FEM results with theoretical results clearly points out the ability of the DP model to represent consolidation processes of structurally complex soils. Limits of applicability of the DP model may arise when the rate of fluid exchange between the two porous systems is represented through oversimplified relations. Results of computations, obtained having assigned reasonable values to the meso-structural and to the experimental apparatus parameters, point out that a partially efficient drainage apparatus strongly influences the distribution along the sample and the time evolution of the interstitial water pressure acting in both systems of pores. Data of consolidation tests in a Rowe's cell on samples of artificially fissured clays reported in the literature are compared with the analytical and numerical results showing a significant agreement.
When the science fails and the ethics works: 'Fail-safe' ethics in the FEM-PrEP study.
Kingori, Patricia
2015-12-01
This paper will explore the concept of 'fail safe' ethics in the FEM PrEP trial, and the practice of research and ethics on the ground. FEM-PrEP examined the efficacy of PrEP in African women after promising outcomes in research conducted with MSM. This was a hugely optimistic time and FEM-PrEP was mobilised using rights-based ethical arguments that women should have access to PrEP. This paper will present data collected during an ethnographic study of frontline research workers involved in FEM-PrEP. During our discussions, 'fail-safe' ethics emerged as concept that encapsulated their confidence that their ethics could not fail. However, in 2011, FEM-PrEP was halted and deemed a failure. The women involved in the study were held responsible because contrary to researcher's expectations they were not taking the oral PrEP being researched. This examination of FEM-PrEP will show that ethical arguments are increasingly deployed to mobilise, maintain and in some cases stop trials in ways which, at times, are superseded or co-opted by other interests. While promoting the interests of women, rights-based approaches are argued to indirectly justify the continuation of individualised, biomedical interventions which have been problematic in other women-centred trials. In this examination of FEM-PrEP, the rights-based approach obscured: ethical concerns beyond access to PrEP; the complexities of power relationships between donor and host countries; the operations of the HIV industry in research-saturated areas and the cumulative effect of unfilled expectations in HIV research and how this has shaped ideas of research and ethics.
Environmental equipment for usages of FEM software. ADVENTURE system user's guide
International Nuclear Information System (INIS)
Yamasaki, Ichirou; Yoshimura, Shinobu
2003-05-01
The community softwares, databases, and other various tools have been installed in the ITBL environment by the Office of ITBL Promotion as a common utility property for each research field. Among those softwares, Finite Element Method (FEM) code, Adventure (which was originally developed by Prof. Yoshimura, the University of Tokyo), is provided as one of structure analysis programs for ITBL users. The code is well known to possess a high performance ability for parallel processing, especially for massively parallel environments. In this report, a chain of processes for usages of the system as well as the installation method to PC cluster are described. (author)
DEFF Research Database (Denmark)
Christensen, Jesper Thøger; Parigi, Dario; Kirkegaard, Poul Henning
2014-01-01
This paper introduces an interactive tool developed to integrate structural analysis in the architectural design environment from the early conceptual design stage. The tool improves exchange of data between the design environment of Rhino Grasshopper and the FEM analysis of Autodesk Robot...... Structural Analysis. Further the tool provides intuitive setup and visual aids in order to facilitate the process. Enabling students and professionals to quickly analyze and evaluate multiple design variations. The tool has been developed inside the Performance Aided Design course at the Master...... of Architecture and Design at Aalborg University...
Mechatronic FEM model of an electromagnetic-force-compensated load cell
International Nuclear Information System (INIS)
Weis, Hanna; Hilbrunner, Falko; Fröhlich, Thomas; Jäger, Gerd
2012-01-01
In this paper, a mechatronic model for an electromagnetic-force-compensated (EMC) load cell is presented. Designed in ANSYS Mechanical APDL®, the model consists of two modules: the mechanical behaviour of the load cell is represented by a FEM model. The electronic and the electromagnetic parts, consisting of a position indicator, controller and electromagnetic actuator, are implemented into the model as a set of differential equations via ANSYS Parametric Design Language (APDL). Optimization of the mechanical, electromagnetic and controller components can be performed using this model, as well as experiments to determine the sensitivity of the complete system to changes of environmental properties, e.g., the stiffness of the support. (paper)
Environmental equipment for usages of FEM software. ADVENTURE system user's guide
Energy Technology Data Exchange (ETDEWEB)
Yamasaki, Ichirou [Japan Atomic Energy Research Inst., Center for Promotion of Computional Science and Engineering, Kizu, Kyoto (Japan); Yoshimura, Shinobu [Tokyo Univ., Tokyo (Japan)
2003-05-01
The community softwares, databases, and other various tools have been installed in the ITBL environment by the Office of ITBL Promotion as a common utility property for each research field. Among those softwares, Finite Element Method (FEM) code, Adventure (which was originally developed by Prof. Yoshimura, the University of Tokyo), is provided as one of structure analysis programs for ITBL users. The code is well known to possess a high performance ability for parallel processing, especially for massively parallel environments. In this report, a chain of processes for usages of the system as well as the installation method to PC cluster are described. (author)
DEFF Research Database (Denmark)
Niu, H.; Wang, H.; Ye, X.
2017-01-01
application. A converter-level finite element simulation (FEM) simulation is carried out to obtain the ambient temperature of electrolytic capacitors and power MOSFETs used in the LED driver, which takes into account the impact of the driver enclosure and the thermal coupling among different components....... Therefore, the proposed method bridges the link between the global ambient temperature profile outside of the enclosure and the local ambient temperature profiles of the components of interest inside the driver. A quantitative comparison of the estimated annual lifetime consumptions of MOSFETs...
Mixed FEM for Second Order Elliptic Problems on Polygonal Meshes with BEM-Based Spaces
Efendiev, Yalchin
2014-01-01
We present a Boundary Element Method (BEM)-based FEM for mixed formulations of second order elliptic problems in two dimensions. The challenge, we would like to address, is a proper construction of H(div)-conforming vector valued trial functions on arbitrary polygonal partitions of the domain. The proposed construction generates trial functions on polygonal elements which inherit some of the properties of the unknown solution. In the numerical realization, the relevant local problems are treated by means of boundary integral formulations. We test the accuracy of the method on two model problems. © 2014 Springer-Verlag.
Identification of the numerical model of FEM in reference to measurements in situ
Jukowski, Michał; Bec, Jarosław; Błazik-Borowa, Ewa
2018-01-01
The paper deals with the verification of various numerical models in relation to the pilot-phase measurements of a rail bridge subjected to dynamic loading. Three types of FEM models were elaborated for this purpose. Static, modal and dynamic analyses were performed. The study consisted of measuring the acceleration values of the structural components of the object at the moment of the train passing. Based on this, FFT analysis was performed, the main natural frequencies of the bridge were determined, the structural damping ratio and the dynamic amplification factor (DAF) were calculated and compared with the standard values. Calculations were made using Autodesk Simulation Multiphysics (Algor).
Energy Technology Data Exchange (ETDEWEB)
Zhang, Dongping
2009-10-26
Lateral forced cooling can significantly increase the temporary overload capacity of a cable system, but the design of such systems requires a time-dependent 3D analysis of the nonlinear thermal behavior as the cooling water along the cable is heated up, resulting in position-dependent and time-dependent heat uptake. For this, a new calculation method was developed on the basis of an available 3D FEM software. The new method enables 3D simulation of force-cooled cables in consideration of the potential partial dryout of soil and of thermal stabilizations. The new method was first applied to a 110 kV wind power transmission cable for different configurations and grid conditions. It was found that with lateral forced cooling, the 110 kV will have a temporal 50 percent overload capacity. Further, the thermal characteristics and limiting capacity of a force-cooled 380 kV cable system were investigated. According to the results so far, laterally cooled cable systems open up new operating options, with advantages in terms of availability, economic efficiency, and flexibility. (orig.) [German] Eine laterale Zwangskuehlung kann die temporaere Ueberlastbarkeit einer Kabelanlage signifikant erhoehen. Der Entwurf solcher zwangsgekuehlter Kabelanlagen erfordert jedoch eine zeitabhaengige, dreidimensionale Analyse des nichtlinearen thermischen Verhaltens, da sich das Kuehlwasser entlang der Trasse erwaermt und sich so eine orts- und zeitabhaengige Waermeaufnahme ergibt. Zu diesem Zweck wurde auf der Basis eines vorhandenen zweidimensionalen FEM-Programms ein neues Berechnungsverfahren entwickelt, das die dreidimensionale Simulation zwangsgekuehlter Kabelanlagen unter Beruecksichtigung einer moeglicherweise auftretenden partiellen Bodenaustrocknung und von thermischen Stabilisierungen erlaubt. Mit Hilfe dieses Berechnungsverfahrens wurde zuerst eine 110-kV-Kabelanlage zur Windenergieuebertragung bei unterschiedlichen Anordnungen und unterschiedlichen Netzsituationen untersucht
Electrical performance analysis of HTS synchronous motor based on 3D FEM
International Nuclear Information System (INIS)
Baik, S.K.; Kwon, Y.K.; Kim, H.M.; Lee, J.D.; Kim, Y.C.; Park, G.S.
2010-01-01
A 1-MW class superconducting motor with High-Temperature Superconducting (HTS) field coil is analyzed and tested. This machine is a prototype to make sure applicability aimed at generator and industrial motor applications such as blowers, pumps and compressors installed in large plants. This machine has the HTS field coil made of Bi-2223 HTS wire and the conventional copper armature (stator) coils cooled by water. The 1-MW class HTS motor is analyzed by 3D electromagnetic Finite Element Method (FEM) to get magnetic field distribution, self and mutual inductance, and so forth. Especially excitation voltage (Back EMF) is estimated by using the mutual inductance between armature and field coils and compared with experimental result. Open and short circuit tests were conducted in generator mode while a 1.1-MW rated induction machine was rotating the HTS machine. Electrical parameters such as mutual inductance and synchronous inductance are deduced from these tests and also compared with the analysis results from FEM.
Calculation of marine propeller static strength based on coupled BEM/FEM
Directory of Open Access Journals (Sweden)
YE Liyu
2017-10-01
Full Text Available [Objectives] The reliability of propeller stress has a great influence on the safe navigation of a ship. To predict propeller stress quickly and accurately,[Methods] a new numerical prediction model is developed by coupling the Boundary Element Method(BEMwith the Finite Element Method (FEM. The low order BEM is used to calculate the hydrodynamic load on the blades, and the Prandtl-Schlichting plate friction resistance formula is used to calculate the viscous load. Next, the calculated hydrodynamic load and viscous correction load are transmitted to the calculation of the Finite Element as surface loads. Considering the particularity of propeller geometry, a continuous contact detection algorithm is developed; an automatic method for generating the finite element mesh is developed for the propeller blade; a code based on the FEM is compiled for predicting blade stress and deformation; the DTRC 4119 propeller model is applied to validate the reliability of the method; and mesh independence is confirmed by comparing the calculated results with different sizes and types of mesh.[Results] The results show that the calculated blade stress and displacement distribution are reliable. This method avoids the process of artificial modeling and finite element mesh generation, and has the advantages of simple program implementation and high calculation efficiency.[Conclusions] The code can be embedded into the code of theoretical and optimized propeller designs, thereby helping to ensure the strength of designed propellers and improve the efficiency of propeller design.
Celmer, M; Opieliński, K J; Dopierała, M
2018-02-01
One of the reasons of distortions in ultrasonic imaging are crosstalk effects. They can be divided into groups according to the way of their formation. One of them is constituted by mechanical crosstalk, which is propagated by a construction of a multi-element array of piezoelectric transducers. When an individual transducer is excited, mechanical vibrations are transferred to adjacent construction components, thereby stimulating neighboring transducers to an undesired operation. In order to explore ways of the propagation of such vibrations, the authors developed the FEM model of the array of piezoelectric transducers designed for calculations in COMSOL Multiphysics software. Simulations of activating individual transducers and calculated electrical voltages appearing on transducers unstimulated intentionally, were performed in the time domain in order to assess the propagation velocity of different vibration modes through the construction elements. On this basis, conclusions were drawn in terms of the participation of various construction parts of the array of piezoelectric transducers in the process of creating the mechanical crosstalk. The elaborated FEM model allowed also to examine the ways aimed at reducing the transmission of mechanical crosstalk vibrations through the components of the array. Studies showed that correct cuts in the fasteners and the front layer improve the reduction of the mechanical crosstalk effect. The model can become a helpful tool in the process of design and modifications of manufactured ultrasonic arrays particularly in terms of mechanical crosstalk reduction. Copyright © 2017 Elsevier B.V. All rights reserved.
Integrity evaluation for stud female threads on pressure vessel according to ASME code using FEM
International Nuclear Information System (INIS)
Kim, Moon Young; Chung, Nam Yong
2003-01-01
The extension of design life among power plants is increasingly becoming a world-wide trend. Kori no.1 unit in Korea is operating two cycle. It has two man-ways for tube inspection in a steam generator which is one of the important components in a nuclear power plant. Especially, stud bolts for man-way cover have damaged by disassembly and assembly several times and degradation for bolt materials for long term operation. It should be evaluated and compared by ASME code criteria for integrity evaluation. Integrity evaluation criteria which has been made by the manufacturer is not applied on the stud bolts of nuclear pressure vessels directly because it is controlled by the yield stress of ASME code. It can apply evaluation criteria through FEM analysis to damaged female threads and to evaluated safety for helical-coil method which is used according to code case-N-496-1. From analysis results, we found that it is the same results between stress intensity which got from FEM analysis on damaged female threads over 10% by manufacture integrity criteria and 2/3 yield strength criteria on ASME code. It was also confirmed that the helical-coil repair method would be safe
1963 Vajont rock slide: a comparison between 3D DEM and 3D FEM
Crosta, Giovanni; Utili, Stefano; Castellanza, Riccardo; Agliardi, Federico; Bistacchi, Andrea; Weng Boon, Chia
2013-04-01
Data on the exact location of the failure surface of the landslide have been used as the starting point for the modelling of the landslide. 3 dimensional numerical analyses were run employing both the discrete element method (DEM) and a Finite Element Method (FEM) code. In this work the focus is on the prediction of the movement of the landlside during its initial phase of detachment from Mount Toc. The results obtained by the two methods are compared and conjectures on the observed discrepancies of the predictions between the two methods are formulated. In the DEM simulations the internal interaction of the sliding blocks and the expansion of the debris is obtained as a result of the kinematic interaction among the rock blocks resulting from the jointing of the rock mass involved in the slide. In the FEM analyses, the c-phi reduction technique was employed along the predefine failure surface until the onset of the landslide occurred. In particular, two major blocks of the landslide were identified and the stress, strain and displacement fields at the interface between the two blocks were analysed in detail.
Investigation of the fittest shear transfer model used to FEM analysis of RC structures
International Nuclear Information System (INIS)
Endo, Tatumi; Aoyagi, Masao; Endo, Takao
1988-01-01
In order to rationalize the design method of reinforced concrete (RC) structures in the nuclear power plant, the structural analysis, which is able to simulate the seismic behavior of RC structures, should be established. In this report, the investigation of shear transfer model at shear plane to be applied to FEM analysis is performed. Main conclusions obtained within the limit of the study are as follows. 1. Development of the shear transfer model at shear plane. 1) Two shear transfer models are developed to be used to the 2-dimensional nonlinear FEM analysis. 2) In one model suggested, reinforcements are modeled by plate elements and the nonlinearity of concrete surrounding reinforcement but the properties of bond-slip relation between concrete and reinforcements is also considered. 3) In another model, reinforcements are modeled by equivalent concrete properties, in which axial regidity and dowel effects of reinforcements are considered. 2. Verification of the suggested model. 1) It is confirmed that the computational results using the above-mentioned model could simulate the experimental ones fairly well. 2) Considering the application to the analysis of RC structures in the design, the model, in which reinforcement are modeled by equivalent concrete properties, is useful in view point of accuracy and simplicity. (author)
Directory of Open Access Journals (Sweden)
Nicolae APOSTOLESCU
2010-12-01
Full Text Available The main objective of this paper is to describe a code for calculating an equivalent systemof concentrate loads for a FEM analysis. The tables from the Aerodynamic Department containpressure field for a whole bearing surface, and integrated quantities both for the whole surface andfor fixed and mobile part. Usually in a FEM analysis the external loads as concentrated loadsequivalent to the distributed pressure field are introduced. These concentrated forces can also be usedin static tests. Commercial codes provide solutions for this problem, but what we intend to develop isa code adapted to the user’s specific needs.
Stress and displacement analysis of a modern design lathe body by the fi nite element method (FEM
Directory of Open Access Journals (Sweden)
R. Staniek
2012-01-01
Full Text Available The Finite element method (FEM was used in this study for the analysis of the strain and stress of a turning machine body. The fi nal design decisions were made on the basis of stress and displacement fi eld analysis of various design versions related to the structure of the considered machine tool. The results presented in this paper will be helpful for practical static and dynamic strength evaluation as well as for the appropriate design of machine tools using the FEM.
Induction Machine with Improved Operating Performances for Electric Trucks. A FEM-Based Analysis
Directory of Open Access Journals (Sweden)
MUNTEANU, A.
2010-05-01
Full Text Available The paper presents a study concerning the performance developed by induction motors destined for motorization of heavy electric vehicles such as trucks. Taking into consideration the imposed restrictions, one presents, in a comparative manner, the main geometrical parameters which come of the classical design algorithms. A special attention is dedicated to the winding design, since it has to ensure two synchronous speeds corresponding to 16 and 8 poles, respectively. Moreover, the influence of the rotor slots shape for the improvement of the start-up is analyzed. Finally, a FEM-based study (approach based on finite element method is performed to put in view specific torque and slip values such as rated, start-up and pull-out ones.
Analytical Calculation And FEM Analysis Main Girder Double Girder Bridge Crane
Directory of Open Access Journals (Sweden)
Muamer Delić
2017-02-01
Full Text Available The cranes are now not replaceable mode of transport of materials and finished products both in production halls and in the open space. This paper made the whole analytical calculation of double girder bridge cranes to be used in laboratories exclusively for testing, determined by the maximum bending stress and deflection of the main girder. After calculating the dimensions, we created a model cranes in software CATIA V5. The same model was subjected to FEM analysis of the same name software. At the end of the paper comparison has been done. The objective of the calculation and analysis of the model was to develop a model crane and to serve for the next tests. Dimensions of the crane are given according to the laboratory where it will be located.
Nodal DG-FEM solution of high-order Boussinesq-type equations
DEFF Research Database (Denmark)
Engsig-Karup, Allan Peter; Hesthaven, Jan S.; Bingham, Harry B.
2006-01-01
We present a discontinuous Galerkin finite element method (DG-FEM) solution to a set of high-order Boussinesq-type equations for modelling highly nonlinear and dispersive water waves in one and two horizontal dimensions. The continuous equations are discretized using nodal polynomial basis...... functions of arbitrary order in space on each element of an unstructured computational domain. A fourth order explicit Runge-Kutta scheme is used to advance the solution in time. Methods for introducing artificial damping to control mild nonlinear instabilities are also discussed. The accuracy...... and convergence of the model with both h (grid size) and p (order) refinement are verified for the linearized equations, and calculations are provided for two nonlinear test cases in one horizontal dimension: harmonic generation over a submerged bar; and reflection of a steep solitary wave from a vertical wall...
Development of seismic analysis model for HTGR core on commercial FEM code
International Nuclear Information System (INIS)
Tsuji, Nobumasa; Ohashi, Kazutaka
2015-01-01
The aftermath of the Great East Japan Earthquake prods to revise the design basis earthquake intensity severely. In aseismic design of block-type HTGR, the securement of structural integrity of core blocks and other structures which are made of graphite become more important. For the aseismic design of block-type HTGR, it is necessary to predict the motion of core blocks which are collided with adjacent blocks. Some seismic analysis codes have been developed in 1970s, but these codes are special purpose-built codes and have poor collaboration with other structural analysis code. We develop the vertical 2 dimensional analytical model on multi-purpose commercial FEM code, which take into account the multiple impacts and friction between block interfaces and rocking motion on contact with dowel pins of the HTGR core by using contact elements. This model is verified by comparison with the experimental results of 12 column vertical slice vibration test. (author)
FEM simulation study on relationship of interfacial morphology and residual stress in TBCs
Energy Technology Data Exchange (ETDEWEB)
Liqiang Chen; Shengkai Gong; Huibin Xu [School of Materials Science and Engineering, Beihang Univ., Beijing, BJ (China)
2005-07-01
It is generally believed that the failure of TBCs is attributed to the spallation occurred in the ceramic coat. The spallation is closed linked with sinuate morphology factors, including its amplitude and period, at the TGO/bond coat interface. In this work, dependence of the residual stress distribution on the sinuate morphology in the TBCs has been studied by means of finite element method (FEM) simulation for isothermally annealed specimens. The simulation results indicated that the maximum value of residual stress existed inside the TGO layer. It was also found that the maximum residual stress occurred at different points, near the TGO/bond coat interface at the peak of the sinuate interface, while near the TGO/ceramic coat interface at the valley, respectively. And the maximum residual stress increased with increasing the ratio of the amplitude to period in the sine morphology, which has been proved by the thermal cycle experimental results. (orig.)
FEM BASED PARAMETRIC DESIGN STUDY OF TIRE PROFILE USING DEDICATED CAD MODEL AND TRANSLATION CODE
Directory of Open Access Journals (Sweden)
Nikola Korunović
2014-12-01
Full Text Available In this paper a finite element method (FEM based parametric design study of the tire profile shape and belt width is presented. One of the main obstacles that similar studies have faced is how to change the finite element mesh after a modification of the tire geometry is performed. In order to overcome this problem, a new approach is proposed. It implies automatic update of the finite elements mesh, which follows the change of geometric design parameters on a dedicated CAD model. The mesh update is facilitated by an originally developed mapping and translation code. In this way, the performance of a large number of geometrically different tire design variations may be analyzed in a very short time. Although a pilot one, the presented study has also led to the improvement of the existing tire design.
FEM analysis of an single stator dual PM rotors axial synchronous machine
Tutelea, L. N.; Deaconu, S. I.; Popa, G. N.
2017-01-01
The actual e - continuously variable transmission (e-CVT) solution for the parallel Hybrid Electric Vehicle (HEV) requires two electric machines, two inverters, and a planetary gear. A distinct electric generator and a propulsion electric motor, both with full power converters, are typical for a series HEV. In an effort to simplify the planetary-geared e-CVT for the parallel HEV or the series HEV we hereby propose to replace the basically two electric machines and their two power converters by a single, axial-air-gap, electric machine central stator, fed from a single PWM converter with dual frequency voltage output and two independent PM rotors. The proposed topologies, the magneto-motive force analysis and quasi 3D-FEM analysis are the core of the paper.
A continuum based fem model for friction stir welding-model development
Energy Technology Data Exchange (ETDEWEB)
Buffa, G. [Ohio State University, Department of Industrial, Welding and Systems Engineering, 1971 Neil Avenue, 210 Baker Systems, Columbus, OH 43210 (United States) and Dipartimento di Tecnologia Meccanica, Produzione e Ingegneria Gestionale, Universita di Palermo, Viale delle Scienze, 90128 Palermo (Italy)]. E-mail: g.buffa@dtpm.unipa.it; Hua, J. [Ohio State University, Department of Industrial, Welding and Systems Engineering, 1971 Neil Avenue, 210 Baker Systems, Columbus, OH 43210 (United States)]. E-mail: hua.14@osu.edu; Shivpuri, R. [Ohio State University, Department of Industrial, Welding and Systems Engineering, 1971 Neil Avenue, 210 Baker Systems, Columbus, OH 43210 (United States)]. E-mail: shivpuri.1@osu.edu; Fratini, L. [Dipartimento di Tecnologia Meccanica, Produzione e Ingegneria Gestionale, Universita di Palermo, Viale delle Scienze, 90128 Palermo (Italy)]. E-mail: abaqus@dtpm.unipa.it
2006-03-15
Although friction stir welding (FSW) has been successfully used to join materials that are difficult-to-weld or unweldeable by fusion welding methods, it is still in its early development stage and, therefore, a scientific knowledge based predictive model is of significant help for thorough understanding of FSW process. In this paper, a continuum based FEM model for friction stir welding process is proposed, that is 3D Lagrangian implicit, coupled, rigid-viscoplastic. This model is calibrated by comparing with experimental results of force and temperature distribution, then is used to investigate the distribution of temperature and strain in heat affect zone and the weld nugget. The model correctly predicts the non-symmetric nature of FSW process, and the relationships between the tool forces and the variation in the process parameters. It is found that the effective strain distribution is non-symmetric about the weld line while the temperature profile is almost symmetric in the weld zone.
3D-FEM Analysis on Geogrid Reinforced Flexible Pavement Roads
Calvarano, Lidia Sarah; Palamara, Rocco; Leonardi, Giovanni; Moraci, Nicola
2017-12-01
Nowadays, the need to increase pavement service life, guarantee high performance, reduce service and maintenance costs has been turned a greater attention on the use of reinforcements. This paper presents findings of a numerical investigation on geogrid reinforced flexible pavement roads, under wheel traffic loads, using a three-dimensional Finite Element Method (FEM). The results obtained show the effectiveness of glass fibre grids as reinforcement which, with appropriate design and correct installation, by improving interface shear resistance, can be used to expand the performance of flexible pavements in different ways: by increasing the road service life providing a relevant contribution against superficial rutting or by decreasing the construction costs due to the reduction in the reinforced HMA layer thickness and thus of mineral aggregate required for its construction.
Popuri, Karteek; Cobzas, Dana; Esfandiari, Nina; Baracos, Vickie; Jägersand, Martin
2016-02-01
The proportions of muscle and fat tissues in the human body, referred to as body composition is a vital measurement for cancer patients. Body composition has been recently linked to patient survival and the onset/recurrence of several types of cancers in numerous cancer research studies. This paper introduces a fully automatic framework for the segmentation of muscle and fat tissues from CT images to estimate body composition. We developed a novel finite element method (FEM) deformable model that incorporates a priori shape information via a statistical deformation model (SDM) within the template-based segmentation framework. The proposed method was validated on 1000 abdominal and 530 thoracic CT images and we obtained very good segmentation results with Jaccard scores in excess of 90% for both the muscle and fat regions.
Mass conservation for instantaneous sources in FEM3 simulations of material dispersion
International Nuclear Information System (INIS)
Rodean, H.C.
1987-11-01
This report presents the results of a systematic study in which it is shown that the numerical integration errors in determining material mass content are negligible; the material phase-change model by itself is not a cause of material mass variation; and a linear relation between fractional mass change and fractional density change at the source center for given mesh and source geometries exists over a range of values from 10 -5 to 10 -1 . This suggests that the omission of the ∂ rho/∂t term from the mass conservation equation is the cause of the observed non-conservation of mass by FEM3. It is shown that these mass variations can be minimized by minimizing the initial density gradients in the source region. 5 refs., 18 figs., 4 tabs
An Experimental Simulation to Validate FEM to Predict Transverse Young’s Modulus of FRP Composites
Directory of Open Access Journals (Sweden)
V. S. Sai
2013-01-01
Full Text Available Finite element method finds application in the analysis of FRP composites due to its versatility in getting the solution for complex cases which are not possible by exact classical analytical approaches. The finite element result is questionable unless it is obtained from converged mesh and properly validated. In the present work specimens are prepared with metallic materials so that the arrangement of fibers is close to hexagonal packing in a matrix as similar arrangement in case of FRP is complex due to the size of fibers. Transverse Young’s moduli of these specimens are determined experimentally. Equivalent FE models are designed and corresponding transverse Young’s moduli are compared with the experimental results. It is observed that the FE values are in good agreement with the experimental results, thus validating FEM for predicting transverse modulus of FRP composites.
FEM simulation of friction testing method based on combined forward rod-backward can extrusion
DEFF Research Database (Denmark)
Nakamura, T; Bay, Niels; Zhang, Z. L
1997-01-01
A new friction testing method by combined forward rod-backward can extrusion is proposed in order to evaluate frictional characteristics of lubricants in forging processes. By this method the friction coefficient mu and the friction factor m can be estimated along the container wall and the conical...... curves are obtained by rigid-plastic FEM simulations in a combined forward rod-backward can extrusion process for a reduction in area R-b = 25, 50 and 70 percent in the backward can extrusion. It is confirmed that the friction factor m(p) on the punch nose in the backward cart extrusion has almost...... in a mechanical press with aluminium alloy A6061 as the workpiece material and different kinds of lubricants. They confirm the analysis resulting in reasonable values for the friction coefficient and the friction factor....
Thermal modal analysis of novel non-pneumatic mechanical elastic wheel based on FEM and EMA
Zhao, Youqun; Zhu, Mingmin; Lin, Fen; Xiao, Zhen; Li, Haiqing; Deng, Yaoji
2018-01-01
A combination of Finite Element Method (FEM) and Experiment Modal Analysis (EMA) have been employed here to characterize the structural dynamic response of mechanical elastic wheel (ME-Wheel) operating under a specific thermal environment. The influence of high thermal condition on the structural dynamic response of ME-Wheel is investigated. The obtained results indicate that the EMA results are in accordance with those obtained using the proposed Finite Element (FE) model, indicting the high reliability of this FE model applied in analyzing the modal of ME-Wheel working under practical thermal environment. It demonstrates that the structural dynamic response of ME-Wheel operating under a specific thermal condition can be predicted and evaluated using the proposed analysis method, which is beneficial for the dynamic optimization design of the wheel structure to avoid tire temperature related vibration failure and improve safety of tire.
FEM Analysis of Brushless DC Servomotor with Fractional Number of Slots per Pole
Directory of Open Access Journals (Sweden)
BALUTA, G.
2014-02-01
Full Text Available The authors present in this paper the analysis with Finite Element Method (FEM of the magnetic circuit for a Brushless DC servomotor with fractional number of slots/pole (9 slots and 10 poles. For this purpose, FEMM 4.2 software package was used for the analysis. To obtain the waveforms of Back-ElectroMotive Forces (BEMFs, electromagnetic and cogging torque for servomotor a program in LUA scripting language (integrated into interactive shell of FEMM4.2 has been created. A comparation with a structure with integer number of slots/pole (18 slots and 6 poles was also realized. The analysis results prove that the structure chosen is an optimal solution: sinusoidal waveforms of BEMFs, improved electromagnetic torque and reduced cogging torque. Therefore, the operating characteristics of the servomotor with 9/10 slots/poles manufactured by Sistem Euroteh Company and included in an integrated electrical drives system are presented in this paper.
Optimization of a Centrifugal Boiler Circulating Pump's Casing Based on CFD and FEM Analyses
Directory of Open Access Journals (Sweden)
Zhigang Zuo
2014-04-01
Full Text Available It is important to evaluate the economic efficiency of boiler circulating pumps in manufacturing process from the manufacturers' point of view. The possibility of optimizing the pump casing with respect to structural pressure integrity and hydraulic performance was discussed. CFD analyses of pump models with different pump casing sizes were firstly carried out for the hydraulic performance evaluation. The effects of the working temperature and the sealing ring on the hydraulic efficiency were discussed. A model with casing diameter of 0.875D40 was selected for further analyses. FEM analyses were then carried out on different combinations of casing sizes, casing wall thickness, and materials, to evaluate its safety related to pressure integrity, with respect to both static and fatigue strength analyses. Two models with forging and cast materials were selected as final results.
Application of FEM analytical method for hydrogen migration behaviour in Zirconium alloys
Energy Technology Data Exchange (ETDEWEB)
Arioka, K; Ohta, H [Takasago Research and Development Center, Mitsubishi Heavy Industries Ltd, Hyogo-ken (Japan)
1997-02-01
It is well recognized that the hydriding behaviours of Zirconium alloys are very significant problems as a safety issues. Also, it is well known that the diffusion of hydrogen in Zirconium alloys are affected not only by concentration but also temperature gradient. But in actual component, especially heat transfer tube such as fuel rod, we can not avoid the temperature gradient in some degree. So, it is very useful to develop the computer code which can analyze the hydrogen diffusion and precipitation behaviours under temperature gradient as a function of the structure of fuel rod. For this objective, we have developed the computer code for hydrogen migration behaviour using FEM analytical methods. So, following items are presented and discussed. Analytical method and conditions; correlation between the computed and test results; application to designing studies. (author). 8 refs, 4 figs, 2 tabs.
International Nuclear Information System (INIS)
Hoeglauer, J.; Bohm, C.; Otremba, R.; Maerz, J.; Nelle, P.; Stecher, M.; Alpern, P.
2006-01-01
Plastic encapsulated devices that are exposed to Temperature Cycling (TC) tests undergo an excessive mechanical stress due to different Coefficients of Thermal Expansion (CTE) of the various materials used in the system. Especially in the corners of the die, passivation cracks and shifted metal lines can be observed, which demonstrates an increasing mechanical stress from chip center to the corners of the die. This effect has been known for a long time. This paper presents a simple measurement technique to quantify the mechanical shear stress at the chip-Mold Compound (MC) interface by measuring the deformation of a periodical metal structure. Based on this deformation measurement, we evaluated the stress distribution within the package, and the influence of different parameters such as number of cycles and chip size. Furthermore, these experimental results were compared with FEM simulation, and showed good agreement but could not account in all cases for the total amount of observed shift
A continuum based fem model for friction stir welding-model development
International Nuclear Information System (INIS)
Buffa, G.; Hua, J.; Shivpuri, R.; Fratini, L.
2006-01-01
Although friction stir welding (FSW) has been successfully used to join materials that are difficult-to-weld or unweldeable by fusion welding methods, it is still in its early development stage and, therefore, a scientific knowledge based predictive model is of significant help for thorough understanding of FSW process. In this paper, a continuum based FEM model for friction stir welding process is proposed, that is 3D Lagrangian implicit, coupled, rigid-viscoplastic. This model is calibrated by comparing with experimental results of force and temperature distribution, then is used to investigate the distribution of temperature and strain in heat affect zone and the weld nugget. The model correctly predicts the non-symmetric nature of FSW process, and the relationships between the tool forces and the variation in the process parameters. It is found that the effective strain distribution is non-symmetric about the weld line while the temperature profile is almost symmetric in the weld zone
A Validation of FEM3MP with Joint Urban 2003 Data
Energy Technology Data Exchange (ETDEWEB)
Chan, S T; Leach, M J
2006-08-29
Under the sponsorship of the U.S. DOE and DHS, we have recently developed a computational fluid dynamics (CFD) model for simulating airflow and dispersion of chemical/biological agents released in urban areas. Our model, FEM3MP, is based on solving the three-dimensional, time-dependent Navier-Stokes equations with appropriate physics submodels on massively parallel computer platforms. It employs finite-element discretization for effective treatment of complex geometries and a semi-implicit projection scheme for efficient time-integration. A simplified CFD approach, using both explicitly resolved and virtual buildings, was implemented to further improve the model's efficiency. Predictions from our model are continuously being verified against measured data from wind tunnel and field studies. Herein our model is further evaluated using observed data from IOPs (intensive operation periods) 3 and 9 of the Joint Urban 2003 field study conducted in Oklahoma City, Oklahoma, in July 2003. Our model predictions of wind and concentration fields in the near and intermediate regions, as well as profiles of wind speed, wind direction, friction velocity, and turbulent kinetic energy (TKE) in the urban wake region, are generally consistent with and compared reasonably well with field observations. In addition, our model was able to predict the observed split plume of IOP 3 and the end vortices along Park Avenue in IOP 9. The dispersion results and TKE profiles at the crane station indicate the effects of convective mixing are relatively important for the daytime release of IOP 3 but the stable effects are relatively unimportant for the nighttime release of IOP 9. Results of this study also suggest that the simplified CFD approach implemented in FEM3MP can be a cost-effective tool for simulating urban dispersion problems.
Fracture Capabilities in Grizzly with the extended Finite Element Method (X-FEM)
Energy Technology Data Exchange (ETDEWEB)
Dolbow, John [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Ziyu [Idaho National Lab. (INL), Idaho Falls, ID (United States); Spencer, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jiang, Wen [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2015-09-01
Efforts are underway to develop fracture mechanics capabilities in the Grizzly code to enable it to be used to perform deterministic fracture assessments of degraded reactor pressure vessels (RPVs). A capability was previously developed to calculate three-dimensional interaction- integrals to extract mixed-mode stress-intensity factors. This capability requires the use of a finite element mesh that conforms to the crack geometry. The eXtended Finite Element Method (X-FEM) provides a means to represent a crack geometry without explicitly fitting the finite element mesh to it. This is effected by enhancing the element kinematics to represent jump discontinuities at arbitrary locations inside of the element, as well as the incorporation of asymptotic near-tip fields to better capture crack singularities. In this work, use of only the discontinuous enrichment functions was examined to see how accurate stress intensity factors could still be calculated. This report documents the following work to enhance Grizzly’s engineering fracture capabilities by introducing arbitrary jump discontinuities for prescribed crack geometries; X-FEM Mesh Cutting in 3D: to enhance the kinematics of elements that are intersected by arbitrary crack geometries, a mesh cutting algorithm was implemented in Grizzly. The algorithm introduces new virtual nodes and creates partial elements, and then creates a new mesh connectivity; Interaction Integral Modifications: the existing code for evaluating the interaction integral in Grizzly was based on the assumption of a mesh that was fitted to the crack geometry. Modifications were made to allow for the possibility of a crack front that passes arbitrarily through the mesh; and Benchmarking for 3D Fracture: the new capabilities were benchmarked against mixed-mode three-dimensional fracture problems with known analytical solutions.
Pregnancy and contraceptive use among women participating in the FEM-PrEP trial.
Callahan, Rebecca; Nanda, Kavita; Kapiga, Saidi; Malahleha, Mookho; Mandala, Justin; Ogada, Teresa; Van Damme, Lut; Taylor, Douglas
2015-02-01
Pregnancy among study participants remains a challenge for trials of new HIV prevention agents despite promotion and provision of contraception. We evaluated contraceptive use, pregnancy incidence, and study drug adherence by contraceptive method among women enrolled in the FEM-PrEP trial of once-daily oral tenofovir disoproxil fumarate and emtricitabine (TDF-FTC) for HIV prevention. We required women to be using effective non-barrier contraception at enrollment. At each monthly follow-up visit, women were counseled on contraceptive use and tested for pregnancy. TDF-FTC adherence was determined by measuring plasma drug concentrations at 4-week intervals. We used Cox proportional hazards models to assess factors associated with incident pregnancy and multivariate logistic regression to examine the relationship between contraceptive method used at enrollment and TDF-FTC adherence. More than half of women were not using effective contraception before enrollment. Ninety-eight percent of these women adopted either injectable (55%) or oral (43%) contraceptives. The overall pregnancy rate was 9.6 per 100 woman-years. Among injectable users and new users of combined oral contraceptives (COCs), the rates were 1.6 and 35.1, respectively. New users of injectables had significantly greater odds of adhering to TDF-FTC than new COC users [odds ratio (95% confidence interval): 4.4 (1.7 to 11.6), P = 0.002], existing COC users [3.1 (1.3 to 7.3), P = 0.01], and existing injectable users [2.4 (1.1 to 5.6), P = 0.04]. Women using COCs during FEM-PrEP, particularly new adopters, were more likely to become pregnant and less likely to adhere to study product than injectable users. HIV prevention trials should consider requiring long-acting methods, including injectables, for study participation.
