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Sample records for reinforced plastics advanced

  1. Advanced in situ multi-scale characterization of hardness of carbon-fiber-reinforced plastic

    Science.gov (United States)

    Wang, Hongxin; Masuda, Hideki; Kitazawa, Hideaki; Onishi, Keiko; Kawai, Masamichi; Fujita, Daisuke

    2016-10-01

    In situ multi-scale characterization of hardness of carbon-fiber-reinforced plastic (CFRP) is demonstrated by a traditional hardness tester, instrumented indentation tester and atomic-force-microscope (AFM)-based nanoindentation. In particular, due to the large residual indentation and nonuniform distribution of the microscale carbon fibers, the Vickers hardness could not be calculated by the traditional hardness tester. In addition, the clear residual microindentation could not be formed on the CFRP by instrumented indentation tester because of the large tip half angle of the Berkovich indenter. Therefore, an efficient technique for characterizing the true nanoscale hardness of CFRP was proposed and evaluated. The local hardness of the carbon fibers or plastic matrix on the nanoscale did not vary with nanoindentation location. The Vickers hardnesses of the carbon fiber and plastic matrix determined by AFM-based nanoindentation were 340 ± 30 and 40 ± 2 kgf/mm2, respectively.

  2. Recycling of Reinforced Plastics

    Science.gov (United States)

    Adams, R. D.; Collins, Andrew; Cooper, Duncan; Wingfield-Digby, Mark; Watts-Farmer, Archibald; Laurence, Anna; Patel, Kayur; Stevens, Mark; Watkins, Rhodri

    2014-02-01

    This work has shown is that it is possible to recycle continuous and short fibre reinforced thermosetting resins while keeping almost the whole of the original material, both fibres and matrix, within the recyclate. By splitting, crushing hot or cold, and hot forming, it is possible to create a recyclable material, which we designate a Remat, which can then be used to remanufacture other shapes, examples of plates and tubes being demonstrated. Not only can remanufacturing be done, but it has been shown that over 50 % of the original mechanical properties, such as the E modulus, tensile strength, and interlaminar shear strength, can be retained. Four different forms of composite were investigated, a random mat Glass Fibre Reinforced Plastic (GFRP) bathroom component and boat hull, woven glass and carbon fibre cloth impregnated with an epoxy resin, and unidirectional carbon fibre pre-preg. One of the main factors found to affect composite recyclability was the type of resin matrix used in the composite. Thermoset resins tested were shown to have a temperature range around the Glass Transition Temperature (Tg) where they exhibit ductile behaviour, hence aiding reforming of the material. The high-grade carbon fibre prepreg was found to be less easy to recycle than the woven of random fibre laminates. One method of remanufacturing was by heating the Remat to above its glass transition temperature, bending it to shape, and then cooling it. However, unless precautions are taken, the geometric form may revert. This does not happen with the crushed material.

  3. Analytical Evaluation of Fibre-Reinforced Plastic Corrugated Sheet

    Directory of Open Access Journals (Sweden)

    C. K. Gautam

    1998-01-01

    Full Text Available Fibre-reinforced' composites playa lead role as advanced materials in modem day structures.This paper reports fabrication and testing offibre-reinforced corrugated sheet employing 4-point bend loading. An in-depth analysis has been carried out using ANSYS, a finite element method package.The theoretical results obtained are compared with the experimental values. The values ofboth inputsshowed similar results. conforming at a particular boundary condition. However, more similarexperiments "on such fibre-reinforced plastic corrugated sheets have been suggested for -better comparison.

  4. Fracture morphology of carbon fiber reinforced plastic composite laminates

    OpenAIRE

    Vinod Srinivasa; Vinay Shivakumar; Vinay Nayaka; Sunil Jagadeeshaiaih; Murali Seethram; Raghavendra Shenoy; Abdelhakim Nafidi

    2010-01-01

    Carbon fiber reinforced plastic (CFRP) composites have been extensively used in fabrication of primary structures for aerospace, automobile and other engineering applications. With continuous and widespread use of these composites in several advanced technology, the frequency of failures is likely to increase. Therefore, to establish the reasons for failures, the fracture modes should be understood thoroughly and unambiguously. In this paper, CFRP composite have been tested in tension, compre...

  5. Applications for fibre-reinforced plastic

    Energy Technology Data Exchange (ETDEWEB)

    Teuschler, V. [Fiberdur-Vanck (Germany)

    1999-07-01

    The outstanding mechanical properties of fibre-reinforced plastic are extolled. It has strength comparable with that of steel, and other physical properties that give it advantages over ferrous materials for use in pipelines, shipbuilding and offshore conduits. It has well established uses in aircraft, automobiles and boats and is probably more resistant to weathering and corrosion than any other material. The electricity-conducting Navicon pipe, the Fiberdur-vinyl ester/epoxy system and the Fiberdur-DOS system are described.

  6. SOVIET TRENDS IN ORIENTED GLASS-FIBER REINFORCED PLASTICS

    Science.gov (United States)

    GLASS TEXTILES, *PLASTICS, *REINFORCING MATERIALS, ADHESION, BINDERS, DEFORMATION, ELASTIC PROPERTIES, EPOXY RESINS , FIBERS, PHYSICAL PROPERTIES, POLYMERS, PROCESSING, SILICATES, STYRENES, TEXTILES, VISCOSITY

  7. Reinforced plastics and aerogels by nanocrystalline cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Alfred C. W.; Lam, Edmond; Chong, Jonathan; Hrapovic, Sabahudin; Luong, John H. T., E-mail: john.luong@cnrc-nrc.gc.ca [National Research Council Canada (Canada)

    2013-05-15

    Nanocrystalline cellulose (NCC), a rigid rod-like nanoscale material, can be produced from cellulosic biomass in powder, liquid, or gel forms by acid and chemical hydrolysis. Owing to its unique and exceptional physicochemical properties, the incorporation of a small amount of NCC into plastic enhances the mechanical strength of the latter by several orders of magnitudes. Carbohydrate-based NCC poses no serious environmental concerns, providing further impetus for the development and applications of this green and renewable biomaterial to fabricate lightweight and biodegradable composites and aerogels. Surface functionalization of NCC remains the main focus of NCC research to tailor its properties for dispersion in hydrophilic or hydrophobic media. It is of uttermost importance to develop tools and protocols for imaging of NCC in a complex matrix and quantify its reinforcement effect.

  8. Reinforced plastics and aerogels by nanocrystalline cellulose

    Science.gov (United States)

    Leung, Alfred C. W.; Lam, Edmond; Chong, Jonathan; Hrapovic, Sabahudin; Luong, John H. T.

    2013-05-01

    Nanocrystalline cellulose (NCC), a rigid rod-like nanoscale material, can be produced from cellulosic biomass in powder, liquid, or gel forms by acid and chemical hydrolysis. Owing to its unique and exceptional physicochemical properties, the incorporation of a small amount of NCC into plastic enhances the mechanical strength of the latter by several orders of magnitudes. Carbohydrate-based NCC poses no serious environmental concerns, providing further impetus for the development and applications of this green and renewable biomaterial to fabricate lightweight and biodegradable composites and aerogels. Surface functionalization of NCC remains the main focus of NCC research to tailor its properties for dispersion in hydrophilic or hydrophobic media. It is of uttermost importance to develop tools and protocols for imaging of NCC in a complex matrix and quantify its reinforcement effect.

  9. Bond tests of fiberglass-reinforced plastic bars in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Larralde, J.; Silva-Rodriquez, R.; Burdette, J.; Harris, B. (Drexel Univ., Philadelphia, PA (United States). Civil and Architectural Engineering Dept.)

    1994-07-01

    Fiberglass Reinforced Plastic (FRP) bars for concrete reinforcement have been commercially available for several years. The main advantage of such bar relative to the conventional steel reinforcing bars is their resistance to corrosion. The reinforced plastic bars are slightly different from the conventional steel bars both geometrically and mechanically. Thus, research is needed to understand their behavior and to be able to use them in concrete reinforcement with adequate reliability. Bond strength of reinforced plastic bars in concrete is one of the mechanical and behavioral differences with the steel bars. This paper presents the results of pullout and beam tests conducted to determine the bond stress-slip behavior of FRP bars in concrete.

  10. Recycling and Utilization of Waste Glass Fiber Reinforced Plastics

    Directory of Open Access Journals (Sweden)

    Feng Yan-chao

    2016-01-01

    Full Text Available This paper mainly introduced the recovery method, classification and comprehensive utilization process of waste glass fiber reinforced plastics (GFRP. Among the current methods of utilization, the physical method is most promising. After pre-processing of waste GFRP, the short glass fiber can be used in gypsum block to improve the anti-cracking and operation performance of the material; waste GFRP powder can be used in plastic fiber reinforced manhole covers to increase the mechanical strength, and the products conformed to JC 1009-2006. Based on these studies, we also point out some problems concerning the utilization of waste glass fiber reinforced plastics.

  11. EXTRUSION DIE CAE OF THE STEEL REINFORCED PLASTIC PIPE

    Institute of Scientific and Technical Information of China (English)

    W.Q. Ma; H.Y. Sun; D.C. Kang; K.D. Zhao

    2004-01-01

    The steel reinforced plastic pipe is a new kind of pressure pipe. It is made up with steel wires and plastic. Because reinforced skeleton of the steel wire increase the complexity of plastic flow during the extrusion phase, the traditional design criteria of extrusion die is not suitable. The study on extrusion die of the kind of pipe is very important step in produce development. Using finite element (FE) method in this paper, the flow rule of molten plastic inside the die has been predicted and a group of optimal structural parameters was obtained. These results are helpful for reducing the design cycle and improve the quality of the final product.

  12. Fracture morphology of carbon fiber reinforced plastic composite laminates

    Directory of Open Access Journals (Sweden)

    Vinod Srinivasa

    2010-09-01

    Full Text Available Carbon fiber reinforced plastic (CFRP composites have been extensively used in fabrication of primary structures for aerospace, automobile and other engineering applications. With continuous and widespread use of these composites in several advanced technology, the frequency of failures is likely to increase. Therefore, to establish the reasons for failures, the fracture modes should be understood thoroughly and unambiguously. In this paper, CFRP composite have been tested in tension, compression and flexural loadings; and microscopic study with the aid of Scanning Electron Microscope (SEM has been performed on failed (fractured composite surfaces to identify the principle features of failure. Efforts have been made in correlating the fracture surface characteristics to the failure mode. The micro-mechanics analysis of failure serves as a useful guide in selecting constituent materials and designing composites from the failure behavior point of view. Also, the local failure initiation results obtained here has been reliably extended to global failure prediction.

  13. Strain gradient plasticity effects in whisker-reinforced metals

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof

    2002-01-01

    A metal reinforced by fibers in the micron range is studied using the strain gradient plasticity theory of Fleck and Hutchinson (2001). Cell-model analyzes are used to study the influence of the material length parameters numerically. Different higher order boundary conditions are considered...... at the fiber-matrix interface. The results are presented as overall stress-strain curves for the whisker-reinforced metal, and also contour plots of effective plastic strain are shown. The strain gradient plasticity theory predicts a significant stiffening effect when compared to conventional models...

  14. Development and Properties of Glass Fiber Reinforced Plastics Geogrid

    Institute of Scientific and Technical Information of China (English)

    WANG Qingbiao; ZHANG Cong; WEN Xiaokang; L Rongshan; LIANG Xunmei; LU Shide

    2015-01-01

    Glassfi ber reinforced plastics geogrid has a wide application in thefi eld of soil reinforcement because of its high strength, good toughness, and resistance to environmental stress, creep resistance and strong stability. In order to get high-powered glassfi ber reinforced plastics geogrid and its mechanical characteristics, the properties and physical mechanical index of geogrid have been got through the study of its raw material, production process and important quality index. The analysis and study have been made to the geogrid’s mechanical properties with loading speed, three-axial compression, temperature tensile test and FLAC3D numerical simulation, thus obtain the mechanical parameters of its displacement time curve, breaking strength and elongation at break. Some conclusions can be drawn as follows: (a) Using glassfi ber materials, knurling and coated projection process, the fracture strength and corrosion resistance of geogrid are greatly improved and the interlocking bite capability of soil is enhanced. (b) The fracture strength of geogrid is related to temperature and loading rate. When the surrounding rock pressure is fixed, the strength and anti-deformation ability of reinforced soil are significantly enhanced with increasing reinforced layers. (c) The pullout test shows the positive correlation between geogrid displacement and action time. (d) As a new reinforced material, the glass fi ber reinforced plastics geogrid is not mature enough in theoretical research and practical experience, so it has become an urgent problem both in theoretical study and practical innovation.

  15. [Carbon fiber-reinforced plastics as implant materials].