Esterhazy, Sofi; Schneider, Felix; Schöberl, Joachim; Perugia, Ilaria; Bokelmann, Götz
2016-04-01
The research on purely numerical methods for modeling seismic waves has been more and more intensified over last decades. This development is mainly driven by the fact that on the one hand for subsurface models of interest in exploration and global seismology exact analytic solutions do not exist, but, on the other hand, retrieving full seismic waveforms is important to get insides into spectral characteristics and for the interpretation of seismic phases and amplitudes. Furthermore, the computational potential has dramatically increased in the recent past such that it became worthwhile to perform computations for large-scale problems as those arising in the field of computational seismology. Algorithms based on the Finite Element Method (FEM) are becoming increasingly popular for the propagation of acoustic and elastic waves in geophysical models as they provide more geometrical flexibility in terms of complexity as well as heterogeneity of the materials. In particular, we want to demonstrate the benefit of high-order FEMs as they also provide a better control on the accuracy. Our computations are done with the parallel Finite Element Library NGSOLVE ontop of the automatic 2D/3D mesh generator NETGEN (http://sourceforge.net/projects/ngsolve/). Further we are interested in the generation of synthetic seismograms including direct, refracted and converted waves in correlation to the presence of an underground cavity and the detailed simulation of the comprehensive wave field inside and around such a cavity that would have been created by a nuclear explosion. The motivation of this application comes from the need to find evidence of a nuclear test as they are forbidden by the Comprehensive Nuclear-Test Ban Treaty (CTBT). With this approach it is possible for us to investigate the wave field over a large bandwidth of wave numbers. This again will help to provide a better understanding on the characteristic signatures of an underground cavity, improve the protocols for
Camas, Mustafa; Sazak Camas, Anil; Kyeremeh, Kwaku
2018-06-01
Through the use of genomes that have undergone millions of years of evolution, marine Actinobacteria are known to have adapted to rapidly changing environmental pressures. The result is a huge chemical and biological diversity among marine Actinobacteria . It is gradually becoming a known fact that, marine Actinobacteria have the capability to produce nanoparticles which have reasonable sizes and structures with possible applications in biotechnology and pharmacology. Mycobacterium sp. BRS2A-AR2 was isolated from the aerial roots of the mangrove plant Rhizophora racemosa . The Mycobacterium was demonstrated for the first time ever to produce AuNPs with sizes that range between 5 and 55 nm. The highest level absorbance of the biosynthesized AuNPs was typical for actinobacterial strains (2.881 at 545 nm). The polydispersity index was measured as 0.207 in DLS and the zeta potential was negatively charged (- 28.3 mV). Significant vibration stretches were seen at 3314, 2358, 1635 and 667 cm -1 in FT-IR spectra. This demonstrated the possible use of small aliphatic compounds containing -COOH, -OH, -Cl and -NH 2 functional groups in the stabilization of the AuNPs. The effect of the biosynthesized AuNPs on HUVEC and HeLA cell lines was measured at 48 h. IC 50 values were determined at 3500 µg/ml concentration for HUVEC and HeLA cell lines at 45.25 and 53.41% respectively.
Directory of Open Access Journals (Sweden)
Vasile Cojocaru
2016-12-01
Full Text Available Several methods can be used in the FEM studies to apply the loads on a plain bearing. The paper presents a comparative analysis of maximum stress obtained for three loading scenarios: resultant force applied on the shaft – bearing assembly, variable pressure with sinusoidal distribution applied on the bearing surface, variable pressure with parabolic distribution applied on the bearing surface.
Energy Technology Data Exchange (ETDEWEB)
Bouzakis, K.D. [Aristoteles Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Vidakis, N. [Aristoteles Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Leyendecker, T. [CemeCon, 52068 Aachen (Germany); Lemmer, O. [CemeCon, 52068 Aachen (Germany); Fuss, H.G. [CemeCon, 52068 Aachen (Germany); Erkens, G. [CemeCon, 52068 Aachen (Germany)
1996-12-15
The impact test, in combination with a finite element method (FEM) simulation, is used to determine stress values that characterise the fatigue behaviour of thin hard coatings, such as TiAlN, TiAlCN, CrN, MoN, etc. The successive impacts of a cemented carbide ball onto a coated probe induce high contact loads, which can vary in amplitude and cause plastic deformation in the substrate. In the present paper FEM calculations are used in order to determine the critical stress values, which lead to coating fatigue failure. The parametric FEM simulation developed considers elastic behaviour for the coating and elastic plastic behaviour for the substrate. The results of the FEM calculations are correlated to experimental data, as well as to SEM observations of the imprints and to microspectrum analyses within the contact region. Herewith, critical values for various stress components, which are responsible for distinctive fatigue failure modes of the coating-substrate compounds can be obtained. (orig.)
Effect of the drift gap between the undulator sections on the operation of the Fusion-FEM
van der Geer, C. A. J.; Militsyn, B. L.; Bongers, W. A.; Bratman, V. L.; Denisov, G. G.; Manintveld, P.; Savilov, A. V.; Varfolomeev, A. A.; Verhoeven, A. G. A.; Urbanus, W. H.
2000-01-01
The 'Fusion-FEM' is a free electron MASER based on an electrostatic accelerator. An electron beam of 12 A, 1.35-2 MeV is injected into a step-tapered undulator to generate 1 MW of radiation in the range 130-250 GHz. The undulator is built from two sections with different field strength
Lof, J.
2001-01-01
The use of the finite element method (FEM) is getting increasingly important in the understanding of processes that occur during aluminium extrusion. The bearing area is one of the most difficult areas to model in a numerical simulation. To investigate the phenomena that occur in the bearing,
Experimental study and FEM simulation of the simple shear test of cylindrical rods
Wirti, Pedro H. B.; Costa, André L. M.; Misiolek, Wojciech Z.; Valberg, Henry S.
2018-05-01
In the presented work an experimental simple shear device for cutting cylindrical rods was used to obtain force-displacement data for a low-carbon steel. In addition, and FEM 3D-simulation was applied to obtain internal shear stress and strain maps for this material. The experimental longitudinal grid patterns and force-displacement curve were compared with numerical simulation results. Many aspects of the elastic and plastic deformations were described. It was found that bending reduces the shear yield stress of the rod material. Shearing starts on top and bottom die-workpiece contact lines evolving in an arc-shaped area. Due to this geometry, stress concentrates on the surface of the rod until the level of damage reaches the critical value and the fracture starts here. The volume of material in the plastic zone subjected to shearing stress has a very complex shape and is function of a dimensionless geometrical parameter. Expressions to calculate the true shear stress τ and strain γ from the experimental force-displacement data were proposed. The equations' constants are determined by fitting the experimental curve with the stress τ and strain γ simulation point tracked data.
Study on vibration characteristics of the shaft system for a dredging pump based on FEM
International Nuclear Information System (INIS)
Zhai, L M; Liu, X; He, L Y; Wang, Z W; Qin, L; Liu, C Y; He, Y
2012-01-01
The dynamic characteristics of the shaft system for a dredging pump were studied with the Finite Element Method (FEM) by SAMCEF ROTOR. At first, the influence of the fluid-solid coupling interaction of mud water and impeller, water sealing and pump shaft on the lateral critical speeds were analyzed. The results indicated that the mud water must be taken into consideration, while the water sealing need not to. Then the effects of radial and thrust rolling bearings on the lateral critical speeds were discussed, which shows that the radial bearing close to the impeller has greatest impact on the 1st order critical speed. At last, the upper and lower limits of the critical speeds of lateral, axial and torsional vibration were calculated. The rated speed of the dredging pump was far less than the predicted critical speed, which can ensure the safe operation of the unit. Each vibration mode is also shown in this paper. This dynamic analysis method offers some reference value on the research of vibration and stability of the shaft system in dredging pump.
Numerical Analyses of Subsoil-structure Interaction in Original Non-commercial Software based on FEM
Cajka, R.; Vaskova, J.; Vasek, J.
2018-04-01
For decades attention has been paid to interaction of foundation structures and subsoil and development of interaction models. Given that analytical solutions of subsoil-structure interaction could be deduced only for some simple shapes of load, analytical solutions are increasingly being replaced by numerical solutions (eg. FEM – Finite element method). Numerical analyses provides greater possibilities for taking into account the real factors involved in the subsoil-structure interaction and was also used in this article. This makes it possible to design the foundation structures more efficiently and still reliably and securely. Currently there are several software that, can deal with the interaction of foundations and subsoil. It has been demonstrated that non-commercial software called MKPINTER (created by Cajka) provides appropriately results close to actual measured values. In MKPINTER software stress-strain analysis of elastic half-space by means of Gauss numerical integration and Jacobean of transformation is done. Input data for numerical analysis were observed by experimental loading test of concrete slab. The loading was performed using unique experimental equipment which was constructed in the area Faculty of Civil Engineering, VŠB-TU Ostrava. The purpose of this paper is to compare resulting deformation of the slab with values observed during experimental loading test.
Slope stability and rockfall assessment of volcanic tuffs using RPAS with 2-D FEM slope modelling
Török, Ákos; Barsi, Árpád; Bögöly, Gyula; Lovas, Tamás; Somogyi, Árpád; Görög, Péter
2018-02-01
Steep, hardly accessible cliffs of rhyolite tuff in NE Hungary are prone to rockfalls, endangering visitors of a castle. Remote sensing techniques were employed to obtain data on terrain morphology and to provide slope geometry for assessing the stability of these rock walls. A RPAS (Remotely Piloted Aircraft System) was used to collect images which were processed by Pix4D mapper (structure from motion technology) to generate a point cloud and mesh. The georeferencing was made by Global Navigation Satellite System (GNSS) with the use of seven ground control points. The obtained digital surface model (DSM) was processed (vegetation removal) and the derived digital terrain model (DTM) allowed cross sections to be drawn and a joint system to be detected. Joint and discontinuity system was also verified by field measurements. On-site tests as well as laboratory tests provided additional engineering geological data for slope modelling. Stability of cliffs was assessed by 2-D FEM (finite element method). Global analyses of cross sections show that weak intercalating tuff layers may serve as potential slip surfaces. However, at present the greatest hazard is related to planar failure along ENE-WSW joints and to wedge failure. The paper demonstrates that RPAS is a rapid and useful tool for generating a reliable terrain model of hardly accessible cliff faces. It also emphasizes the efficiency of RPAS in rockfall hazard assessment in comparison with other remote sensing techniques such as terrestrial laser scanning (TLS).
The FEM simulation of continuous rotary extrusion (CRE) of aluminum alloy AA3003
Rajendran, Nijenthan; Valberg, Henry; Misiolek, Wojciech Z.
2017-10-01
Continuous Rotary Extrusion (CRE) process is also known in literature under Conform TM name and it is mainly used for the continuous extrusion of Aluminum and Copper alloys. CRE use a feedstock in the form of rod, powders and chips, which are fed into the groove of the rotating wheel. As the wheel rotates the feedstock moves along with it due to friction with the wheel. Once the feedstock reaches the abutment the material deforms plastically and it is extruded through the die. CRE has lot to offer when compared to other more conventional extrusion processes such as low energy input, no limit in billet length as it is a continuous process as well as improved material physical properties due to plastic deformation under constant parameters. In this work a FEM model has been developed using Deform TM 3D, to study the metal flow and state variables of AA3003 CRE extrusion. The effect of extrusion wheel velocity has been investigated. The results show that increase in wheel velocity will heat up the feedstock metal due to high shear deformation and higher friction, which significantly changes metal flow conditions at the die exit.
Performance Analysis of FEM Algorithmson GPU and Many-Core Architectures
Khurram, Rooh
2015-04-27
The roadmaps of the leading supercomputer manufacturers are based on hybrid systems, which consist of a mix of conventional processors and accelerators. This trend is mainly due to the fact that the power consumption cost of the future cpu-only Exascale systems will be unsustainable, thus accelerators such as graphic processing units (GPUs) and many-integrated-core (MIC) will likely be the integral part of the TOP500 (http://www.top500.org/) supercomputers, beyond 2020. The emerging supercomputer architecture will bring new challenges for the code developers. Continuum mechanics codes will particularly be affected, because the traditional synchronous implicit solvers will probably not scale on hybrid Exascale machines. In the previous study[1], we reported on the performance of a conjugate gradient based mesh motion algorithm[2]on Sandy Bridge, Xeon Phi, and K20c. In the present study we report on the comparative study of finite element codes, using PETSC and AmgX solvers on CPU and GPUs, respectively [3,4]. We believe this study will be a good starting point for FEM code developers, who are contemplating a CPU to accelerator transition.
Reliability techniques and Coupled BEM/FEM for interaction pile-soil
Directory of Open Access Journals (Sweden)
Ahmed SAHLI
2017-06-01
Full Text Available This paper deals with the development of a computational code for the modelling and verification of safety in relation to limit states of piles found in foundations of current structures. To this end, it makes use of reliability techniques for the probabilistic analysis of piles modelled with the finite element method (FEM coupled to the boundary element method (BEM. The soil is modelled with the BEM employing Mindlin's fundamental solutions, suitable for the consideration of a three-dimensional infinite half-space. The piles are modelled as bar elements with the MEF, each of which is represented in the BEM as a loading line. The finite element of the employed bar has four nodes and fourteen nodal parameters, three of which are displacements for each node plus two rotations for the top node. The slipping of the piles in relation to the mass is carried out using adhesion models to define the evolution of the shaft tensions during the transfer of load to the soil. The reliability analysis is based on three methods: first order second moment (FOSM, first order reliability method and Monte Carlo method.
Slope stability and rockfall assessment of volcanic tuffs using RPAS with 2-D FEM slope modelling
Directory of Open Access Journals (Sweden)
Á. Török
2018-02-01
Full Text Available Steep, hardly accessible cliffs of rhyolite tuff in NE Hungary are prone to rockfalls, endangering visitors of a castle. Remote sensing techniques were employed to obtain data on terrain morphology and to provide slope geometry for assessing the stability of these rock walls. A RPAS (Remotely Piloted Aircraft System was used to collect images which were processed by Pix4D mapper (structure from motion technology to generate a point cloud and mesh. The georeferencing was made by Global Navigation Satellite System (GNSS with the use of seven ground control points. The obtained digital surface model (DSM was processed (vegetation removal and the derived digital terrain model (DTM allowed cross sections to be drawn and a joint system to be detected. Joint and discontinuity system was also verified by field measurements. On-site tests as well as laboratory tests provided additional engineering geological data for slope modelling. Stability of cliffs was assessed by 2-D FEM (finite element method. Global analyses of cross sections show that weak intercalating tuff layers may serve as potential slip surfaces. However, at present the greatest hazard is related to planar failure along ENE–WSW joints and to wedge failure. The paper demonstrates that RPAS is a rapid and useful tool for generating a reliable terrain model of hardly accessible cliff faces. It also emphasizes the efficiency of RPAS in rockfall hazard assessment in comparison with other remote sensing techniques such as terrestrial laser scanning (TLS.
3-D FEM Modeling of fiber/matrix interface debonding in UD composites including surface effects
International Nuclear Information System (INIS)
Pupurs, A; Varna, J
2012-01-01
Fiber/matrix interface debond growth is one of the main mechanisms of damage evolution in unidirectional (UD) polymer composites. Because for polymer composites the fiber strain to failure is smaller than for the matrix multiple fiber breaks occur at random positions when high mechanical stress is applied to the composite. The energy released due to each fiber break is usually larger than necessary for the creation of a fiber break therefore a partial debonding of fiber/matrix interface is typically observed. Thus the stiffness reduction of UD composite is contributed both from the fiber breaks and from the interface debonds. The aim of this paper is to analyze the debond growth in carbon fiber/epoxy and glass fiber/epoxy UD composites using fracture mechanics principles by calculation of energy release rate G II . A 3-D FEM model is developed for calculation of energy release rate for fiber/matrix interface debonds at different locations in the composite including the composite surface region where the stress state differs from the one in the bulk composite. In the model individual partially debonded fiber is surrounded by matrix region and embedded in a homogenized composite.
FEM modeling on the compaction of Fe and Al composite powders
Directory of Open Access Journals (Sweden)
Han P.
2015-01-01
Full Text Available The compaction process of Fe and Al composite powders subjected to single action die compaction was numerically modeled by FEM method. The relationship between the overall relative density and compaction pressure of the compacts with various Al contents was firstly identified, and the influences of Al content on the local relative density, stress, and their distributions were studied. Then the compaction pressure effects on the above properties with fixed Al content were discussed. Furthermore, detailed flow behaviors of the composite powders during compaction and the relationship between the compaction pressure and the ejection force/spring back of the compact were analyzed. The results show that: (1 With each compaction pressure, higher relative density can be realized with the increase of Al content and the relative density distribution tends to be uniform; (2 When the Al content is fixed, higher compaction pressure can lead to composite compact with higher relative density, and the equivalent Von Mises stress in the central part of the compact increases gradually; (3 Convective flow occurs at the top and bottom parts of the compact close to the die wall, each indicates a different flow behavior; (4 The larger the compaction pressure for each case, the higher the residual elasticity, and the larger the ejection force needed.
Design and beam transport simulations of a multistage collector for the Israeli EA-FEM
Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.
2001-12-01
A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.
Design and beam transport simulations of a multistage collector for the Israeli EA-FEM
Energy Technology Data Exchange (ETDEWEB)
Tecimer, M. E-mail: tecimer@post.tau.ac.il; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J
2001-12-21
A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 {pi} mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.
Design and beam transport simulations of a multistage collector for the Israeli EA-FEM
International Nuclear Information System (INIS)
Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.
2001-01-01
A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design
From LIDAR Scanning to 3d FEM Analysis for Complex Surface and Underground Excavations
Chun, K.; Kemeny, J.
2017-12-01
Light detection and ranging (LIDAR) has been a prevalent remote-sensing technology applied in the geological fields due to its high precision and ease to use. One of the major applications is to use the detailed geometrical information of underground structures as a basis for the generation of three-dimensional numerical model that can be used in FEM analysis. To date, however, straightforward techniques in reconstructing numerical model from the scanned data of underground structures have not been well established or tested. In this paper, we propose a comprehensive approach integrating from LIDAR scanning to finite element numerical analysis, specifically converting LIDAR 3D point clouds of object containing complex surface geometry into finite element model. This methodology has been applied to the Kartchner Caverns in Arizona for the stability analysis. Numerical simulations were performed using the finite element code ABAQUS. The results indicate that the highlights of our technologies obtained from LIDAR is effective and provide reference for other similar engineering project in practice.
Directory of Open Access Journals (Sweden)
Ennio Bramanti
2017-01-01
Full Text Available The aim of this paper is to underline the mechanical properties of dental single crown prosthodontics materials in order to differentiate the possibility of using each material for typical clinical condition and masticatory load. Objective of the investigation is to highlight the stress distribution over different common dental crowns by using computer-aided design software and a three-dimensional virtual model. By using engineering systems of analyses like FEM and Von Mises investigations it has been highlighted the strength over simulated lower first premolar crowns made by chrome cobalt alloy, golden alloy, dental resin, and zirconia. The prosthodontics crown models have been created and put on simulated chewing stresses. The three-dimensional models were subjected to axial and oblique forces and both guaranteed expected results over simulated masticatory cycle. Dental resin presented the low value of fracture while high values have been recorded for the metal alloy and zirconia. Clinicians should choose the better prosthetic solution for the teeth they want to restore and replace. Both prosthetic dental crowns offer long-term success if applied following the manufacture guide limitations and suggestions.
Bramanti, Ennio; Cervino, Gabriele; Lauritano, Floriana; Fiorillo, Luca; D'Amico, Cesare; Sambataro, Sergio; Denaro, Deborah; Famà, Fausto; Ierardo, Gaetano; Polimeni, Antonella; Cicciù, Marco
2017-01-01
The aim of this paper is to underline the mechanical properties of dental single crown prosthodontics materials in order to differentiate the possibility of using each material for typical clinical condition and masticatory load. Objective of the investigation is to highlight the stress distribution over different common dental crowns by using computer-aided design software and a three-dimensional virtual model. By using engineering systems of analyses like FEM and Von Mises investigations it has been highlighted the strength over simulated lower first premolar crowns made by chrome cobalt alloy, golden alloy, dental resin, and zirconia. The prosthodontics crown models have been created and put on simulated chewing stresses. The three-dimensional models were subjected to axial and oblique forces and both guaranteed expected results over simulated masticatory cycle. Dental resin presented the low value of fracture while high values have been recorded for the metal alloy and zirconia. Clinicians should choose the better prosthetic solution for the teeth they want to restore and replace. Both prosthetic dental crowns offer long-term success if applied following the manufacture guide limitations and suggestions.
First lasing of the Dutch fusion-FEM in the long-pulse configuration
Energy Technology Data Exchange (ETDEWEB)
Militsyn, B.L. E-mail: militsyn@rijnh.nl; Bongers, W.A.; Bratman, V.L.; Caplan, M.; Denisov, G.G.; Geer, C.A.J. van der; Manintveld, P.; Oomens, A.A.M.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Riet, M.; Savilov, A.V.; Smeets, P.H.M.; Tito, C.J.; Turk, G.H.B.; Varfolomeev, A.A.; Urbanus, W.H
2002-05-01
The Dutch Fusion-FEM is the prototype of a high-power, long-pulse, rapid-tunable free-electron maser. The target is to generate mm-wave power in a frequency range of 130-260 GHz, e.g. for tokamak heating and diagnostics experiments in fusion devices. For these applications a high system efficiency is needed. The electron beam is first DC-accelerated to the FEL interaction region. The unused electron beam energy is recovered by a DC-decelerator and a three-stage depressed collector. In short-pulse regime, without energy recovery system, 730 kW, 200 GHz of net output power was generated. Single-frequency operation and tunability have been demonstrated. In the present set-up, with the energy recovery system being operational, initial experiments showed a net output power of 110 kW on average and 140 kW peak power at a pulse length of 40 {mu}s. During the full-pulse length, a stable-frequency operation around 170 GHz has been observed.
The fusion-FEM: 0,75 MW of mm-wave power
Energy Technology Data Exchange (ETDEWEB)
Smeets, P.H.M.; Bongers, W.A.; Brons, S.; Geer, C.A.J. van der; Lingier, K.L.; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Sterk, A.B.; Verhoeven, A.G.A.; Urbanus, W.H. [FOM Inst. voor Plasmafysica ' Rijnhuizen' , Nieuwegein (Netherlands); Bratman, V.L.; Denisov, G.G.; Savilov, A.V. [Inst. of Applied Physics, Nizhny Novgorod (Russian Federation); Caplan, M. [Lawrence Livermore National Lab., CA (United States); Varfolomeev, A.A. [Russian Research Center ' Kurchatov Inst.' , Moscow (Russian Federation)
1998-07-01
The free-electron maser for fusion applications (Fusion-FEM) is the prototype for a high power, rapid tunable mm-wave source. The basic parameters such as frequency range (130 - 260 GHz) and output power (1 MW) are dedicated to Electron Cyclotron Resonance applications on future plasma fusion research devices, such as ITER. In October 1996 the electron beam was successfully accelerated and transported through the undulator and the mm-wave cavity. Loss currents are below 0.05 %. In October 1997 first lasing was achieved. The mm-wave output power has been measured at various frequencies and for various electron beam currents and energies. The highest output power reached so far is 730 kW at 205 GHz, for an electron beam of 7.2 A and 1.77 MeV. Both output power and start-up time correspond well with simulation results. The output beam has a Gaussian mode content of more than 99.8 % for all operating frequencies. So far, the pulse length was limited to 12{mu}s, because the electron beam recovery system was not yet installed. This system, an electron decelerator and a 3-stage depressed collector, is presently under construction. It serves to recover the charge and energy of the spend electron beam. In this paper we will address some aspects of the design of the collector. (author)
The fusion-FEM: 0,75 MW of mm-wave power
International Nuclear Information System (INIS)
Smeets, P.H.M.; Bongers, W.A.; Brons, S.; Geer, C.A.J. van der; Lingier, K.L.; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Sterk, A.B.; Verhoeven, A.G.A.; Urbanus, W.H.; Bratman, V.L.; Denisov, G.G.; Savilov, A.V.; Caplan, M.; Varfolomeev, A.A.
1998-01-01
The free-electron maser for fusion applications (Fusion-FEM) is the prototype for a high power, rapid tunable mm-wave source. The basic parameters such as frequency range (130 - 260 GHz) and output power (1 MW) are dedicated to Electron Cyclotron Resonance applications on future plasma fusion research devices, such as ITER. In October 1996 the electron beam was successfully accelerated and transported through the undulator and the mm-wave cavity. Loss currents are below 0.05 %. In October 1997 first lasing was achieved. The mm-wave output power has been measured at various frequencies and for various electron beam currents and energies. The highest output power reached so far is 730 kW at 205 GHz, for an electron beam of 7.2 A and 1.77 MeV. Both output power and start-up time correspond well with simulation results. The output beam has a Gaussian mode content of more than 99.8 % for all operating frequencies. So far, the pulse length was limited to 12μs, because the electron beam recovery system was not yet installed. This system, an electron decelerator and a 3-stage depressed collector, is presently under construction. It serves to recover the charge and energy of the spend electron beam. In this paper we will address some aspects of the design of the collector. (author)
A new meshless approach to map electromagnetic loads for FEM analysis on DEMO TF coil system
International Nuclear Information System (INIS)
Biancolini, Marco Evangelos; Brutti, Carlo; Giorgetti, Francesco; Muzzi, Luigi; Turtù, Simonetta; Anemona, Alessandro
2015-01-01
Graphical abstract: - Highlights: • Generation and mapping of magnetic load on DEMO using radial basis function. • Good agreement between RBF interpolation and EM TOSCA computations. • Resultant forces are stable with respect to the target mesh used. • Stress results are robust and accurate even if a coarse cloud is used for RBF interpolation. - Abstract: Demonstration fusion reactors (DEMO) are being envisaged to be able to produce commercial electrical power. The design of the DEMO magnets and of the constituting conductors is a crucial issue in the overall engineering design of such a large fusion machine. In the frame of the EU roadmap of the so-called fast track approach, mechanical studies of preliminary DEMO toroidal field (TF) coil system conceptual designs are being enforced. The magnetic field load acting on the DEMO TF coil conductor has to be evaluated as input in the FEM model mesh, in order to evaluate the stresses on the mechanical structure. To gain flexibility, a novel approach based on the meshless method of radial basis functions (RBF) has been implemented. The present paper describes this original and flexible approach for the generation and mapping of magnetic load on DEMO TF coil system.
Design and beam transport simulations of a multistage collector for the Israeli EA-FEM
Tecimer, M; Efimov, S; Gover, A; Sokolowski, J
2001-01-01
A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 pi mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic i...
First lasing of the Dutch fusion-FEM in the long-pulse configuration
Militsyn, B L; Bratman, V L; Caplan, M; Denisov, G G; Geer, C A J; Manintveld, P; Oomens, A A M; Plomp, J; Pluygers, J; Poelman, A J; Riet, M; Savilov, A V; Smeets, P H M; Tito, C J; Turk, G H B; Varfolomeev, A A; Urbanus, W H
2002-01-01
The Dutch Fusion-FEM is the prototype of a high-power, long-pulse, rapid-tunable free-electron maser. The target is to generate mm-wave power in a frequency range of 130-260 GHz, e.g. for tokamak heating and diagnostics experiments in fusion devices. For these applications a high system efficiency is needed. The electron beam is first DC-accelerated to the FEL interaction region. The unused electron beam energy is recovered by a DC-decelerator and a three-stage depressed collector. In short-pulse regime, without energy recovery system, 730 kW, 200 GHz of net output power was generated. Single-frequency operation and tunability have been demonstrated. In the present set-up, with the energy recovery system being operational, initial experiments showed a net output power of 110 kW on average and 140 kW peak power at a pulse length of 40 mu s. During the full-pulse length, a stable-frequency operation around 170 GHz has been observed.
Toroidal HTS transformer with cold magnetic core - analysis with FEM software
International Nuclear Information System (INIS)
Grzesik, B; Stepien, M; Jez, R
2010-01-01
The aim of this paper is to present a thorough characterization of the toroidal HTS transformer by means of FEM analysis. The analysis was a 2D/3D harmonic electromagnetic and thermal analysis. The toroidal transformer operated in LN2 by being immersed together with the magnetic core in it, for which its power losses were acceptable. Two extreme variants of windings were analysed. The first one called parallel and the second called perpendicular. Three variants of the magnetic core were considered. In the first one the core was put outside of the windings, in the second the core was inside of the windings and in the third variant the core was outside as well as inside of the windings. The windings were made of HTS tape BiSCCO-2223/Ag while the magnetic core was made of the nanocrystalline material Finemet. The two windings, with a 1:1 turn-to-turn ratio, were uniformly distributed along the whole torus circumference. The output power, efficiency and power density are in the results of the analysis. The temperature distribution was also calculated. In summary, the performance of the transformer is better than those currently known.
FEM correlation and shock analysis of a VNC MEMS mirror segment
Aguayo, Eduardo J.; Lyon, Richard; Helmbrecht, Michael; Khomusi, Sausan
2014-08-01
Microelectromechanical systems (MEMS) are becoming more prevalent in today's advanced space technologies. The Visible Nulling Coronagraph (VNC) instrument, being developed at the NASA Goddard Space Flight Center, uses a MEMS Mirror to correct wavefront errors. This MEMS Mirror, the Multiple Mirror Array (MMA), is a key component that will enable the VNC instrument to detect Jupiter and ultimately Earth size exoplanets. Like other MEMS devices, the MMA faces several challenges associated with spaceflight. Therefore, Finite Element Analysis (FEA) is being used to predict the behavior of a single MMA segment under different spaceflight-related environments. Finite Element Analysis results are used to guide the MMA design and ensure its survival during launch and mission operations. A Finite Element Model (FEM) has been developed of the MMA using COMSOL. This model has been correlated to static loading on test specimens. The correlation was performed in several steps—simple beam models were correlated initially, followed by increasingly complex and higher fidelity models of the MMA mirror segment. Subsequently, the model has been used to predict the dynamic behavior and stresses of the MMA segment in a representative spaceflight mechanical shock environment. The results of the correlation and the stresses associated with a shock event are presented herein.
Optimization Design and Performance Analysis of a PM Brushless Rotor Claw Pole Motor with FEM
Directory of Open Access Journals (Sweden)
Zhenyang Zhang
2016-07-01
Full Text Available A new type of permanent magnet (PM brushless claw pole motor (CPM with soft magnetic composite (SMC core is designed and analyzed in this paper. The PMs are mounted on the claw pole surface, and the three-phase stator windings are fed by variable-frequency three-phase AC currents. The advantages of the proposed CPM are that the slip rings on the rotor are cast off and it can achieve the efficiency improvement and higher power density. The effects of the claw-pole structure parameters, the air-gap length, and the PM thinner parameter of the proposed CPM on the output torque are investigated by using three-dimensional time-stepping finite element method (3D TS-FEM. The optimal rotor structure of the proposed CPM is obtained by using the response surface methodology (RSM and the particle swarm optimization (PSO method and the comparison of full-load performances of the proposed CPM with different material cores (SMC and silicon steel is analyzed.
Nazari, Esmaeil; Löbbe, Christian; Gallus, Stefan; Izadyar, S. Ahmad; Tekkaya, A. Erman
2018-05-01
The incremental tube forming (ITF) is a process combination of the kinematic tube bending and spinning to shape high strength and tailored tubes with variable diameters and thicknesses. In contrast to conventional bending methods, the compressive stress superposition by the spinning process facilitates low bending stresses, so that geometrical errors are avoided and the shape accuracy is improved. The study reveals the interaction of plastic strains of the rolling and bending process through an explicit FEM investigation. For this purpose, the three-dimensional machine set-up is discretized and modeled in terms of the fully disclosed spinning process during the gradual deflection of the tube end for bending. The analysis shows that, depending on the forming tool shape, the stress superposition is accompanied by high plastic strains. Furthermore, this phenomenon is explained by the three dimensional normal and shear strains during the incremental spinning. Analyzing the strains history also shows a nonlinearity between the strains by bending and spinning. It is also shown that process parameters like rotational velocity of the spinning rolls have a huge influence on the deformation pattern. Finally, the method is used for the manufacturing of an example product, which reveals the high process flexibility. In one clamp a component with a graded wall thickness and outside diameter along the longitudinal axis is produced.
Ring rotational speed trend analysis by FEM approach in a Ring Rolling process
Allegri, G.; Giorleo, L.; Ceretti, E.
2018-05-01
Ring Rolling is an advanced local incremental forming technology to fabricate directly precise seamless ring-shape parts with various dimensions and materials. In this process two different deformations occur in order to reduce the width and the height of a preform hollow ring; as results a diameter expansion is obtained. In order to guarantee a uniform deformation, the preform is forced toward the Driver Roll whose aim is to transmit the rotation to the ring. The ring rotational speed selection is fundamental because the higher is the speed the higher will be the axial symmetry of the deformation process. However, it is important to underline that the rotational speed will affect not only the final ring geometry but also the loads and energy needed to produce it. Despite this importance in industrial environment, usually, a constant value for the Driver Roll angular velocity is set so to result in a decreasing trend law for the ring rotational speed. The main risk due to this approach is not fulfilling the axial symmetric constrain (due to the diameter expansion) and to generate a high localized ring section deformation. In order to improve the knowledge about this topic in the present paper three different ring rotational speed trends (constant, linearly increasing and linearly decreasing) were investigated by FEM approach. Results were compared in terms of geometrical and dimensional analysis, loads and energies required.
Prediction of flow- induced dynamic stress in an axial pump impeller using FEM
International Nuclear Information System (INIS)
Gao, J Y; Hou, Y S; Xi, S Z; Cai, Z H; Yao, P P; Shi, H L
2013-01-01
Axial pumps play an important role in water supply and flood control projects. Along with growing requirements for high reliability and large capacity, the dynamic stress of axial pumps has become a key problem. Unsteady flow is a significant reason which results structural dynamic stress of a pump. This paper reports on a flow-induced dynamic stress simulation in an axial pump impeller at three flow conditions by using FEM code. The pressure pulsation obtained from flow simulation using CFD code was set as the force boundary condition. The results show that the maximum stress of impeller appeared at joint between blade and root flange near trailing edge or joint between blade and root flange near leading edge. The dynamic stress of the two zones was investigated under three flow conditions (0.8Q d , 1.0Q d , 1.1Q d ) in time domain and frequency domain. The frequencies of stress at zones of maximum stress are 22.9Hz and 37.5Hz as the fundamental frequency and its harmonics. The fundamental frequencies are nearly equal to vane passing frequency (22.9 Hz) and 3 times blade passing frequency (37.5Hz). The first dominant frequency at zones of maximum stress is equal to the vane passing frequency due to rotor-stator interaction between the vane and the blade. This study would be helpful for axial pumps in reducing stress, improving structure design and fatigue life
Chen, Xiaodong; Sadineni, Vikram; Maity, Mita; Quan, Yong; Enterline, Matthew; Mantri, Rao V
2015-12-01
Lyophilization is an approach commonly undertaken to formulate drugs that are unstable to be commercialized as ready to use (RTU) solutions. One of the important aspects of commercializing a lyophilized product is to transfer the process parameters that are developed in lab scale lyophilizer to commercial scale without a loss in product quality. This process is often accomplished by costly engineering runs or through an iterative process at the commercial scale. Here, we are highlighting a combination of computational and experimental approach to predict commercial process parameters for the primary drying phase of lyophilization. Heat and mass transfer coefficients are determined experimentally either by manometric temperature measurement (MTM) or sublimation tests and used as inputs for the finite element model (FEM)-based software called PASSAGE, which computes various primary drying parameters such as primary drying time and product temperature. The heat and mass transfer coefficients will vary at different lyophilization scales; hence, we present an approach to use appropriate factors while scaling-up from lab scale to commercial scale. As a result, one can predict commercial scale primary drying time based on these parameters. Additionally, the model-based approach presented in this study provides a process to monitor pharmaceutical product robustness and accidental process deviations during Lyophilization to support commercial supply chain continuity. The approach presented here provides a robust lyophilization scale-up strategy; and because of the simple and minimalistic approach, it will also be less capital intensive path with minimal use of expensive drug substance/active material.
A two-step FEM-SEM approach for wave propagation analysis in cable structures
Zhang, Songhan; Shen, Ruili; Wang, Tao; De Roeck, Guido; Lombaert, Geert
2018-02-01
Vibration-based methods are among the most widely studied in structural health monitoring (SHM). It is well known, however, that the low-order modes, characterizing the global dynamic behaviour of structures, are relatively insensitive to local damage. Such local damage may be easier to detect by methods based on wave propagation which involve local high frequency behaviour. The present work considers the numerical analysis of wave propagation in cables. A two-step approach is proposed which allows taking into account the cable sag and the distribution of the axial forces in the wave propagation analysis. In the first step, the static deformation and internal forces are obtained by the finite element method (FEM), taking into account geometric nonlinear effects. In the second step, the results from the static analysis are used to define the initial state of the dynamic analysis which is performed by means of the spectral element method (SEM). The use of the SEM in the second step of the analysis allows for a significant reduction in computational costs as compared to a FE analysis. This methodology is first verified by means of a full FE analysis for a single stretched cable. Next, simulations are made to study the effects of damage in a single stretched cable and a cable-supported truss. The results of the simulations show how damage significantly affects the high frequency response, confirming the potential of wave propagation based methods for SHM.