    Science.gov (United States)

    Bader, R; Steinhauser, E; Rechl, H; Siebels, W; Mittelmeier, W; Gradinger, R

    2003-01-01

    Carbon fiber-reinforced plastics have been used clinically as an implant material for different applications for over 20 years.A review of technical basics of the composite materials (carbon fibers and matrix systems), fields of application,advantages (e.g., postoperative visualization without distortion in computed and magnetic resonance tomography), and disadvantages with use as an implant material is given. The question of the biocompatibility of carbon fiber-reinforced plastics is discussed on the basis of experimental and clinical studies. Selected implant systems made of carbon composite materials for treatments in orthopedic surgery such as joint replacement, tumor surgery, and spinal operations are presented and assessed. Present applications for carbon fiber reinforced plastics are seen in the field of spinal surgery, both as cages for interbody fusion and vertebral body replacement.

  16. Automobile materials competition: energy implications of fiber-reinforced plastics

    Energy Technology Data Exchange (ETDEWEB)

    Cummings-Saxton, J.

    1981-10-01

    The embodied energy, structural weight, and transportation energy (fuel requirement) characteristics of steel, fiber-reinforced plastics, and aluminum were assessed to determine the overall energy savings of materials substitution in automobiles. In body panels, a 1.0-lb steel component with an associated 0.5 lb in secondary weight is structurally equivalent to a 0.6-lb fiber-reinforced plastic component with 0.3 lb in associated secondary weight or a 0.5-lb aluminum component with 0.25 lb of secondary weight. (Secondary weight refers to the combined weight of the vehicle's support structure, engine, braking system, and drive train, all of which can be reduced in response to a decrease in total vehicle weight.) The life cycle transportation energy requirements of structurally equivalent body panels (including their associated secondary weights) are 174.4 x 10/sup 3/ Btu for steel, 104.6 x 10/sup 3/ Btu for fiber-reinforced plastics, and 87.2 x 10/sup 3/ Btu for aluminum. The embodied energy requirements are 37.2 x 10/sup 3/ Btu for steel, 22.1 x 10/sup 3/ Btu for fiber-reinforced plastics, and 87.1 x 10/sup 3/ Btu for aluminum. These results can be combined to yield total energy requirements of 211.6 x 10/sup 3/ Btu for steel, 126.7 x 10/sup 3/ Btu for fiber-reinforced plastics, and 174.3 x 10/sup 3/ Btu for aluminum. Fiber-reinforced plastics offer the greatest improvements over steel in both embodied and total energy requirements. Aluminum achieves the greatest savings in transportation energy.

  17. Structural Analysis of Basalt Fiber Reinforced Plastic Wind Turbine Blade

    Directory of Open Access Journals (Sweden)

    Mengal Ali Nawaz

    2014-07-01

    Full Text Available In this study, Basalt fiber reinforced plastic (BFRP wind turbine blade was analyzed and compared with Glass fiber reinforced plastic blade (GFRP. Finite element analysis (FEA of blade was carried out using ANSYS. Data for FEA was obtained by using rule of mixture. The shell element in ANSYS was used to simulate the wind turbine blade and to conduct its strength analysis. The structural analysis and comparison of blade deformations proved that BFRP wind turbine blade has better strength compared to GFRP wind turbine blade.

  18. Rigid-plastic seismic design of reinforced concrete structures

    DEFF Research Database (Denmark)

    Costa, Joao Domingues; Bento, R.; Levtchitch, V.

    2007-01-01

    In this paper a new seismic design procedure for Reinforced Concrete (R/C) structures is proposed-the Rigid-Plastic Seismic Design (RPSD) method. This is a design procedure based on Non-Linear Time-History Analysis (NLTHA) for systems expected to perform in the non-linear range during a lifetime...

  19. Waste Plastic Fibre Reinforced Self Compacting Concrete

    Directory of Open Access Journals (Sweden)

    Mrs. Vijaya G.S Assistant Professor

    2016-05-01

    Full Text Available Self-compacting concrete is high performance concrete which is highly flowable, non-segregating, spread on its own weight and doesn‟t need any compaction. This paper deals with flow and strength characteristics such as compressive strength, split tensile strength, flexural strength and impact strength of Self-compacting concrete with various percentages of waste plastic fibres like 0%, 0.25%, 0.5%, 0.75%, 1.0%, 1.1%, 1.20%, 1.3% and 1.4% is added by weight of cement. The mix proportion for M40 grade of concrete was done by using Nan Su method (Cement: GGBS: Fine aggregate: Course aggregate 1: 0.705: 3.34: 2.62. Water powder (W/P ratio 0.36, cement content 280kg/m3 , GGBS 220 kg/m3 was calculated and maintained as constant throughout the experimental work for all eight mixes, only the superplastizers dosage was varied for different percentage of fibres. In this experimental investigation one control mix and eight (8 different mixes were considered. Totally 81 Cube, beam, Cylindrical specimens and square plates were casted, cured and tested as per IS specifications. For determining impact strength drop weight method was used. The results obtained indicate that fresh (workability characteristics satisfy the lower and upper limit as suggested by EFNARC. The tests on hardened properties indicate that the compressive strength, split tensile strength, flexural strength was improved proportionally with the addition of waste plastic fibers upto 1.0% by weight of cement and then decreases. The impact strength improved proportionally with addition of fibres upto 1.2% by weight of cement and then decreases.

  20. Analytical Evaluation of Fibre-Reinforced Plastic Corrugated Sheet

    OpenAIRE

    C. K. Gautam; R. C. Pathak

    1998-01-01

    Fibre-reinforced' composites playa lead role as advanced materials in modem day structures.This paper reports fabrication and testing offibre-reinforced corrugated sheet employing 4-point bend loading. An in-depth analysis has been carried out using ANSYS, a finite element method package.The theoretical results obtained are compared with the experimental values. The values ofboth inputsshowed similar results. conforming at a particular boundary condition. However, more similarexperiments "on ...

  1. Fibre Reinforced Plastic Concepts for Structural Chassis Parts

    OpenAIRE

    Deißer, Oliver; Friedrich, Horst E.; Kopp, Gundolf

    2014-01-01

    Abstract Fibre reinforced plastics (FRP) have a high potential for reducing masses of automotive parts, but are seldom used for structural parts in the chassis. If the whole chassis concept is adapted to the new material, then a high weight saving potential can be gained and new body concepts can result. DLR Institute of Vehicle Concepts designed and dimensioned a highly stressed structural part in FRP. A topology optimisation of a defined working space with the estimated loads was perform...