A Simple FEM Formulation Applied to Nonlinear Problems of Impact with Thermomechanical Coupling
Directory of Open Access Journals (Sweden)
João Paulo de Barros Cavalcante
Full Text Available Abstract The thermal effects of problems involving deformable structures are essential to describe the behavior of materials in feasible terms. Verifying the transformation of mechanical energy into heat it is possible to predict the modifications of mechanical properties of materials due to its temperature changes. The current paper presents the numerical development of a finite element method suitable for nonlinear structures coupled with thermomechanical behavior; including impact problems. A simple and effective alternative formulation is presented, called FEM positional, to deal with the dynamic nonlinear systems. The developed numerical is based on the minimum potential energy written in terms of nodal positions instead of displacements. The effects of geometrical, material and thermal nonlinearities are considered. The thermodynamically consistent formulation is based on the laws of thermodynamics and the Helmholtz free-energy, used to describe the thermoelastic and the thermoplastic behaviors. The coupled thermomechanical model can result in secondary effects that cause redistributions of internal efforts, depending on the history of deformation and material properties. The numerical results of the proposed formulation are compared with examples found in the literature.
Analysis of submerged implant towards mastication load using 3D finite element method (FEM
Directory of Open Access Journals (Sweden)
Widia Hafsyah Sumarlina Ritonga
2016-11-01
Full Text Available Introduction: The surgical procedure for implantation of a surgical implant comprising a stage for the implant design nonsubmerged and two stages for submerged. Submerged implant design often used in Faculty of Dentistry Universitas Padjadjaran because it is safer in achieving osseointegration. This study was conducted to evaluate the failure of dental implant based on location and the value of internal tensiones as well as supporting tissues when given mastication load by using the 3D Finite Element Method (FEM. Methods: This study used a photograph of the mandibular CBCT patient and CT Scan Micro one implant submerged. Radiograph image was then converted into a digital model of the 3D computerized finite element, inputted the material properties, pedestal, then simulated the occlusion load as much as 87N and 29N of frictional Results: The maximum tension location on the implant was located on the exact side of the contact area between the implant and alveolar crest. The maximum tension value was 193.31MPa on the implant body. The value was below the limit value of the ability of the titanium alloy to withstand fracture (860 MPa. Conclusion: The location of the maximum tension on the body of the implant was located on the exact contact area between the implant-abutment and alveolar crest. Under the mastication load, this implant design found no failure.
A study on directional resistivity logging-while-drilling based on self-adaptive hp-FEM
Liu, Dejun; Li, Hui; Zhang, Yingying; Zhu, Gengxue; Ai, Qinghui
2014-12-01
Numerical simulation of resistivity logging-while-drilling (LWD) tool response provides guidance for designing novel logging instruments and interpreting real-time logging data. In this paper, based on self-adaptive hp-finite element method (hp-FEM) algorithm, we analyze LWD tool response against model parameters and briefly illustrate geosteering capabilities of directional resistivity LWD. Numerical simulation results indicate that the change of source spacing is of obvious influence on the investigation depth and detecting precision of resistivity LWD tool; the change of frequency can improve the resolution of low-resistivity formation and high-resistivity formation. The simulation results also indicate that the self-adaptive hp-FEM algorithm has good convergence speed and calculation accuracy to guide the geologic steering drilling and it is suitable to simulate the response of resistivity LWD tools.
Huang, Wen; Koric, Seid; Yu, Xin; Hsia, K Jimmy; Li, Xiuling
2014-11-12
Micro- and nanoscale tubular structures can be formed by strain-induced self-rolled-up nanomembranes. Precision engineering of the shape and dimension determines the performance of devices based on this platform for electronic, optical, and biological applications. A transient quasi-static finite element method (FEM) with moving boundary conditions is proposed as a general approach to design diverse types of three-dimensional (3D) rolled-up geometries. This method captures the dynamic release process of membranes through etching driven by mismatch strain and accurately predicts the final dimensions of rolled-up structures. Guided by the FEM modeling, experimental demonstration using silicon nitride membranes was achieved with unprecedented precision including controlling fractional turns of a rolled-up membrane, anisotropic rolling to form helical structures, and local stress control for 3D hierarchical architectures.
FEM-model of the Naesliden Mine: requirements and limitations at the outset of the project. [Sweden
Energy Technology Data Exchange (ETDEWEB)
Krauland, N.
1980-05-15
The design of any instrument depends entirely on the application planned for the instrument. This applies also to the FEM-representation of the Naesliden Mine. With reference to the aims of the project the requirements on the model are outlined with regard to - simulation of the mining process - modelling with special reference to the aims of the project - comparison of FEM-results with in situ observations to determine the validity of the model. The proposed model is two-dimensional and incorporates joint elements to simulate the weak alteration zone between orebody and sidewall rock. The remainder of the model exhibits linear elastic behaviour. This model is evaluated with respect to the given requirements. The limitations of the chosen model are outlined.
International Nuclear Information System (INIS)
Uchibori, Akihiro; Ohshima, Hiroyuki
2008-01-01
A numerical analysis method for melting/solidification phenomena has been developed to evaluate a feasibility of several candidate techniques in the nuclear fuel cycle. Our method is based on the eXtended Finite Element Method (X-FEM) which has been used for moving boundary problems. Key technique of the X-FEM is to incorporate signed distance function into finite element interpolation to represent a discontinuous gradient of the temperature at a moving solid-liquid interface. Construction of the finite element equation, the technique of quadrature and the method to solve the equation are reported here. The numerical solutions of the one-dimensional Stefan problem, solidification in a two-dimensional square corner and melting of pure gallium are compared to the exact solutions or to the experimental data. Through these analyses, validity of the newly developed numerical analysis method has been demonstrated. (author)
Zhang, Ziyu; Jiang, Wen; Dolbow, John E.; Spencer, Benjamin W.
2018-01-01
We present a strategy for the numerical integration of partial elements with the eXtended finite element method (X-FEM). The new strategy is specifically designed for problems with propagating cracks through a bulk material that exhibits inelasticity. Following a standard approach with the X-FEM, as the crack propagates new partial elements are created. We examine quadrature rules that have sufficient accuracy to calculate stiffness matrices regardless of the orientation of the crack with respect to the element. This permits the number of integration points within elements to remain constant as a crack propagates, and for state data to be easily transferred between successive discretizations. In order to maintain weights that are strictly positive, we propose an approach that blends moment-fitted weights with volume-fraction based weights. To demonstrate the efficacy of this simple approach, we present results from numerical tests and examples with both elastic and plastic material response.
Directory of Open Access Journals (Sweden)
Seyed Abbas Taher
2011-01-01
Full Text Available In this article, a new fault detection technique is proposed for squirrel cage induction motor (SCIM based on detection of rotor bar failure. This type of fault detection is commonly carried out, while motor continues to work at a steady-state regime. Recently, several methods have been presented for rotor bar failure detection based on evaluation of the start-up transient current. The proposed method here is capable of fault detection immediately after bar breakage, where a three-phase SCIM is modelled in finite element method (FEM using Maxwell2D software. Broken rotor bars are then modelled by the corresponding outer rotor impedance obtained by GA, thereby presenting an analogue model extracted from FEM to be simulated in a flexible environment such as MATLAB/SIMULINK. To improve the failure recognition, the stator current signal was analysed using discrete wavelet transform (DWT.
Kurz, S
1999-01-01
In this paper a new technique for the accurate calculation of magnetic fields in the end regions of superconducting accelerator magnets is presented. This method couples Boundary Elements (BEM) which discretize the surface of the iron yoke and Finite Elements (FEM) for the modelling of the nonlinear interior of the yoke. The BEM-FEM method is therefore specially suited for the calculation of 3-dimensional effects in the magnets, as the coils and the air regions do not have to be represented in the finite-element mesh and discretization errors only influence the calculation of the magnetization (reduced field) of the yoke. The method has been recently implemented into the CERN-ROXIE program package for the design and optimization of the LHC magnets. The field shape and multipole errors in the two-in-one LHC dipoles with its coil ends sticking out of the common iron yoke is presented.
Discrete Maximum Principle for a 1D Problem with Piecewise-Constant Coefficients Solved by hp-FEM
Czech Academy of Sciences Publication Activity Database
Vejchodský, Tomáš; Šolín, Pavel
2007-01-01
Roč. 15, č. 3 (2007), s. 233-243 ISSN 1570-2820 R&D Projects: GA ČR GP201/04/P021; GA ČR GA102/05/0629 Institutional research plan: CEZ:AV0Z10190503; CEZ:AV0Z20570509 Keywords : discrete maximum principle * hp-FEM * Poisson equation Subject RIV: BA - General Mathematics
Pariisis jagati Cesare / Aare Ermel
Ermel, Aare, 1957-2013
2006-01-01
Sel aastal sai prantsuse rahvuslike filmiauhindade Cesaride jagamisel kõige enam (8) auhindu J. Audiard'i mängufilm "Mu süda jättis vahele löögi" ("De battre mon coeur s'est arrete"). Näitlejapreemiad said Michel Bouquet, Nathalie Baye
Vabaduse tuuled Ungarist / Aare Ermel
Ermel, Aare, 1957-2013
2006-01-01
Sõpruse kinos algab homme filmiprogramm "Vabaduse tuuled" Ungari 1956.a. ülestõusule pühendatud mängufilmide programm (6 ungari filmi aastaist 1965-2004) : Ungari Instituudi, kino "Sõprus" ja PÖFFi koostööprojekt
Werner Herzog Tallinnas / Aare Ermel
Ermel, Aare, 1957-2013
2002-01-01
Detsembris toimuvat Pimedate Ööde Filmifestivali laiendatakse ka suvele, et sobivates paikades näidata väärtfilme. Alates 6. juunist näidatakse Katariina kirikus kuuel õhtul algusega kell 22 Werner Herzogi (1942) filme. Režissöörist ja näidatavatest filmidest
Pattulangemine ja lunastus / Aare Ermel
Ermel, Aare, 1957-2013
2005-01-01
PÖFFi filme - "Taevane lahing" ("Batalla en el cielo" : režissöör Carlos Reygadas : Mehhiko - Prantsusmaa - Saksamaa - Belgia 2005, "Valede kammitsas" ("Separate Lies") : Nigel Balchini rom. "A Way Through the Wood" järgi režissöör Julian Fellowes : Suurbritannia 2005
Aare, Juhan, 1948-
1999-01-01
Järg Jan/5;6;7;8;9;11;12;13;14;15;16;18;19;20;21;22;23;25;26;27;28;29;30/Feb/1;2;3;4;5;6;8;9;10;11;12;13;15;16;17;18;19;20;22;23;25;26;27/Mar/1;2;3;4;5;6;8;9;10;11;12;13;15;16;17;18;20;22;23;24;25;26;27;29;30;31/Apr/1;2;35;6;7;8;9;10;12;13;14;15;16;17;19;20;21;22;23;24;26;27;28;29;30/May/3;4;5;6;7;8;10;11;12;13;14;15;17;18;19;20;21;22;24;25;26;27;28;29;31
Tõeline Crocodile Dundee / Aare Ermel
Ermel, Aare, 1957-2013
2006-01-01
4. sept. hukkus veealuse dokfilmi võtetel Austraalia loodusuurija, loomakaitsja, telekanali Animal Planet sarja "Krokodillikütt" ("Crocodile Hunter") populaarne autor ja esineja Steve Irwin (1962-2006)
Almodovari esimesed katsetused / Aare Ermel
Ermel, Aare, 1957-2013
2006-01-01
Pedro Almodovarile tehti ettepanek restaureerida oma esimesi eksperimentaalseid katsetusi "Kaks hoora / Armastuslugu, mis lõpeb pulmadega" (1974), "Seks tuleb, seks läheb" (1977), Soodoma lõpp (1979)
Veebruarikuus 2000 lahkunuid / Aare Ermel
Ermel, Aare, 1957-2013
2000-01-01
Surid : Autant-Lara, Claude prantsuse režissöör (5.08.1903-5.02.2000), Vadim, Roger ukraina päritolu prantsuse režissöör (26.01.1928-11.02.2000), Kedrova, Lila vene päritolu prantsuse näitlejanna (1918-16.02.2000), Martelli, Otello itaalia filmioperaator (19.05.1903-20.02.2000)
Feodaalne verepulm teleekraanil / Aare Ermel
Ermel, Aare, 1957-2013
2011-01-01
Alates 8. septembrist Fox Life'i eestikeelsel kanalil jooksma hakkavast George R. R. Martini raamatul põhinevast USA telekanali HBO telesarjast "Troonide mäng" (sarja loojad David Benioff ja Dan Weiss)
International Nuclear Information System (INIS)
Du, Q.; Cen, Z.; Zhu, H.
1989-01-01
This paper reports linear elastic fracture analysis based upon the stress intensity factor evaluation successfully applied to safety assessments of cracked structures. The nozzle junction are usually subjected to high pressure and thermal loads simultaneously. In validity of linear elastic fracture analysis, K can be decomposed into K P (caused by mechanic loads) and K τ (caused by thermal loads). Under thermal transient loading, explicit analysis (say by the FEM or BEM) of K tracing an entire history respectively for a range of crack depth may be much more time consuming. The techniques of weight function provide efficient means for transforming the problem into the stress computation of the uncracked structure and generation of influence function (for the given structure and size of crack). In this paper, a combination of BE-FEM has been used for the analysis of the cracked nozzle structure by techniques of weight function. The influence functions are obtained by coupled BE-FEM and the uncracked structure stress are computed by finite element methods
Kalkkuhl, J; Hunt, K J; Fritz, H
1999-01-01
An finite-element methods (FEM)-based neural-network approach to Nonlinear AutoRegressive with eXogenous input (NARX) modeling is presented. The method uses multilinear interpolation functions on C0 rectangular elements. The local and global structure of the resulting model is analyzed. It is shown that the model can be interpreted both as a local model network and a single layer feedforward neural network. The main aim is to use the model for nonlinear control design. The proposed FEM NARX description is easily accessible to feedback linearizing control techniques. Its use with a two-degrees of freedom nonlinear internal model controller is discussed. The approach is applied to modeling of the nonlinear longitudinal dynamics of an experimental lorry, using measured data. The modeling results are compared with local model network and multilayer perceptron approaches. A nonlinear speed controller was designed based on the identified FEM model. The controller was implemented in a test vehicle, and several experimental results are presented.
Hemanth, M; Deoli, Shilpi; Raghuveer, H P; Rani, M S; Hegde, Chatura; Vedavathi, B
2015-09-01
Simulation of periodontal ligament (PDL) using non-linear finite element method (FEM) analysis gives better insight into understanding of the biology of tooth movement. The stresses in the PDL were evaluated for intrusion and lingual root torque using non-linear properties. A three-dimensional (3D) FEM model of the maxillary incisors was generated using Solidworks modeling software. Stresses in the PDL were evaluated for intrusive and lingual root torque movements by 3D FEM using ANSYS software. These stresses were compared with linear and non-linear analyses. For intrusive and lingual root torque movements, distribution of stress over the PDL was within the range of optimal stress value as proposed by Lee, but was exceeding the force system given by Proffit as optimum forces for orthodontic tooth movement with linear properties. When same force load was applied in non-linear analysis, stresses were more compared to linear analysis and were beyond the optimal stress range as proposed by Lee for both intrusive and lingual root torque. To get the same stress as linear analysis, iterations were done using non-linear properties and the force level was reduced. This shows that the force level required for non-linear analysis is lesser than that of linear analysis.
Energy Technology Data Exchange (ETDEWEB)
Hartman, P S; De Wilde, D; Dwarakanath, V N [Texas Christian Univ., Fort Worth, TX (United States). Dept. of Biology
1995-06-01
The utility of a new target gene (fem-3) is described for investigating the molecular nature of mutagenesis in the nematode Caenorhabditis elegans. As a principal attribute, this system allows for the selection, maintenance and molecular analysis of any type of mutation that disrupts the gene, including deletions. In this study, 86 mutant strains were isolated, of which 79 proved to have mutations in fem-3. Twenty of these originally tested as homozygous inviable. Homozygous inviability was expected, as Stewart and coworkers had previously observed that, unlike in other organisms, most UV radiation-induced mutations in C. elegans are chromosomal rearrangements of deficiencies (Mutat. Res 249, 37-54, 1991). However, additional data, including Southern blot analyses on 49 of the strains, indicated that most of the UV radiation-induced fem-3 mutations were not deficiencies, as originally inferred from their homozygous inviability. Instead, the lethals were most likely ``coincident mutations`` in linked, essential genes that were concomitantly induced. As such, they were lost owing to genetic recombination during stock maintenance. As in mammalian cells, yeast and bacteria, the frequency of coincident mutations was much higher than would be predicted by chance. (Author).
Directory of Open Access Journals (Sweden)
Hao Yang
2014-11-01
Full Text Available Terrestrial laser scanning technology (TLS is a new technique for quickly getting three-dimensional information. In this paper we research the health assessment of concrete structures with a Finite Element Method (FEM model based on TLS. The goal focuses on the benefits of 3D TLS in the generation and calibration of FEM models, in order to build a convenient, efficient and intelligent model which can be widely used for the detection and assessment of bridges, buildings, subways and other objects. After comparing the finite element simulation with surface-based measurement data from TLS, the FEM model is determined to be acceptable with an error of less than 5%. The benefit of TLS lies mainly in the possibility of a surface-based validation of results predicted by the FEM model.
Yang, Hao; Xu, Xiangyang; Neumann, Ingo
2014-11-19
Terrestrial laser scanning technology (TLS) is a new technique for quickly getting three-dimensional information. In this paper we research the health assessment of concrete structures with a Finite Element Method (FEM) model based on TLS. The goal focuses on the benefits of 3D TLS in the generation and calibration of FEM models, in order to build a convenient, efficient and intelligent model which can be widely used for the detection and assessment of bridges, buildings, subways and other objects. After comparing the finite element simulation with surface-based measurement data from TLS, the FEM model is determined to be acceptable with an error of less than 5%. The benefit of TLS lies mainly in the possibility of a surface-based validation of results predicted by the FEM model.
A FEM-BEM interactive coupling for modeling the piezoelectric health monitoring systems
Directory of Open Access Journals (Sweden)
Abid A. Shah
Full Text Available In this research, finite element and boundary element methods are coupled together to model the interaction of a piezoelectric ceramic working as an actuator with an elastic material. Piezoelectric-elastic material's interaction occurs in smart structures. This work is aimed at determining the actuation effects being transferred from the actuators to the host and the resulting overall structural response. To obtain the amount of these actuations, the system of the host structure and an actuator has been modeled by using coupled finite element boundary element method in frequency domain. The host structure, which is assumed as an isotropic elastic solid region is modeled as a half space. The piezoelectric ceramic region is modeled by the 3-D finite element method, while the elastic half space with boundary element method. Finite element model of piezoelectric ceramic and boundary element model of the elastic half space are coupled together at their interface such that the vibrations of the piezo-actuator induce vibrations in the elastic half space. A couple of examples are given to show the induced displacement field around the piezo-actuator on the surface of the elastic medium. The results show that high jump in magnitude of horizontal displacements at the corners of the actuator attached to the structure occurs, which is an indication of high stress concentration, of the shear stress type at the corners. This stress concentration sometimes causes complete debonding of the actuator from the base structure. By using the suggested BEM-FEM coupled model for actuators with different dimensions or material properties much useful information concerning the amount of actuation and load transfer can be obtained. The presented work is a step towards modeling of structural health monitoring systems.
Analysis on the geometrical shape of T-honeycomb structure by finite element method (FEM)
Zain, Fitri; Rosli, Muhamad Farizuan; Effendi, M. S. M.; Abdullah, Mohamad Hariri
2017-09-01
Geometric in design is much related with our life. Each of the geometrical structure interacts with each other. The overall shape of an object contains other shape inside, and there shapes create a relationship between each other in space. Besides that, how geometry relates to the function of the object have to be considerate. In this project, the main purpose was to design the geometrical shape of modular furniture with the shrinking of Polyethylene Terephthalate (PET) jointing system that has good strength when applied load on it. But, the goal of this paper is focusing on the analysis of Static Cases by FEM of the hexagonal structure to obtain the strength when load apply on it. The review from the existing product has many information and very helpful to finish this paper. This project focuses on hexagonal shape that distributed to become a shelf inspired by honeycomb structure. It is very natural look and simple in shape and its modular structure more easily to separate and combine. The method discusses on chapter methodology are the method used to analysis the strength when the load applied to the structure. The software used to analysis the structure is Finite Element Method from CATIA V5R21 software. Bending test is done on the jointing part between the edges of the hexagonal shape by using Universal Tensile Machine (UTM). The data obtained have been calculate by bending test formulae and sketch the graph between flexural strains versus flexural stress. The material selection of the furniture is focused on wood. There are three different types of wood such as balsa, pine and oak, while the properties of jointing also be mentioned in this thesis. Hence, the design structural for honeycomb shape already have in the market but this design has main objective which has a good strength that can withstand maximum load and offers more potentials in the form of furniture.
Modelling the tearing crack growth in a ductile ferritic steel using X-FEM elements
International Nuclear Information System (INIS)
Simatos, A.; Prabel, B.; Marie, S.; Nedelec, M.; Combescure, A.
2012-01-01
Extended Finite Element Method (X-FEM) is used to model a cracked structure without meshing explicitly the crack. Indeed, the crack is represented by a discontinuity of the displacement field through additional degrees of freedom using Heaviside type function or derived from the Irwin's singular fields. Initially, the stress integration in the XFEM framework supposed to divide the cut elements into sub-triangles that are conform to the crack. This was motivated in order to integrate the behaviour accurately on both sides of the crack in particular at proximity of the crack tip where singular enrichments are present. This strategy induces field projections from the usual Gauss point configuration to a variable new one that depends on the crack position in the element. For ductile fracture modelization, this approach is not applicable, because in presence of large scale yield, the projection of internal variable fields is not conservative, in particular at proximity of the crack tip. In order to circumvent this problem, a new integration strategy was proposed by B. Prabel. It consists in using 64 Gauss points that are placed without regards to the crack position. This simple integration scheme permits to take implicitly into account the crack position and the fields in the element in an accurate and consistent way. This strategy was used in problem calculation for which the plastic radius remained small. It allowed introducing the over integrated elements in the probable propagation zone, just before plastification. In the case of ductile tearing, the plasticity is not confined near the crack tip and an improvement of the proposed strategy is made. This is then used to model large ductile crack growth in a ductile ferritic steel. To validate the predictions, the modelization is compared to a second F.E. calculation using the node release technique for the crack propagation. It is then shown that the two predictions are strictly equivalents. (authors)
A FEM simulation study of the solid state hydrostatic extrusion of PMMA
Costa, André L. M.; Riffel, Douglas B.; Misiolek, Wojciech Z.; Valberg, Henry S.
2018-05-01
Solid state hydrostatic extrusion (SSHE) of polymers below glass transition temperature is used to obtain highly oriented structures. Experimental studies on the SSHE of polymethyl-methacrylate (PMMA) have been made since early eighties but there is no information on internal temperature, stress and strain distribution. In this work we have made 3D FEM simulations of SSHE of PMMA by using the commercial DEFORM package with experimental flow curves and thermal properties from literature. The initial temperature of tooling and workpiece was 90°C, ram speeds were 1.0 and 10.0 mm/min with extrusion ratio R = 3.0. For a comparative analysis, SSHE simulation of the AA7108 aluminum alloy at 400°C was also performed. These ranges of parameters were chosen in order to encompass the parameters found in previously mentioned experiments. The best correlation with experimental hydrostatic pressure was verified for a shear friction coefficient at the material-conical die interface m = 0.50. Force-displacement curve for PMMA presented a constitutive and thermal softening in contrast to a constant force curve for aluminum. The internal temperature in the deformation zone increased in a characteristic "owl's face" profile in contrast to quasi-constant profile of aluminum alloy. In both PMMA and aluminum the stress is hydrostatic inside the container, but the stress profiles are significantly different inside the deformation zone. As expected, the strain and strain-rate profiles are practically the same for the two materials, but the temperature profile has promoted slightly differences in material flow. The velocity gradient from center to surface is higher in PMMA than aluminum. It's supposed that during hydrostatic extrusion solid PMMA has a characteristic thermally-inducted mechanical behavior.
A FEM-based method to determine the complex material properties of piezoelectric disks.
Pérez, N; Carbonari, R C; Andrade, M A B; Buiochi, F; Adamowski, J C
2014-08-01
Numerical simulations allow modeling piezoelectric devices and ultrasonic transducers. However, the accuracy in the results is limited by the precise knowledge of the elastic, dielectric and piezoelectric properties of the piezoelectric material. To introduce the energy losses, these properties can be represented by complex numbers, where the real part of the model essentially determines the resonance frequencies and the imaginary part determines the amplitude of each resonant mode. In this work, a method based on the Finite Element Method (FEM) is modified to obtain the imaginary material properties of piezoelectric disks. The material properties are determined from the electrical impedance curve of the disk, which is measured by an impedance analyzer. The method consists in obtaining the material properties that minimize the error between experimental and numerical impedance curves over a wide range of frequencies. The proposed methodology starts with a sensitivity analysis of each parameter, determining the influence of each parameter over a set of resonant modes. Sensitivity results are used to implement a preliminary algorithm approaching the solution in order to avoid the search to be trapped into a local minimum. The method is applied to determine the material properties of a Pz27 disk sample from Ferroperm. The obtained properties are used to calculate the electrical impedance curve of the disk with a Finite Element algorithm, which is compared with the experimental electrical impedance curve. Additionally, the results were validated by comparing the numerical displacement profile with the displacements measured by a laser Doppler vibrometer. The comparison between the numerical and experimental results shows excellent agreement for both electrical impedance curve and for the displacement profile over the disk surface. The agreement between numerical and experimental displacement profiles shows that, although only the electrical impedance curve is
Energy Technology Data Exchange (ETDEWEB)
Frosi, Paolo, E-mail: paolo.frosi@enea.it [Unità Tecnica Fusione-ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati (Italy); Mazzone, Giuseppe [Unità Tecnica Fusione-ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati (Italy); You, Jeong-Ha [Max Planck Institute of Plasma Physics, Boltzmann Str. 2, 85748 Garching (Germany)
2016-11-01
This paper deals with the early steps in developing a structural fem model of DEMO Divertor. The study is focused on the thermal and structural analysis of the Cassette Body: a new geometry has been developed for this component: it is foreseen that the plasma facing component (PFC) will be directly placed on the cassette but for the Dome no choice has been adopted yet. For now the model contains only a suitable schematization of the Cassette Body and its objective is to analyze the effect produced by the main loads (electromagnetic loads, coolant pressure, thermal neutron and convective loads) on itself: an available estimate of loads is that one derived from ITER: for a proper translation some assumptions have been made and they are described in the paper. Now it is not a primary purpose to obtain some definitive statements about stresses, displacements, temperatures and so on; the authors want to construct a set of FEM models that will help all the decisions of DEMO Divertor design in its future development. This set is conceived as a tool that shall be improved to account for all the main enhancements that will be found in geometry, in material properties data and in load evaluations. Moreover, the main design variables (loads, material properties, some geometric items, mesh element size) are defined as parameters. This work considers also an introductive approach for future structural verification of the Divertor Cassette Body: so a concern of the Design and Construction Rules for Mechanical Components of Nuclear Installation (RCC-MRx) has been implemented. The FEM code used is Ansys rel. 15.
Directory of Open Access Journals (Sweden)
Jennifer Headley
Full Text Available Incidence rates in the FEM-PrEP and VOICE trials demonstrate that women from diverse sub-Saharan African communities continue to be at substantial HIV risk.To describe and compare the sexual risk context of the study population from two FEM-PrEP trial sites-Bondo, Kenya, and Pretoria, South Africa.At baseline we collected information about demographics, sexual behaviors, and partnership beliefs through quantitative questionnaires with all participants (Bondo, n = 720; Pretoria, n = 750. To explore the sexual risk context, we also conducted qualitative, semi-structured interviews with HIV-negative participants randomly selected at several time points (Bondo, n = 111; Pretoria, n = 69.Demographics, sexual behavior, and partnership beliefs varied significantly between the sites. Bondo participants were generally older, had fewer years of schooling, and were more likely to be employed and married compared to Pretoria participants. Bondo participants were more likely to report multiple partners and not knowing whether their partner had HIV than Pretoria participants. A significantly higher percentage of Bondo participants reported engaging in sex without a condom with their primary and other partners compared to Pretoria participants. We found a borderline association between participants who reported not using condoms in the 4 weeks prior to baseline and lower risk of HIV infection, and no association between having more than one sexual partner at baseline and HIV infection.Despite significantly different demographics, sexual behaviors, and partnership beliefs, many women in the FEM-PrEP trial were at risk of acquiring HIV as demonstrated by the sites' high HIV incidence. Though gender dynamics differed between the populations, they appear to play a critical role in women's sexual practices. The findings highlight different ways women from diverse contexts may be at-risk for HIV and the importance of providing HIV prevention options
Baldino, L; Naddeo, F; Cardea, S; Naddeo, A; Reverchon, E
2015-11-01
Scaffolds have been produced by supercritical CO2 drying of Poly-L-Lactid Acid (PLLA) gels loaded with micrometric fructose particles used as porogens. These structures show a microporous architecture generated by the voids left in the solid material by porogen leaching, while they maintain the nanostructure of the gel, consisting of a network of nanofilaments. These scaffolds have also been loaded with Hydroxyapatite (HA) nanoparticles, from 10 to 50% w/w with respect to the polymer, to improve the mechanical properties of the PLLA structure. Based on miscroscopic and mechanical considerations, we propose a parametric Finite Element Method (FEM) model of PLLA-HA composites that describes the microporous structure as a close-packing of equal spheres and the nanoscale structure as a space frame of isotropic curved fibers. The effect of HA on the mechanical properties of the scaffolds has been modeled on the basis of SEM images and by taking into consideration the formation of concentric cylinders of HA nanoparticles around PLLA nanofibers. Modeling analysis confirms that mechanical properties of these scaffolds depend on nanofibrous network connections and that bending is the major factor causing deformation of the network. The FEM model also takes into account the formation of HA multi-layer coating on some areas in the nanofiber network and its increase in thickness with HA percentage. The Young modulus tends to a plateau for HA percentages larger than 30% w/w and when the coverage of the nanofibers produced by HA nanoparticles reaches a loaded surface index of 0.14 in the FEM model. Copyright © 2015 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Miyagi, D.; Amadutsumi, Y.; Takahashi, N.; Tsukamoto, O.
2007-01-01
AC transport current losses of coated conductors with ferromagnetic substrates are higher than the loss calculated by the Norris equation. In order to reduce the AC transport current loss we propose in this paper a structure of the coated conductor that has wider substrate than the SC (Superconducting) layer. The current distribution and AC loss of the proposed model are analyzed by means of FEM. The AC transport current loss is reduced due to the change of current density distribution near the edge of SC layer, consequent to the high value of magnetic permeability of the ferromagnetic substrate, that is wider than the SC layer
Directory of Open Access Journals (Sweden)
Superczyńska M.
2016-09-01
Full Text Available The paper presents results of numerical calculations of a diaphragm wall model executed in Poznań clay formation. Two selected FEM codes were applied, Plaxis and Abaqus. Geological description of Poznań clay formation in Poland as well as geotechnical conditions on construction site in Warsaw city area were presented. The constitutive models of clay implemented both in Plaxis and Abaqus were discussed. The parameters of the Poznań clay constitutive models were assumed based on authors’ experimental tests. The results of numerical analysis were compared taking into account the measured values of horizontal displacements.
Simple rules for design of exhaust mufflers and a comparison with four-pole and FEM calculations
DEFF Research Database (Denmark)
Jensen, Morten Skaarup; Ødegaard, John
1999-01-01
For good muffler design it is advisable to use an advanced computational method such as four-pole theory or FEM or BEM. To get a starting points for these methods and to suggest adjustments to the geometry and materials it is useful to have some simple rules of thumb. This paper presents a number...... of such "rules", and illustrates their reliability and limitations by comparing with results using some of the advanced computational methods. At the same time, this investigation also gives a comparison between four-pole theory and BEM....
DEFF Research Database (Denmark)
Bottasso, C. L.; Campagnolo, F.; Croce, A.
2014-01-01
model fully-populated cross sectional stiffness matrices. Next, a "fine"-level 3D FEM model is used for the refinement of the coarse-level solution. Improved results obtained at the level of the 3D model are utilized at the following coarse-level iteration through a heuristic modification of the design...... constraints. In addition, a buckling analysis is performed at the fine description level, which in turn affects the nonstructural blade mass. The updated constraint bounds and mass make their effects felt at the next coarse-level constrained design optimization, thereby closing the loop between the coarse...
FEM Analysis of Beam-coupling Impedance and RF Contacts Criticality on the LHC UA9 Piezo Goniometer
Danisi, A; Passarelli, A; Masi, A; Losito, R; Salvant, B
2014-01-01
The UA9 piezo-goniometer has been designed to guarantee micro-radians-accuracy angular positioning of a silicon crystal for a crystal collimation experiment in the LHC, and to minimize the impact on the LHC beam coupling impedance. This paper presents a Finite Element Method (FEM) study of the device, in both parking and operational positions, to evaluate its impact on the LHC impedance budget. In addition, the shielding contribution of the RF gaskets has been carefully evaluated, with the objective to assess the consequences for operation in case of their failure. A final word is drawn on the overall device impedance criticality.
Energy Technology Data Exchange (ETDEWEB)
Yao, T; Fujikubo, M; Yanagihara, D; Irisawa, M [Hiroshima University, Hiroshima (Japan). Faculty of Engineering
1997-10-01
Buckling and plastic collapse of upper decks and bottom outer plates of a hull results directly in longitudinal bending collapse of the hull. Therefore, discussions were given on analysis for pressure destruction strength of a detection control panel which assumes an upper deck and a bottom outer plate. Pressure destruction behavior of the panting panel is a complex phenomenon accompanying non-linearity and geometrical non-linearity of the materials. Its whole phenomenon may be analyzed by using the finite element method (FEM) as a principle, but the analysis is not efficient. Therefore, considerations were given in relation to modeling when using the FEM. The considerations were given on a panel attached with flat steel panting members with respect to the modeling scope which considers the buckling mode according to the aspect ratio of the panel partitioned by the deflection control members. If the local buckling mode of the panel is an even number wave mode in the longitudinal direction, a triple span model is required. A modeling scope for a case of being subjected to water pressure and in-plane compression was considered on a panel attached with angle-type steel members having non-symmetric cross section. In this case, a triple bay model is more preferable to reproduce the behavior under water pressure loading. 1 ref., 6 figs.
Energy Technology Data Exchange (ETDEWEB)
Chung, Y.D., E-mail: ydchung@suwon.ac.kr [Department of Electrical Engineering, Suwon University, Bongdang Eup, Hwaseong Si 445-743 (Korea, Republic of); Lee, C.Y. [Korea Railroad Research Institute, Woram Dong, Uiwang Si 437-757 (Korea, Republic of); Jang, J.Y. [Department of Electrical Engineering, Ansan College of Technology, Choji-Dong, Ansan Si 425-792 (Korea, Republic of); Yoon, Y.S. [Department of Electrical and Electronic Engineering, Yonsei University, Sinchon-dong, Seoul 120-749 (Korea, Republic of); Ko, T.K. [Department of Electrical Engineering, Ansan College of Technology, Choji-Dong, Ansan Si 425-792 (Korea, Republic of)
2011-11-15
We examine levitation and propulsion forces of the proto-type maglev vehicle system based on 3D FEM. The levitation force increases over 15% due to AC current of the guideway. The levitation force by HTS electromagnet (EM) and AC current is larger over 30% than that of only HTS EM. We have been constructed a proto-type electromagnetic suspension (EMS) based maglev vehicle system. The maglev concept utilizes magnetic forces for noncontact suspension, guidance and propulsion. The suspension system with high temperature superconducting (HTS) hybrid electromagnet (EM) is composed of HTS coils and normal coils, which consume little power to keep large suspension gap. The magnetic forces realize to guide the vehicle, propel the vehicle along the guide-way and assist in braking action. The proto-type EMS-based Maglev model is designed to keep the suspension gap of 20 mm. This paper presents the theoretical analysis of the maglev vehicle based on the EMS model to obtain the designing parameters for levitation and propulsion forces. The magnetic field distributions of the electromagnetic forces with hybrid EM and propulsion stator coils are analyzed based on three dimension (3D) finite element method (FEM) analysis. From the simulation results, appropriately design parameters of the suspension, guidance and propulsion were obtained.
International Nuclear Information System (INIS)
Chung, Y.D.; Lee, C.Y.; Jang, J.Y.; Yoon, Y.S.; Ko, T.K.
2011-01-01
We examine levitation and propulsion forces of the proto-type maglev vehicle system based on 3D FEM. The levitation force increases over 15% due to AC current of the guideway. The levitation force by HTS electromagnet (EM) and AC current is larger over 30% than that of only HTS EM. We have been constructed a proto-type electromagnetic suspension (EMS) based maglev vehicle system. The maglev concept utilizes magnetic forces for noncontact suspension, guidance and propulsion. The suspension system with high temperature superconducting (HTS) hybrid electromagnet (EM) is composed of HTS coils and normal coils, which consume little power to keep large suspension gap. The magnetic forces realize to guide the vehicle, propel the vehicle along the guide-way and assist in braking action. The proto-type EMS-based Maglev model is designed to keep the suspension gap of 20 mm. This paper presents the theoretical analysis of the maglev vehicle based on the EMS model to obtain the designing parameters for levitation and propulsion forces. The magnetic field distributions of the electromagnetic forces with hybrid EM and propulsion stator coils are analyzed based on three dimension (3D) finite element method (FEM) analysis. From the simulation results, appropriately design parameters of the suspension, guidance and propulsion were obtained.
International Nuclear Information System (INIS)
Dubcova, Lenka; Solin, Pavel; Hansen, Glen; Park, HyeongKae
2011-01-01
Multiphysics solution challenges are legion within the field of nuclear reactor design and analysis. One major issue concerns the coupling between heat and neutron flow (neutronics) within the reactor assembly. These phenomena are usually very tightly interdependent, as large amounts of heat are quickly produced with an increase in fission events within the fuel, which raises the temperature that affects the neutron cross section of the fuel. Furthermore, there typically is a large diversity of time and spatial scales between mathematical models of heat and neutronics. Indeed, the different spatial resolution requirements often lead to the use of very different meshes for the two phenomena. As the equations are coupled, one must take care in exchanging solution data between them, or significant error can be introduced into the coupled problem. We propose a novel approach to the discretization of the coupled problem on different meshes based on an adaptive multimesh higher-order finite element method (hp-FEM), and compare it to popular interpolation and projection methods. We show that the multimesh hp-FEM method is significantly more accurate than the interpolation and projection approaches considered in this study.
International Nuclear Information System (INIS)
Jaksic, Nikola; Greuner, Henri; Herrmann, Albrecht
2013-01-01
Highlights: • New solid tungsten divertor for fusion experiment ASDEX Upgrade. • Design validation in the high heat flux (HHF) test facility GLADIS (Garching Large Divertor Sample Test Facility). • FEA simulation. -- Abstract: A new solid tungsten divertor for the fusion experiment ASDEX Upgrade is under construction at present. A new divertor tile design has been developed to improve the thermal performance of the current divertor made of tungsten coated fine grain graphite. Compared to thin tungsten coatings, divertor tiles made of massive tungsten allow to extend the operational range and to study the plasma material interaction of tungsten in more detail. The improved design for the solid tungsten divertor was tested on different full scale prototypes with a hydrogen ion beam. The influence of a possible material degradation due to thermal cracking or recrystallization can be studied. Furthermore, intensive Finite Element Method (FEM) numerical analysis with the respective test parameters has been performed. The elastic–plastic calculation was applied to analyze thermal stress and the observed elastic and plastic deformation during the heat loading. Additionally, the knowledge gained by the tests and especially by the numerical analysis has been used to optimize the shape of the divertor tiles and the accompanying divertor support structure. This paper discusses the main results of the high heat flux tests and their numerical simulations. In addition, results from some special structural mechanic analysis by means of FEM tools are presented. Finally, first results from the numerical lifecycle analysis of the current tungsten tiles will be reported
Smith, Andrew; LaVerde, Bruce; Waldon, James; Hunt, Ron
2014-01-01
Marshall Space Flight Center has conducted a series of ground acoustic tests with the dual goals of informing analytical judgment, and validating analytical methods when estimating vibroacoustic responses of launch vehicle subsystems. The process of repeatedly correlating finite element-simulated responses with test-measured responses has assisted in the development of best practices for modeling and post-processing. In recent work, force transducers were integrated to measure interface forces at the base of avionics box equipment. Other force data was indirectly measured using strain gauges. The combination of these direct and indirect force measurements has been used to support and illustrate the advantages of implementing the Force Limiting approach for equipment qualification tests. The comparison of force response from integrated system level tests to measurements at the same locations during component level vibration tests provides an excellent illustration. A second comparison of the measured response cases from the system level acoustic tests to finite element simulations has also produced some principles for assessing the suitability of Finite Element Models (FEMs) for making vibroacoustics estimates. The results indicate that when FEM models are employed to guide force limiting choices, they should include sufficient detail to represent the apparent mass of the system in the frequency range of interest.
Diarra, Harona; Mazel, Vincent; Busignies, Virginie; Tchoreloff, Pierre
2013-09-10
This work studies the influence of visco-elastic behavior in the finite element method (FEM) modeling of die compaction of pharmaceutical products and how such a visco-elastic behavior may improve the agreement between experimental and simulated compression curves. The modeling of the process was conducted on a pharmaceutical excipient, microcrystalline cellulose (MCC), by using Drucker-Prager cap model coupled with creep behavior in Abaqus(®) software. The experimental data were obtained on a compaction simulator (STYLCAM 200R). The elastic deformation of the press was determined by performing experimental tests on a calibration disk and was introduced in the simulation. Numerical optimization was performed to characterize creep parameters. The use of creep behavior in the simulations clearly improved the agreement between the numerical and experimental compression curves (stresses, thickness), mainly during the unloading part of the compaction cycle. For the first time, it was possible to reproduce numerically the fact that the minimum tablet thickness is not obtained at the maximum compression stress. This study proves that creep behavior must be taken into account when modeling the compaction of pharmaceutical products using FEM methods. Copyright © 2013 Elsevier B.V. All rights reserved.
Elwassif, Maged M.; Datta, Abhishek; Rahman, Asif; Bikson, Marom
2012-08-01
There is a growing interest in the use of deep brain stimulation (DBS) for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. magnetic resonance imaging) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method (FEM) simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: (1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); (2) it does not interfere with device efficacy; and (3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure.
Energy Technology Data Exchange (ETDEWEB)
Chang, H. Y.; Lim, B. T.; Kim, K. S.; Kim, J. W.; Park, H. B. [KEPCO Engineering and Construction Company, Gimcheon (Korea, Republic of); Kim, Y. S.; Kim, K. T. [Andong National University, Andong (Korea, Republic of)
2017-06-15
Coal tar-coated pipes buried in a domestic nuclear power plant have operated under the cathodic protection. This work conducted the simulation of the coating performance of these pipes using a FEM method. The pipes, being ductile cast iron have been suffered under considerably high cathodic protection condition beyond the appropriate condition. However, cathodic potential measured at the site revealed non-protected status. Converting from 3D CAD data of the power plant to appropriate type for a FEM simulation was conducted and cathodic potential under the applied voltage and current was calculated using primary and secondary current distribution and physical conditions. FEM simulation for coal tar-coated pipe without defects revealed over-protection condition if the pipes were well-coated. However, the simulation for coal tar-coated pipes with many defects predict that the coated pipes may be severely degraded. Therefore, for high risk pipes, direct examination and repair or renewal of pipes are strongly recommended.
Directory of Open Access Journals (Sweden)
Elizabeth Mesa-Múnera
2012-12-01
Full Text Available The realistic simulation of tool-tissue interactions is necessary for the development of surgical simulators and one of the key element for it realism is accurate bio-mechanical tissue models. In this paper, we determined the mechanical properties of soft tissue by minimizing the diﬀerence between experimental measurements and the analytical or simulated solution of the deformation. Then, we selected the best model parameters that ﬁt the experimental data to simulate a bonded compression and a needle indentation with a ﬂat-tip. We show that the inverse FEM allows accurate material property estimation. We also validated our results using multiple tool-tissue interactions over the same specimen.Una simulación realista de la interacción tejido-herramienta es necesaria para desarrollar simuldores quirúrgicos, y la presición en modelos biomecánicos de tejidos es determinante para cumplir tal ﬁn. Los trabajos previos han caracterizado las propiedades de tejidos blandos; sin embargo, ha faltado una validación apropiada de los resultados. En este trabajo se determinaron las propiedades mecánicas de un tejido blando minimizando la diferencia entre las mediciones experimentales y la solución analítica o simulada del problema. Luego, fueron seleccionados los parámetros que mejor se ajustaron a los datos experimentales para simular una compresión con fricción y la indentación de una aguja con punta plana. Se concluye que el inverse-FEM permite la precisa estimación de las propiedades del material. Además, estos resultados fueron validados con varias interacciones tejido-herramienta sobre el mismo espécimen.
Structural FEM analysis of the strut-to-fuselage joint of a two-seat composite aircraft
International Nuclear Information System (INIS)
Vargas-Rojas, Erik; Camarena-Arellano, Diego; Hernández-Moreno, Hilario
2014-01-01
An analysis of a strut-to-fuselage joint is realized in order to evaluate the zones with a high probability of failure by means of a safety factor. The whole section is analyzed using the Finite Element Method (FEM) so as to estimate static resistance behavior, therefore it is necessary a numerical mock-up of the section, the mechanical properties of the Carbon-Epoxy (C-Ep) material, and to evaluate the applied loads. Results of the analysis show that the zones with higher probability of failure are found around the wing strut and the fuselage joint, with a safety factor lower than expected in comparison with the average safety factor used on aircrafts built mostly with metals
Directory of Open Access Journals (Sweden)
Ionescu Viorel
2016-01-01
Full Text Available Proton Exchange Membrane Fuel Cells (PEMFC are highly efficient power generators, achieving up to 50–60% conversion efficiency, even in sizes of a few kilowatts. Comsol Multiphysics, a commercial solver based on the Finite Element Method (FEM was used for developing a three dimensional model of a high temperature PEMFC that can deal with both anode and cathode flow field for examining the micro flow channel with electrochemical reaction. Cathode gas flow velocity influence on the cell performance was investigated at first. Polarization curves for three different channel widths (0.8, 1.6 and 2.4 mm and three different channel depths (1, 2 and 3 mm were computed at a cathode inlet flow velocity of 0.06 m/s. Oxygen molar concentration at cathode catalyst layer-GDL channel interface and local current density variation along the cell length were also studied for specific gas channel geometries.
Directory of Open Access Journals (Sweden)
R. Citarella
2017-02-01
Full Text Available Wendelstein 7-X is the world’s largest nuclear fusion experiment of stellarator type, in which a hydrogen plasma is confined by a magnet field generated with external superconducting coils, allowing the plasma to be heated up to the fusion temperature. The water-cooled Plasma Facing Components (PFC protect the Plasma Vessel (PV against radiative and convective heat from the plasma. After the assembly process of heat shields and baffles, several cracks were found in the braze and cooling pipes. Due to heat load cycles occurring during each Operational Phase (OP, thermal stresses are generated in the heat sinks, braze root and cooling pipes, capable to drive fatigue crack-growth and, possibly, a water leak through the pipe thickness. The aim of this study is to assess the most dangerous initial crack configurations in one of the most critical baffles by using numerical models based on a FEM-DBEM approach.
International Nuclear Information System (INIS)
Kessler, L.; Beier, Th.; Werner, H.; Horstkott, D.; Dell, H.; Gese, H.
2005-01-01
An increasing use of combining more than one process step is noticed for coupling crash simulations with the results of forming operations -- mostly by inheriting the forming history like plastic strain and material hardening. Introducing a continuous failure model allows a further benefit of these coupling processes; it sometimes can even be the most attractive result of such a work. In this paper the algorithm CrachFEM for fracture prediction has been used to generate more benefit of the successive forming and crash simulations -- especially for ultra high strength steels. The choice and selection of the material grade in combination with the component design can therefore be done far before the prototyping might show an unsuccessful crash result; and in an industrial applicable manner
DEFF Research Database (Denmark)
Nakamura, T; Bay, Niels
1998-01-01
A new friction testing method based on combined forward conical can-backward straight can extrusion is proposed in order to evaluate friction characteristics in severe metal forming operations. By this method the friction coefficient along the conical punch surface is determined knowing...... the friction coefficient along the die wall. The latter is determined by a combined forward and backward can extrusion of straight cans. Calibration curves determining the relationship between punch travel, can heights, and friction coefficient for the two rests are calculated based on a rigid-plastic FEM...... analysis. Experimental friction tests are carried out in a mechanical press with aluminium alloy A6061 as the workpiece material and different kinds of lubricants. They confirm that the theoretical analysis results irt reasonable values for the friction coefficient....
Cone Beam X-Ray Luminescence Tomography Imaging Based on KA-FEM Method for Small Animals.
Chen, Dongmei; Meng, Fanzhen; Zhao, Fengjun; Xu, Cao
2016-01-01
Cone beam X-ray luminescence tomography can realize fast X-ray luminescence tomography imaging with relatively low scanning time compared with narrow beam X-ray luminescence tomography. However, cone beam X-ray luminescence tomography suffers from an ill-posed reconstruction problem. First, the feasibility of experiments with different penetration and multispectra in small animal has been tested using nanophosphor material. Then, the hybrid reconstruction algorithm with KA-FEM method has been applied in cone beam X-ray luminescence tomography for small animals to overcome the ill-posed reconstruction problem, whose advantage and property have been demonstrated in fluorescence tomography imaging. The in vivo mouse experiment proved the feasibility of the proposed method.
International Nuclear Information System (INIS)
Park, Chan Yuk; Sung, Jin Ho; Jeong, Jong Seob
2015-01-01
In this paper, a linear-array transducer capable of overcoming the faults of a single element and phased array transducers with convex shape for non-destructive ultrasonic testing was designed and fabricated. A 5.5 MHz linear-array transducer was designed using the PiezoCAD program based on the KLM analysis and the PZFlex program based on the FEM analysis. A 2-2 composite structure was employed to achieve broad-band characteristics. A 128 element linear-array transducer was fabricated and its performance was compared with the simulation results. The center frequency of the fabricated transducer was 5.5 Mhzand the -6 dB frequency bandwidth was 70 %. Thus, we expect that the designed transducer can provide an effective inner image of the test material during non-destructive ultrasonic testing.
Energy Technology Data Exchange (ETDEWEB)
Park, Chan Yuk; Sung, Jin Ho; Jeong, Jong Seob [Dept. of Medical Biotechnology, Dongguk University Biomedi Campus, Goyang (Korea, Republic of)
2015-04-15
In this paper, a linear-array transducer capable of overcoming the faults of a single element and phased array transducers with convex shape for non-destructive ultrasonic testing was designed and fabricated. A 5.5 MHz linear-array transducer was designed using the PiezoCAD program based on the KLM analysis and the PZFlex program based on the FEM analysis. A 2-2 composite structure was employed to achieve broad-band characteristics. A 128 element linear-array transducer was fabricated and its performance was compared with the simulation results. The center frequency of the fabricated transducer was 5.5 Mhzand the -6 dB frequency bandwidth was 70 %. Thus, we expect that the designed transducer can provide an effective inner image of the test material during non-destructive ultrasonic testing.
International Nuclear Information System (INIS)
Romppanen, A.-J.; Immonen, E.
2013-12-01
The residual stresses formed as a result of Electronic Beam welding (EB-welding) in copper are investigated by Posiva. In the present study, residual stresses of EB-welded copper plates were studied with contour method. In the method eleven copper plates (X436 - X440 and X453 - X458) were cut in half with wire electric discharge machining (EDM) after which the deformation due to stress relaxation was measured with coordinate measurement system. The measured data was then used as boundary displacement data for the FEM analyses, in which the corresponding residual stresses were calculated. Before giving the corresponding displacement boundary conditions to the FE models, the deformation data was processed and smoothed appropriately. The residual stress levels of the copper plates were found to be around 40 - 55 MPa at maximum. This corresponds to other reported residual stress measurements and current state of knowledge with this material in Posiva. (orig.)
Wehmiller, J.F.; Harris, W.B.; Boutin, B.S.; Farrell, K.M.
2012-01-01
The use of amino acid racemization (AAR) for estimating ages of Quaternary fossils usually requires a combination of kinetic and effective temperature modeling or independent age calibration of analyzed samples. Because of limited availability of calibration samples, age estimates are often based on model extrapolations from single calibration points over wide ranges of D/L values. Here we present paired AAR and 87Sr/ 86Sr results for Pleistocene mollusks from the North Carolina Coastal Plain, USA. 87Sr/ 86Sr age estimates, derived from the lookup table of McArthur et al. [McArthur, J.M., Howarth, R.J., Bailey, T.R., 2001. Strontium isotopic stratigraphy: LOWESS version 3: best fit to the marine Sr-isotopic curve for 0-509 Ma and accompanying Look-up table for deriving numerical age. Journal of Geology 109, 155-169], provide independent age calibration over the full range of amino acid D/L values, thereby allowing comparisons of alternative kinetic models for seven amino acids. The often-used parabolic kinetic model is found to be insufficient to explain the pattern of racemization, although the kinetic pathways for valine racemization and isoleucine epimerization can be closely approximated with this function. Logarithmic and power law regressions more accurately represent the racemization pathways for all amino acids. The reliability of a non-linear model for leucine racemization, developed and refined over the past 20 years, is confirmed by the 87Sr/ 86Sr age results. This age model indicates that the subsurface record (up to 80m thick) of the North Carolina Coastal Plain spans the entire Quaternary, back to ???2.5Ma. The calibrated kinetics derived from this age model yield an estimate of the effective temperature for the study region of 11??2??C., from which we estimate full glacial (Last Glacial Maximum - LGM) temperatures for the region on the order of 7-10??C cooler than present. These temperatures compare favorably with independent paleoclimate information
Application of multi-thread computing and domain decomposition to the 3-D neutronics Fem code Cronos
International Nuclear Information System (INIS)
Ragusa, J.C.
2003-01-01
The purpose of this paper is to present the parallelization of the flux solver and the isotopic depletion module of the code, either using Message Passing Interface (MPI) or OpenMP. Thread parallelism using OpenMP was used to parallelize the mixed dual FEM (finite element method) flux solver MINOS. Investigations regarding the opportunity of mixing parallelism paradigms will be discussed. The isotopic depletion module was parallelized using domain decomposition and MPI. An attempt at using OpenMP was unsuccessful and will be explained. This paper is organized as follows: the first section recalls the different types of parallelism. The mixed dual flux solver and its parallelization are then presented. In the third section, we describe the isotopic depletion solver and its parallelization; and finally conclude with some future perspectives. Parallel applications are mandatory for fine mesh 3-dimensional transport and simplified transport multigroup calculations. The MINOS solver of the FEM neutronics code CRONOS2 was parallelized using the directive based standard OpenMP. An efficiency of 80% (resp. 60%) was achieved with 2 (resp. 4) threads. Parallelization of the isotopic depletion solver was obtained using domain decomposition principles and MPI. Efficiencies greater than 90% were reached. These parallel implementations were tested on a shared memory symmetric multiprocessor (SMP) cluster machine. The OpenMP implementation in the solver MINOS is only the first step towards fully using the SMPs cluster potential with a mixed mode parallelism. Mixed mode parallelism can be achieved by combining message passing interface between clusters with OpenMP implicit parallelism within a cluster
Application of multi-thread computing and domain decomposition to the 3-D neutronics Fem code Cronos
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Ragusa, J.C. [CEA Saclay, Direction de l' Energie Nucleaire, Service d' Etudes des Reacteurs et de Modelisations Avancees (DEN/SERMA), 91 - Gif sur Yvette (France)
2003-07-01
The purpose of this paper is to present the parallelization of the flux solver and the isotopic depletion module of the code, either using Message Passing Interface (MPI) or OpenMP. Thread parallelism using OpenMP was used to parallelize the mixed dual FEM (finite element method) flux solver MINOS. Investigations regarding the opportunity of mixing parallelism paradigms will be discussed. The isotopic depletion module was parallelized using domain decomposition and MPI. An attempt at using OpenMP was unsuccessful and will be explained. This paper is organized as follows: the first section recalls the different types of parallelism. The mixed dual flux solver and its parallelization are then presented. In the third section, we describe the isotopic depletion solver and its parallelization; and finally conclude with some future perspectives. Parallel applications are mandatory for fine mesh 3-dimensional transport and simplified transport multigroup calculations. The MINOS solver of the FEM neutronics code CRONOS2 was parallelized using the directive based standard OpenMP. An efficiency of 80% (resp. 60%) was achieved with 2 (resp. 4) threads. Parallelization of the isotopic depletion solver was obtained using domain decomposition principles and MPI. Efficiencies greater than 90% were reached. These parallel implementations were tested on a shared memory symmetric multiprocessor (SMP) cluster machine. The OpenMP implementation in the solver MINOS is only the first step towards fully using the SMPs cluster potential with a mixed mode parallelism. Mixed mode parallelism can be achieved by combining message passing interface between clusters with OpenMP implicit parallelism within a cluster.
Gollub, Erica L; Cyrus, Elena; Dévieux, Jessy G; Jean-Gilles, Michèle; Neptune, Sandra; Pelletier, Valerie; Michel, Hulda; Sévère, Marie; Pierre, Laurinus
2015-01-01
Worldwide, women report the need for safe, non-hormonal, woman-initiated methods of family planning. Cervical barriers provide such technology but are under-researched and under-promoted. In the USA, there are few studies of cervical barriers among women at high unmet need for contraception. A feasibility study of the FemCap™ was conducted among US women of Haitian origin. Participants were heterosexual and seeking to avoid pregnancy. At first visit, participants completed baseline assessments, underwent group counselling and were fitted with FemCap™. Women were asked to insert or use the cap at home. The second visit (2-3 weeks) included an interviewer-administered questionnaire and a focus-group discussion. Participants (n = 20) were Haitian-born (70%), married (55%) and parous (85%). Their mean age was 32.6 years. Seventy percent reported recent unprotected sex. All women inserted the device at home and 9 women used it during intercourse, including 5 without prior partner negotiation. Of 20 women, 11 liked FemCap™ very much or somewhat; 7 considered it 'OK'; 2 disliked it. Best-liked attributes were comfort, discreet wear and reusability. Difficulties with removal abated over time. Qualitative data revealed a high value placed on lack of systemic side effects. Use of FemCap™ was feasible and acceptable, supporting expansion of research, particularly among relevant populations with unmet need.
Haufe, Stefan; Huang, Yu; Parra, Lucas C
2015-08-01
In electroencephalographic (EEG) source imaging as well as in transcranial current stimulation (TCS), it is common to model the head using either three-shell boundary element (BEM) or more accurate finite element (FEM) volume conductor models. Since building FEMs is computationally demanding and labor intensive, they are often extensively reused as templates even for subjects with mismatching anatomies. BEMs can in principle be used to efficiently build individual volume conductor models; however, the limiting factor for such individualization are the high acquisition costs of structural magnetic resonance images. Here, we build a highly detailed (0.5mm(3) resolution, 6 tissue type segmentation, 231 electrodes) FEM based on the ICBM152 template, a nonlinear average of 152 adult human heads, which we call ICBM-NY. We show that, through more realistic electrical modeling, our model is similarly accurate as individual BEMs. Moreover, through using an unbiased population average, our model is also more accurate than FEMs built from mismatching individual anatomies. Our model is made available in Matlab format.
FEM design and simulation of a short, 10 MV, S-band Linac with Monte Carlo dose simulations
International Nuclear Information System (INIS)
Baillie, Devin; Aubin, J. St.; Steciw, S.; Fallone, B. G.
2015-01-01
Purpose: Current commercial 10 MV Linac waveguides are 1.5 m. The authors’ current 6 MV linear accelerator–magnetic resonance imager (Linac–MR) system fits in typical radiotherapy vaults. To allow 10 MV treatments with the Linac–MR and still fit within typical vaults, the authors design a 10 MV Linac with an accelerator waveguide of the same length (27.5 cm) as current 6 MV Linacs. Methods: The first design stage is to design a cavity such that a specific experimental measurement for breakdown is applicable to the cavity. This is accomplished through the use of finite element method (FEM) simulations to match published shunt impedance, Q factor, and ratio of peak to mean-axial electric field strength from an electric breakdown study. A full waveguide is then designed and tuned in FEM simulations based on this cavity design. Electron trajectories are computed through the resulting radio frequency fields, and the waveguide geometry is modified by shifting the first coupling cavity in order to optimize the electron beam properties until the energy spread and mean energy closely match values published for an emulated 10 MV Linac. Finally, Monte Carlo dose simulations are used to compare the resulting photon beam depth dose profile and penumbra with that produced by the emulated 10 MV Linac. Results: The shunt impedance, Q factor, and ratio of peak to mean-axial electric field strength are all matched to within 0.1%. A first coupling cavity shift of 1.45 mm produces an energy spectrum width of 0.347 MeV, very close to the published value for the emulated 10 MV of 0.315 MeV, and a mean energy of 10.53 MeV, nearly identical to the published 10.5 MeV for the emulated 10 MV Linac. The depth dose profile produced by their new Linac is within 1% of that produced by the emulated 10 MV spectrum for all depths greater than 1.5 cm. The penumbra produced is 11% narrower, as measured from 80% to 20% of the central axis dose. Conclusions: The authors have successfully
Thermomechanical behaviour of two heterogeneous tungsten materials via 2D and 3D image-based FEM
International Nuclear Information System (INIS)
Zivelonghi, Alessandro
2011-01-01
An advanced numerical procedure based on imaging of the material microstructure (Image- Based Finite Element Method or Image-Based FEM) was extended and applied to model the thermomechanical behaviour of novel materials for fusion applications. Two tungsten based heterogeneous materials with different random morphologies have been chosen as challenging case studies: (1) a two-phase mixed ductile-brittle W/CuCr1Zr composite and (2) vacuum plasma-sprayed tungsten (VPS-W 75 vol.%), a porous coating system with complex dual-scale microstructure. Both materials are designed for the future fusion reactor DEMO: W/CuCr1Zr as main constituent of a layered functionally graded joint between plasma-facing armor and heat sink whereas VPS-W for covering the first wall of the reactor vessel in direct contact with the plasma. The primary focus of this work was to investigate the mesoscopic material behaviour and the linkage to the macroscopic response in modeling failure and heat-transfer. Particular care was taken in validating and integrating simulation findings with experimental inputs. The solution of the local thermomechanical behaviour directly on the real material microstructure enabled meaningful insights into the complex failure mechanism of both materials. For W/CuCr1Zr full macroscopic stress-strain curves including the softening and failure part could be simulated and compared with experimental ones at different temperatures, finding an overall good agreement. The comparison of simulated and experimental macroscopic behaviour of plastic deformation and rupture also showed the possibility to indirectly estimate micro- and mesoscale material parameters. Both heat conduction and elastic behaviour of VPS-W have been extensively investigated. New capabilities of the Image-Based FEM could be shown: decomposition of the heat transfer reduction as due to the individual morphological phases and back-fitting of the reduced stiffness at interlamellar boundaries. The
Efendiev, Yalchin R.
2013-08-21
In this paper, we propose multilevel Monte Carlo (MLMC) methods that use ensemble level mixed multiscale methods in the simulations of multiphase flow and transport. The contribution of this paper is twofold: (1) a design of ensemble level mixed multiscale finite element methods and (2) a novel use of mixed multiscale finite element methods within multilevel Monte Carlo techniques to speed up the computations. The main idea of ensemble level multiscale methods is to construct local multiscale basis functions that can be used for any member of the ensemble. In this paper, we consider two ensemble level mixed multiscale finite element methods: (1) the no-local-solve-online ensemble level method (NLSO); and (2) the local-solve-online ensemble level method (LSO). The first approach was proposed in Aarnes and Efendiev (SIAM J. Sci. Comput. 30(5):2319-2339, 2008) while the second approach is new. Both mixed multiscale methods use a number of snapshots of the permeability media in generating multiscale basis functions. As a result, in the off-line stage, we construct multiple basis functions for each coarse region where basis functions correspond to different realizations. In the no-local-solve-online ensemble level method, one uses the whole set of precomputed basis functions to approximate the solution for an arbitrary realization. In the local-solve-online ensemble level method, one uses the precomputed functions to construct a multiscale basis for a particular realization. With this basis, the solution corresponding to this particular realization is approximated in LSO mixed multiscale finite element method (MsFEM). In both approaches, the accuracy of the method is related to the number of snapshots computed based on different realizations that one uses to precompute a multiscale basis. In this paper, ensemble level multiscale methods are used in multilevel Monte Carlo methods (Giles 2008a, Oper.Res. 56(3):607-617, b). In multilevel Monte Carlo methods, more accurate
Kwak, Nam-su; Kim, Jae-Yeol
2012-04-01
The world, coming into the 21st century, is preparing a new revolution called a knowledge-based society after the industrial society. The interest of the world is concentrated on information technology, Nano-technology and biotechnology. In particular, the Nano-technology of which study was originally started from an alternative for overcoming semiconductor micro-technology. It can be applied to most industry subject such as electronics, information and communication, machinery, chemistry, bioengineering, energy, etc. They are emerging into the technology that can change civilization of human beings. Specially, ultra precision machining is quickly applied to Nano-technology in the field of machinery. Lately, with rapid development of electronics industry and optic industry, there are needs for super precision finishing of various core parts required in such related apparatuses. This paper handles stability of a super precision micro cutting machine that is a core unit of such a super precision finisher, and analyzes the results depending on the hinge type and material change, using FEM analysis. By reviewing the stability, it is possible to achieve the effect of basic data collection for unit control and to reduce trials and errors in unit design and manufacturing.
International Nuclear Information System (INIS)
Gao, Kai; Fu, Shubin; Gibson, Richard L.; Chung, Eric T.; Efendiev, Yalchin
2015-01-01
It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both the boundaries and interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale medium property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and discontinuous Galerkin formulation of the multiscale method, both of which have pros and cons. Applications of the multiscale method to three heterogeneous models show that our multiscale method can effectively model the elastic wave propagation in anisotropic media with a significant reduction in the degrees of freedom in the modeling system
Zhang, Tao; Jiang, Feng; Yan, Lan; Xu, Xipeng
2017-12-26
The high-temperature hardness test has a wide range of applications, but lacks test standards. The purpose of this study is to develop a finite element method (FEM) model of the relationship between the high-temperature hardness and high-temperature, quasi-static compression experiment, which is a mature test technology with test standards. A high-temperature, quasi-static compression test and a high-temperature hardness test were carried out. The relationship between the high-temperature, quasi-static compression test results and the high-temperature hardness test results was built by the development of a high-temperature indentation finite element (FE) simulation. The simulated and experimental results of high-temperature hardness have been compared, verifying the accuracy of the high-temperature indentation FE simulation.The simulated results show that the high temperature hardness basically does not change with the change of load when the pile-up of material during indentation is ignored. The simulated and experimental results show that the decrease in hardness and thermal softening are consistent. The strain and stress of indentation were analyzed from the simulated contour. It was found that the strain increases with the increase of the test temperature, and the stress decreases with the increase of the test temperature.
Romano, F; Trasatti, E; Lorito, S; Piromallo, C; Piatanesi, A; Ito, Y; Zhao, D; Hirata, K; Lanucara, P; Cocco, M
2014-07-09
The 2011 Tohoku earthquake (Mw = 9.1) highlighted previously unobserved features for megathrust events, such as the large slip in a relatively limited area and the shallow rupture propagation. We use a Finite Element Model (FEM), taking into account the 3D geometrical and structural complexities up to the trench zone, and perform a joint inversion of tsunami and geodetic data to retrieve the earthquake slip distribution. We obtain a close spatial correlation between the main deep slip patch and the local seismic velocity anomalies, and large shallow slip extending also to the North coherently with a seismically observed low-frequency radiation. These observations suggest that the friction controlled the rupture, initially confining the deeper rupture and then driving its propagation up to the trench, where it spreads laterally. These findings are relevant to earthquake and tsunami hazard assessment because they may help to detect regions likely prone to rupture along the megathrust, and to constrain the probability of high slip near the trench. Our estimate of ~40 m slip value around the JFAST (Japan Trench Fast Drilling Project) drilling zone contributes to constrain the dynamic shear stress and friction coefficient of the fault obtained by temperature measurements to ~0.68 MPa and ~0.10, respectively.
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Gao, Kai, E-mail: kaigao87@gmail.com [Department of Geology and Geophysics, Texas A& M University, College Station, TX 77843 (United States); Fu, Shubin, E-mail: shubinfu89@gmail.com [Department of Mathematics, Texas A& M University, College Station, TX 77843 (United States); Gibson, Richard L., E-mail: gibson@tamu.edu [Department of Geology and Geophysics, Texas A& M University, College Station, TX 77843 (United States); Chung, Eric T., E-mail: tschung@math.cuhk.edu.hk [Department of Mathematics, The Chinese University of Hong Kong, Shatin, NT (Hong Kong); Efendiev, Yalchin, E-mail: efendiev@math.tamu.edu [Department of Mathematics, Texas A& M University, College Station, TX 77843 (United States); Numerical Porous Media SRI Center (NumPor), King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)
2015-08-15
It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both the boundaries and interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale medium property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and discontinuous Galerkin formulation of the multiscale method, both of which have pros and cons. Applications of the multiscale method to three heterogeneous models show that our multiscale method can effectively model the elastic wave propagation in anisotropic media with a significant reduction in the degrees of freedom in the modeling system.
Directory of Open Access Journals (Sweden)
Denise-Penelope N. Kontoni
2018-01-01
Full Text Available An existing riverine platform in Egypt, together with its pile group foundation, is analyzed under environmental loads using 3D FEM structural analysis software incorporating soil-pile interaction. The interaction between the transfer plate and the piles supporting the platform is investigated. Two connection conditions were studied assuming fixed or hinged connection between the piles and the reinforced concrete platform for the purpose of comparison of the structural behavior. The analysis showed that the fixed or hinged connection condition between the piles and the platform altered the values and distribution of displacements, normal force, bending moments, and shear forces along the length of each pile. The distribution of piles in the pile group affects the stress distribution on both the soil and platform. The piles were found to suffer from displacement failure rather than force failure. Moreover, the resulting bending stresses on the reinforced concrete plate in the case of a fixed connection between the piles and the platform were almost doubled and much higher than the allowable reinforced concrete stress and even exceeded the ultimate design strength and thus the environmental loads acting on a pile-supported riverine offshore platform may cause collapse if they are not properly considered in the structural analysis and design.
Gao, Kai
2015-04-14
It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both boundaries and the interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale medium property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and discontinuous Galerkin formulation of the multiscale method, both of which have pros and cons. Applications of the multiscale method to three heterogeneous models show that our multiscale method can effectively model the elastic wave propagation in anisotropic media with a significant reduction in the degrees of freedom in the modeling system.
Makhrojan, Agus; Suprihadi, Agus; Budi, Sigit Setijo; Jamari, J.; Ismail, Rifky
2017-01-01
The electric car is transportation which growing and constantly put through improvisation vehicle design. One of the structural components of the electric car which holds a major role is a frame. The purpose of this study is to get monocoque frame design which lightweight and powerful for a city car with two passengers that was able to improve the efficiency of the battery voltage source. Monocoque frame should be able to accept the normal loads such as the weight of batteries, passenger, and body. The most important thing, monocoque frame should also be able to protect the driver and passengers in the event of a collision. Mild steel was chosen for the design because it is easy to obtain and reasonable price as well as easy to shaped for two-seater electric car. FEM (finite element method) was used to determine stress determination and rigidity of the monocoque frame when receiving a static load. The results show that the monocoque frame was still able to withstand the required loads with minimal deflection.
Study of Corona Discharge on 160 KeV, 10 mA Electron Accelerator Facility Using FEM
International Nuclear Information System (INIS)
Ghazali, Abu Bakar Mhd; Sobri, Rokiah Mohd
2008-01-01
This paper describes a method to verify the overall design of our electron accelerator. It is free from corona or spark discharge phenomenon. This locally designed electron accelerator facility is located at Nuclear Malaysia Complex, Bangi, Selangor. In this study, we describe the geometry of the pressure vessel filled with SF 6 gas at 2 atm to enclose the high voltage area of the accelerating tube. The Poisson's equation is used to calculate the contours of the electric field that is created between the cathode of -160 kV maximum and the wall of the vessel. The nearest sharp edge between the cathode and the pressure wall is 163 mm apart. The calculation is based on finite element method (FEM) for electrostatic charges in order to obtain an electric field contour in two-dimensional plane. We found that the surface charge density of the cathode is 1.1x10 -5 C/m 2 for the corona glowing seen at -90 kV. Moreover, the highest electric field near to (about 5 mm from) the sharp edge is about 2.7 MV/m, which is less than the dielectric strength of SF 6 gas, i.e. 6 MV/m and therefore, it proved that our design of the pressure vessel is save from corona or spark discharges
Study of Corona Discharge on 160 KeV, 10 mA Electron Accelerator Facility Using FEM
Ghazali, Abu Bakar Mhd; Sobri, Rokiah Mohd
2008-05-01
This paper describes a method to verify the overall design of our electron accelerator. It is free from corona or spark discharge phenomenon. This locally designed electron accelerator facility is located at Nuclear Malaysia Complex, Bangi, Selangor. In this study, we describe the geometry of the pressure vessel filled with SF6 gas at 2 atm to enclose the high voltage area of the accelerating tube. The Poisson's equation is used to calculate the contours of the electric field that is created between the cathode of -160 kV maximum and the wall of the vessel. The nearest sharp edge between the cathode and the pressure wall is 163 mm apart. The calculation is based on finite element method (FEM) for electrostatic charges in order to obtain an electric field contour in two-dimensional plane. We found that the surface charge density of the cathode is 1.1×10-5 C/m2 for the corona glowing seen at -90 kV. Moreover, the highest electric field near to (about 5 mm from) the sharp edge is about 2.7 MV/m, which is less than the dielectric strength of SF6 gas, i.e. 6 MV/m and therefore, it proved that our design of the pressure vessel is save from corona or spark discharges.
Directory of Open Access Journals (Sweden)
Guzmán Juan
2015-07-01
Full Text Available There are a lot of applications of the Thomson ring: levitation of superconductor materials, power interrupters (used as actuator and elimination of electric arcs. Therefore, it is important the numerical modeling of Thomson ring. The aim of this work is to model the stationary levitation of the Thomson ring. This Thomson ring consists of a copper coil with ferromagnetic core and an aluminum ring threaded in the core. The coil is fed by a cosine voltage to ensure that the aluminum ring is in a stationary levitated position. In this situation, the state of the electromagnetic field is stable and can be used the phasor equations of the electromagnetic field. These equations are discretized using the Galerkin method in the Lagrange base space (finite element method, FEM. These equations are solved using the COMSOL software. A methodology is also described (which uses the Newton-Raphson method that obtains the separation between coil and aluminum ring. The numerical solutions of this separation are compared with experimental data. The conclusion is that the magnetic coupling of the aluminum ring on the coil can be neglected if the source voltage is high.
Directory of Open Access Journals (Sweden)
Tao Zhang
2017-12-01
Full Text Available The high-temperature hardness test has a wide range of applications, but lacks test standards. The purpose of this study is to develop a finite element method (FEM model of the relationship between the high-temperature hardness and high-temperature, quasi-static compression experiment, which is a mature test technology with test standards. A high-temperature, quasi-static compression test and a high-temperature hardness test were carried out. The relationship between the high-temperature, quasi-static compression test results and the high-temperature hardness test results was built by the development of a high-temperature indentation finite element (FE simulation. The simulated and experimental results of high-temperature hardness have been compared, verifying the accuracy of the high-temperature indentation FE simulation.The simulated results show that the high temperature hardness basically does not change with the change of load when the pile-up of material during indentation is ignored. The simulated and experimental results show that the decrease in hardness and thermal softening are consistent. The strain and stress of indentation were analyzed from the simulated contour. It was found that the strain increases with the increase of the test temperature, and the stress decreases with the increase of the test temperature.
Directory of Open Access Journals (Sweden)
Zhu Xinglin
2016-06-01
Full Text Available During radial–axial ring rolling process, cooperative strategy of the radial–axial feed is critical for dimensional accuracy and thermo mechanical parameters distribution of the formed ring. In order to improve the comprehensive quality of the ring parts, response surface method (RSM is employed for the first time to optimize the cooperative feed strategy for radial–axial ring rolling process by combining it with an improved and verified 3D coupled thermo-mechanical finite element model. The feed trajectory is put forward to describe cooperative relationship of the radial–axial feed and three variables are designed based on the feed trajectory. In order to achieve multi-objective optimization, four responses including thermo mechanical parameters distribution and rolling force are proposed. Based on the FEM results, RSM is used to establish a response model to depict the function relationship between the objective response and design variables. Through this approximate model, effects of different variables on ring rolling process are analyzed connectedly and optimal feed strategy is obtained by resorting to the optimal chart specific to a constraint condition.