  2. Plastic Fibre Reinforced Soil Blocks as a Sustainable Building Material

    Science.gov (United States)

    Prasad, C. K. Subramania; Nambiar, E. K. Kunhanandan; Abraham, Benny Mathews

    2012-10-01

    Solid waste management, especially the huge quantity of waste plastics, is one of the major environmental concerns nowadays. Their employability in block making in the form of fibres, as one of the methods of waste management, can be investigated through a fundamental research. This paper highlights the salient observations from a systematic investigation on the effect of embedded fibre from plastic waste on the performance of stabilised mud blocks. Stabilisation of the soil was done by adding cement, lime and their combination. Plastic fibre in chopped form from carry bags and mineral water bottles were added (0.1% & 0.2% by weight of soil) as reinforcement. The blocks were tested for density, and compressive strength, and observed failure patterns were analysed. Blocks with 0.1% of plastic fibres showed an increase in strength of about 3 to 10%. From the observations of failure pattern it can be concluded that benefits of fibre reinforcement includes both improved ductility in comparison with raw blocks and inhibition of crack propogation after its initial formation.

  3. Evaluation of Hybrid Reinforcement (Fiber-Reinforced-Plastic Rod with Steel Core)

    Science.gov (United States)

    1993-08-01

    Kaci, S. (1992), "Cables Composites pour la Precontrainte : Etude de la Relaxation," Advanced Composite Materials in Bridges and Structures, 1st...Nishizaki, I., Sasaki, I. (1992), "Evaluation of the Durability of Advanced Composites for Applications to Prestressed Concrete Bridges ," Advanced...7:4 z ... ýs (*AA4 - 2-0 4 Theodor Krauthammer Professor of Civil Engineering ABSTRACT The corrosion of concrete reinforcement is a problem that

  4. The new structure of fibre glass reinforced plastics bolt

    Institute of Scientific and Technical Information of China (English)

    马念杰; 刘社育

    2003-01-01

    The develop actuality and direction of FRP(fibre glass reinforced plastics) bolt in the world are analyzed. The new type structure of FRP bolt was designed. Trial data indicate that, all kinds of capability target of this FRP bolt all achieve and exceed the country standard, substitute present metal bolt,wood bolt and bamboo bolt and other side bolt, it can gain magnitude technology and economy benefit. FRP bolt mechanization product line produce efficiency is high, its throughput a day are 750 base, this can meet demand of hit-small mining company.

  5. Strain gradient plasticity effects in whisker-reinforced metals

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof

    2003-01-01

    A metal reinforced by fibers in the micron range is studied using the strain gradient plasticity theory of Fleck and Hutchinson (J. Mech. Phys. Solids 49 (2001) 2245). Cell-model analyses are used to study the influence of the material length parameters numerically, for both a single parameter...... version and the multiparameter theory, and significant differences between the predictions of the two models are reported. It is shown that modeling fiber elasticity is important when using the present theories. A significant stiffening effect when compared to conventional models is predicted, which...... is a result of a significant decrease in the level of plastic strain. Moreover, it is shown that the relative stiffening effect increases with fiber volume fraction. The higher-order nature of the theories allows for different higher-order boundary conditions at the fiber-matrix interface, and these boundary...

  6. Evaluating plastic shrinkage and permeability of polypropylene fiber reinforced concrete

    Directory of Open Access Journals (Sweden)

    G.M. Sadiqul Islam

    2016-12-01

    Full Text Available Plastic concrete is susceptible to develop cracks due to shrinkage in dry and windy conditions. Addition of fibers could reduce propagation of this crack. On the other hand, permeability determines the durability properties of concrete. This study evaluated strength, plastic shrinkage and permeability (gas and water of concrete incorporating ‘polypropylene’ fiber (aspect ratio 300 in various proportions (viz. 0.10%, 0.15%, 0.2%, 0.25% and 0.3% by volume of concrete. Plane concrete samples were also prepared and tested for reference purpose. Inclusion of 0.1% fiber gave minor reduction (2% in compressive strength while the tensile strength increased by 39% with same fiber content compared to the plain concrete. A significant reduction in crack generation, appearance period of first crack and crack area between plane concrete and fiber reinforced concretes was found. The experimental result with inclusion of 0.1–0.3% fiber in concrete indicated that plastic shrinkage cracks were reduced by 50–99% compared to the plain concrete. For reference concrete (without fiber, test within the high temperature and controlled humidity chamber gave higher crack width than the acceptable limit (3 mm specified by the ACI 224. With the inclusion of 0.1% fiber reduced the crack width down to 1 mm and the trend was continued with the addition of more fibers. However, results showed that with the addition of polypropylene fiber both water and gas permeability coefficient was increased. Therefore, it is concluded that the fiber reinforced concrete would work better for plastic shrinkage susceptible structural elements (flat elements such as slab; however, it requires careful judgement while applying to a water retaining structures.

  7. Arrangement for connecting a fiber-reinforced plastic pipe to a stainless steel flange

    Science.gov (United States)

    Allais, Arnaud; Hoffmann, Ernst

    2008-02-05

    Arrangement for connecting a fiber-reinforced plastic pipe (18) to a stainless steel flange (12, 16), in which the end of the fiber-reinforced plastic pipe (18) is accommodated in a ring-shaped groove (12a, 16a) in the flange (12, 16), the groove conforming to the dimensions of the fiber-reinforced plastic pipe (18), where the gap remaining between the end of the fiber-reinforced plastic pipe (18) and the ring-shaped groove (12a, 16a) is filled with a sealant (19).

  8. Particulate Filled Composite Plastic Materials from Recycled Glass Fibre Reinforced Plastics

    Directory of Open Access Journals (Sweden)

    Aare ARUNIIT

    2011-09-01

    Full Text Available Glass fibre reinforced plastic (GFRP scrap consisted of acrylic plastic with glass fibre reinforcement in polyester resin matrix was used in our experiments. The multi-functional DS-series disintegrator mills were used for mechanical processing of GFRP scrap. Preceding from the results characterization of the milled powder particles size, shape and other properties the numerical algorithm for modelling of the density of the new filler material was developed. The main goal of the current study is to develop new particulate filled composite plastic material from recycled GFRP scrap. With recovered plastic powder material the higher filler content in polyester resin matrix can be achieved. The new composite is modelled on basis of the properties of new material. Such an approach requires tests of the new material. The considered target characteristics of the new material are the tensile strength, elongation at break and the cost. The multicriteria optimization problem has been formulated and solved by use of physical programming techniques and Pareto optimality concept. The designed new composites were manufactured in different mixing ratios of powder and binder agent. The strength and stiffness properties of new composite material were tested. http://dx.doi.org/10.5755/j01.ms.17.3.593