D'Urso, Gianluca; Giardini, Claudio
2016-08-11
The present study was carried out to evaluate how the friction stir spot welding (FSSW) process parameters affect the temperature distribution in the welding region, the welding forces and the mechanical properties of the joints. The experimental study was performed by means of a CNC machine tool obtaining FSSW lap joints on AA7050 aluminum alloy plates. Three thermocouples were inserted into the samples to measure the temperatures at different distance from the joint axis during the whole FSSW process. Experiments was repeated varying the process parameters, namely rotational speed, axial feed rate and plunging depth. Axial welding forces were measured during the tests using a piezoelectric load cell, while the mechanical properties of the joints were evaluated by executing shear tests on the specimens. The correlation found between process parameters and joints properties, allowed to identify the best technological window. The data collected during the experiments were used to validate a simulation model of the FSSW process, too. The model was set up using a 2D approach for the simulation of a 3D problem, in order to guarantee a very simple and practical solution for achieving results in a very short time. A specific external routine for the calculation of the thermal energy due to friction acting between pin and sheet was developed. An index for the prediction of the joint mechanical properties using the FEM simulations was finally presented and validated.
Directory of Open Access Journals (Sweden)
Gianluca D’Urso
2016-08-01
Full Text Available The present study was carried out to evaluate how the friction stir spot welding (FSSW process parameters affect the temperature distribution in the welding region, the welding forces and the mechanical properties of the joints. The experimental study was performed by means of a CNC machine tool obtaining FSSW lap joints on AA7050 aluminum alloy plates. Three thermocouples were inserted into the samples to measure the temperatures at different distance from the joint axis during the whole FSSW process. Experiments was repeated varying the process parameters, namely rotational speed, axial feed rate and plunging depth. Axial welding forces were measured during the tests using a piezoelectric load cell, while the mechanical properties of the joints were evaluated by executing shear tests on the specimens. The correlation found between process parameters and joints properties, allowed to identify the best technological window. The data collected during the experiments were used to validate a simulation model of the FSSW process, too. The model was set up using a 2D approach for the simulation of a 3D problem, in order to guarantee a very simple and practical solution for achieving results in a very short time. A specific external routine for the calculation of the thermal energy due to friction acting between pin and sheet was developed. An index for the prediction of the joint mechanical properties using the FEM simulations was finally presented and validated.
International Nuclear Information System (INIS)
Han, Zhaolong; Li, Jiasong; Singh, Manmohan; Wu, Chen; Liu, Chih-hao; Raghunathan, Raksha; Larin, Kirill V; Vantipalli, Srilatha; Aglyamov, Salavat R; Twa, Michael D
2016-01-01
Air-pulse optical coherence elastography (OCE) is a promising technique for quantifying biomechanical properties of the cornea. This technique typically involves imaging and analysis of the propagation of the air-pulse induced elastic waves to reconstruct corneal biomechanical properties using an analytical model. However, the effect of the fluid-structure interface (FSI) at the corneal posterior surface on the elastic wave velocity is not accounted for in many models. In this study, we examined the effect of the FSI with OCE experiments on contact lenses with and without fluid in the posterior gap. Finite element models (FEM), also with and without the FSI, were constructed to simulate the elastic wave propagation based on the OCE measurements. The FEM and OCE results were in good agreement demonstrating the feasibility of the method. To further investigate the effect of the FSI, OCE experiments and subsequent FEM simulations were conducted on in situ rabbit corneas before and after rose bengal/green light corneal collagen cross-linking (RGX). Both the OCE experiments and the FE simulations demonstrated that the FSI significantly reduced the group velocity of the elastic wave, and thus, should be considered when determining corneal biomechanical properties from an appropriate mechanical model. By matching the FEM-calculated velocity to the OCE-measured velocity, the corneal elasticity was quantified. The Young’s modulus of the rabbit cornea before RGX was E = 65 ± 10 kPa at a controlled intraocular pressure (IOP) of 15 mmHg. After RGX, the Young’s modulus increased to E = 102 ± 7 kPa at the same IOP. (letter)
Chen, Changguo; Zhao, Qiangyuan; Guo, Jianwei; Li, Yanjun; Chen, Qiuyuan
2017-08-01
The aim of this study was to develop a rapid detection assay to identify methicillin-resistant Staphylococcus aureus by simultaneous testing for the mecA, nuc, and femB genes using the loop-mediated isothermal amplification (LAMP) method. LAMP primers were designed using online bio-software ( http://primerexplorer.jp/e/ ), and amplification reactions were performed in an isothermal temperature bath. The products were then examined using 2% agarose gel electrophoresis. MecA, nuc, and femB were confirmed by triplex TaqMan real-time PCR. For better naked-eye inspection of the reaction result, hydroxy naphthol blue (HNB) was added to the amplification system. Within 60 min, LAMP successfully amplified the genes of interest under isothermal conditions at 63 °C. The results of 2% gel electrophoresis indicated that when the Mg 2+ concentration in the reaction system was 6 μmol, the amplification of the mecA gene was relatively good, while the amplification of the nuc and femB genes was better at an Mg 2+ concentration of 8 μmol. Obvious color differences were observed by adding 1 μL (3.75 mM) of HNB into 25 μL reaction system. The LAMP assay was applied to 128 isolates cases of methicillin-resistant Staphylococcus aureus, which were separated from the daily specimens and identified by Vitek microbial identification instruments. The results were identical for both LAMP and PCR. LAMP offers an alternative detection assay for mecA, nuc, and femB and is faster than other methods.
Energy Technology Data Exchange (ETDEWEB)
Bouzakis, K.D.; Vidakis, N. [Aristotle Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Leyendecker, T.; Erkens, G.; Wenke, R.
1997-10-31
The coating impact test, in combination with its finite elements method (FEM) simulation, is used to quantitatively characterize the fatigue behaviour of thin hard physical vapour deposited (PVD) coatings as well as of multilayer ones. Successive impacts of a cemented carbide ball onto a plane coated specimen induce severe contact loads and strain superficially the layered compound. The fatigue failure mode of each specimen is classified by means of scanning electron microscope (SEM) observations, microspectral analyses and profilometry. FEM simulating models of the impact test are used to determine the critical stress components, which introduce coating fatigue failure. The FEM computational results are correlated to the experimental ones and used to interpret them quantitatively. Herewith, critical values for stress components, responsible for distinctive fatigue failure modes of the coating substrate compounds are obtained and the fatigue limits of the examined multilayer coatings are inserted in general applicable Smith diagrams. Furthermore, the derived critical stresses are verified by investigating the same multilayer coatings on different substrates. (orig.) 14 refs.
Directory of Open Access Journals (Sweden)
Kikinis Ron
2006-03-01
Full Text Available Abstract Introduction Mitral Valve (MV 3D structural data can be easily obtained using standard transesophageal echocardiography (TEE devices but quantitative pre- and intraoperative volume analysis of the MV is presently not feasible in the cardiac operation room (OR. Finite element method (FEM modelling is necessary to carry out precise and individual volume analysis and in the future will form the basis for simulation of cardiac interventions. Method With the present retrospective pilot study we describe a method to transfer MV geometric data to 3D Slicer 2 software, an open-source medical visualization and analysis software package. A newly developed software program (ROIExtract allowed selection of a region-of-interest (ROI from the TEE data and data transformation for use in 3D Slicer. FEM models for quantitative volumetric studies were generated. Results ROI selection permitted the visualization and calculations required to create a sequence of volume rendered models of the MV allowing time-based visualization of regional deformation. Quantitation of tissue volume, especially important in myxomatous degeneration can be carried out. Rendered volumes are shown in 3D as well as in time-resolved 4D animations. Conclusion The visualization of the segmented MV may significantly enhance clinical interpretation. This method provides an infrastructure for the study of image guided assessment of clinical findings and surgical planning. For complete pre- and intraoperative 3D MV FEM analysis, three input elements are necessary: 1. time-gated, reality-based structural information, 2. continuous MV pressure and 3. instantaneous tissue elastance. The present process makes the first of these elements available. Volume defect analysis is essential to fully understand functional and geometrical dysfunction of but not limited to the valve. 3D Slicer was used for semi-automatic valve border detection and volume-rendering of clinical 3D echocardiographic
Ionescu , Irina; Moës , Nicolas; Cartraud , Patrice; Béringhier , Marianne
2007-01-01
International audience; The advances of material characterization by means of imaging techniques require powerful computational methods for numerical analyses. This paper focuses on the advantages of coupling the X-FEM and level sets to solve microstructures with complex geometry. The level set information is obtained from a digital image and then used within a X-FEM computation, where the mesh does not need to conform to the material interface. An example of homogeniza-tion is presented.; La...
A Flexible Method for Producing F.E.M. Analysis of Bone Using Open-Source Software
Boppana, Abhishektha; Sefcik, Ryan; Meyers, Jerry G.; Lewandowski, Beth E.
2016-01-01
This project, performed in support of the NASA GRC Space Academy summer program, sought to develop an open-source workflow methodology that segmented medical image data, created a 3D model from the segmented data, and prepared the model for finite-element analysis. In an initial step, a technological survey evaluated the performance of various existing open-source software that claim to perform these tasks. However, the survey concluded that no single software exhibited the wide array of functionality required for the potential NASA application in the area of bone, muscle and bio fluidic studies. As a result, development of a series of Python scripts provided the bridging mechanism to address the shortcomings of the available open source tools. The implementation of the VTK library provided the most quick and effective means of segmenting regions of interest from the medical images; it allowed for the export of a 3D model by using the marching cubes algorithm to build a surface mesh. To facilitate the development of the model domain from this extracted information required a surface mesh to be processed in the open-source software packages Blender and Gmsh. The Preview program of the FEBio suite proved to be sufficient for volume filling the model with an unstructured mesh and preparing boundaries specifications for finite element analysis. To fully allow FEM modeling, an in house developed Python script allowed assignment of material properties on an element by element basis by performing a weighted interpolation of voxel intensity of the parent medical image correlated to published information of image intensity to material properties, such as ash density. A graphical user interface combined the Python scripts and other software into a user friendly interface. The work using Python scripts provides a potential alternative to expensive commercial software and inadequate, limited open-source freeware programs for the creation of 3D computational models. More work
Directory of Open Access Journals (Sweden)
Monica Namburi
2017-01-01
Full Text Available Abstract Background Extraction of premolars and retracting the anterior teeth using mini-implants and anterior retraction hooks became advent now a day. In such treatments, consolidation of arches is not done in regular practice. So, the present study is concentrated on effects of consolidation in two implant and three implant combinations of retraction and intrusion. Methods A three-dimensional FEM model of maxillary teeth and periodontal ligament housed in the alveolar bone with the first premolars extracted is generated with appropriate number of elements and nodes. The models were broadly divided into two groups according to the no. of implants. Mini-implants were placed bilaterally between the second premolar and molar at varying heights (7, 10, 13 mm in group I, and along with bilateral implants, an additional mid-implant is placed between the central incisors as group II. Brackets with 0.022 slot were placed on the teeth, 19 × 25 SS wire is placed in the brackets, an anterior retraction hook was placed at 9 mm height, and analysis was done to evaluate the stresses and displacement patterns in consolidation and non-consolidation models. Results The results showed that consolidation of the anterior teeth during intrusion and retraction shows various advantages such as less stresses on the bone, PDL, implant, teeth, and no labial flaring of the anterior teeth and three implant system, i.e., two bilateral implant at 10 mm and a mid-implant at 12 mm between the centrals has shown to be better than other models as bodily movement is observed. Conclusion Consolidation is better than non consolidation during enmasse retraction and intrusion.
Fem landskabsstrategiske principper
DEFF Research Database (Denmark)
Bach, Rune Christian; Juel Clemmensen, Thomas
2005-01-01
to their return as investment, and less in respect to their physical surroundings. Consequently the space “between” the building enclaves becomes increasingly relevant in the architectural planning in terms of creating cohesion in the built environment. (Smets) This change of perspective from the built...... influence on the physical environment in the new urban-rural landscape? Global market economy and the withdrawal of public authority create a situation where urban development is increasingly influenced by fluctuations on the real estate market and where buildings are considered more in respect...
International Nuclear Information System (INIS)
Aurich, D.; Brocks, W.; Noack, D.; Veith, H.
1981-01-01
From a three-dimensional elastic-plastic stress-distortion analysis according to the finite element method (FEM) for a straight inner edge crack at room temperature in a nozzle of the intermediate vessel ZB 2 made of 22 NiMoCr 37 steel, the results obtained for stresses and strains in the ligament before the crack front, the crack opening profile, and the propagation of the plastic zone as a function of internal pressure until through-plastifying of the ligament are shown and explained. (orig.) [de
Energy Technology Data Exchange (ETDEWEB)
Wang, Yaqi; Rabiti, Cristian; Palmiotti, Giuseppe, E-mail: yaqi.wang@inl.gov, E-mail: cristian.rabiti@inl.gov, E-mail: giuseppe.palmiotti@inl.gov [Idaho National Laboratory, Idaho Falls, ID (United States)
2011-07-01
This paper proposes a new set of Krylov solvers, CG and GMRes, as an alternative of the Red-Black (RB) algorithm on on solving the steady-state one-speed neutron transport equation discretized with PN in angle and hybrid FEM (Finite Element Method) in space. A pre conditioner with the low-order RB iteration is designed to improve their convergence. These Krylov solvers can reduce the cost of pre-assembling the response matrices greatly. Numerical results with the INSTANT code are presented in order to show that they can be a good supplement on solving the PN-HFEM system. (author)
International Nuclear Information System (INIS)
Wang, Yaqi; Rabiti, Cristian; Palmiotti, Giuseppe
2011-01-01
This paper proposes a new set of Krylov solvers, CG and GMRes, as an alternative of the Red-Black (RB) algorithm on on solving the steady-state one-speed neutron transport equation discretized with PN in angle and hybrid FEM (Finite Element Method) in space. A pre conditioner with the low-order RB iteration is designed to improve their convergence. These Krylov solvers can reduce the cost of pre-assembling the response matrices greatly. Numerical results with the INSTANT code are presented in order to show that they can be a good supplement on solving the PN-HFEM system. (author)
Digitaalallkirja seadus saab sisu / Aare Reivart
Reivart, Aare, 1968-
2000-01-01
Sideoperaatorid ja pangad hakkavad välja töötama ühtset avalikku võtme infrastruktuuri (PKI), mis võimaldab telefoni ja interneti vahendusel kasutada mitmesuguseid teenuseid kiiresti ja turvaliselt
Poeetilisest mõõtmest / Aare Pilv
Pilv, Aare, 1976-
2016-01-01
Luule tõlkimisest, selgitades mõistet "poeetiline mõõde". Artikli teises pooles käsitletakse ka sama keeleruumi klassikaliste luuletuste tõlkimist tänapäeva keelde, kasutades Aleksandr Puškini luuletuse "A. P. Kernile" näidet
Avariide kiuste Monte Carlosse / Aare Arula
Arula, Aare
2007-01-01
Vt. ka Tehnika dlja Vsehh nr. 3, lk. 26-27. 26. jaanuaril 1937 Tallinnast Monte Carlo tähesõidule startinud Karl Siitanit ja tema meeskonda ootasid ees seiklused, mis oleksid neile peaaegu elu maksnud
Kõik algas tinapanekuga saunas / Aare Ermel
Ermel, Aare, 1957-2013
2007-01-01
Eldar Rjazanov ja tema aastavahetuse menufilmid. "Saatuse iroonia ehk Hüva leili!" (1975) järjefilm "Saatuse iroonia: lugu läheb edasi" ("Ironija sudbõ. Prodolzhenije") : režissöör Timur Bekmambetov : Venemaa 2007
Saaremaa Fond turgutab õppureid / Aare Laine
Laine, Aare, 1951-
2012-01-01
Saaremaa Fond andis kõrgkoolides häid õpitulemusi näidanud ja pere kõrvalt õppivatele tudengitele üle aastastipendiumid. Õppiva pere stipendium: Viljandi kultuuriakadeemias rahvuslikku käsitööd õppiv Alliki Oidekivi, Tallinna ülikoolis 2. kursusel kutsepedagoogikat õppiv Ahti Paju ning Tallinna ülikoolis magistriõppes haridustehnoloogiat õppiv Irena Sink. Peeter Palu nimeline stipendium: Eesti mereakadeemia tüürimehe eriala 2. kursuse tudengile Ott Kuusele. Tallinna Sadama nimelise stipendium: mereakadeemias tüürimehe eriala õppiv Dmitri Mišin
Avastamata aare - Soomaa / Merle Adams, Rait Parts
Adams, Merle
2009-01-01
Euroopa Komisjoni algatatud rahvusvahelisest projektist EDEN "European Tourist Destinations of Exellence" ning selle raames toimunud Euroopa kontekstis loodusturismi sihtkohtade konkursi "European Destinations of Exellence" Eesti 2009. aasta sihtkoha tiitli võitnud Soomaa rahvuspargist
Pictures of fear and horror / Aare Pilv
Pilv, Aare, 1976-
2009-01-01
Autor lapsena unes hirmu põhjustanud piltidest. Ants Laikmaa pastellmaalist "Marie Underi portree (1904), selle sarnasusest Edvard Munchi kujutatud naistega ("Angstgefühl", 1896). Jüri Arraku illustratsioonist "Vanapagan" lasteraamatule "Suur Tõll" (1982). Otsa vaatavatest portreedest (Leonardo da Vinci "Mona Lisa")
Retrofilm kultusõudukast / Aare Ermel
Ermel, Aare, 1957-2013
2004-01-01
Mängufilm "Vampiiri vari" ("The Shadow of the Vampire") : režissöör E. Elias Merhige : Ameerika Ühendriigid - Suurbritannia 2000. Inspireerituna samast F.W. Murnau õudusfilmist "Nosferatu, õuduste sümfoonia" (1922), oli ka Werner Herzog loonud 1978.a. filmi "Nosferatu - öö fantoom"
Poola teadlane uurib kraatrit / Aare Laine
Laine, Aare, 1951-
2004-01-01
Poznani ülikooli geoloogiainstituudi direktor Wojciech Stankowaki koos tudengitega võtab pinnaseproove edasiseks uurimiseks. Kahe riigi koostöö toimub mõlema riigi teaduste akadeemia ühisprogrammi "Eesti ja Poola meteoriidikraatrite võrdlev uurimine" alusel
Karl Kello - elukutse olla saarlane / Aare Laine
Laine, Aare, 1951-
2004-01-01
Kuressaare Kuursaalis näidati kadripäeval nelja Ruta Celma ja Karl Kello kultuuriloolist dokumentaalfilmi : "Narr Jumala kojas" (2000), "Phaetonit otsides" (1999), "Eestlased Lätis" (2004) ja Kalevipoja temaatikat arendav "Küll siis Kalev..." (2004). Filmide operaator on Arvo Vilu. Artikli autor kõneleb Karl Kellost, tema Karja kiriku ja Kaali järve problemaatika arendustest peale filmide ka kirjasõnas
Silmatagusest teatrist / Sirle Põdersoo, Aare Pilv
Põdersoo, Sirle
2003-01-01
J. Tombergi ja Andreas W "Aurora temporalis" H. Toompere jun lavastuses Tartu Sadamateatris, Lendava Hollandlase ja Tartu Teatrilabori projekt ning "Maja Jaama uulitsas" M. Heinsaare juttude põhjal Tartu Teatrilaboris, projektijuht J. Jaanus, lavastus ja tants T. Mölder, H. Reitsnik, K. Essenson, E. Ülevain, M. Plakso, A. Vamper
Kivisildnik versus Under : lausuvad subjektid / Aare Pilv
Pilv, Aare, 1976-
2016-01-01
Sven Kivisildniku tekstidest, eriti "Märg Viktor" ja seal leiduvast intertekstuaalsusest. Artikli aluseks on 18.-19. apr. 1997 Otepääl TÜ ja TPÜ kirjandustudengite ja -magistrantide konverentsil 'Vaade sillalt' peetud ettekanne
Lugu, milles puuduvad kangelased / Aare Ermel
Ermel, Aare, 1957-2013
2001-01-01
W.M. Thackeray (1811-1863) romaani "Edevuse laat" ekraniseeringutest. Lähemalt Suurbritannias 1998. aastal valminud 6-osalisest teleseriaalist ja selle kesksetest osatäitjatest. Ka : Teleleht nr. 6, lk. 36-38
Ise kaklevad, ise lepivad / Aare Ermel
Ermel, Aare, 1957-2013
2001-01-01
Mängufilm "Kes kardab Virginia Woolfi?" ("Who's Afraid Of Virginia Woolf?") : stsenarist Ernest Lehman Edward Albee näidendi järgi : režissöör Mike Nichols : Ameerika Ühendriigid 1966. Ka : Teleleht nr. 11, lk.4
Huvitavaid kohtulahendeid kindlustusasjades / Aare-Matti Inglist
Inglist, Aare-Matti
2007-01-01
Kindlustushüvitise määramisest tules hävinud elumaja ja koduse vara näitel (Riigikohtu lahendid 3-2-1-155-05 ja 3-21-1-155-06) ning lepinguvälise kahju hüvitamisest liiklusõnnetusjuhtumi näitel (Riigikohtu lahend 3-2-1-81-04)
International Nuclear Information System (INIS)
Ju, D Y; Han, B
2015-01-01
In this paper, in order to approach this problem, specimens of pure titanium were treated with WCP, and the subsequent changes in microstructure, residual stress, and surface morphologies were investigated as a function of WCP duration. The influence of water cavitation peening (WCP) treatment on the microstructure of pure titanium was investigated. A novel combined finite element and dislocation density method (FEM/DDM), proposed for predicting macro and micro residual stresses induced on the material subsurface treated with water cavitation peening, is also presented. A bilinear elastic-plastic finite element method was conducted to predict macro-residual stresses and a dislocation density method was conducted to predict micro-residual stresses. These approaches made possible the prediction of the magnitude and depth of residual stress fields in pure titanium. The effect of applied impact pressures on the residual stresses was also presented. The results of the FEM/DDM modeling were in good agreement with those of the experimental measurements. (paper)
Directory of Open Access Journals (Sweden)
Collalti A
2017-08-01
Full Text Available Simulation, calibration and validation protocols for the model 3D-CMCC-CNR-FEM: a case study in the Bonis’ watershed (Calabria, Italy. At present, the climate changes issue is perhaps the greatest threat that is affecting people and the environment. Forest ecosystems have a key role in the mitigation of climate change. In this context, the prediction of the evolution and growth dynamics of the forests including carbon and water fluxes, and in relation to forest management has become a primary objective. The present study aims at defining a protocol for data collection and the workflow for using the 3D-CMCC-CNR-FEM model in a small mountain watershed in the Calabria region. Within this work we synergistically integrate data coming from different methods (e.g., LiDAR, eddy covariance and sample area to predict forest dynamics (growth, carbon and water fluxes. Carbon and water fluxes will be simulated considering also the effects of forest management.
Huan, Huiting; Mandelis, Andreas; Liu, Lixian
2018-04-01
Determining and keeping track of a material's mechanical performance is very important for safety in the aerospace industry. The mechanical strength of alloy materials is precisely quantified in terms of its stress-strain relation. It has been proven that frequency-domain photothermoacoustic (FD-PTA) techniques are effective methods for characterizing the stress-strain relation of metallic alloys. PTA methodologies include photothermal (PT) diffusion and laser thermoelastic photoacoustic ultrasound (PAUS) generation which must be separately discussed because the relevant frequency ranges and signal detection principles are widely different. In this paper, a detailed theoretical analysis of the connection between thermoelastic parameters and stress/strain tensor is presented with respect to FD-PTA nondestructive testing. Based on the theoretical model, a finite element method (FEM) was further implemented to simulate the PT and PAUS signals at very different frequency ranges as an important analysis tool of experimental data. The change in the stress-strain relation has an impact on both thermal and elastic properties, verified by FEM and results/signals from both PT and PAUS experiments.
Wetter, Oliver; Tuttenuj, Daniel
2016-04-01
systematically analysed the period from 1446-1542 and could prove a large number of pre-instrumental flood events of river Rhine, Birs, Birsig and Wiese in Basel. All in all the weekly led account books contained 54 Rhine flood events, whereas chroniclers and annalists only recorded seven floods during the same period. This is a ratio of almost eight to one. This large difference points to the significantly sharper "observation skills" of the account books towards smaller floods, which may be explained by the fact that bridges can be endangered by relatively small floods because of driftwood, whereas it is known that chroniclers or annalists were predominantly focussing on spectacular (extreme) flood events. We [Oliver Wetter and Daniel Tuttenuj] are now able to present first preliminary results of reconstructed peak water levels and peak discharges of pre instrumental river Aare-, Emme-, Limmat-, Reuss-, Rhine- and Saane floods. These first results clearly show the strengths as well as the limits of the data and method used, depending mainly on the river types. Of the above mentioned rivers only the floods of river Emme could not be reconstructed whereas the long-term development of peak water levels and peak discharges of the other rivers clearly correlate with major local and supra-regional Swiss flood corrections over time. PhD student Daniel Tuttenuj is going to present the results for river Emme and Saane (see Abstract Daniel Tuttenuj), whereas Dr Oliver Wetter is going to present the results for the other rivers and gives a first insight on long-term recurring periods of smaller river Birs-, Birsig-, Rhine- and Wiese flood events based on the analysis of the weekly led account books "Wochenausgabenbücher der Stadt Basel" (see also Abstract of Daniel Tuttenuj).
Tuttenuj, Daniel; Wetter, Oliver
2016-04-01
contained 54 Rhine flood events, whereas chroniclers and annalists only recorded seven floods during the same period. This is a ratio of almost eight to one. This large difference points to the significantly sharper "observation skills" of the account books towards smaller floods, which may be explained by the fact that bridges can be endangered by relatively small floods because of driftwood, whereas it is known that chroniclers or annalists were predominantly focussing on spectacular (extreme) flood events. We [Oliver Wetter and Daniel Tuttenuj] are now able to present first preliminary results of reconstructed peak water levels and peak discharges of pre instrumental river Aare-, Emme-, Limmat-, Reuss-, Rhine- and Saane floods. These first results clearly show the strengths as well as the limits of the data and method used, depending mainly on the river types. Of the above mentioned rivers only the floods of river Emme could not be reconstructed whereas the long-term development of peak water levels and peak discharges of the other rivers clearly correlate with major local and supra-regional Swiss flood corrections over time. PhD student Daniel Tuttenuj is going to present the results of river Emme and Saane, whereas Dr Oliver Wetter is going to present the results for the other rivers and gives a first insight on long-term recurring periods of smaller river Birs, Birsig, Rhine and Wiese flood events based on the analysis of the weekly led account books "Wochenausgabenbücher der Stadt Basel" (see Abstract Oliver Wetter).
Energy Technology Data Exchange (ETDEWEB)
Lindstroem, E A; Bremnes, T; Johansen, S W
1994-12-31
Regulation of river courses may have several environmental effects. This report describes investigations in NIVA`s experimental troughs near Oset, Maridalsvannet, Oslo, Norway. The main topic is algae periphyton and benthic invertebrates, with different emphasis on the different components. In 1989 the problem of ``the impact of benthic invertebrates on algae periphyton`` was illuminated, and In 1990 the converse, ``the impact of algae periphyton on benthic invertebrates`` as well as the effects of various additives of readily available phosphorus on algae periphyton. It is found that small additions of phosphorus (0.5 {mu}g P/l) may lay the foundation for a dramatic increase in growth rate and biomass. Some groups of benthic invertebrates responded quickly to the increased mass of algae. In 1991 the research was concentrated on establishing algae periphyton over a long time, at various temperatures, with and without the addition of phosphorus. The results of three years of research form, with similar results from the literature, the foundation of certain conclusions about the conditions for the establishment of algae mass in running water. The report states five levels of phosphorus concentration which may develop different levels of biomass. At the highest levels the size of the biomass is described as ``problematic``. 100 refs., 55 figs., 97 tabs.
Energy Technology Data Exchange (ETDEWEB)
Steinnes, Eiliv; Berg, Torunn; Uggerud, Hilde Thelle; Pfaffhuber, Katrine Aspmo
2011-07-01
The geographical distribution of atmospheric deposition of heavy metals in Norway was mapped in 2010 by analysis of moss samples from 464 sites all over the country. This report provides a presentation of the results and a comparison with data from a series of corresponding moss surveys starting 1977. The survey is part of an international program comprising large parts of Europe. The survey primarily concerns the ten metals of priority in the European program: vanadium, chromium, iron, nickel, copper, zinc, arsenic, cadmium, mercury, and lead. In addition data are reported for another 42 elements in the moss. The discussion of the obtained data mainly refers to contributions from air pollution. In addition influence from natural processes to the elemental composition of the moss and how it may influence the interpretation of the data is discussed. (Author)
Ronchin, Erika; Masterlark, Timothy; Dawson, John; Saunders, Steve; Martì Molist, Joan
2017-06-01
We test an innovative inversion scheme using Green's functions from an array of pressure sources embedded in finite-element method (FEM) models to image, without assuming an a-priori geometry, the composite and complex shape of a volcano deformation source. We invert interferometric synthetic aperture radar (InSAR) data to estimate the pressurization and shape of the magma reservoir of Rabaul caldera, Papua New Guinea. The results image the extended shallow magmatic system responsible for a broad and long-term subsidence of the caldera between 2007 February and 2010 December. Elastic FEM solutions are integrated into the regularized linear inversion of InSAR data of volcano surface displacements in order to obtain a 3-D image of the source of deformation. The Green's function matrix is constructed from a library of forward line-of-sight displacement solutions for a grid of cubic elementary deformation sources. Each source is sequentially generated by removing the corresponding cubic elements from a common meshed domain and simulating the injection of a fluid mass flux into the cavity, which results in a pressurization and volumetric change of the fluid-filled cavity. The use of a single mesh for the generation of all FEM models avoids the computationally expensive process of non-linear inversion and remeshing a variable geometry domain. Without assuming an a-priori source geometry other than the configuration of the 3-D grid that generates the library of Green's functions, the geodetic data dictate the geometry of the magma reservoir as a 3-D distribution of pressure (or flux of magma) within the source array. The inversion of InSAR data of Rabaul caldera shows a distribution of interconnected sources forming an amorphous, shallow magmatic system elongated under two opposite sides of the caldera. The marginal areas at the sides of the imaged magmatic system are the possible feeding reservoirs of the ongoing Tavurvur volcano eruption of andesitic products on the
Directory of Open Access Journals (Sweden)
Srinivasa Raju R.
2016-01-01
Full Text Available In this research paper, we found both numerical and analytical solutions for the effect of chemical reaction on unsteady, incompressible, viscous fluid flow past an exponentially accelerated vertical plate with heat absorption and variable temperature in a magnetic field. The flow problem is governed by a system of coupled non-linear partial differential equations with suitable boundary conditions. We have solved the governing equations by an efficient, accurate, powerful finite element method (FEM as well as Laplace transform technique (LTT. The evaluation of the numerical results are performed and graphical results for the velocity, temperature and concentration profiles within the boundary layer are discussed. Also, the expressions for the skin-friction, Nusselt number and the Sherwood number coefficients have been derived and discussed through graphs and tabular forms for different values of the governing parameters.
Yanamadala, J; Noetscher, G M; Makarov, S N; Pascual-Leone, A
2017-07-01
Transcranial magnetic stimulation (TMS) for treatment of depression during pregnancy is an appealing alternative to fetus-threatening drugs. However, no studies to date have been performed that evaluate the safety of TMS for a pregnant mother patient and her fetus. A full-body FEM model of a pregnant woman with about 100 tissue parts has been developed specifically for the present study. This model allows accurate computations of induced electric field in every tissue given different locations of a shape-eight coil, a biphasic pulse, common TMS pulse durations, and using different values of the TMS intensity measured in SMT (Standard Motor Threshold) units. Our simulation results estimate the maximum peak values of the electric field in the fetal area for every fetal tissue separately and for the TMS intensity of one SMT unit.
Dodig, H.
2017-11-01
This contribution presents the boundary integral formulation for numerical computation of time-harmonic radar cross section for 3D targets. Method relies on hybrid edge element BEM/FEM to compute near field edge element coefficients that are associated with near electric and magnetic fields at the boundary of the computational domain. Special boundary integral formulation is presented that computes radar cross section directly from these edge element coefficients. Consequently, there is no need for near-to-far field transformation (NTFFT) which is common step in RCS computations. By the end of the paper it is demonstrated that the formulation yields accurate results for canonical models such as spheres, cubes, cones and pyramids. Method has demonstrated accuracy even in the case of dielectrically coated PEC sphere at interior resonance frequency which is common problem for computational electromagnetic codes.
Sandström, Carolina; Eriksson, Sofie
2011-01-01
Denna uppsats behandlar förändring av förpackning som en möjlig utökning av produktkategorin i Kotler & Kellers utvidgade marknadsmix. I marknadsmixen behandlas förpackningen som statisk under en varas livstid och studiens syfte var att se om förpackningsförändringar istället bör ske vid flertalet tillfällen. Genom existerande litteratur identifierades tre centrala begrepp som ansågs betydelsefulla för studien; förpackning, förändring av förpackning och differentiering. Fem olika företag ...
Energy Technology Data Exchange (ETDEWEB)
Conde, J.C.; Chiussi, S.; Gontad, F.; Gonzalez, P. [Dpto. Fisica Aplicada, E.T.S.I.I. University of Vigo, Campus Universitario, Rua Maxwell s/n, 36310 Vigo (Spain); Martin, E. [Dpto. de Mecanica, Maquinas, Motores Termicos y Fluidos, E.T.S.I.I. University of Vigo, Campus Universitario, Rua Maxwell s/n, 36310 Vigo (Spain)
2011-03-15
Research on epitaxial crystalline silicon (c-Si) and silicon-germanium (Si{sub 1-x}Ge{sub x}) alloys growth and annealing for microelectronic purposes, such as Micro- or Nano-Electro-Mechanical Systems (MEMS or NEMS) and Silicon-On-Nothing (SON) devices is continuously in progress. Laser assisted annealing techniques using commercial ArF Excimer Laser sources are based on ultra-rapid heating and cooling cycles induced by the 193 nm pulses of 20 ns, which are absorbed in the near surface region of the heterostructures. During and after the absorption of these laser pulses, complex physical processes appear that strongly depend on sample structure and applied laser pulse energy densities. The control of the experimental parameters is therefore a key task for obtaining high quality alloys. The Finite ElementsMethod (FEM) is a powerful tool for the optimization of such treatments, because it provides the spatial and temporal temperature fields that are produced by the laser pulses. In this work, we have used a FEM commercial software, to predict the temperatures gradients induced by ArF excimer laser over a wide energy densities range, 0.1<{phi}<0.4 J/cm{sup 2}, on different SiO{sub 2}/Si/Si{sub (1-x)}Ge{sub (x)} thin films deposited on SOI substrate. These numerical results allow us to predict the threshold energies needed to reach the melting point (MP) of the Si and SiGe alloy without oxidation of the thin films system. Therefore, it is possible to optimize the conditions to achieve high quality epitaxy films. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
DVD. Aare Ermel tutvustab : "Rome : The Complete First Season" / Aare Ermel
Ermel, Aare, 1957-2013
2006-01-01
6 DVD-na on saadaval 12-osaline ajalooline kostüümidraama - seriaal Rooma impeeriumi ajast "Rooma" ("Rome"), mille tootsid aastail 2005-2006 Ameerika tootja Home Box Office (HBO) ja inglaste BBC. Levitab Home Box Office, Inc
DVD. Aare Ermel soovitab "Meie isade lipud", "Kirjad Iwo Jimalt" / Aare Ermel
Ermel, Aare, 1957-2013
2007-01-01
Clint Eastwoodi kaks filmi on Teises Maailmasõjas USA-Jaapani Iwo Jima saarel peetud lahingu teemal. USA poolt vaadatuna - "Meie isade lipud" ("Flags of Our Fathers"), Jaapani poolt - "Kirjad Iwo Jimalt" ("Letters From Iwo Jima") : Ameerika Ühendriigid 2006
Energy Technology Data Exchange (ETDEWEB)
Conde, J.C., E-mail: jconde@uvigo.es [Dpto. Fisica Aplicada, Universidade de Vigo, Rua Maxwell s/n, Campus Universitario Lagoas Marcosende, Vigo (Spain); Martin, E. [Dpto. Mecanica, Maquinas, Motores Termicos y Fluidos, Universidade de Vigo, Rua Maxwell s/n, Campus Universitario Lagoas Marcosende, Vigo (Spain); Stefanov, S. [Dpto. Fisica Aplicada, Universidade de Vigo, Rua Maxwell s/n, Campus Universitario Lagoas Marcosende, Vigo (Spain); Alpuim, P. [Departamento de Fisica, Universidade do Minho, 4800-058 Guimaraes (Portugal); Chiussi, S. [Dpto. Fisica Aplicada, Universidade de Vigo, Rua Maxwell s/n, Campus Universitario Lagoas Marcosende, Vigo (Spain)
2012-09-15
Highlights: Black-Right-Pointing-Pointer nc-Si:H is a material with growing importance for a large-area of nano-electronic, photovoltaic or biomedical devices. Black-Right-Pointing-Pointer UV-ELA technique causes a rapid heating that provokes the H{sub 2} desorption from the Si surface and bulk material. Black-Right-Pointing-Pointer Next, diffusion of P doped nc-Si films and eventually, for high energy densities would be possible to reach the melting point. Black-Right-Pointing-Pointer These multilayer structures consisting of thin alternating a-Si:H(10 nm) and n-doped nc-Si:H(60 nm) films deposited on SiO{sub 2}. Black-Right-Pointing-Pointer To optimize parameters involved in this processing, FEM numerical analysis of multilayer structures have been performed. Black-Right-Pointing-Pointer The numerical results are compared with exhaustive characterization of the experimental results. - Abstract: UV excimer laser annealing (UV-ELA) is an alternative annealing process that, during the last few years, has gained enormous importance for the CMOS nano-electronic technologies, with the ability to provide films and alloys with electrical and optical properties to fit the desired device performance. The UV-ELA of amorphous (a-) and/or doped nano-crystalline (nc-) silicon films is based on the rapid (nanoseconds) formation of temperature profiles caused by laser radiation that is absorbed in the material and lead to crystallisation, diffusion in solid or even in liquid phase. To achieve the desired temperature profiles and to optimize the parameters involved in the processing of hydrogenated nanocrystalline silicon (nc-Si:H) films with the UV-ELA, a numerical analysis by finite element method (FEM) of a multilayer structure has been performed. The multilayer structures, consisting of thin alternating a-Si:H(10 nm) and n-doped nc-Si:H(60 nm) layers, deposited on a glass substrate, has also been experimentally analyzed. Temperature profiles caused by 193 nm radiation with 25
International Nuclear Information System (INIS)
Conde, J.C.; Martín, E.; Stefanov, S.; Alpuim, P.; Chiussi, S.
2012-01-01
Highlights: ► nc-Si:H is a material with growing importance for a large-area of nano-electronic, photovoltaic or biomedical devices. ► UV-ELA technique causes a rapid heating that provokes the H 2 desorption from the Si surface and bulk material. ► Next, diffusion of P doped nc-Si films and eventually, for high energy densities would be possible to reach the melting point. ► These multilayer structures consisting of thin alternating a-Si:H(10 nm) and n-doped nc-Si:H(60 nm) films deposited on SiO 2 . ► To optimize parameters involved in this processing, FEM numerical analysis of multilayer structures have been performed. ► The numerical results are compared with exhaustive characterization of the experimental results. - Abstract: UV excimer laser annealing (UV-ELA) is an alternative annealing process that, during the last few years, has gained enormous importance for the CMOS nano-electronic technologies, with the ability to provide films and alloys with electrical and optical properties to fit the desired device performance. The UV-ELA of amorphous (a-) and/or doped nano-crystalline (nc-) silicon films is based on the rapid (nanoseconds) formation of temperature profiles caused by laser radiation that is absorbed in the material and lead to crystallisation, diffusion in solid or even in liquid phase. To achieve the desired temperature profiles and to optimize the parameters involved in the processing of hydrogenated nanocrystalline silicon (nc-Si:H) films with the UV-ELA, a numerical analysis by finite element method (FEM) of a multilayer structure has been performed. The multilayer structures, consisting of thin alternating a-Si:H(10 nm) and n-doped nc-Si:H(60 nm) layers, deposited on a glass substrate, has also been experimentally analyzed. Temperature profiles caused by 193 nm radiation with 25 ns pulse length and energy densities ranging from 50 mJ/cm 2 to 400 mJ/cm 2 have been calculated. Numerical results allowed us to estimate the dehydrogenation
López Campos, José Ángel; Segade Robleda, Abraham; Vilán Vilán, José Antonio; García Nieto, Paulino José; Blanco Cordero, Javier
2015-01-01
Current knowledge of the behavior of heavy quadricycles under impact is still very poor. One of the most significant causes is the lack of energy absorption in the vehicle frame or its steel chassis structure. For this reason, special steels (with yield stresses equal to or greater than 350 MPa) are commonly used in the automotive industry due to their great strain hardening properties along the plastic zone, which allows good energy absorption under impact. This paper presents a proposal for a steel quadricycle energy absorption system which meets the percentages of energy absorption for conventional vehicles systems. This proposal is validated by explicit dynamics simulation, which will define the whole problem mathematically and verify behavior under impact at speeds of 40 km/h and 56 km/h using the finite element method (FEM). One of the main consequences of this study is that this FEM–based methodology can tackle high nonlinear problems like this one with success, avoiding the need to carry out experimental tests, with consequent economical savings since experimental tests are very expensive. Finally, the conclusions from this innovative research work are given. PMID:28793607
Directory of Open Access Journals (Sweden)
José Ángel López Campos
2015-10-01
Full Text Available Current knowledge of the behavior of heavy quadricycles under impact is still very poor. One of the most significant causes is the lack of energy absorption in the vehicle frame or its steel chassis structure. For this reason, special steels (with yield stresses equal to or greater than 350 MPa are commonly used in the automotive industry due to their great strain hardening properties along the plastic zone, which allows good energy absorption under impact. This paper presents a proposal for a steel quadricycle energy absorption system which meets the percentages of energy absorption for conventional vehicles systems. This proposal is validated by explicit dynamics simulation, which will define the whole problem mathematically and verify behavior under impact at speeds of 40 km/h and 56 km/h using the finite element method (FEM. One of the main consequences of this study is that this FEM–based methodology can tackle high nonlinear problems like this one with success, avoiding the need to carry out experimental tests, with consequent economical savings since experimental tests are very expensive. Finally, the conclusions from this innovative research work are given.
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyonam; Namgung, Ihn [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)
2014-10-15
For the stabilization of the RPV the in-vessel retention strategy with external reactor vessel cooling (IVR-ERVC) is adopted in APR1400. Under this severe accident condition, a good understanding of the mechanical behavior of the reactor vessel lower head (RVLH) is necessary both for verification of structural integrity and for improving the design applying appropriate accident mitigation strategies. The purpose of this study is to develop the analysis method of the RVLH with thermo-mechanical analysis using FEM tool (ANSYS v.15) in case of core-melting severe accident condition, and then analyze the RVLH of APR1400 including creep behavior. The plastic strain can be the major cause of lower head failure on the reactor vessel, and the creep cannot be not negligible factor of the failure under the severe accident condition. In the study, we applied constant convection coefficient at assumed temperature on the outside wall of RPV and substitute creep data of SA-508. In addition, it was found that the steel ablation at the interface between corium and vessel steel is not only a thermal phenomenon in the METCOR experiments. Corrosion processes and the formation of eutectics lead to the erosion of the vessel steel at temperatures that are significantly lower than the melting temperature of steel. It called thermo-chemical attack of the corium (corrosion). Reduced wall thickness because of the thermo-chemical effect by corium increase the equivalent plastic strain, and decrease the minimum time to reach 20% creep strain.
Directory of Open Access Journals (Sweden)
Muhammad Zubair Aslam
2018-05-01
Full Text Available A Finite Element Method (FEM simulation study is conducted, aiming to scrutinize the sensitivity of Sezawa wave mode in a multilayer AlN/SiO2/Si Surface Acoustic Wave (SAW sensor to low concentrations of Volatile Organic Compounds (VOCs, that is, trichloromethane, trichloroethylene, carbon tetrachloride and tetrachloroethene. A Complimentary Metal-Oxide Semiconductor (CMOS compatible AlN/SiO2/Si based multilayer SAW resonator structure is taken into account for this purpose. In this study, first, the influence of AlN and SiO2 layers’ thicknesses over phase velocities and electromechanical coupling coefficients (k2 of two SAW modes (i.e., Rayleigh and Sezawa is analyzed and the optimal thicknesses of AlN and SiO2 layers are opted for best propagation characteristics. Next, the study is further extended to analyze the mass loading effect on resonance frequencies of SAW modes by coating a thin Polyisobutylene (PIB polymer film over the AlN surface. Finally, the sensitivity of the two SAW modes is examined for VOCs. This study concluded that the sensitivity of Sezawa wave mode for 1 ppm of selected volatile organic gases is twice that of the Rayleigh wave mode.
International Nuclear Information System (INIS)
West, O.R.; Toran, L.E.
1994-04-01
Modeling the movement of hazardous waste in groundwater was identified by the US Department of Energy (DOE) as one of the grand challenges in scientific computation. In recognition of this need, DOE has provided support for a group of scientists from several national laboratories and universities to conduct research and development in groundwater flow and contaminant transport modeling. This group is part of a larger consortium of researchers, collectively referred to as the Partnership in Computational Science (PICS), that has been charged with the task of applying high-performance computational tools and techniques to grand challenge areas identified by DOE. One of the goals of the PICS Groundwater Group is to develop a new three-dimensional groundwater flow and transport code that is optimized for massively parallel computers. An existing groundwater flow code, 3DFEMWATER, was parallelized in order to serve as a benchmark for these new models. The application of P-FEM, the parallelized version of 3DFEMWATER, to a real field site is the subject of this report
Directory of Open Access Journals (Sweden)
Niklas Karol
2018-03-01
Full Text Available Like other means of transport, merchant ships face the problem of increasing requirements concerning the environment protection, which, among other issues, implies the reduction of fuel consumption by the ship. Here, the conventional approach which consists in making use of higher strength steels to decrease the mass of the ship hull can be complemented by the use of new steel structures of sandwich panel type. However, the lack of knowledge and experience concerning, among other issues, fatigue strength assessment of thin-walled sandwich structures makes their use limited. Untypical welds imply the need for individual approach to the fatigue analysis. The article presents the effect of numerical FEM modelling with the aid of two-dimensional (2D and three-dimensional (3D elements on the results of strain and stress distributions in the areas of toe and root notches of the analysed laser weld. The presented results of computer simulation reveal that modelling of strain and stress states in 2D (instead of full 3D affects only the results in close vicinity of the notch, and the observed differences rapidly disappear at a distance of 0.05 mm from the bottom of the notch. The obtained results confirm the possibility of use of numerically effective 2D strain and stress state models for analysing the fatigue strength of laser weld according to local approach.
Directory of Open Access Journals (Sweden)
Yu-Jun Zhang
2012-01-01
Full Text Available The models of stress corrosion and pressure solution established by Yasuhara et al. were introduced into the 2D FEM code of thermo-hydro-mechanical-migratory coupling analysis for dual-porosity medium developed by the authors. Aiming at a hypothetical model for geological disposal of nuclear waste in an unsaturated rock mass from which there is a nuclide leak, two computation conditions were designed. Then the corresponding two-dimensional numerical simulation for the coupled thermo-hydro-mechanical-migratory processes were carried out, and the states of temperatures, rates and magnitudes of aperture closure, pore and fracture pressures, flow velocities, nuclide concentrations and stresses in the rock mass were investigated. The results show: the aperture closure rates caused by stress corrosion are almost six orders higher than those caused by pressure solution, and the two kinds of closure rates climb up and then decline, furthermore tend towards stability; when the effects of stress corrosion and pressure solution are considered, the negative fracture pressures in near field rise very highly; the fracture aperture and porosity are decreases in the case 1, so the relative permeability coefficients reduce, therefore the nuclide concentrations in pore and fracture in this case are higher than those in case 2.
Rossi, Francesca; Zingoni, Tiziano; Di Cicco, Emiliano; Manetti, Leonardo; Pini, Roberto; Fortuna, Damiano
2011-07-01
Laser light is nowadays routinely used in the aesthetic treatments of facial skin, such as in laser rejuvenation, scar removal etc. The induced thermal damage may be varied by setting different laser parameters, in order to obtain a particular aesthetic result. In this work, it is proposed a theoretical study on the induced thermal damage in the deep tissue, by considering different laser pulse duration. The study is based on the Finite Element Method (FEM): a bidimensional model of the facial skin is depicted in axial symmetry, considering the different skin structures and their different optical and thermal parameters; the conversion of laser light into thermal energy is modeled by the bio-heat equation. The light source is a CO2 laser, with different pulse durations. The model enabled to study the thermal damage induced into the skin, by calculating the Arrhenius integral. The post-processing results enabled to study in space and time the temperature dynamics induced in the facial skin, to study the eventual cumulative effects of subsequent laser pulses and to optimize the procedure for applications in dermatological surgery. The calculated data where then validated in an experimental measurement session, performed in a sheep animal model. Histological analyses were performed on the treated tissues, evidencing the spatial distribution and the entity of the thermal damage in the collageneous tissue. Modeling and experimental results were in good agreement, and they were used to design a new optimized laser based skin resurfacing procedure.
Energy Technology Data Exchange (ETDEWEB)
West, O.R.; Toran, L.E.
1994-04-01
Modeling the movement of hazardous waste in groundwater was identified by the US Department of Energy (DOE) as one of the grand challenges in scientific computation. In recognition of this need, DOE has provided support for a group of scientists from several national laboratories and universities to conduct research and development in groundwater flow and contaminant transport modeling. This group is part of a larger consortium of researchers, collectively referred to as the Partnership in Computational Science (PICS), that has been charged with the task of applying high-performance computational tools and techniques to grand challenge areas identified by DOE. One of the goals of the PICS Groundwater Group is to develop a new three-dimensional groundwater flow and transport code that is optimized for massively parallel computers. An existing groundwater flow code, 3DFEMWATER, was parallelized in order to serve as a benchmark for these new models. The application of P-FEM, the parallelized version of 3DFEMWATER, to a real field site is the subject of this report.
Ashimoto, A; Hamada, T; Adachi, A; Tanigawa, T; Tanaka, Y
1995-01-01
Staphylococcus spp. were isolated from the ward environment and antibiotic susceptibility tests were performed. Twenty-nine strains out of 274 isolates were S. aureus, and 41.4% of the S. aureus strains were methicillin resistant (MRSA). All 12 strains of MRSA were also resistant to oxacillin, ceftizoxime, ampicillin and clindamycin. Among the coagulase-negative staphylococci (CNS), methicillin-resistant (MR) strains of S. epidermidis, S. capitis, S. warneri, S. haemolyticus, S. hominis, S. auricularis, S. saprophyticus and S. cohnii were isolated. Eight of the 10 S. Haemolyticus strains were methicillin resistant. The femA gene was detected in S. aureus (MSSA and MRSA), but not in CNS by polymerase chain reaction (PCR) analysis and Southern blot analysis. The mecA gene was found in all the MRSA and MR-S. epidermidis strains tested, and one of the two MR-S. hominis strains, but not in MSSA, MS-S. epidermidis, MS-S. hominis, or MS-S. haemolyticus. DNA from one strain of MR-S. hominis and 2 strains of MR-S. haemolyticus was not amplified by PCR using the mecA gene primer, or hybridized by Southern blotting. The ambiguity that mecA was detected in some MR-CNS strains, but not in others is discussed.
Directory of Open Access Journals (Sweden)
Marcin Krzeszowiec
2015-03-01
Full Text Available Computer simulations of physical phenomena are at the moment common both in science and industry. The possibility of finding approximate solutions for complicated systems of differential equations, mathematically describing issues in the fields of mechanics, physics or chemistry, allows for shorten design and research time, often significantly reducing the need for expensive experimental studies or costly production of prototypes. However, the mentioned prevalence of these methods, particularly the Finite Element Method, resulted in analysis outcomes to be often in advance regarded as accurate ones. The purpose of the article is to showcase, on a simple stress analysis problem, how parameters such as the density of the finite element mesh, finite element formulation or integration scheme significantly influence on the simulation results and how easy it is to end up with the results that do not hold any physical sense, despite the fact that all the basic assumptions of correct analysis (suitable boundary conditions, total system energy stored etc. have been met. The results of this study can serve as a warning against premature conclusion drawing from calculations carried out by means of FEM simulation.[b]Keywords[/b]: computational mechanics, finite element method, shell elements, numerical integration
Ronchin, Erika; Masterlark, Timothy; Dawson, John; Saunders, Steve; Martí Molist, Joan
2015-04-01
In this study, we present a method to fully integrate a family of finite element models (FEMs) into the regularized linear inversion of InSAR data collected at Rabaul caldera (PNG) between February 2007 and December 2010. During this period the caldera experienced a long-term steady subsidence that characterized surface movement both inside the caldera and outside, on its western side. The inversion is based on an array of FEM sources in the sense that the Green's function matrix is a library of forward numerical displacement solutions generated by the sources of an array common to all FEMs. Each entry of the library is the LOS surface displacement generated by injecting a unity mass of fluid, of known density and bulk modulus, into a different source cavity of the array for each FEM. By using FEMs, we are taking advantage of their capability of including topography and heterogeneous distribution of elastic material properties. All FEMs of the family share the same mesh in which only one source is activated at the time by removing the corresponding elements and applying the unity fluid flux. The domain therefore only needs to be discretized once. This precludes remeshing for each activated source, thus reducing computational requirements, often a downside of FEM-based inversions. Without imposing an a-priori source, the method allows us to identify, from a least-squares standpoint, a complex distribution of fluid flux (or change in pressure) with a 3D free geometry within the source array, as dictated by the data. The results of applying the proposed inversion to Rabaul InSAR data show a shallow magmatic system under the caldera made of two interconnected lobes located at the two opposite sides of the caldera. These lobes could be consistent with feeding reservoirs of the ongoing Tavuvur volcano eruption of andesitic products, on the eastern side, and of the past Vulcan volcano eruptions of more evolved materials, on the western side. The interconnection and
International Nuclear Information System (INIS)
Sarajaervi, U.; Cronvall, O.
2007-03-01
Fatigue is produced by cyclic application of stresses by mechanical or thermal loading. The metal subjected to fluctuating stress will fail at stresses much lower than those required to cause fracture in a single application of load. The key parameters are the range of stress variation and the number of its occurrences. Low-cycle fatigue, usually induced by mechanical and thermal loads, is distinguished from high-cycle fatigue, mainly associated with vibration or high number of small thermal fluctuations. Numerical models describing fatigue behaviour of austenitic stainless piping steels under cyclic loading and their applicability for modelling of low-cycle-fatigue are discussed in this report. In order to describe the cyclic behaviour of the material for analysis with finite element method (FEM) based analysis code ABAQUS, the test data, i.e. stress-strain curves, have to be processed. A code to process the data all through the test duration was developed within this study. A description of this code is given also in this report. Input data for ABAQUS was obtained to describe both kinematic and isotropic hardening properties. Further, by combining the result data for various strain amplitudes a mathematic expression was be created which allows defining a parameter surface for cyclic (i.e. isotropic) hardening. Input data for any strain amplitude within the range of minimum and maximum strain amplitudes of the test data can be assessed with the help of the developed 3D stress-strain surface presentation. The modelling of the fatigue induced initiation and growth of cracks was not considered in this study. On the other hand, a considerable part of the fatigue life of nuclear power plant (NPP) piping components is spent in the phase preceding the initiation and growth of cracks. (au)
Corneli, Amy L; McKenna, Kevin; Perry, Brian; Ahmed, Khatija; Agot, Kawango; Malamatsho, Fulufhelo; Skhosana, Joseph; Odhiambo, Jacob; Van Damme, Lut
2015-04-15
FEM-PrEP was unable to determine whether once-daily, oral emtricitabine/tenofovir disoproxil fumarate reduces the risk of HIV acquisition among women because of low adherence. Self-reported adherence was high, and pill-count data suggested good adherence. Yet, drug concentrations revealed limited pill use. We conducted a follow-up study with former participants in Bondo, Kenya, and Pretoria, South Africa, to understand factors that had influenced overreporting of adherence and to learn the whereabouts of unused pills. Qualitative, semistructured interviews were conducted with 88 participants, and quantitative, audio computer-assisted self-interviews were conducted with 224 participants. We used thematic analysis and descriptive statistics to analyze the qualitative and quantitative data, respectively. In audio computer-assisted self-interviews, 31% (n = 70) said they had overreported adherence; the main reason was the belief that nonadherence would result in trial termination (69%, n = 48). A considerable percentage (35%, n = 78) acknowledged discarding unused pills. Few acknowledged giving their pills to someone else (4%, n = 10), and even fewer acknowledged giving them to someone with HIV (2%, n = 5). Many participants in the semistructured interviews said other participants had counted and removed pills from their bottles to appear adherent. Despite repeated messages that nonadherence would not upset staff, participants acknowledged several perceived negative consequences of reporting nonadherence, which made it difficult to report accurately. Uneasiness continued in the follow-up study, as many said they had not overreported during the trial. Efforts to improve self-reported measures should include identifying alternative methods for creating supportive environments that allow participants to feel comfortable reporting actual adherence.
Energy Technology Data Exchange (ETDEWEB)
Sarajaervi, U.; Cronvall, O. [VTT (Finland)
2007-03-15
Fatigue is produced by cyclic application of stresses by mechanical or thermal loading. The metal subjected to fluctuating stress will fail at stresses much lower than those required to cause fracture in a single application of load. The key parameters are the range of stress variation and the number of its occurrences. Low-cycle fatigue, usually induced by mechanical and thermal loads, is distinguished from high-cycle fatigue, mainly associated with vibration or high number of small thermal fluctuations. Numerical models describing fatigue behaviour of austenitic stainless piping steels under cyclic loading and their applicability for modelling of low-cycle-fatigue are discussed in this report. In order to describe the cyclic behaviour of the material for analysis with finite element method (FEM) based analysis code ABAQUS, the test data, i.e. stress-strain curves, have to be processed. A code to process the data all through the test duration was developed within this study. A description of this code is given also in this report. Input data for ABAQUS was obtained to describe both kinematic and isotropic hardening properties. Further, by combining the result data for various strain amplitudes a mathematic expression was be created which allows defining a parameter surface for cyclic (i.e. isotropic) hardening. Input data for any strain amplitude within the range of minimum and maximum strain amplitudes of the test data can be assessed with the help of the developed 3D stress-strain surface presentation. The modelling of the fatigue induced initiation and growth of cracks was not considered in this study. On the other hand, a considerable part of the fatigue life of nuclear power plant (NPP) piping components is spent in the phase preceding the initiation and growth of cracks. (au)
MacGinnis, Matt; Chu, Howard; Youssef, George; Wu, Kimberley W; Machado, Andre Wilson; Moon, Won
2014-08-29
Orthodontic palatal expansion appliances have been widely used with satisfactory and, most often, predictable clinical results. Recently, clinicians have successfully utilized micro-implants with palatal expander designs to work as anchors to the palate to achieve more efficient skeletal expansion and to decrease undesired dental effects. The purpose of the study was to use finite element method (FEM) to determine the stress distribution and displacement within the craniofacial complex when simulated conventional and micro-implant-assisted rapid palatal expansion (MARPE) expansion forces are applied to the maxilla. The simulated stress distribution produced within the palate and maxillary buttresses in addition to the displacement and rotation of the maxilla could then be analyzed to determine if micro-implants aid in skeletal expansion. A three-dimensional (3D) mesh model of the cranium with associated maxillary sutures was developed using computed tomography (CT) images and Mimics modeling software. To compare transverse expansion stresses in rapid palatal expansion (RPE) and MARPE, expansion forces were distributed to differing points on the maxilla and evaluated with ANSYS simulation software. The stresses distributed from forces applied to the maxillary teeth are distributed mainly along the trajectories of the three maxillary buttresses. In comparison, the MARPE showed tension and compression directed to the palate, while showing less rotation, and tipping of the maxillary complex. In addition, the conventional hyrax displayed a rotation of the maxilla around the teeth as opposed to the midpalatal suture of the MARPE. This data suggests that the MARPE causes the maxilla to bend laterally, while preventing unwanted rotation of the complex. In conclusion, the MARPE may be beneficial for hyperdivergent patients, or those that have already experienced closure of the midpalatal suture, who require palatal expansion and would worsen from buccal tipping of the teeth
FEM Simulation of Incremental Shear
International Nuclear Information System (INIS)
Rosochowski, Andrzej; Olejnik, Lech
2007-01-01
A popular way of producing ultrafine grained metals on a laboratory scale is severe plastic deformation. This paper introduces a new severe plastic deformation process of incremental shear. A finite element method simulation is carried out for various tool geometries and process kinematics. It has been established that for the successful realisation of the process the inner radius of the channel as well as the feeding increment should be approximately 30% of the billet thickness. The angle at which the reciprocating die works the material can be 30 deg. . When compared to equal channel angular pressing, incremental shear shows basic similarities in the mode of material flow and a few technological advantages which make it an attractive alternative to the known severe plastic deformation processes. The most promising characteristic of incremental shear is the possibility of processing very long billets in a continuous way which makes the process more industrially relevant
Naesliden project: FEM modelling strategies
Energy Technology Data Exchange (ETDEWEB)
Borg, T.
1980-05-15
A schematized description is given of the different stages in the project. The aim is to show the development of the project and the strategies which have been chosen. The four different stages in the project are treated from the following points of view: the reasons for the choice of material models; the determination of model properties; and the control of the calculated values. In the origin plan for the project it was stated to only use a joint element model. However, it was shown to be a reasonable strategy to use both a general linear elastic model and a geometric restricted model with joint elements. During the course of the Project's development stages, it was found that a reduction in the number of rock types could be made without loss of generality. A modified strategy is suggested based on more studies of the rock bahavior and less advanced calculations in the first stages of the project.
Simulation of Biosensor using FEM
International Nuclear Information System (INIS)
Sheeparamatti, B G; Hebbal, M S; Sheeparamatti, R B; Math, V B; Kadadevaramath, J S
2006-01-01
Bio-Micro Electro Mechanical Systems/Nano Electro Mechanical Systems include a wide variety of sensors, actuators, and complex micro/nano devices for biomedical applications. Recent advances in biosensors have shown that sensors based on bending of microfabricated cantilevers have potential advantages over earlier used detection methods. Thus, a simple cantilever beam can be used as a sensor for biomedical, chemical and environmental applications. Here, microfabricated multilayered cantilever beam is exposed to sensing environment. Lower layer being pure structural silicon or polymer and upper layer is of polymer with antigen/antibody immobilized in it. Obviously, it has an affinity towards its counterpart i.e. antibody/antigen. In the sensing environment, if counter elements exists, they get captured by this sensing beam head, and the cantilever beam deflects. This deflection can be sensed and the presence of counter elements in the environment can be predicted. In this work, a finite element model of a biosensor for sensing antibody/antigen reaction is developed and simulated using ANSYS/Multiphysics. The optimal dimensions of the microcantilever beam are selected based on permissible deflection range with the aid of MATLAB. In the model analysis, both weight and surface stress effects on the cantilever are considered. Approximate weights are taken into account because of counter elements, considering their molecular weight and possible number of elements required for sensing. The results obtained in terms of lateral deflection are presented
Bistacchi, A.; Pisterna, R.; Romano, V.; Rust, D.; Tibaldi, A.
2009-04-01
The plumbing system that connects a sub-volcanic magma reservoir to the surface has been the object of field characterization and mechanical modelling efforts since the pioneering work by Anderson (1936), who produced a detailed account of the spectacular Cullin Cone-sheet Complex (Isle of Skye, UK) and a geometrical and mechanical model aimed at defining the depth to the magma chamber. Since this work, the definition of the stress state in the half space comprised between the magma reservoir and the surface (modelled either as a flat surface or a surface comprising a volcanic edifice) was considered the key point in reconstructing dike propagation paths from the magma chamber. In fact, this process is generally seen as the propagation in an elastic media of purely tensional joints (mode I or opening mode propagation), which follow trajectories perpendicular to the least compressive principal stress axis. Later works generally used different continuum mechanics methodologies (analytic, BEM, FEM) to solve the problem of a pressure source (the magma chamber, either a point source or a finite volume) in an elastic (in some cases heterogeneous) half space (bounded by a flat topography or topped by a "volcano"). All these models (with a few limited exceptions) disregard the effect of the regional stress field, which is caused by tectonic boundary forces and gravitational body load, and consider only the pressure source represented by the magma chamber (review in Gudmundsson, 2006). However, this is only a (sometimes subordinate) component of the total stress field. Grosfils (2007) first introduced the gravitational load (but not tectonic stresses) in an elastic model solved with FEM in a 2D axisymmetric half-space, showing that "failure to incorporate gravitational loading correctly" affect the calculated stress pattern and many of the predictions that can be drawn from the models. In this contribution we report on modelling results that include: 2D axisymmetric or true
Olsson, Eva
2005-01-01
Uppsatsen undersöker fem mäns berättelser kring krigsfilmen Saving Private Ryan, med fokus på maskulinitet. Föreställningarna och bilderna kring maskulinitet som kan urskiljas i intervjupersonernas berättelser, knyts till R.W. Connells teoretiska ramverk kring hegemonisk maskulinitet och de hierarkiska relationerna mellan olika maskuliniteter. Vidare resoneras det kring hur berättelserna exemplifierar en syn på mediepublik som aktiva meningsskapare, då intervjupersonerna tar fasta på olika as...
Kowalczyk, Piotr
2009-12-01
The aim of the paper is to analyse an influence of the shape of the layers in photo-cured dental restorations of Class I on distribution of shrinkage stresses along the tooth-restoration interface. The study is a continuation of the previous considerations (Kowalczyk and Gambin (2008) [1]), where techniques, which reduce stress concentration at the top of the tooth-restoration interface, were considered. The analysis leads to proposition of new layer forming techniques, which diminish the stress peaks at the interface and prevent the crack propagation process. To find the stress distributions in the dental restoration layers and the tooth tissues the finite element method implemented in the ABAQUS (Simulia, Providence, USA) software is used. For Class I restoration of the premolar tooth, the axisymmetrical model is assumed. The restoration is made of four layers of a photo-cured composite. Between the tooth tissues and the restoration, a layer of bonding agent 0.01mm thick is placed and modeled by FEM with help of the cohesive elements. The assumed model takes into account an influence of changes of elastic properties and viscous effects. For each case of the restoration layers system, the Huber-Mises stresses are analysed. The investigations show that the stresses near the restoration-tooth tissue interface are reduced due to viscous flow of the cured material and due to existence of a thin layer of the bonding agent. However, the stress distribution both, in the restoration and in the tooth tissues, is strongly dependent on a shape of the filling layers. Numerical simulations disclose that stress peaks are located at the top corners of each layer. The top corners of the last layer are the places where microleakage may occur. Stress concentrations at the corners of the preceding layers may lead to a growth of uprising crack. It will be shown that the flat layers in the restoration create relatively high values of the stress peaks. The rounded layers, with shapes
International Nuclear Information System (INIS)
Kubis, M.; Gutfleisch, O.; Gebel, B.; Mueller, K.-H.; Schultz, L.
1999-01-01
Microstructural investigations by means of scanning electron microscopy and X-ray diffraction showed that the formation of high amounts of α-Fe in as-cast Sm 2 (Fe,M) 17 alloys can be suppressed by using the substitutions M=Al or Si together with excess Sm. Ga, on the other hand, does not induce this beneficial effect. The hydrogen absorption and desorption behaviour was investigated by temperature-pressure-analysis and hydrogen differential thermal analysis. Decreasing amounts of hydrogen were absorbed in Sm 2 (Fe,M) 17 for increasing contents of all substitutions M=Ga, Al and Si due to their stabilising effect on the 2:17 phase with regard to its disproportionation. Compared with the homogenised alloys, the as-cast materials show a weaker interstitial hydrogen absorption and a stronger disproportionation reaction at lower temperatures due to the higher content of Sm-rich phases in the as-cast alloys. A second cycle of the hydrogenation-disproportionation-desorption-recombination (HDDR) process leads to a faster disproportionation reaction at lower temperatures due to the grain refinement during the first cycle. Magnetic properties of as-cast and homogenised materials were investigated after HDDR treatment and nitrogenation or carburisation of pre-milled powders. Nitrogenated and carburised samples showed coercivities up to 3.0 T and 2.3 T, respectively. There were only slight differences of the magnetic properties of materials prepared from homogenised and from as-cast samples. (orig.)
International Nuclear Information System (INIS)
Fu, Haiying; Nagasaka, Takuya; Muroga, Takeo; Guan, Wenhai; Nogami, Shuhei; Serizawa, Hisashi; Geng, Shaofei; Yabuuchi, Kiyohiro; Kimura, Akihiko
2016-01-01
The joint between 9Cr-ODS and JLF-1 made by electron beam welding (EBW) fractured at the JLF-1 base metal (BM) during uniaxial tensile tests. Thus, the bonding strength of the joint was not determined and was estimated as more than the ultimate tensile strength of the BM in this case. Symmetric four-point bend tests which concentrate the stress inside the inner span including the weld metal (WM) were carried out at room temperature (RT) and 550 °C to investigate how the bonding strength is more than the ultimate tensile strength of the BM. The normal stress at the center of the weld bead can be calculated with elastic theory up to only 0.25% in strain, though the joint showed more than 10% in strain due to plastic deformation. Thus, finite element method (FEM) was utilized to simulate the plastic deformation behavior of the joint during bend tests. According to the fitting of the FEM output, such as load and displacement of the upper jig contacting the specimens, to the experimental results, the bonding strength of the joint at RT and 550 °C were estimated as 854 MPa and 505 MPa, respectively.
Energy Technology Data Exchange (ETDEWEB)
Fu, Haiying [SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); Nagasaka, Takuya; Muroga, Takeo [SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Guan, Wenhai; Nogami, Shuhei [Tohoku University, 6-6-01-2 Aramaki-aza-Aoba, Aoba-ku, Sendai 980-8578 (Japan); Serizawa, Hisashi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki 567-0047 (Japan); Geng, Shaofei [SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); Yabuuchi, Kiyohiro; Kimura, Akihiko [Institute of Advanced Energy, Kyoto University, Uji 611-0011 (Japan)
2016-01-15
The joint between 9Cr-ODS and JLF-1 made by electron beam welding (EBW) fractured at the JLF-1 base metal (BM) during uniaxial tensile tests. Thus, the bonding strength of the joint was not determined and was estimated as more than the ultimate tensile strength of the BM in this case. Symmetric four-point bend tests which concentrate the stress inside the inner span including the weld metal (WM) were carried out at room temperature (RT) and 550 °C to investigate how the bonding strength is more than the ultimate tensile strength of the BM. The normal stress at the center of the weld bead can be calculated with elastic theory up to only 0.25% in strain, though the joint showed more than 10% in strain due to plastic deformation. Thus, finite element method (FEM) was utilized to simulate the plastic deformation behavior of the joint during bend tests. According to the fitting of the FEM output, such as load and displacement of the upper jig contacting the specimens, to the experimental results, the bonding strength of the joint at RT and 550 °C were estimated as 854 MPa and 505 MPa, respectively.
International Nuclear Information System (INIS)
Kanatani, Mamoru; Tochigi, Hitoshi; Kawai, Tadashi
1999-01-01
In the development of the man-made island siting technology of nuclear power plants, assessing the stability of the seawall against large ocean waves and earthquakes is indispensable. Concerning with the seismic stability of the seawall, prediction of the deformation like sliding and settlement of the seawall during earthquake including the armour units in front of the caisson becomes important factor. For this purpose, the authors have developed the two-dimensional DEM-FEM coupled analysis method (SEAWALL-2D) to predict the deformation of the seawall covered with the armour units during earthquake. In this method, movements of the armour units are calculated in DEM analysis part and deformation of the caisson, rubble moundsand seabed and back fill are calculated in FEM analysis part taking the nonlinearity of the soil materials based on the effective stress into account. Numerical simulations of dynamic centrifuge model tests of the seawall are conducted to verify the applicability of this method. Results of the simulation analyses have successfully reproduced the movements of the armour units and the residual deformation of the caisson, sand seabed and back fill compared with the test results. (author)
Vene telesarjad sõnaga Sirbis (VII) / Aare Ermel
Ermel, Aare, 1957-2013
2007-01-01
Kümnejaolisest telepõnevikust "Kooljate teater" ("Teatr obretshjonnõh"), stsenaristid T. Artseulova ja A. Suvorova, Mihhail Marti romaani motiividel, režissöör A. Parhomenko (MakDos/Iljuzionfilmz 2006). Võrdlus Rainer Sarneti "Libahundi needusega"
Sõjas nagu sõjas ikka / Aare Ermel
Ermel, Aare, 1957-2013
2006-01-01
10-osaline sõjaseriaal "Relvavennad" ("Band of Brothers") ajalooprofessor Stephen Ambrose'i raamatu järgi : produtsendid Tom Hanks, Steven Spielberg : režissöörid Tom Hanks, David Frenkel jt. : Ameerika Ühendriigid - Suurbritannia 2001. Lühidalt ka teistest ilmasõda kajastavatest seriaalidest
Armastusest kahel ajajärgul / Aare Ermel
Ermel, Aare, 1957-2013
2000-01-01
Mängufilm "Prantsuse leitnandi naine" ("The French Lieutenant's Woman") : stsenarist Harold Pinter John Fowles'i romaani järgi : režissöör Karel Reisz : Suurbritannia 1981. Ka : Nädal nr. 35, lk. 14
Tantsijast poksipoiss, aristokraadid ja hulluõde / Aare Ermel
Ermel, Aare, 1957-2013
2000-01-01
IV Pimedate Ööde Filmifestivalil linastunud mängufilmidest : Suurbritannia "Billy Elliot" : režissöör Stephen Daldry, Ungari-Austria-Kanada "Päikesepaiste" ("Sunshine") : režissöör István Szab̤ ja Saksamaa "Keisrinna ja sõjamees" ("Der Krieger und die Keiserin") : režissöör Tom Tykwer
The energy situation in year 2050; Energilaeget aar 2050
Energy Technology Data Exchange (ETDEWEB)
Azar, C.; Lindgren, K.; Hijino, E. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Physical Resource Theory
1998-07-01
This study outlines the Swedish energy system for the case where international agreements have been reached to stabilize the atmospheric CO2 levels at 400-500 ppm. Energy scenarios for Sweden in 2050 examine the possibility to reduce emissions of CO2, phase-out nuclear power and still maintain high growth for the standard of living. In a `post-materialistic` scenario, a CO2 reduction of 75% is used, while the two `materialistic` scenarios use a reduction of 75% or 50%. In the materialistic scenarios, activities grow by 50%-100% in most sectors (markedly higher for some sectors, e.g. transportation). The post-materialistic scenarios has a lower growth. According to the authors, there exists no insurmountable technical or economic problems to realize these scenarios. Higher energy efficiency, increased use of renewable energy sources (in particular biofuels) and a modest use of natural gas will be sufficient for the energy supplies needed - about 5-20 % lower than 1995 100 refs, 24 figs, 11 tabs
Kirjanik Truman Capote ja tema teosed valgel linal / Aare Ermel
Ermel, Aare, 1957-2013
2006-01-01
Ameerika kirjanik Truman Capote (1924-1984) oli stsenarist viiele filmile. Tema kaks romaani on aluseks filmidele "Külmavereliselt" (RIchard Brooks, 1967) ja "Hommikueine Tiffany juures" (Blake Edwards, 1961). Edukas on mängufilm kirjanikust "Capote" : režissöör Bennett Miller : kirjanik Truman Capote' rollis Philip Seymour Hoffman : Ameerika Ühendriigid - Kanada 2005
Veemajandus saab jõudsalt areneda / Aare Lepaste
Lepaste, Aare, 1970-
2004-01-01
8. detsembril kirjutasid seitsme vee-ettevõtte esindajad, KIK-i juhataja ja keskkonnaminister alla Eesti suurimale keskkonnaprojektile. Projekti eesmärk on viia omavalitsuste veemajanduse infrastruktuur vastavusse EL-i direktiividega.
The IT problems / the year; Norne: Erfaringer etter ett aar
Energy Technology Data Exchange (ETDEWEB)
Staerkebye, Jon
1998-07-01
This presentation discusses the year 2000 problem as dealt with by Saga. The project ''Year 2000 in Saga Petroleum'' was formally established in December 1997. Its mandate was to identify risk areas and systems related to the date problem and to establish the necessary action to reduce or eliminate the Y2K problems. The target was (1) To be ''Year 2000 Compliant'' for the most critical systems within 1.4.1999, (2) To ensure the continuity of Saga's operational and business management affairs, (3) Priority to health, environment and safety, (4) Authorities and partners should be satisfied with the way Saga carries out the Y2K project work. Few serious problems were detected, but Y2K compliance information was more difficult to obtain than expected. Major suppliers take the problem seriously, but surprisingly many have started late.