  9. The High-Frequency Dielectric Properties of Glass Fibre Reinforced Plastic and Honeycomb Layers

    Science.gov (United States)

    1989-06-29

    The dielectric constant and the dielectric loss angle tangent of glass fibre reinforced plastic are both relatively small; it is a good wave...practical value. This paper introduces the work we have done in this area. The dielectric properties of glass fibre reinforced plastic have a close

  10. Fatigue behaviour of carbon fibre reinforced plastic under spectrum loading

    Energy Technology Data Exchange (ETDEWEB)

    Sudha, J. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India)], E-mail: sudhaj@platinum.materials.iisc.ernet.in; Kumar, Subodh [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Srinivasan, Prabha; Vijayaraju, K. [Aeronautical Development Agency, Bangalore (India)

    2009-02-15

    In the present investigation the fatigue behaviour of carbon fibre reinforced plastic laminates under realistic service loading conditions has been examined. Laminates with different lay-up sequences have been tested for fatigue under spectrum loading with three different peak load levels. The damage in the laminates was characterized by using ultrasonic C-Scan as well as dynamic mechanical analysis and the damage mechanism was analyzed using scanning electron microscope. A similar investigation was also conducted on laminates with a hole. The results indicate that the spectrum loading did affect the modulus and fibre/matrix interfacial properties of all type of laminates investigated and also caused delamination in the laminate with a hole due to stress concentration around the hole.

  11. Strength of anisotropic wood and synthetic materials. [plywood, laminated wood plastics, glass fiber reinforced plastics, polymeric film, and natural wood

    Science.gov (United States)

    Ashkenazi, Y. K.

    1981-01-01

    The possibility of using general formulas for determining the strength of different anisotropic materials is considered, and theoretical formulas are applied and confirmed by results of tests on various nonmetallic materials. Data are cited on the strength of wood, plywood, laminated wood plastics, fiber glass-reinforced plastics and directed polymer films.

  12. Numerical modelling of reinforced concrete beams with fracture-plastic material

    Directory of Open Access Journals (Sweden)

    O. Sucharda

    2014-10-01

    Full Text Available This paper describes the use of models of fracture-plastic materials for reinforced concrete in numerical modelling of beams made from reinforced concrete. The purpose of the paper is to use of a model of concrete for modelling of a behaviour of reinforced concrete beams which have been tested at the University of Toronto within re-examination of classic concrete beam tests. The original tests were performed by Bresler- Scordelis. A stochastic modelling based on LHS (Latin Hypercube Sampling has been performed for the reinforced concrete beam. An objective of the modelling is to evaluate the total bearing capacity of the reinforced concrete beams depending on distribution of input data. The beams from the studied set have longitudinal reinforcement only. The beams do not have any shear reinforcement. The software used for the fracture-plastic model of the reinforced concrete is the ATENA.

  13. 40 CFR Table 2 to Subpart Wwww of... - Compliance Dates for New and Existing Reinforced Plastic Composites Facilities

    Science.gov (United States)

    2010-07-01

    ... Reinforced Plastic Composites Facilities 2 Table 2 to Subpart WWWW of Part 63 Protection of Environment...: Reinforced Plastic Composites Production Pt. 63, Subpt. WWWW, Table 2 Table 2 to Subpart WWWW of Part 63—Compliance Dates for New and Existing Reinforced Plastic Composites Facilities As required in §§ 63.5800...

  14. Effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells

    Institute of Scientific and Technical Information of China (English)

    Chu-lin YU; Zhi-ping CHEN; Ji WANG; Shun-juan YAN; Li-cai YANG

    2012-01-01

    The effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells is investigated through experimental and numerical buckling analysis using six welded steel cylindrical shell specimens.The relationship between the amplitude of weld reinforcement and the axial plastic buckling critical load is explored.The effect of the material yield strength and the number of circumferential welds on the axial plastic buckling is studied.Results show that circumferential weld reinforcement represents a severe imperfect form of axially compressed welded steel cylindrical shells and the axial plastic buckling critical load decreases with the increment of the mean amplitude of circumferential weld reinforcement.The material yield strength and the number of circumferential welds are found to have no significant effect on buckling waveforms; however,the axial plastic buckling critical load can be decreased to some extent with the increase of the number of circumferential welds.

  15. Modification of polyester resins during molding of glass-fiber-reinforced plastics

    Science.gov (United States)

    Yakushin, V.; Jansons, J.; Bulmanis, V.; Cabulis, U.; Bulmanis, A.

    2013-11-01

    The effect of addition of two new urethane prepolymers on the mechanical properties of unsaturated polyester resins and glass-fiber-reinforced plastics based on them is investigated. The effect of concentration of these additives on the elastic modulus, elongation at break, and flexural strength of hardened orthophthalic resins is evaluated. A significant increase in the strength of the binders and glass-fiber-reinforced plastics (GFRPs) based on them is observed upon adding urethane prepolymers to the resins. The properties of laminated and randomly reinforced glass-fiber plastics with the modified orthophthalic resins are compared with those of similar GFRPs based on popular brands of industrial resins.

  16. Impact properties of aluminium - glass fiber reinforced plastics sandwich panels

    Directory of Open Access Journals (Sweden)

    Mathivanan Periasamy

    2012-06-01

    Full Text Available Aluminium - glass fiber reinforced plastics (GFRP sandwich panels are hybrid laminates consisting of GFRP bonded with thin aluminum sheets on either side. Such sandwich materials are increasingly used in airplane and automobile structures. Laminates with varying aluminium thickness fractions, fiber volume fractions and orientation in the layers of GFRP were fabricated by hand lay up method and evaluated for their impact performance by conducting drop weight tests under low velocity impacts. The impact energy required for initiating a crack in the outer aluminium layer as well as the energy required for perforation was recorded. The impact load-time history was also recorded to understand the failure behavior. The damage depth and the damage area were measured to evaluate the impact resistance. Optical photography and scanning electron micrographs were taken to visualize the crack and the damage zone. The bidirectional cross-ply hybrid laminate (CPHL has been found to exhibit better impact performance and damage resistance than the unidirectional hybrid laminate (UDHL. Increase in aluminium thickness fraction (Al tf and fiber volume fraction (Vf resulted in an increase in the impact energy required for cracking and perforation. On an overall basis, the sandwich panels exhibited better impact performance than the monolithic aluminium.