Industrial trigeneration using ammonia-water absorption refrigeration systems (AAR)
International Nuclear Information System (INIS)
Colonna, Piero; Gabrielli, Sandro
2003-01-01
In many industrial processes there is a simultaneous need for electric power and refrigeration at low temperatures. Examples are in the food and chemical industries. Nowadays the increase in fuel prices and the ecological implications are giving an impulse to energy technologies that better exploit the primary energy source and integrated production of utilities should be considered when designing a new production plant. The number of so-called trigeneration systems installations (electric generator and absorption refrigeration plant) is increasing. If low temperature refrigeration is needed (from 0 to -40 deg. C), ammonia-water absorption refrigeration plants can be coupled to internal combustion engines or turbogenerators. A thermodynamic system study of trigeneration configurations using a commercial software integrated with specifically designed modules is presented. The study analyzes and compares heat recovery from the primary mover at different temperature levels. In the last section a simplified economic assessment that takes into account disparate prices in European countries compares conventional electric energy supply from the grid and optimized trigeneration plants in one test case (10 MW electric power, 7000 h/year)
Irooniline pilguheit Iirima lähiajaloole / Aare Ermel
Ermel, Aare, 1957-2013
2001-01-01
Mängufilm "Väike lihunik" ("The Butcher Boy") : Stsenaristid Neil Jordan ja Patrick McCabe viimase samanimelise romaani järgi : režissöör Neil Jordan : Ameerika Ühendriigid 1997. Ka : Teleleht nr. 1, lk. 4
Meri on mereriigi majanduskasvu eeldus / Aare-Maldus Uustalu
Uustalu, Aare-Maldus, 1935-
2005-01-01
Eesti majanduskasvu edukus merenduse ja siseveetranspordi arendamise valdkonnas sõltub mitte üksnes teadlaste panusest, vaid suurel määral riigiametnike töö kvaliteedist, nende suutlikkusest ja vastutustundest, leiab autor. Tabelid. Kaart
San Sebastiani festivali varjutasid hiljutised terroriaktid / Aare Ermel
Ermel, Aare, 1957-2013
2001-01-01
San Sebastiani rahvusvahelisel filmifestivalil sai Suure Kuldse merikarbi tšiillase Orlando Lubberti film "Takso kolmele". Parima režissööri auhinna pälvis Jean-Pierre Ameris realistliku draamaga "C'est la vie". Ka teistest auhinnatutest
Luupaljas hüljesnaine ja mineviku vangid / Aare Ermel
Ermel, Aare, 1957-2013
2010-01-01
PÖFFi filmidest: Neil Jordani "Undiin" (Iirimaa - USA, 2009), Debra Graniku "Luupaljas" (USA, 2010), Urszula Antoniaki "Ei midagi isiklikku" (Iirimaa - Holland, 2009) ja Juan Jose Campanella "Saladus nende silmades" (Hispaania - Argentiina, 2009)
Perekonnaportree interjööris / Aare Ermel
Ermel, Aare, 1957-2013
2005-01-01
Lühiseriaal Mannide kirjanikedünastia saatusest 1930-1940-ndail aastail "Mannide perekond" ("Die Manns") : stsenaristid Heinrich Breloer ja Horst Königstein : režissöör Heinrich Breloer : Saksamaa 2001
Halvad, halvemad ja äravalitud / Aare Ermel
Ermel, Aare, 1957-2013
2003-01-01
Ameerika Filmiinstituudi küsitluse järgi on maailma kõigi aegade kõige meeldejäävamaks kurjuse kehastuseks kinolinal Hannibal Lecter mängufilmides "Voonakeste vaikimine", "Hannibal" ja "Punane draakon" Anthony Hopkinsi kehastuses. Kõige sümpaatsemaks positiivseks tegelaseks valiti Atticus Finch draamas "Tappa laulurästast" Gregory Pecki kehastuses
Podczeck, Fridrun; Newton, J Michael; Fromme, Paul
2014-12-30
Flat, round tablets may have a breaking ("score") line. Pharmacopoeial tablet breaking load tests are diametral in their design, and industrially used breaking load testers often have automatic tablet feeding systems, which position the tablets between the loading platens of the machine with the breaking lines in random orientation to the applied load. The aim of this work was to ascertain the influence of the position of the breaking line in a diametral compression test using finite element methodology (FEM) and to compare the theoretical results with practical findings using commercially produced bevel-edged, scored tablets. Breaking line test positions at an angle of 0°, 22.5°, 45°, 67.5° and 90° relative to the loading plane were studied. FEM results obtained for fully elastic and elasto-plastic tablets were fairly similar, but they highlighted large differences in stress distributions depending on the position of the breaking line. The stress values at failure were predicted to be similar for tablets tested at an angle of 45° or above, whereas at lower test angles the predicted breaking loads were up to three times larger. The stress distributions suggested that not all breaking line angles would result in clean tensile failure. Practical results, however, did not confirm the differences in the predicted breaking loads, but they confirmed differences in the way tablets broke. The results suggest that it is not advisable to convert breaking loads obtained on scored tablets into tablet tensile strength values, and comparisons between different tablets or batches should carefully consider the orientation of the breaking line with respect to the loading plane, as the failure mechanisms appear to vary. Copyright © 2014 Elsevier B.V. All rights reserved.
Directory of Open Access Journals (Sweden)
Escolano-Sánchez, F.
2015-03-01
Full Text Available Direct foundations with continuous elements, such as slabs, provide more advantages than direct foundations with isolated elements, such as footings, and deep foundations, such as piles, in the case of soil with natural or man-made cavities. The slabs are usually designed by two-dimensional models which show their shape on the plant, on a lineal elastic support, represented by a modulus of soil reaction. Regarding the settlement estimation, the following article compares the Finite Elements Method (FEM versus the classical Method (CM to select the modulus of soil reaction used to design foundations slabs in sensitive soils and sites with possible cavities or collapses. This analysis includes one of these cavities in the design to evaluate the risk of fail.Las cimentaciones directas con elementos continuos «losas», tienen ventajas sobre las cimentaciones directas con elementos aislados «zapatas» y sobre las cimentaciones profundas «pilotes», frente a la presencia de terrenos problemáticos. Las losas se diseñan de forma habitual con modelos bidimensionales que representan su forma en planta, apoyada en un medio elástico y lineal, representado por un módulo de balasto. En el presente artículo se realiza un análisis comparativo, para la estimación de asientos, entre el Método de Elementos Finitos (FEM y el Método Clásico (MC, para la elección de los módulos de balasto que se utilizan en el diseño de losas de cimentación en terrenos con blandones y cavidades naturales o antrópicas. Este análisis considera el peligro de la presencia de una de estas cavidades dentro de su diseño, de esta forma, el riesgo de fallo puede ser valorado por ambos métodos.
Anderson, Aare, 1966-
2006-01-01
Elva endine linnapea ja aselinnapea, rahandusministeeriumi töötaja vastab küsimustele, mis on seotud tema ametikohaga, Elvaga, võimalusega siduda end tulevikus poliitikaga. Isamaa ja Res Publica Liidu loosungist "Õnn ei ole rahas"
Energy Technology Data Exchange (ETDEWEB)
Zhang, Y.; Lu, T., E-mail: likesurge@sina.com
2016-12-01
Highlights: • Two characteristic parameters of the temperature fluctuations are used for qualitative analysis. • A quantitative assessment method for high-cycle thermal fatigue of a T-pipe is proposed. • The time-dependent curves for the temperature and thermal stress are not always “in-phase”. • Large magnitude of thermal stresses may not mean large number of fatigue cycles. • The normalized fatigue damage rate and normalized RMS temperature are positively related. - Abstract: With the development of nuclear power and nuclear power safety, high-cycle thermal fatigue of the pipe structures induced by the flow and heat transfer of the fluid in pipes have aroused more and more attentions. Turbulent mixing of hot and cold flows in a T-pipe is a well-recognized source of thermal fatigue in piping system, and thermal fatigue is a significant long-term degradation mechanism. It is not an easy work to evaluate thermal fatigue of a T-pipe under turbulent flow mixing because of the thermal loads acting at fluid–structure interface of the pipe are so complex and changeful. In this paper, a one-way Computational Fluid Dynamics-Finite Element Method (CFD-FEM method) coupling based on the ANSYS Workbench 15.0 software has been developed to calculate transient thermal stresses with the temperature fields of turbulent flow mixing, and thermal fatigue assessment has been carried out with this obtained fluctuating thermal stresses by programming in the software platform of Matlab based on the rainflow counting method. In the thermal analysis, the normalized mean temperatures and the normalized root mean square (RMS) temperatures are obtained and compared with the experiment of the test case from the Vattenfall benchmark facility to verify the accuracy of the CFD calculation and to determine the position which thermal fatigue is most likely to occur in the T-junction. Besides, more insights have been obtained in the coupled CFD-FEM analysis and the thermal fatigue
International Nuclear Information System (INIS)
Kawai, Tadashi; Ishimaru, Makoto
2009-01-01
During the Niigataken Chuetsu-oki earthquake, rather large settlements of the backfill ground around the rigid and stable buildings were observed. In this study, five cases of centrifuge tests with shaking events were conducted to reproduce the similar type of the settlements in order to examine the mechanism of the settlements. The results from those tests showed that the ground was settled by the negative dilatancy of sandy soils anywhere in the model ground and the additional settlements were suddenly caused when the backfill ground was apart from the rigid wall modeling the rigid and stable buildings, namely a sliding failure in an active state was occurred in the backfill ground near the structure. It was confirmed that these settlements were able to be estimated by a simple method proposed in this report, in which only the differences between the self-weight of the sliding block and the soil strength calculated at the initial stress conditions were considered as the driving forces of the sliding failure, and then the accelerations calculated from the forces being divided by the mass of the sliding block were simply integrated two times with respected to the time when the ground was apart from the structure. Further, a numerical simulation by using FEM about a typical test result was conducted, and these settlements were well simulated. (author)
Pourazadi, Shahram; Ahmadi, Sadegh; Menon, Carlo
2015-11-05
One of the recommended treatments for disorders associated with the lower extremity venous insufficiency is the application of external mechanical compression. Compression stockings and elastic bandages are widely used for the purpose of compression therapy and are usually designed to exert a specified value or range of compression on the leg. However, the leg deforms under external compression, which can lead to undesirable variations in the amount of compression applied by the compression bandages. In this paper, the use of an active compression bandage (ACB), whose compression can be regulated through an electrical signal, is investigated. The ACB is based on the use of dielectric elastomer actuators. This paper specifically investigates, via both analytical and non-linear numerical simulations, the potential pressure the ACB can apply when the compliancy of the human leg is taken into account. The work underpins the need to account for the compressibility of the leg when designing compression garments for lower extremity venous insufficiency. A mathematical model is used to simulate the volumetric change of a calf when compressed. Suitable parameters for this calf model are selected from the literature where the calf, from ankle to knee, is divided into six different regions. An analytical electromechanical model of the ACB, which considers its compliancy as a function of its pre-stretch and electricity applied, is used to predict the ACB's behavior. Based on these calf and ACB analytical models, a simulation is performed to investigate the interaction between the ACB and the human calf with and without an electrical stimulus applied to the ACB. This simulation is validated by non-linear analysis performed using a software based on the finite element method (FEM). In all simulations, the ACB's elastomer is stretched to a value in the range between 140 and 220 % of its initial length. Using data from the literature, the human calf model, which is examined in
Dziadek, Ricarda; Gohl, Karsten; Kaul, Norbert
2017-04-01
The West Antarctic Rift System (WARS) is one of the largest rift systems in the world, which displays unique coupled relationships between tectonic processes and ice sheet dynamics. Palaeo-ice streams have eroded troughs across the Amundsen Sea Embayment (ASE) that today route warm ocean deep water to the West Antarctic Ice Sheet (WAIS) grounding zone and reinforce dynamic ice sheet thinning. Rift basins, which cut across West Antarctica's landward-sloping shelves, promote ice sheet instability. Young, continental rift systems are regions with significantly elevated geothermal heat flux (GHF), because the transient thermal perturbation to the lithosphere caused by rifting requires 100 m.y. to reach long-term thermal equilibrium. The GHF in this region is, especially on small scales, poorly constrained and suspected to be heterogeneous as a reflection of the distribution of tectonic and volcanic activity along the complex branching geometry of the WARS, which reflects its multi-stage history and structural inheritance. We investigate the crustal architecture and the possible effects of rifting history from the WARS on the ASE ice sheet dynamics, by the use of depth-to-the-bottom of the magnetic source (DBMS) estimates. These are based on airborne-magnetic anomaly data and provide an additional insight into the deeper crustal properties. With the DBMS estimates we reveal spatial changes at the bottom of the igneous crust and the thickness of the magnetic layer, which can be further incorporated into tectonic interpretations. The DBMS also marks an important temperature transition zone of approximately 580°C and therefore serves as a boundary condition for our numerical FEM models in 2D and 3D. On balance, and by comparison to global values, we find average GHF of 90 mWm-2 with spatial variations due to crustal heterogeneities and volcanic activities. This estimate is 30% more than commonly used in ice sheet models in the ASE region.
CFD and FEM modeling of PPOOLEX experiments
Energy Technology Data Exchange (ETDEWEB)
Paettikangas, T.; Niemi, J.; Timperi, A. (VTT Technical Research Centre of Finland (Finland))
2011-01-15
Large-break LOCA experiment performed with the PPOOLEX experimental facility is analysed with CFD calculations. Simulation of the first 100 seconds of the experiment is performed by using the Euler-Euler two-phase model of FLUENT 6.3. In wall condensation, the condensing water forms a film layer on the wall surface, which is modelled by mass transfer from the gas phase to the liquid water phase in the near-wall grid cell. The direct-contact condensation in the wetwell is modelled with simple correlations. The wall condensation and direct-contact condensation models are implemented with user-defined functions in FLUENT. Fluid-Structure Interaction (FSI) calculations of the PPOOLEX experiments and of a realistic BWR containment are also presented. Two-way coupled FSI calculations of the experiments have been numerically unstable with explicit coupling. A linear perturbation method is therefore used for preventing the numerical instability. The method is first validated against numerical data and against the PPOOLEX experiments. Preliminary FSI calculations are then performed for a realistic BWR containment by modeling a sector of the containment and one blowdown pipe. For the BWR containment, one- and two-way coupled calculations as well as calculations with LPM are carried out. (Author)
MAXWELL3, 3-D FEM Electromagnetism
International Nuclear Information System (INIS)
Grant, J.B.
2001-01-01
1 - Description of program or function: MAXWELL3 is a linear, time domain, finite element code designed for simulation of electromagnetic fields interacting with three-dimensional objects. The simulation region is discretized into 6-sided, 8-nodded elements which need not form a logically regular grid. Scatterers may be perfectly conducting or dielectric. Restart capability and a Muer-type radiating boundary are included. MAXWELL3 can be run in a two-dimensional mode or on infinitesimally thin geometries. The output of time histories on surfaces, or shells, in addition to volumes, is allowed. Two post-processors are included - HIST2XY, which splits the MAXWELL3 history file into simple xy data files, and FFT A BS, which performs fast Fourier transformations on the xy data. 2 - Method of solution: The numerical method requires that the model be discretized with a mesh generator. MAXWELL3 then uses the mesh and computes the time domain electric and magnetic fields by integrating Maxwell's divergence-free curl equations over time. The output from MAXWELL3 can then be used with a post-processor to get the desired information in a graphical form. The explicit time integration is done with a leap-frog technique that alternates evaluating the electric and magnetic fields at half time steps. This allows for centered time differencing accurate in second order. The algorithm is naturally robust and requires no parameters. 3 - Restrictions on the complexity of the problem: MAXWELL3 has no mesh generation capabilities. Anisotropic, nonlinear, and magnetic materials cannot be modeled. Material interfaces only account for dielectric changes and neglect any surface charges that would be present at the surface of a partially conducting material. The radiation boundary algorithm is only accurate for normally incident fields and becomes less accurate as the angle of incidence increases. Thus, only models using scattered fields should use the radiation boundary. This limits MAXWELL3's applicability to models incorporating directed fields such as unshielded transmission lines including microstrip waveguides
FEM effective suggestion of guitar construction
Directory of Open Access Journals (Sweden)
Vladimír Dániel
2006-01-01
Full Text Available Modal analysis of the whole guitar construction was performed. The results of eigenfrequencies were obtained. Stress in strings affects not only static loading of material, but also shift of eigenfrequencies. From obtained natural frequencies for solved spectrum such frequencies were used which coincides with assumed ribs new positions of ribs were suggested. Other ribs which do not carry out the mechanical function were removed. Also static reaction was evaluated and new position of ribs was adjusted. For final model new eigenfrequencies were computed and compared with previous ones. Significant changes were revealed in low frequencies (bellow 400 Hz where fewer amounts of natural shapes were obtained. Approximately 50% were lost by adding of ribs. For chosen frequencies of equal temperament the harmonic analysis was performed. The analysis proved ability of oscillation for frequencies far of natural frequencies. The final model satisfies the requirement of minimization of static stress in material due to strings and allows very effective oscillation of top the guitar resonance board. In comparison with literature good agreement in amplitude size of front board and amount of modes in appropriate frequencies were achieved. Suggested model even offers higher amount of natural shapes in comparison with literature, namely in high frequencies. From additional comparison of eigenfrequencies and natural shapes the influence of ribs position on natural shapes was approved.
Numerical analysis of laminated elastomer by FEM
International Nuclear Information System (INIS)
Mazda, T.; Shiojiri, H.
1993-01-01
A Computer code based on mixed finite element method was developed for three dimensional large strain analyses of laminated elastomers including nonlinear bulk stress vs. bulk strain relationships. The adopted element is the variable node element with maximum node numbers of 27 for displacements and 4 for pressures. At first, the displacements and pressures were calculated by the code using single element under various loading conditions. The results were compared with theoretical solutions and the both results' exactly coincided with each other. Next, the analyses of laminated elastomers subjected to axial loadings were conducted using both the new code and ABAQUS code, and the results were compared with the test results. The agreement of the results of the present code were better than ABAQUS code mainly due to the capability of handling wider range of material properties. Lastly, the shearing tests of laminated elastomers were simulated by the new code. The results were shown to be in good agreement with the test results. (author)
Fem Modelling of Lumbar Vertebra System
Directory of Open Access Journals (Sweden)
Rimantas Kačianauskas
2014-02-01
Full Text Available The article presents modeling of human lumbar vertebra and it‘sdeformation analysis using finite elements method. The problemof tissue degradation is raised. Using the computer aided modelingwith SolidWorks software the models of lumbar vertebra(L1 and vertebra system L1-L4 were created. The article containssocial and medical problem analysis, description of modelingmethods and the results of deformation test for one vertebramodel and for model of 4 vertebras (L1-L4.
FEM analysis of magnetic flake composites
Claassen, J. H.
2009-07-01
A composite comprised of layered flake-like magnetic particles embedded in an insulating medium has been proposed as a low permeability, low loss core material. This would be an alternative to "distributed air gap" compressed powder cores that are widely used for inductors in power applications. Since the lowest loss metallic materials are manufactured in the form of very thin sheets, the particles after pulverizing would be in the form of flakes. The effective permeability and average core loss have been computed for model systems of flake composites in a two-dimensional approximation. The core loss is modeled by eddy current dissipation in the low-frequency limit, where the conductor thickness is much less than the skin depth. It is found that useful values of permeability should be obtained for a modest filling fraction of magnetic material, in contrast to the powder cores which require a value close to unity. The core loss will scale as the inverse of filling fraction, with a small additional enhancement due to perpendicular field components. It is thus expected that useful core materials may be attainable without the necessity of large compaction forces.
Energy Technology Data Exchange (ETDEWEB)
Bjerknes, V.; Kvellestad, A.; Berntssen, M.
1996-06-01
The new Norwegian hydroelectric power station Hekni Power Station in the river Otra began operation in the autumn of 1995. Out of consideration for the landlocked salmon in the Byglandsfjord, valuable and nationally deserving of preservation as it is, the tunnel was gradually filled with water so as to avoid large amounts of suspended sediments downstream. During start-up, several environmental investigations were made, as discussed in this report: registrations and analyses of the water from Otra, experimental exposure of landlocked salmon, assessment of wild fish and collection of bottom animals from river stretches exposed to suspended sediments and from unexposed control stretches. Exposed salmon show clear evidence of typical gill changes due to acidification while there is no evidence of changes caused by suspended sediment particles. The changes in population densities of wild fish and bottom animals from before start-up to after start-up is primarily related to the altered water discharge. However, the absence of groups of particle sensitive bottom animals after exposure may be due to particle emission from the power station. The chemically unstable particles may have temporarily increased the pH and calcium concentration and reduced the concentration of unstable aluminium in the most affected part of the river system, while the particle level itself may have been too low to cause noticeable effects on fish. The extent to which the bottom ecology may have been damaged is not sufficiently well known. 34 refs., 8 figs., 6 tabs.
Sada ja üks Eesti poliitilist karikatuuri / Aare Kasemets, Eiki Berg
Kasemets, Aare, 1963-
2004-01-01
Eesti ajalehtede poliitilised karikatuurid on Lääne-Euroopa ja USA ajakirjanduse pilapiltidega võrreldes üldjuhul inimsõbralikud, leiavad autorid. Tabel. Lisa: 2003. aasta karikatuurivalimise tulemused
Short outlines of books by Estonian authors / Berk Vaher, Aare Pilv
Vaher, Berk, 1975-
2005-01-01
Tutvustus: Raudam, Toomas. Nips. Tallinn : Eesti Keele Sihtasutus, 2004 ; Ilus Armin : eesti lühiproosat 1987-2002 / koost. Udo Uibo. Tallinn : Varrak, 2004 ; Ehlvest, Jüri von. Rahuldus. Tartu : Ilukirjandus, 2004 ; Ki:wa. Roboti tee on nihe ; Salatühik. Tallinn : Eesti Kunstimuuseum, 2004 ; Sommer, Lauri. Nõidade õrnus. Sännä : Tiivaalune, 2004 ; Kalkun, Andreas. Pääväraamat. Tartu : Erakkond, 2004 ; Jõerüüt, Jaak. Uus raamat. Tallinn : Tuum, 2004 ; Krull, Hasso. Meeter ja Demeeter. Tallinn : Vagabund, 2004 ; Kõiv, Madis. Päev. Tartu : Akkon, 2004 ; Mihkelson, Ene. Uroboros. Tallinn : Tuum, 2004 ; Soomets, Triin. Toormaterjal. Tallinn : Verb, 2004 ; Vaher, Berk. Sekeldaja päevad. Tallinn : Tuum, 2004
Sissejuhatus suure kirjaniku loomingusse : Edgar Allan Poe' väändunud maailm / Aare Ermel
Ermel, Aare, 1957-2013
2001-01-01
Prantsusmaa-Itaalia 1968.a. ühisfilm "Erakordsed lood" ("Histoires extraordinaires"), mis koosneb Edgar Allan Poe kolme novelli ekraniseeringutest : "Metzengerstein" (režissöör Roger Vadim), "William Wilson" (režissöör Louis Malle) ja "Toby Dammit" (režissöör Federico Fellini). Ka : Nädal nr. 25, lk. 14
Parlamentide info- ja analüüsiteenistuste koostöövõrgud / Aare Kasemets
Kasemets, Aare, 1963-
2003-01-01
Euroopa parlamentide teabe- ja analüüsiteenistused ning raamatukogud teevad koostööd mitmes võrgustikus, millest kaks suuremat on Euroopa Parlamendiuuringute ja -dokumentatsiooni Keskus (ECPRD) ning Rahvusvaheline Raamatukoguühingute ja -institutsioonide Liidu (IFLA) parlamendisektsioon. Ülevaade koostöövõrgustikest. Tabel: ECPRD seminarid 2002. ja 2003. aastal
Perfektse käsitöö poeetiline realism / Aare Ermel
Ermel, Aare, 1957-2013
1999-01-01
Rootsi filmiklassik Jan Troell (1931) ja tema filmid ning mängufilmid "Läbisegi" ("Topsy-Turvy") : režissöör Mike Leigh, "Rotipüüdja" ("Ratcatcher") : režissöör Lynne Ramsay ja "Püssirohutünn" ("Pure baruta") : režissöör Goran Paskaljevic Tallinnas III Pimedate Ööde Filmifestivalil
Eesti võimalused Soome lahe kasvukolmnurgas / Aare-Maldus Uustalu
Uustalu, Aare-Maldus, 1935-
2005-01-01
Euroopa Komisjoni ekspert logistika, transpordi ja regionaalökonoomika alal, TTÜ Tallinna Kolledzhi dotsent 2002. aasta alguses käivitatud Soome lahe kasvukolmnurga projektist, Eesti majanduse arenguperspektiivist projekti raames ning Eesti riigiametnike ükskõiksusest projekti suhtes. Via Baltica lisakoridoride projekti Via Islands ideest
Püsiva tegevuskoha mõiste rahvusvahelistes maksulepingutes ja Eesti tulumaksuseaduses / Aare Kurist
Kurist, Aare, 1974-
1998-01-01
Püsiva tegevuskoha mõistest vastavalt OECD 1992. a. tulu ja kapitali maksustamise mudelkonventsioonile ning selle alusel riikide vahel sõlmitud topeltmaksustamise vältimise ning maksudest hoidumise tõkestamise lepingutele
Inimelu võlu ja vaev, rassipuhtus ja koolera / Aare Ermel
Ermel, Aare, 1957-2013
2007-01-01
PÖFFi filmidest: "Uus inimene" ("Den nya människan", rezh. Klaus Härö, Soome 2007), "Teie, kes te elate" ("Du levande", rezh. Roy Andersson, Rootsi 2007), "Armastus koolera ajal" ("Love in the Time of Cholera", Gabriel Garcia Marqueze romaani ekraniseering, rezh. Mike Newell, USA 2007)
Kreisis käis Jõgeval grand prix' järel / Aare Laine
Laine, Aare, 1951-
2005-01-01
Jõgeva kultuurikeskuses toimunud Betti Alveri 13. luulepäevadel võitis Saaremaa Ühisgümnaasiumi kooliteater Kreisis peaauhinna. Sama kooli luuleteatri Krevera juhendaja R. Ilves võttis vastu juhendaja eripreemia
Marianne : [luuletused] / Paul Celan ; saksa k. tlk. [ja järelsõna]: Aare Pilv
Celan, Paul, pseud., 1920-1970
2004-01-01
Sisu: Marianne ; Corona ; "Pimestu juba täna..." ; "Kaste. Ja ma heitsin su kõrvale, sina, keset prügi..." ; "Liigaastasajad, liig-..." ; "Kaevukaevaja tuules..." ; "Hooralik teinekord. Ja igavik..." ; Largo ; "Kõik unekujud, kristallist..."
Uustalu, Aare-Maldus, 1935-
2002-01-01
Kasut. kirj. lk. 80. - Kokkuvõte ingl. k. lk. 81-82. Soome lahe kasvukolmnurga rakendamise edukus Eestis sõltub mitte üksnes teadlaste panusest, vaid suurel määral riigiametnike töö kvaliteedist, nende suutlikkusest ja vastutustundest
Mõned noad luule selga / P. I. Filimonov ; vene keelest tõlkinud Aare Pilv
Filimonov, P. I., pseud., 1975-
2011-01-01
Autori arvates ei ole luule midagi sakraalset, ta on nii rahvuslik kui rahvusülene - ükski tõlge ei anna täielikku pilti tekstist sellisena nagu see oli autori emakeeles. Luuletused on eelkõige reaktsioon mingile sündmusele. Samuti sünnivad-valmivad erinevatel inimestel erinevad luuletused-värsid
Johannes Hindi abil Arnold Rüütli vastu / Aare Vets
Vets, Aare
2006-01-01
President Arnold Rüütli vastastest rünnakutest presidendivalimiste kampaanias, näitena Eesti Ekspressis ilmunud artikkel, mille järgi Arnold Rüütel on vastutav Johannes Hindi vangistamises. J. Hindi tegevusest silikaltsiidi tootmisel ja Desintegraatori direktorina, kriminaalasja algatamisest ja karistamisest Eesti NSV-s
Sherlock Holmesi salapärane päritolu / Aare Ermel
Ermel, Aare, 1957-2013
2004-01-01
Sir Arthur Conan Doyle'i detektiivilugudest BBC poolt aastail 2000-2001 toodetud 6-osalisest telesarjast "Mõrvatoad" ilmus Eestis kaht filmi sisaldav DVD "Sherlock Holmesi salapärane päritolu" ja "Sherlock Holmes : Patsiendi silmad"
DVD-peegel : Mondo-šokkerite pioneer Jacopetti 90 / Aare Ermel
Ermel, Aare, 1957-2013
2009-01-01
Itaalia dokumentalistide Gualtiero Jacopetti ja Franco Prosperi šokidokumentaalidest "Mondo cane" ja "Mondo Cane 2" (1962-1963) ning "Africa Blood and Guts or Farewell Africa" ("Africa addio"/"Hüvasti, aafrika", 1966)
2011-08-05
... Plan list in August 1994. In May 1997, NRC inspectors performed a limited radiation survey of the CSXT..., 1997, letter; the report identified three locations with elevated levels of thorium in the soil (ADAMS... CSXT property. Based on the survey and sampling results, as well as an all- pathways analysis of the...
Tegelikult keskmine pension 2007. a. ei tõusegi! / Aare Kitsing
Kitsing, Aare
2006-01-01
Ilmunud ka: Maaleht 2. nov. lk. 8, Harjumaa 7. nov. lk. 2, Vesti Nedeli Den za Dnjom 1. dets. lk. 14. . Eesti Pensionäride Liidu aseesimees selgitab vanaduspensioni arvestamist, mille järgi pensioni tõus 3490 kroonini puudutab vaid osa kodanikke. Pensionäride Liidu nõudmised Riigikogule ja valitsusele
Vittorio De Sica viis meistritööd / Aare Ermel
Ermel, Aare, 1957-2013
2008-01-01
DVD-st "Vittorio De Sica Masterpiece Collection", kus on peal itaalia filmirežissööri Vittorio De Sica viis teost: "Jalgratavargad" ("Ladri di biciclette", 1948), "Ime Milanos" ("Miraclo a milano", 1951), "Umberto D." (1952), "Eile täna, homme" ("Ieri, oggi, domani", 1963), "Ajatu filmikunst" ("Cinema senza tempo: Cosi e la vita", 2001)
Laval võib teha kõike, ainult mitte valetada / Aare Toikka
Toikka, Aare
1999-01-01
Saksamaa teatribiennaal "Augenblick mal" Berliinis ja ASSITEJ 13. maailmakongress ning festival Tromsø's Norramaal. ASSITEJ Eesti Keskuse delegaatidena osalesid Ivo Eensalu ja Mart Kampus. Eestit esindas festivalil VAT Teatri lavastus "Tuudur, Plutt ja Magdaleena". Juttu lasteteatritest Saksamaal (GRIPS Teater, Halle nukuteater, Theater Junge Generation Dresdenist, Neubrandenburgi Kammerteater), Taanis (Paraply-teater, teatritrupp "Batida", Egnsteatret Gruppe 38), Hollandis (Teater "Artemis"), Rootsis (Unga Klara teatrikompanii Stockholmi Linnateatri juures) ja Austraalias (Zeal Theater)
Eesti saarte parvlaevaühendus : probleemid ja lahendused / Enno Lend, Aare-Maldus Uustalu
Lend, Enno, 1957-
2003-01-01
Eesti saarte laevaühenduse hetkeolukorrast ja kasutatavate reisi- ning parvlaevade vastavusest tänapäevasele teenindustasemele ning veonõuetele. Eesti suuremate saarte ülevaade. Tabelid. Graafikud. Diagramm
Aisteetika, ehk, Miks maailma ei oleks teatrita parem paik / Aare Pilv
Pilv, Aare, 1976-
2014-01-01
Esteetika mõistest, selle etümoloogilisest seosest tajumisega. Madis Kõivu tekstidest (sisaldab Madis Kõivu esseed "Kultuursõna on ülesemiotiseeritud"), Jaan Toomiku purgi-installatsiooni rekonstruktsioonist Tartu Kunstimuuseumis 2012. a., Mihkel Kunnuse mõttekäikudest afektiivsete kunstide kohta, Jacques Rancière'i ideedest kunsti loomuse kohta. Teatri olulisusest afektiivse kunstina
Masendav pilguheit Ida-Saksamaa lähiajaloole / Aare Ermel
Ermel, Aare, 1957-2013
2006-01-01
10. PÖFFi filme: Sakslase Florian Henkel von Donnersmarcki debüütlavastus, äsja parimaks Euroopa filmiks tunnistatud "Teiste elu" ("Das Leben der Anderen"), mehhiklase Guillermo Del Toro "Paani labürint" ("El laberinto del fauno", Mehhiko - Hispaania 2006), itaallase Nanni Moretti "Kaiman" ("The Caiman")
David Cronenberg ja William S. Burroughs kutsuvad teid lantshile / Aare Ermel
Ermel, Aare, 1957-2013
1999-01-01
Mängufilm "Alasti eine" ("Naked Lunch") William S. Burroughs' teose järgi : režissöör ja stsenarist David Cronenberg : Suurbritannia - Kanada 1991. Lähemalt režissööri kohta. Ka Nädal nr. 35, lk. 29
Kaitseliit leinab major Benno Leesikut / Aare Lepaste, Mati Määrits
Lepaste, Aare, 1970-
2006-01-01
Vastavalt kaitseväe juhataja korraldusele on kõigil Kaitseliidu malevatel heisatud leinalipud kuni ülema matusteni 2. aprillil. Kaitseliidu ülema kohuseid täidab Kaitseliidu peastaabi ülem major Urmas Muld
"Sa oled mul teine" : teisesusest eesti kultuuri eneseanalüüsis / Aare Pilv
Pilv, Aare, 1976-
2008-01-01
Kolmest eesti kultuuri eneseanalüüsi kontseptsioonist: "katkestus" (Hasso Krull), "eksistentsialistlik absurdiprojekt" (Jaan Undusk), "enesekolonisatsioon" (Tiit Hennoste). Poleemikat T. Hennoste enesekolonisatsiooni teooriaga (olulisim tekst selle kohta on 2006. a. avaldatud artikkel "Noor-Eesti kui lõpetamata enesekoloniseerimisprojekt"). Sisaldab bibliograafiat. Autorist lk. 249
Märkmeid ja viiteid Ojasoo-Semperi teatri kohta / Aare Pilv
Pilv, Aare, 1976-
2006-01-01
Tiit Ojasoo ja Ene-Liis Semperi NO99 teater Eesti teatripildis kui uudne nähtus. Peatutakse pikemalt lavastustel "Vahel on tunne, et elu saab otsa ja armastust polnudki", "Seitse samuraid", aga ka "Verevennad" ja Draamateatris tehtud lavastusel "Julia". Kommentaarid, lk. 20
Alkali-aggregate reactivity (AAR) workshops for engineers and practitioners reference manual.
2013-01-01
Funding for the Federal Highway Administration (FHWA) Alkali-Silica Reactivity (ASR) Development and Deployment Program was provided under SAFETEA-LU. A related Conference Report provides additional guidance stating that project and programs related ...
Production and use of biogas year 2009; Produktion och anvaendning av biogas aar 2009
Energy Technology Data Exchange (ETDEWEB)
2010-11-15
In the present study, a total of 230 biogas-producing sites were identified. These produced a total of 1363 GWh of energy. The 230 biogas-producing plants were distributed in 136 sewage treatment plants, 57 landfills, 21 co-digestion plants, four industries and 12 farm sites. The number of upgrading plants amounted to 38 and at seven locations injection of upgraded biogas into the natural gas network took place. 44% of the biogas generated in sewage treatment plants, 25% were produced in landfills, 22% of co-digestion plants, 8% in industrial plants and 1% on farm installations. The total biogas production in 2009 was slightely higher than last year, but the division between the different plant types has changed. Production increased for co-digestion plants and farm installations, while production was relatively unchanged for sewage treatment plants. Production in landfills and industrial sites decreased compared with 2008. A larger proportion of the biogas came to use in 2009 compared with previous years. 667 GWh (49%) was used for heating, which also includes heat loss, 488 GWh (36%) were upgraded, 64 GWh (5%) of electricity was generated and 135 GWh (10%) was torched. The main substrates for biogas production were different types of waste such as sewage sludge, source separated food waste and waste from food industry. In addition to biogas, co-digestion plants and the farm plants together produced 537 403 tonnes (wet weight) biofertilizer, and the waste water treatment plants 214 000 tonnes (dry weight) sludge. The provincial breakdown shows that biogas production was greatest in metropolitan areas
Michael, Bryane
2007-01-01
Motivatsioonidest ja viisidest, kuidas korruptsioonivastased programmid parlamendis aitavad parlamendiliikmetel koguda poliitilist kapitali valijate nõudmiste, poliitilise võitluse, eestkoste jne. haldamisel. Lisatud graafikud, tabelid ja diagramm
Higi ja ehmatus. Näitlemise piiripealsusest / Sirle Põdersoo, Aare Pilv
Põdersoo, Sirle
2004-01-01
Nelja 2003. aastal etendunud lavastuse - "Stiil ehk Mis on maailma nimi?" Von Krahli Teatris (lav. M. Unt), "Dekameron ehk Mea culpa ..." Ugalas (lav. V. Ibrahimoglu), "Kolumats" VAT Teatris (lav. C. Römer) ning "Meister ja Margarita" Vanemuises (lav. M. Unt) - põhjal näitlejatöödest. Kasut. kirjandus lk. 143
Possibilities, advantages and disadvantages of application FEM in nuclear technology
International Nuclear Information System (INIS)
Jankovic, D.
1997-01-01
Possibilities of applying the finite element method in nuclear technology are shown in this paper. It has an example of application numerical procedure in fluid mechanics and description of its basic principles. (author)
FEM Simulation of Small Wind Power Generating System Using PMSG
Kesamaru, Katsumi; Ohno, Yoshihiro; Sonoda, Daisuke
The paper describes a new approach to simulate the small wind power generating systems using PMSG, in which the output is connected to constant resistive load, such as heaters, through the rectifier and the dc chopper. The dynamics of the wind power generating system is presented, and it is shown by simulation results that this approach is useful for system dynamics, such as starting phenomena.
FEM Optimal Design of Energy Efficient Induction Machines
Directory of Open Access Journals (Sweden)
TUDORACHE, T.