  17. Guided wave propagation in porous unidirectional carbon fiber reinforced plastic

    Science.gov (United States)

    Dobmann, Nicolas; Bach, Martin

    2017-02-01

    Networks of piezoelectric transducers mounted on aircraft structures for Acousto Ultrasonics (AU) purposes are designed to be applied during the service life of the aircraft. The approach to integrate these sensor networks already during the manufacture of carbon fiber reinforced plastic (CFRP) host structures prompts ideas to achieve an additional benefit by their application for cure monitoring, thus extending their use to the manufacturing chain. This benefit could be extended even further if guided waves generated by AU sensor networks could be used for porosity testing extensively applied for CFRP aircraft structures. In light of this, an experimental study was conducted to investigate effects of porosity on the propagation of guided waves in a basic configuration of unidirectional CFRP. Several samples were manufactured at different porosity levels by variation of the processing pressure. Wave fields were acquired using an ultrasonic scanning device. In the present work, phase velocities are chosen as best measurable and quantifiable propagation feature and the approach for the analysis of phase velocities in porosity samples is outlined. First results are presented and discussed regarding the influence of porosity on guided wave phase velocity and basic applicability for porosity testing of aircraft structures.

  18. Characteristics of Impact Damage and Post-Impact Strength in Glass-Fibre-Reinforced Plastics with Different Reinforcement Architecture

    Directory of Open Access Journals (Sweden)

    Michał BARCIKOWSKI

    2013-12-01

    Full Text Available Fiber-reinforced plastics (FRP are nowadays used commonly for constructions subjected to impacts of different energies and velocities; therefore, the problem of impact resistance is crucial. This paper presents the results of high-velocity impact tests and post-impact evaluation of damage in glass-fiber-reinforced plastics, depending on the architecture of reinforcing material (different woven fabrics, mat. Composites reinforced with continuous-filament mat, woven roving, roving fabric and twisted-yarn fabric were prepared and subjected to intermediate- and high-velocity impact. After the ballistic impact, damage extent and residual strength, as well as water leakage through the composites, were evaluated. The damage was also investigated under a microscope. The damage extent was confirmed to be linearly dependent on impact energy. The addition of rubber was found to decrease damage extent and increase post-impact residual strength, as well as decrease water leakage rate.

  19. An application of asymmetrical glass fibre-reinforced plastics for the manufacture of curved fibre reinforced concrete

    OpenAIRE

    Funke, Henrik; Gelbrich, Sandra; Ulke-Winter , Lars; Kroll, Lothar; Petzoldt, Carolin

    2015-01-01

    There was developed a novel technological and constructive approach for the low-cost production of curved freeform formworks, which allow the production of single and double-curved fibre reinforced concrete. The scheduled approach was based on a flexible, asymmetrical multi-layered formwork system, which consists of glass-fibre reinforced plastic (GFRP). By using of the unusual anisotropic structural behavior, these GFRP formwork elements permitted a specific adjustment of defined curvature. ...

  20. The Effects of Weathering on Mechanical Properties of Glass Fiber Reinforced Plastics (Grp) Materials

    OpenAIRE

    Abdullah, H.; S. Al Araimi and R. A. Siddiqui

    2012-01-01

    Glass fiber reinforced plastics composite is extensively used as a structural material for pools, oil pipes and tanks because it has good corrosion resistance properties.  The effects of weathering on the mechanical properties of glass fiber reinforced plastics (GRP) in the Sultanate of Oman have been studied.  The tensile and three point bend specimens were exposed to outdoor conditions (open atmosphere) in sunlight and tested for various intervals of time.  It was observed th...

  1. Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide

    Directory of Open Access Journals (Sweden)

    Tae-Il Seo

    2013-05-01

    Full Text Available Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %. The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents.

  2. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    NARCIS (Netherlands)

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable resourc

  3. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    NARCIS (Netherlands)

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable resourc

  4. A bio-based fibre-reinforced plastic pedestrian bridge for Schiphol

    NARCIS (Netherlands)

    Smits, J.E.P.; Gkaidatzis, R.

    2015-01-01

    The present paper investigates Bio-based fibre-reinforced plastics, used as a load-bearing element of a bridge. We aim to increase the renewable content and decreasing the embodied energy of FRP. To achieve that, the consisting raw materials of these plastics which are based on non-renewable

  5. Direct electroplating of plastic for advanced electrical applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Hansen, Hans Nørgaard; Tang, Peter Torben

    2017-01-01

    for direct electroplating of plastic eliminating the need for slow and expensive processes like electroless metal deposition, PVD coating, painting with conductive inks etc. The results obtained from the test demonstrate the potential of direct electroplating of plastic to enhance the electrical conductivity...... and the use of electroplated plastics for advanced applications like Moulded Interconnect Devices (MIDs)....

  6. Analysis on plastic properties of reactive powder concrete continuous beams reinforced with GFRP bars

    Institute of Scientific and Technical Information of China (English)

    LU Shan-shan; ZHENG Wen-zhong

    2010-01-01

    To study the plastic properties of reactive powder concrete continuous beams reinforced with GFRP bars,the calculation programs for moment redistribution coefficients are prepared by using nonlinear analysis methods such as moment-curvature,conjugate beam method and so on.By comparing the test results of existed FRP bars reinforced concrete continuous beams with simulation results,the accuracy of the calculation program is verified.Then 18 simulated GFRP bars reinforced reactive powder concrete continuous beams are selected whose change parameters are reinforcement ratio of mid-span and middle support.Through the nonlinear analysis of simulated beams,moment redistribution coefficients under mid-span concentrated loads,one-third point loads and uniformly distributed loads are obtained respectively.Thus the formula of moment redistribution coefficients is obtained by fitting moment redistribution coefficients and factors.The results show that the reactive powder concrete continuous beams reinforced with GFRP bars have good plastic properties.

  7. CRAG (Composite Research Advisory Group) Test Methods for the Measurement of the Engineering Properties of Fibre Reinforced Plastics

    Science.gov (United States)

    1988-02-01

    coefficients in fibre reinforced plastic laminates. RAE Technical Report 81105, August 1981. UNLIMITED fig 900.1 00 Z a r40 N 6)l I...through- thickness moisture distribution and diffusion coefficients in fibre reinforced plastic laminates. RAE Technical Report 81105, August 1981. 4 C...procedures to be used to determine the fibre volume fraction (Vf) and the resin volume fraction (Vr) of cured fibre reinforced plastic laminates. It is not

  8. Circular Functions Based Comprehensive Analysis of Plastic Creep Deformations in the Fiber Reinforced Composites

    Science.gov (United States)

    Monfared, Vahid

    2016-06-01

    Analytically based model is presented for behavioral analysis of the plastic deformations in the reinforced materials using the circular (trigonometric) functions. The analytical method is proposed to predict creep behavior of the fibrous composites based on basic and constitutive equations under a tensile axial stress. New insight of the work is to predict some important behaviors of the creeping matrix. In the present model, the prediction of the behaviors is simpler than the available methods. Principal creep strain rate behaviors are very noteworthy for designing the fibrous composites in the creeping composites. Analysis of the mentioned parameter behavior in the reinforced materials is necessary to analyze failure, fracture, and fatigue studies in the creep of the short fiber composites. Shuttles, spaceships, turbine blades and discs, and nozzle guide vanes are commonly subjected to the creep effects. Also, predicting the creep behavior is significant to design the optoelectronic and photonic advanced composites with optical fibers. As a result, the uniform behavior with constant gradient is seen in the principal creep strain rate behavior, and also creep rupture may happen at the fiber end. Finally, good agreements are found through comparing the obtained analytical and FEM results.

  9. Circular Functions Based Comprehensive Analysis of Plastic Creep Deformations in the Fiber Reinforced Composites

    Science.gov (United States)

    Monfared, Vahid

    2016-12-01

    Analytically based model is presented for behavioral analysis of the plastic deformations in the reinforced materials using the circular (trigonometric) functions. The analytical method is proposed to predict creep behavior of the fibrous composites based on basic and constitutive equations under a tensile axial stress. New insight of the work is to predict some important behaviors of the creeping matrix. In the present model, the prediction of the behaviors is simpler than the available methods. Principal creep strain rate behaviors are very noteworthy for designing the fibrous composites in the creeping composites. Analysis of the mentioned parameter behavior in the reinforced materials is necessary to analyze failure, fracture, and fatigue studies in the creep of the short fiber composites. Shuttles, spaceships, turbine blades and discs, and nozzle guide vanes are commonly subjected to the creep effects. Also, predicting the creep behavior is significant to design the optoelectronic and photonic advanced composites with optical fibers. As a result, the uniform behavior with constant gradient is seen in the principal creep strain rate behavior, and also creep rupture may happen at the fiber end. Finally, good agreements are found through comparing the obtained analytical and FEM results.

  10. Tensile Properties of Unsaturated Polyester and Epoxy Resin Reinforced with Recycled Carbon-Fiber-Reinforced Plastic

    Science.gov (United States)

    Okayasu, Mitsuhiro; Kondo, Yuta

    2017-08-01

    To better understand the mechanical properties of recycled carbon-fiber-reinforced plastic (rCFRP), CFRP crushed into small pieces was mixed randomly in different proportions (0-30 wt%) with two different resins: unsaturated polyester and epoxy resin. Two different sizes of crushed CFRP were used: 0.1 mm × 0.007 mm (milled CFRP) and 30 mm × 2 mm (chopped CFRP). The tensile strength of rCFRP was found to depend on both the proportion and the size of the CFRP pieces. It increased with increasing proportion of chopped CFRP, but decreased with increasing proportion of milled CFRP. There was no clear dependence of the tensile strength on the resin that was used. A low fracture strain was found for rCFRP samples made with chopped CFRP, in contrast to those made with milled CFRP. The fracture strain was found to increase with increasing content of milled CFRP up to 20 wt%, at which point, coalescence of existing microvoids occurred. However, there was a reduction in fracture strain for rCFRP with 30 wt% of milled CFRP, owing to the formation of defects (blow holes). Overall, the fracture strain was higher for rCFRPs based on epoxy resin than for those based on unsaturated polyester with the same CFRP content, because of the high ductility of the epoxy resin. The different tensile properties reflected different failure characteristics, with the use of chopped CFRP leading to a complicated rough fracture surface and with milled CFRP causing ductile failure through the presence of tiny dimple-like fractures. However, for a high content of milled CFRP (30 wt%), large blow holes were observed, leading to low ductility.

  11. Advanced Fibre Reinforced Methyl Nadicimide Resins .

    Directory of Open Access Journals (Sweden)

    Sarfaraz Alam

    1996-07-01

    Full Text Available Glass/carbon/kevlar-reinforced composites were fabricated using two structurally different methl nadicimide resins. The resin content of the laminates was in the range of 32-39 per cent. Interlaminar shear strength (ILSSand flexual strength (FS depended on the structure of the methyl nadicimide resins. A significant decrease in the ILSS was observed on treatment with boiling water for 500 h and on isothermal ageing at 300 degree celsius for 100,250 and 500 h. The limiting oxygen index (LOI was the lowest for laminates based on Kevlar fabrics (i.e.54 whereas the laminates based on glass/carbon showed very high LOI(>90.

  12. Expansive cement couplers: A means of pre-tensioning fibre-reinforced plastic tendons

    OpenAIRE

    1995-01-01

    This is the peer reviewed version of: Lees J.M., Gruffydd-Jones, B. and Burgoyne C.J. (1995) "Expansive Cement Couplers - A Means of Pre-tensioning Fibre-Reinforced Plastic Tendons", published in 'Construction and Building Materials', v. 9, is. 6, pp. 413-423 December 1995. The published version is at http://dx.doi.org/10.1016/0950-0618(95)00070-4 Fibre reinforced plastics describes a group of materials composed of inorganic or organic fibres embedded in a resin matrix. frps are strong, n...

  13. Investigation of basalt plastic reinforcement and its Adhesion with Concrete

    Directory of Open Access Journals (Sweden)

    Kustikova Yulia Olegovna

    2014-03-01

    Full Text Available The load-bearing capacity and durability of concrete structures with metal or other reinforcement depends on their physical and mechanical properties and adhesion values with concrete. In this regard, there is an urgent need in the definition of adhesion of basalt reinforcement and concrete of various compositions and classes. One of the main problems with the use of basalt rods in concrete structures is - providing a high degree of load-carrying capacity in different conditions of stress-strain state of the structure, and the related amount of its adhesion with concrete. Meeting these requirements can be achieved with load-bearing capacity of individual rods, adhesion value, in general, of basalt reinforcement with concrete.

  14. Revealing homogeneous plastic deformation in dendrite-reinforced Ti-based metallic glass composites under tension

    Science.gov (United States)

    Wu, F. F.; Wei, J. S.; Chan, K. C.; Chen, S. H.; Zhao, R. D.; Zhang, G. A.; Wu, X. F.