2009-06-01
Full Text Available This paper deals with a comparative numerical analysis of performances of several design solutions of induction machines with improved energy efficiency. Starting from a typical cast aluminum cage induction machine this study highlights the benefit of replacing the classical cast aluminum cage with a cast copper cage in the manufacture of future generation of high efficiency induction machines used as motors or generators. Then the advantage of replacement of standard electrical steel with higher grade steel with smaller losses is pointed out. The numerical analysis carried out in the paper is based on 2D plane-parallel finite element approach of the induction machine, the numerical results being discussed and compared with experimental measurements.
Dual permeability FEM models for distributed fiber optic sensors development
Aguilar-López, Juan Pablo; Bogaard, Thom
2017-04-01
Fiber optic cables are commonly known for being robust and reliable mediums for transferring information at the speed of light in glass. Billions of kilometers of cable have been installed around the world for internet connection and real time information sharing. Yet, fiber optic cable is not only a mean for information transfer but also a way to sense and measure physical properties of the medium in which is installed. For dike monitoring, it has been used in the past for detecting inner core and foundation temperature changes which allow to estimate water infiltration during high water events. The DOMINO research project, aims to develop a fiber optic based dike monitoring system which allows to directly sense and measure any pore pressure change inside the dike structure. For this purpose, questions like which location, how many sensors, which measuring frequency and which accuracy are required for the sensor development. All these questions may be initially answered with a finite element model which allows to estimate the effects of pore pressure change in different locations along the cross section while having a time dependent estimation of a stability factor. The sensor aims to monitor two main failure mechanisms at the same time; The piping erosion failure mechanism and the macro-stability failure mechanism. Both mechanisms are going to be modeled and assessed in detail with a finite element based dual permeability Darcy-Richards numerical solution. In that manner, it is possible to assess different sensing configurations with different loading scenarios (e.g. High water levels, rainfall events and initial soil moisture and permeability conditions). The results obtained for the different configurations are later evaluated based on an entropy based performance evaluation. The added value of this kind of modelling approach for the sensor development is that it allows to simultaneously model the piping erosion and macro-stability failure mechanisms in a time dependent manner. In that way, the estimated pore pressures may be related to the monitored one and to both failure mechanisms. Furthermore, the approach is intended to be used in a later stage for the real time monitoring of the failure.
Bilateral suprapubisk abscesdannelse fem år efter inkontinensoperation
DEFF Research Database (Denmark)
Bech, Lenette Tove; Sander, Pia; Lose, Gunnar
2009-01-01
recovery. As opposed to the macroporous types (e.g. tension-free vaginal tape), the microporous structure of the IVS-sling causes a higher rate of erosion and infection. Complete sling removal is important in case of IVS-complications. The monitoring of complications related to new medical devices...
Analysis of end-face seals by FEM
Directory of Open Access Journals (Sweden)
Juraszek J.
2002-09-01
Full Text Available The end face-seals joint simultaneously the function of seal, bearing and heat exchanger. In order to improve the design of end-face seals the analysis of this type of joint by means of finite element method, was developed. The temperature distribution is indispensable to the analysis of displacement and stress in this type of face seal. In this work the values of temperature and stress in end-face seals were calculated. The numerical results were confirmed by measurements in the laboratory.
Fem Formulation for Heat and Mass Transfer in Porous Medium
Azeem; Soudagar, Manzoor Elahi M.; Salman Ahmed, N. J.; Anjum Badruddin, Irfan
2017-08-01
Heat and mass transfer in porous medium can be modelled using three partial differential equations namely, momentum equation, energy equation and mass diffusion. These three equations are coupled to each other by some common terms that turn the whole phenomenon into a complex problem with inter-dependable variables. The current article describes the finite element formulation of heat and mass transfer in porous medium with respect to Cartesian coordinates. The problem under study is formulated into algebraic form of equations by using Galerkin's method with the help of two-node linear triangular element having three nodes. The domain is meshed with smaller sized elements near the wall region and bigger size away from walls.
Creep analysis of boiler tubes by fem | Taye | Zede Journal
African Journals Online (AJOL)
In this paper an analysis is developed for the determination of creep deformation of an axisymmetric boiler tubes subjected to axisymmetric loads. The stresses and the permanent strains at a particular time and at the steady state condition, resulting from loading of the tube under constant internal pressure and elevated ...
FEM analysis of hollow hub forming in rolling extrusion process
Directory of Open Access Journals (Sweden)
J. Bartnicki
2014-10-01
Full Text Available In this paper are presented the results of numerical calculations of rolling extrusion process of a hollow hub. As the flanges manufacturing at both sides of the product is required, in the analyzed process of rolling extrusion, a rear bumper was implemented as additional tool limiting axial metal flow. Numerical calculations of the hub forming process were conducted basing on finite element method, applying software Deform3D and Simufact in conditions of three dimensional state of strain. The obtained satisfactory results show that it is possible to conduct the further research works of experimental character, with the application of a modernized aggregate for the rolling extrusion process PO-2.
ORMGEN3D, 3-D Crack Geometry FEM Mesh Generator
International Nuclear Information System (INIS)
Bass, B.R.; Bryson, J.W.
1994-01-01
1 - Description of program or function: ORMGEN3D is a finite element mesh generator for computational fracture mechanics analysis. The program automatically generates a three-dimensional finite element model for six different crack geometries. These geometries include flat plates with straight or curved surface cracks and cylinders with part-through cracks on the outer or inner surface. Mathematical or user-defined crack shapes may be considered. The curved cracks may be semicircular, semi-elliptical, or user-defined. A cladding option is available that allows for either an embedded or penetrating crack in the clad material. 2 - Method of solution: In general, one eighth or one-quarter of the structure is modelled depending on the configuration or option selected. The program generates a core of special wedge or collapsed prism elements at the crack front to introduce the appropriate stress singularity at the crack tip. The remainder of the structure is modelled with conventional 20-node iso-parametric brick elements. Element group I of the finite element model consists of an inner core of special crack tip elements surrounding the crack front enclosed by a single layer of conventional brick elements. Eight element divisions are used in a plane orthogonal to the crack front, while the number of element divisions along the arc length of the crack front is user-specified. The remaining conventional brick elements of the model constitute element group II. 3 - Restrictions on the complexity of the problem: Maxima of 5,500 nodes, 4 layers of clad elements
FORMakademisk – Fem års jubileum - Five years anniversary
Directory of Open Access Journals (Sweden)
Janne Beate Reitan
2013-01-01
Full Text Available When we first published FORMakademisk five years ago, we stated in the very first editorial on page 1 in Volume 1, Issue 1 that:The aim of the journal is to provide a venue for research in design and design education, and thereby develop an interest and working community of scholars in the field. The editorial team perceives design as a generic term that includes creative and performing activities in the great span of the artefacts ‘from the spoon to the city’. The editorial team relates to design education as a field that includes the dissemination of design in society and the teaching of design at all levels general education, vocational preparation, professional education and research education—from kindergarten to doctorate.Since then we have published two issues every year, nine all together, with more than 50 articles. The editorial team saw that future contributors to FORMakademisk would mainly be recruited from researchers within the design disciplines, and their research interests would have their roots in creative and artistic design practice. At the same time, FORMakademisk has invited scientists from established academic disciplines, when their interest has been directed towards design issues.
AUTOMATED CALIBRATION OF FEM MODELS USING LIDAR POINT CLOUDS
Directory of Open Access Journals (Sweden)
B. Riveiro
2018-05-01
Full Text Available In present work it is pretended to estimate elastic parameters of beams through the combined use of precision geomatic techniques (laser scanning and structural behaviour simulation tools. The study has two aims, on the one hand, to develop an algorithm able to interpret automatically point clouds acquired by laser scanning systems of beams subjected to different load situations on experimental tests; and on the other hand, to minimize differences between deformation values given by simulation tools and those measured by laser scanning. In this way we will proceed to identify elastic parameters and boundary conditions of structural element so that surface stresses can be estimated more easily.
FEM Modeling of Crack Propagation in a Model Multiphase Alloy
Institute of Scientific and Technical Information of China (English)
Lihe QIAN; Seishi NISHIDO; Hiroyuki TODA; Tosliro KOBAYASHI
2006-01-01
In this paper, several widely applied fracture criteria were first numerically examined and the crack-tip-region Jintegral criterion was confirmed to be more applicable to predict fracture angle in an elastic-plastic multiphase material. Then, the crack propagation in an idealized dendritic two-phase Al-7%Si alloy was modeled using an elastic-plastic finite element method. The variation of crack growth driving force with crack extension was also demonstrated. It is found that the crack path is significantly influenced by the presence of α-phase near the crack tip, and the crack growth driving force varies drastically from place to place. Lastly, the simulated fracture path in the two-phase model alloy was compared with the experimentally observed fracture path.
FEM Updating of the Heritage Court Building Structure
DEFF Research Database (Denmark)
Ventura, C. E.; Brincker, Rune; Dascotte, E.
2001-01-01
. The starting model of the structure was developed from the information provided in the design documentation of the building. Different parameters of the model were then modified using an automated procedure to improve the correlation between measured and calculated modal parameters. Careful attention......This paper describes results of a model updating study conducted on a 15-storey reinforced concrete shear core building. The output-only modal identification results obtained from ambient vibration measurements of the building were used to update a finite element model of the structure...
Fem Formulation of Heat Transfer in Cylindrical Porous Medium
Azeem; Khaleed, H. M. T.; Soudagar, Manzoor Elahi M.
2017-08-01
Heat transfer in porous medium can be derived from the fundamental laws of flow in porous region ass given by Henry Darcy. The fluid flow and energy transport inside the porous medium can be described with the help of momentum and energy equations. The heat transfer in cylindrical porous medium differs from its counterpart in radial and axial coordinates. The present work is focused to discuss the finite element formulation of heat transfer in cylindrical porous medium. The basic partial differential equations are derived using Darcy law which is the converted into a set of algebraic equations with the help of finite element method. The resulting equations are solved by matrix method for two solution variables involved in the coupled equations.
Vibration analysis of gas turbine blade using FEM
International Nuclear Information System (INIS)
Iqbal, M.J.; Chohan, G.Y.; Khusnood, S.; Khan, M.A.
2003-01-01
In a typical turbo-machine, there is a stator row of blades, which guide the gases onto a rotor row of blades, to extract the mechanical power from the machine. A typical rotor blade was sees upstream disturbance from the stator row and as it rotates, receive a corresponding number of increasing and decreasing lift and moment forces alternating periodically, depending on the number of stator blades/nozzles/guide vanes. Thus all the blades in a turbo-machine receiver their major periodic excitation at a frequency equal to nozzle passing frequency. Since these forces are periodic, one has to consider several number of these harmonics in determining whether resonance takes place, when one of these harmonics coincides with any of the natural frequencies of the blades. Turbine blades have a variety of natural modes of vibration, predominantly as blade alone but also in combination with flexing of the disc rim. These mode occur at characteristic frequencies, which are determined by the distribution of mass and stiffness (in bending or torsion), resulting from the variable thickness over the blade area. Since the advent of steam turbines and their application in various sectors of industry, it is a common experience that a blade failure is a major cause of breakdown in these machines. Blade failures due to fatigue are predominantly vibration related. The dynamic loads on the blading can arise from many sources, the predominant being the source of the operation principles on which the machine is designed. This work deals with vibration analysis of a gas turbine blade using a finite element package ANSYS. Determined the natural frequencies and mode shapes for a turbine blade and a rectangular blade. Results have been validated experimentally using a rectangular blade. ANSYS results have also been compared against published results. (author)
Study of displacements of a bridge abutment using FEM
Directory of Open Access Journals (Sweden)
Wymysłowski Michał
2016-06-01
Full Text Available Steel sheet piles are often used to support excavations for bridge foundations. When they are left in place in the permanent works, they have the potential to increase foundation bearing capacity and reduce displacements; but their presence is not usually taken into account in foundation design. In this article, the results of finite element analysis of a typical abutment foundation, with and without cover of sheet piles, are presented to demonstrate these effects. The structure described is located over the Więceminka river in the town of Kołobrzeg, Poland. It is a single-span road bridge with reinforced concrete slab.
Study of displacements of a bridge abutment using FEM
Wymysłowski, Michał; Kurałowicz, Zygmunt
2016-06-01
Steel sheet piles are often used to support excavations for bridge foundations. When they are left in place in the permanent works, they have the potential to increase foundation bearing capacity and reduce displacements; but their presence is not usually taken into account in foundation design. In this article, the results of finite element analysis of a typical abutment foundation, with and without cover of sheet piles, are presented to demonstrate these effects. The structure described is located over the Więceminka river in the town of Kołobrzeg, Poland. It is a single-span road bridge with reinforced concrete slab.
Design of the 1-Mw, 200-Ghz, Fom Fusion Fem
Urbanus, W. H.; Best, R. W. B.; Bongers, W. A.; Vaningen, A. M.; Manintveld, P.; Sterk, A. B.; Verhoeven, A. G. A.; van der Wiel, M. J.; Caplan, M.; Bratman, V. L.; Denisov, G. G.; Varfolomeev, A. A.; Khlebnikov, A. S.
1993-01-01
The FOM Institute for Plasma Physics has obtained funding for the development of a 1 MW, long pulse, 140-250 GHz free-electron maser. The engineering design is presently being performed in an international collaboration. In this paper the main components of the free-electron maser, the electron beam
Continuous and Discontinuous Modelling of Fracture in Concrete Using FEM
Tejchman, Jacek
2013-01-01
The book analyzes a quasi-static fracture process in concrete and reinforced concrete by means of constitutive models formulated within continuum mechanics. A continuous and discontinuous modelling approach was used. Using a continuous approach, numerical analyses were performed using a finite element method and three different enhanced continuum models: isotropic elasto-plastic, isotropic damage and anisotropic smeared crack one. The models were equipped with a characteristic length of micro-structure by means of a non-local and a second-gradient theory. So they could properly describe the formation of localized zones with a certain thickness and spacing and a related deterministic size effect. Using a discontinuous FE approach, numerical results of cracks using a cohesive crack model and XFEM were presented which were also properly regularized. Finite element analyses were performed with concrete elements under monotonic uniaxial compression, uniaxial tension, bending and shear-extension. Concrete beams un...
DYNA3D2000*, Explicit 3-D Hydrodynamic FEM Program
International Nuclear Information System (INIS)
Lin, J.
2002-01-01
1 - Description of program or function: DYNA3D2000 is a nonlinear explicit finite element code for analyzing 3-D structures and solid continuum. The code is vectorized and available on several computer platforms. The element library includes continuum, shell, beam, truss and spring/damper elements to allow maximum flexibility in modeling physical problems. Many materials are available to represent a wide range of material behavior, including elasticity, plasticity, composites, thermal effects and rate dependence. In addition, DYNA3D has a sophisticated contact interface capability, including frictional sliding, single surface contact and automatic contact generation. 2 - Method of solution: Discretization of a continuous model transforms partial differential equations into algebraic equations. A numerical solution is then obtained by solving these algebraic equations through a direct time marching scheme. 3 - Restrictions on the complexity of the problem: Recent software improvements have eliminated most of the user identified limitations with dynamic memory allocation and a very large format description that has pushed potential problem sizes beyond the reach of most users. The dominant restrictions remain in code execution speed and robustness, which the developers constantly strive to improve
FEM assisted design and simulation of novel electrothermal actuators
Deladi, S.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt
2003-01-01
In this work the authors present the design, simulation, and experimental results of novel electrothermal actuators, such as the trimorph actuator for out-of-plane motion, the coupled in-plane actuator for in-plane motion and an actuator providing combined in- and out-of-plane motion that have been
Bilateral suprapubisk abscesdannelse fem år efter inkontinensoperation
DEFF Research Database (Denmark)
Bech, Lenette; Sander, Pia; Lose, Gunnar
2009-01-01
recovery. As opposed to the macroporous types (e.g. tension-free vaginal tape), the microporous structure of the IVS-sling causes a higher rate of erosion and infection. Complete sling removal is important in case of IVS-complications. The monitoring of complications related to new medical devices......This report presents a case of vaginal erosion and bilateral suprabupic abscesses five years after insertion of an intravaginal slingplasty (IVS) midurethral incontinence sling in a 53-year-old female patient. Partial removal was insufficient. After complete removal, the patient achieved full...
FEM performance of concrete beams reinforced by carbon fiber bars
Directory of Open Access Journals (Sweden)
Hasan Hashim
2018-01-01
Full Text Available Concrete structures may be vulnerable to harsh environment, reinforcement with Fiber Reinforced Polymer (FRP bars have an increasing acceptance than normal steel. The nature of (FRP bar is (non-corrosive which is very beneficial for increased durability as well as the reinforcement of FRP bar has higher strength than steel bar. FRP usage are being specified more and more by public structural engineers and individual companies as main reinforcement and as strengthening of structures. Steel reinforcement as compared to (FRP reinforcement are decreasingly acceptable for structural concrete reinforcement including precast concrete, cast in place concrete, columns, beams and other components. Carbon Fiber Reinforcement Polymer (CFRP have a very high modulus of elasticity “high modulus” and very high tensile strength. In aerospace industry, CFRP with high modulus are popular among all FRPs because it has a high strength to weight ratio. In this research, a finite element models will be used to represent beams with Carbon Fiber Reinforcement and beams with steel reinforcement. The primary objective of the research is the evaluation of the effect of (CFR on beam reinforcement.
Transducers for Sound and Vibration - FEM Based Design
DEFF Research Database (Denmark)
Liu, Bin
2001-01-01
Design of transducers for measurement of vibration (piezoelectric accelerometers) and sound (condenser microphones) is a very labour intensive work. The design work is mostly based on experience and on simple analogies to electrical circuit design. Often a time consuming itterative loop is used......: Specification of the transducer, production of a physical prototype, measurements on the prototype, changed specification of the transducer etc. Furthermore are many transducers made based on customer requirements which also increases the amount of required design work. For these reasons there is a need...... for methods that can reduce the design time consumption and the number of itterations. The present work proposes to use finite element based programs for simulating the behaviour of a transducer with a given set of specifications. A simulation program for accelerometers was developed and has been tested...
Design of fire resistant concrete structures, using validated Fem models
Erich, S.J.F.; Overbeek, van A.B.M.; Heijden, van der G.H.A.; Pel, L.; Huinink, H.P.; Vervuurt, A.H.J.M.; Schlangen, E.; Schlutter, de G.
2008-01-01
Fire safety of buildings and structures is an important issue, and has a great impact on human life and economy. One of the processes negatively affecting the strength of a concrete building or structure during fire is spalling. Many examples exists in which spalling of concrete during fire has
Buckling analysis of SMA bonded sandwich structure – using FEM
Katariya, Pankaj V.; Das, Arijit; Panda, Subrata K.
2018-03-01
Thermal buckling strength of smart sandwich composite structure (bonded with shape memory alloy; SMA) examined numerically via a higher-order finite element model in association with marching technique. The excess geometrical distortion of the structure under the elevated environment modeled through Green’s strain function whereas the material nonlinearity counted with the help of marching method. The system responses are computed numerically by solving the generalized eigenvalue equations via a customized MATLAB code. The comprehensive behaviour of the current finite element solutions (minimum buckling load parameter) is established by solving the adequate number of numerical examples including the given input parameter. The current numerical model is extended further to check the influence of various structural parameter of the sandwich panel on the buckling temperature including the SMA effect and reported in details.
Adaptive stochastic Galerkin FEM with hierarchical tensor representations
Eigel, Martin
2016-01-01
PDE with stochastic data usually lead to very high-dimensional algebraic problems which easily become unfeasible for numerical computations because of the dense coupling structure of the discretised stochastic operator. Recently, an adaptive
Grip Analysis of Road Surface and Tire Footprint Using FEM
Sabri, M.; Abda, S.
2018-02-01
Road grip involve a touch between road pavement and the tire tread pattern. The load bearing surface, which depends on pavement roughness and local pressures in the contact patch. This research conducted to develop a Finite element model for simulating the experimentally testing of asphalt in Jl. AH Nasution Medan, North Sumatera Indonesia base on the value of grip coefficient from various tire loads and the various speed of the vehicle during contact to the road. A tire model and road pavement are developed for the analyses the geometry of tire footprint. The results showed that the greater the mass of car will increase grip coefficient. The coefficient of grip on the road surface contact trough the tire footprint strongly influence the kinetic coefficient of friction at certain speeds. Experimentally show that Concrete road grip coefficient of more than 34% compared to the asphalt road at the same IRI parameters (6-8). Kinetic friction coefficient more than 0.33 was obtained in a asphalt path at a speed of 30-40 Km/hour.
Powerful FEM-generator driven by microsecond sheet beam
Energy Technology Data Exchange (ETDEWEB)
Agafonov, M A; Arzhannikov, A V; Sinitskij, S L; Tarasov, A V [Institute of Nuclear Physics, Novosibirsk (Russian Federation); Ginzburg, N S; Peskov, N Yu [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)
1997-12-31
The results of experimental and theoretical investigations in the creation of a powerful mm-band generator driven by a sheet beam are presented. A microsecond pulse of mm-radiation with a 200 J energy content was obtained in the experiments. The possibility of increasing this energy content up to tens of kJ was demonstrated. 3 figs., 8 refs.
Numerical FEM Analyses of primary coolant system at NPP Temelin
International Nuclear Information System (INIS)
Junek, L.; Slovacek, M.; Ruzek, L.; Moulis, P.
2003-01-01
The main goal of this paper is to inform about the beginning and first steps of implementation of an aging management system at the Temelin NPP. The aging management system is important not only for achieving the current safety level but also for reaching operational reliability of a production unit equipment above the life time assumed by the original design, typically over 40 years. A method to locate the most prominent degradation regions is described. A global shell model of the primary coolant system including all loops and their components - reactor pressure vessel (RPV), steam generator (SG), main coolant pump (MCP), pressurizer, feed water and steam pipelines system is presented. The results of stress-strain analysis on the measured service parameters base are given. Validation of the results is very important and the method to compare the service measurement data with the numerical results is described. The global/local approach is mentioned and discussed. The effects of the complete global system on the individual components under monitoring are transformed into more accurate local spatial models. The local spatial models are used to analyze the gradual lifetime exhaustion of a facility during its service operation. Two spatial local models are presented, viz. feed water nozzle of SG and main coolant piping system T-brunch. The results of analysis of the local spatial models are processed by the neural network computing method, which is also described. The actual gradual damage of the material of the components under monitoring can be obtained based on the analyses performed and on the results from the neural network in combination with the knowledge of the real material characteristics. The procedures applied are included in the DIALIFE diagnostic system
FEM Updating of Tall Buildings using Ambient Vibration Data
DEFF Research Database (Denmark)
Ventura, C. E.; Lord, J. F.; Turek, M.
2005-01-01
Ambient vibration testing is the most economical non-destructive testing method to acquire vibration data from large civil engineering structures. The purpose of this paper is to demonstrate how ambient vibration Modal Identification techniques can be effectively used with Model Updating tools...... to develop reliable finite element models of large civil engineering structures. A fifteen story and a forty-eight story reinforced concrete buildings are used as case studies for this purpose. The dynamic characteristics of interest for this study were the first few lateral and torsional natural frequencies...... the information provided in the design documentation of the building. Different parameters of the model were then modified using an automated procedure to improve the correlation between measured and calculated modal parameters. Careful attention was placed to the selection of the parameters to be modified...
IGA-ADS: Isogeometric analysis FEM using ADS solver
Łoś, Marcin M.; Woźniak, Maciej; Paszyński, Maciej; Lenharth, Andrew; Hassaan, Muhamm Amber; Pingali, Keshav
2017-08-01
In this paper we present a fast explicit solver for solution of non-stationary problems using L2 projections with isogeometric finite element method. The solver has been implemented within GALOIS framework. It enables parallel multi-core simulations of different time-dependent problems, in 1D, 2D, or 3D. We have prepared the solver framework in a way that enables direct implementation of the selected PDE and corresponding boundary conditions. In this paper we describe the installation, implementation of exemplary three PDEs, and execution of the simulations on multi-core Linux cluster nodes. We consider three case studies, including heat transfer, linear elasticity, as well as non-linear flow in heterogeneous media. The presented package generates output suitable for interfacing with Gnuplot and ParaView visualization software. The exemplary simulations show near perfect scalability on Gilbert shared-memory node with four Intel® Xeon® CPU E7-4860 processors, each possessing 10 physical cores (for a total of 40 cores).
Impact comparative study of phone carcasses behavior by FEM
Constantin, Cărăuşu; Plăvănescu, Simona; Dumitru, Nedelcu
2015-07-01
A constant concern of scientific research is based on plastics replace with biodegradable materials that reduce the adverse impact of waste on the environment. A biodegradable material that arouses interest lately is Arboform which is made of lignin, a component of wood and woody plants. Replacing plastic with Arboform in carrying components of products requires technical and economic studies on the implications of such replacement. Numerical simulation methods are a fast and economical way of analyzing the behavior of a product in various mechanical, thermal, electromagnetic and so on. The paper presents comparative results of numerical simulation using the software package SolidWorks impact behavior through the “Drop Test” of half shells made of High Density Polyethylene (HDPE) and of the Arboform LV3 Nature. Simulation watched the half-carcass behavior in three cases of accidental impact, “head”, “corner” and the “back side”. We analyzed the size and location of the maximum voltage and maximum deformation resulting from impact. Simulations have shown for all three cases a maximum voltage increase when using Arboform to use PEDH 93% for impact “forward” and “corner” and only 48.77% “back side” impact. If the maximum displacement, it increasing from carcasses of Arboform 4% for impact “head” and 6% for impact “corner”, but fell by 2.7% for the “back side” impact. The significant increase of stress can be attributed to the higher density of Arboform to PEDH, which led to different weights of the two half-carcasses.
Mechanical property estimation with ABI and FEM simulation
International Nuclear Information System (INIS)
Sharma, Kamal; Singh, P.K.; Das, Gautam; Bhasin, Vivek; Vaze, K.K.; Ghosh, A.K.
2007-01-01
A combined mechanical property evaluation methodology with ABI (Automated Ball Indentation) simulation and Artificial Neural Network (ANN) analysis is evolved to evaluate the mechanical properties for material. The experimental load deflection data is converted into meaningful mechanical properties for this material. An ANN database is generated with the help of contact type finite element analysis by numerically simulating the ABI process for various magnitudes of yield strength (σ yp ) (200 MPa - 500 MPa) with a range of strain hardening exponent (n) (0.1 - 0.5) and strength coefficient (K) (500 MPa - 1500 MPa). For the present problem, a ball indenter of 1.57 mm diameter having Young's modulus approximately 100 times more than the test piece is used to minimize the error due to indenter deformation. Test piece dimension is kept large enough in comparison to the indenter configuration in the simulation to minimize the deflection at the outer edge of the test piece. Further this database after the neural network training; is used to analyze measured material properties of different test pieces. The ANN predictions are reconfirmed with contact type finite element analysis for an arbitrary selected test sample. The methodology evolved in this work can be extended to predict material properties for any irradiated nuclear material in the service. (author)
Efficient implicit FEM simulation of sheet metal forming
van den Boogaard, Antonius H.; Meinders, Vincent T.; Huetink, Han
2003-01-01
For the simulation of industrial sheet forming processes, the time discretisation is one of the important factors that determine the accuracy and efficiency of the algorithm. For relatively small models, the implicit time integration method is preferred, because of its inherent equilibrium check.
A heterogeneous stochastic FEM framework for elliptic PDEs
International Nuclear Information System (INIS)
Hou, Thomas Y.; Liu, Pengfei
2015-01-01
We introduce a new concept of sparsity for the stochastic elliptic operator −div(a(x,ω)∇(⋅)), which reflects the compactness of its inverse operator in the stochastic direction and allows for spatially heterogeneous stochastic structure. This new concept of sparsity motivates a heterogeneous stochastic finite element method (HSFEM) framework for linear elliptic equations, which discretizes the equations using the heterogeneous coupling of spatial basis with local stochastic basis to exploit the local stochastic structure of the solution space. We also provide a sampling method to construct the local stochastic basis for this framework using the randomized range finding techniques. The resulting HSFEM involves two stages and suits the multi-query setting: in the offline stage, the local stochastic structure of the solution space is identified; in the online stage, the equation can be efficiently solved for multiple forcing functions. An online error estimation and correction procedure through Monte Carlo sampling is given. Numerical results for several problems with high dimensional stochastic input are presented to demonstrate the efficiency of the HSFEM in the online stage
Tamm, Triinu
2017-01-01
Eesti Kirjanike Liidu tõlkijate sektsiooni noortele, gümnasistidele ja tudengitele suunatud ilukirjanduse tõlkevõistlusest ja koolitusest. Koos Tallinna ülikooli ja Postimehega käima lükatud uuel tõlkevõistlusel tõlgiti proosatekste vene, prantsuse, inglise ja jaapani keelest. Kommenteerivad tõlkevõistluse žüriide esindajad. Kõige rohkem töid oli Tartu ülikooli üliõpilastelt - 50, Tallinna ülikooli tudengeilt 25, gümnasistide töid oli 59
Li, M.O.
2014-01-01
Air-to-air refuelling is a way to improve fuel efficiency of the overall transport system without waiting for the improvement of basic aviation technology. To take full advantage of such an operation, both passenger aircraft and tanker aircraft (which deliver required fuel to the passenger aircraft
Filmikurioosumid : Kõige, kõige, kõige filmid : Zorrod läbi aegade / Aare Ermel
Ermel, Aare, 1957-2013
2002-01-01
1919. aastal ilmunud Johnston McCulley jutustus "Capistrano needus" pani aluse lugematutele vaeste eest maskis ja pimeduse varjus kättemaksva Zorro lugudele trükisõnas ja kinolinal. Samast tüvest on pärit ka Batmani (looja Bob Kane) ja Supermani lood
Nukufilm võttis enda kanda tänuväärse rolli Eesti riigi filmiajaloos / Aare Lepaste
Lepaste, Aare, 1970-
2007-01-01
Eesti seni ainus filmirestauraator, Nukufilm OÜs töötav Tõnu Talivee nukufilmide restaureerimisest. Pikemalt räägib ta tehtud tööst äsja restaureeritud Heino Parsi nukufilmiga "Operaator Kõps seeneriigis"
Nelja- ja poolesaja aastane Pädaste mõis ärkas uuele elule / Aare Laine
Laine, Aare, 1951-
2008-01-01
Mõisahärrad Martin Breuer ja Imre Sooäär kutsusid Pädaste mõisa renoveeritud peamaja avamisele ka president Toomas Hendrik Ilvese koos proua Evelin Ilvesega, Riigikogu spiikri Ene Ergma, välisriikide diplomaatilisi esindajaid, Riigikogu liikmeid, kultuuri- ja kunstiinimesi. Vt. samas: Nüüd on Muhus Presidendi alleel ka president Ilvese puu. 6. juunil 2008 Muhus eraviisilisel külaskäigul viibinud president T. H. Ilves istutas Väikese väina tammi lähedale Presidendi alleele pärna
Kasemets, Aare, 1963-
2007-01-01
Looduslikest pühapaikadest kui kultuuri- ja looduspärandi kooshoidjatest. Riigi õigusloomest ja suhtest omakultuuriga. Looduslike pühapaikade arengukavast kui jätkusuutlikkuse eeldusest. Seadustest, juhenditest ja ettepanekutest arengukava rakendamiseks. Lühidalt autorist lk. 317
Energy Technology Data Exchange (ETDEWEB)
Bertelsen Blume, S
2008-02-15
According to climate change observations and foresights several countries including Denmark have committed to reduce GHGemissions. However, the transport sector is still increasing its GHGemissions. Substitution of fossil fuels with biofuels seems to be the best way to reduce CO{sub 2}-emission from this sector on the shorter term. This project evaluates how Denmark can produce enough biofuels to fulfil the political goal of 10 % substitution of the fossil fuel consumption in the year of 2020. This project also approaches the suitability of different crop species to the biofuel industry. Maize and sugar beet are the most suitable crops for biofuel production when only focusing on maximum biofuel yield. Alfalfa is likewise showings great potential and is the most suitable crop in terms of sustainable biofuel production, because of low energy requirements (diesel, fertilizer, pesticide and irrigation) during cropping. Even though maize has higher needs for energy during cropping, it will still be suitable for sustainable biofuel production because of the high biofuel yield. Present calculations show that it is possible to meet the required amount of biofuels by using domestic biomass, which is currently exported (cereal grain) or not utilized (eg. straw). However, these calculations assume that it will become possible to convert the whole amount of carbohydrates into biofuel before 2020. In terms of assessing the biofuel production potential three storylines are defined for the development until 2020. Changes in land use and crop composition are suggested for each storyline to adjust the biofuel production to Danish agriculture. The biofuel production potential is also assessed for two regions in Denmark. Here the region of Storstroem shows greater potential than the region of Soenderjylland because of low density of domestic animals. (au)
An unknown travel account from Livonia of 1645-1646 / Magnus Mörner, Aare Mörner
Mörner, Magnus, 1924-
2005-01-01
Edmund Firgeliuse reisist Liivimaale 1645-1646. Firgelius kirjeldab oma päevikus Läti ja Eesti talunaiste riietust, rahvausundit, matusekombeid. Lisatud ärakiri Uppsala ülikooli raamatukogus säilitatavast reisipäeviku koopiast
Energy Technology Data Exchange (ETDEWEB)
Loekke, K.
1996-12-31
The present conference paper deals with the Norwegian power and energy balance towards the year of 2010 based on the rate of domestic energy consumption, development of new power plants, and international supply agreements. The efficiency of power transmission compared to the level of delivered energy in the Norwegian power grid within the period from 1975 to 1992 has increased from 83% to 91% with an equivalency of 5.5 TWh. Aspects in connection with the long-range programme are discussed. 12 figs.
Energy Technology Data Exchange (ETDEWEB)
Ilstad, S; Lund, I
1983-01-01
The present study represents a behavioral approach to residential energy (electricity) conservation. It is especially concerned with socio-psychological variabales like habits, attitudes, social control and mass communication. In addition to that, the effects of family structural variables (size, age, occupation, absence from home), some physical environmental variables and household equipment and appliances are investigated. (Some data on the use of private cars are also included). The sample consists of 113 appartments of identical size (94 m/sup 2/), heated by electricity. The data collection procedure included reading the electric meters in May and September 1982 and systematic interviews with each family after the second reading. The general purpose of the data analysis was to explain the variance in electricity consumption. The most important determinants for differences between families in electricity consumption during the investigated summer period were found to be: family size, number of weeks away from home, use of heating equipment, and attitudes toward energy conservation at home. A number of other factors also contributed substantially to the differences, e.g. age, the use of hot water, size and placement of home freezer, frequency of using washing mashine and dish washer, the use of light, perceived consequences of energy conservation, family cooperation etc. Practical implications for disseminating information on energy conservation in the residential sector through mass media campaigns are discussed.
FLEXURAL STRESS ANALYSIS OF RIGID PAVEMENTS USING AXI-SYMMETRIC AND PLANE STRAIN FEM
Directory of Open Access Journals (Sweden)
V.A. Sawant
2017-11-01
Full Text Available The design of pavement involves a study of soils and paving materials, their response under load for different climatic conditions. In the present study, an attempt has been made to compare stresses predicted using two finite element analyses. First analysis is based on the twodimensional plane strain assumption where as in second approach axi-symmetric condition is assumed to consider three-dimensional behavior of rigid pavement. The results are compared with flexural stresses obtained from conventional Portland Cement Association method. The computed flexural stresses obtained from axi-symmetric condition are found to be in close agreement with PCA method. Results of plane strain analysis show a fair agreement after application of an appropriate multiplication factor
Simulation of Small Wind Turbine Generation System Using Ring Winding Slotless PMSG by FEM
徳永, 翔平; 袈裟丸, 勝己; Tokunaga, Shohei; Kesamaru, Katsumi
2011-01-01
This paper describes a novel small wind turbine generation system with ring winding slotless PMSG. To reduce cogging torque, ring winding PM generator is used for a wind turbine generator. Using finite element analysis, the characteristics of slotless PMSGs are elucidated and the dynamic performance of the proposed system with MPPT control is represented. In this paper, the constant wind test and the quasi-natural wind test are conducted. The results of these tests indicate the proposed syste...
FEM Simulation of Influence of Protective Encapsulation on MEMS Pressure Sensor
DEFF Research Database (Denmark)
Yao, Qingshan; Janting, Jakob; Branebjerg, Jens
2003-01-01
The objective of the work is to evaluate the feasibility of packaging a MEMS silicon pressure sensor by using either a polymer encapsulation or a combination of a polymer encapsulation and a metallic protection Membrane (fig. 1). The potential application of the protected sensor is for harsh...... environments. Several steps of simulation are carried out:1) Comparisons of the sensitivities are made among the non-encapsulated silicon sensor, the polymer encapsulated and polymer with metal encapsulated sensor. This is for evaluating whether the encapsulating materials reduce the pressure sensitivity...... whether the metallic membrane / coating will peel off when applying the maximum pressure, which is 4000 bar leading to high shear stress between the metallic membrane and the polymer encapsulation material.3) Thermal calculations are made to evaluate the influence of the environment on the packaged sensor...
DEFF Research Database (Denmark)
Lauring, Jakob
2003-01-01
Mangfoldighedsledelse er per definition et bredt begreb. Man kan tale om mangfoldighed baseret på nationalitet, etnicitet, religion, alder, køn, seksuel orientering, handicap, uddannelse og meget mere. Som regel vil flere typer af mangfoldighed være til stede i en organisation. Denne mangfoldighed...... nationaliteter og etnisk oprindelse i virksomheder - hvad jeg kalder kulturel mangfoldighed. En type af mangfoldighed man ofte finder i internationale forretningsmiljøer, og som ofte er rekrutteret udelukkende ud fra et motiv om at skabe forretningsmæssige fordele. Som forudsætning for min analyse antager jeg...
FEM analysis of foundation raft for 500 MWe pressurized heavy water reactor building
International Nuclear Information System (INIS)
Kulkarni, N.N.; Goray, J.S.; Joshi, M.H.; Paramasivam, V.
1989-01-01
Foundation raft supports the containment structure and internals for 500 MWe PHW reactor building. It also serves as bottom envelop of the containment structure. In view of this, the design of foundation raft assumes great importance. The foundation raft is subjected to various load, most significant of them are dead load of structure, equipment loads transferred through a system of floors, walls and structural steel columns, pressure load during accident conditions, seismic loads, earth pressure, uplift due to buoyancy loads, foundation reaction etc. In order to achieve optimum design, the detailed structural analysis is required to be performed methodically and in most realistic manner. Finite element methods which have come in vogue with the developments in digital computers can be successfully applied in this area. The paper describes the above methods in detail for the analysis of foundation raft for the various load combinations required to be considered for safe and optimum design