    2017-01-01

    The tensile plastic deformation of dendrite-reinforced Ti-based metallic glass composites (MGCs) was investigated. It was found that there is a critical normalized strain-hardening rate (NSHR) that determines the plastic stability of MGCs: if the NSHR is larger than the critical value, the plastic deformation of the MGCs will be stable, i.e. the necking and strain localization can be effectively suppressed, resulting in homogeneous plastic elongation. In addition, dendrite-reinforce MGCs are verified as being intrinsically ductile, and can be used as good coatings for improving the surface properties of pure titanium or titanium alloys. These findings are helpful in designing, producing, and using MGCs with improved performance properties. PMID:28195216

  15. Coupling of plasticity and damage in glass fibre reinforced polymer composites

    Directory of Open Access Journals (Sweden)

    Osnes H.

    2012-08-01

    Full Text Available This study addresses the nonlinear stress-strain response in glass fibre reinforced polymer composite laminates. Loading and unloading of these laminates indicate that the nonlinear response is caused by both damage and plasticity. A user defined material model is implemented in the finite element code LS-DYNA. The damage evolution is based on the Puck failure criterion [1], and the plastic behaviour is based on the quadratic Hill yield criterion for anisotropic materials [2].

  16. Dynamic Elasto-Plastic Model for Reinforced Concrete Members

    NARCIS (Netherlands)

    Van der Veen, C.; Blaauwendraad. J.

    1983-01-01

    It is becoming increasingly necessary to investigate the strength of reinforced concrete structures subjected to dynamic loading. Experience and knowledge relating to the non-linear dynamic behaviour of such structures is still limited, however. Attempts to solve this type of problems with the aid o

  17. The Compressive Strength of Carbon Fibre Reinforced Plastics.

    Science.gov (United States)

    1982-08-01

    and resin properties . Therefore, throughout this Report the term compressive failure will imply a microbuckling failure mode. A microbuckling failure...Compressive strength of fibre reinforced composite materials. ASTM STP 580, pp 364-377 (1975) 16 D.B.S. Berry Handbook of resin properties . Part A - cast

  18. Size effects in plastic hinges of reinforced concrete members

    NARCIS (Netherlands)

    Bigaj-van Vliet, A.J.; Walraven, J.C.

    2002-01-01

    Reasons for size dependence of rotation capacity of plastic hinges are discussed. The increase of ductility with decreasing member size is interpreted from the viewpoint of fracture mechanics of concrete. The results of the introductory test series on simply supported slender beams loaded in three-p

  19. Size Effects in Plastic Hinges of Reinforced Concrete Members

    NARCIS (Netherlands)

    Bigaj, A.; Walraven, J.C.

    2002-01-01

    Reasons for size dependence of rotation capacity of plastic hinges are discussed. The increase of ductility with decreasing member size is interpreted from the viewpoint of fracture mechanics of concrete. The results of the introductory test series on simply supported slender beams loaded in three-p

  20. Plastic Deformation of Copper-Based Alloy Reinforced with Incoherent Nanoparticles

    Science.gov (United States)

    Matvienko, O. V.; Daneiko, O. I.; Kovalevskaya, T. A.

    2017-06-01

    The paper deals with research carried out into plastic deformation of a heavy-wall pipe made of nanoparticle reinforced copper-based alloy. We present an original approach which combines methods of crystal plasticity and deformable solid mechanics, thereby allowing to study the stress-strain state of the heavy-wall pipe strengthened with incoherent nanoparticles using a homogeneous internal pressure. Dependences are constructed for the yielding area and the pressure, the limit of elasto-plastic resistance is obtained for the heavy-wall pipe and its deformation degree is described. It is shown that the particle size has an effect on strength properties of the material.

  1. Decay resistance of wood-plastic composites reinforced with extracted or delignified wood flour

    Science.gov (United States)

    Rebecca E. Ibach; Yao Chen; Nicole M. Stark; Mandla A. Tshabalala; Yongming Fan; Jianmin Gao

    2014-01-01

    The moisture and decay resistance of wood-plastic composites (WPCs) reinforced with extracted or delignified wood flour (WF) was investigated. Three different extractions were preformed: toluene/ethanol (TE), acetone/water (AW), and hot water (HW). Delignification (DL) was performed using a sodium chlorite/acetic acid solution. All WPCs specimens were made with 50% by...

  2. Crack Growth Monitoring by Embedded Optical Fibre Bragg Grating Sensors: Fibre Reinforced Plastic Crack Growing Detection

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    This article presents a novel method to asses a crack growing/damage event in fibre reinforced plastic, or adhesive using Fibre Bragg Grating (FBG) sensors embedded in a host material. Different features of the crack mechanism that induce a change in the FBG response were identified. Double Canti...

  3. Prediction of thermal strains in fibre reinforced plastic matrix by discretisation of the temperature exposure history

    Science.gov (United States)

    Ngoy, E. K.

    2016-07-01

    Prediction of environmental effects on fibre reinforced plastics habitually is made difficult due to the complex variability of the natural service environment. This paper suggests a method to predict thermal strain distribution over the material lifetime by discretisation of the exposure history. Laboratory results show a high correlation between predicted and experimentally measured strain distribution

  4. Design aid for shear strengthening of reinforced concrete T-joints using carbon fiber reinforced plastic composites

    Science.gov (United States)

    Gergely, Ioan

    The research presented in the present work focuses on the shear strengthening of beam column joints using carbon fiber composites, a material considered in seismic retrofit in recent years more than any other new material. These composites, or fiber reinforced polymers, offer huge advantages over structural steel reinforced concrete or timber. A few of these advantages are the superior resistance to corrosion, high stiffness to weight and strength to weight ratios, and the ability to control the material's behavior by selecting the orientation of the fibers. The design and field application research on reinforced concrete cap beam-column joints includes analytical investigations using pushover analysis; design of carbon fiber layout, experimental tests and field applications. Several beam column joints have been tested recently with design variables as the type of composite system, fiber orientation and the width of carbon fiber sheets. The surface preparation has been found to be critical for the bond between concrete and composite material, which is the most important factor in joint shear strengthening. The final goal of this thesis is to develop design aids for retrofitting reinforced concrete beam column joints. Two bridge bents were tested on the Interstate-15 corridor. One bent was tested in the as-is condition. Carbon fiber reinforced plastic composite sheets were used to externally reinforce the second bridge bent. By applying the composite, the displacement ductility has been doubled, and the bent overall lateral load capacity has been increased as well. The finite element model (using DRAIN-2DX) was calibrated to model the actual stiffness of the supports. The results were similar to the experimental findings.

  5. Recyclability assessment of nano-reinforced plastic packaging

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez, C., E-mail: csanchez@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Hortal, M., E-mail: mhortal@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Aliaga, C., E-mail: caliaga@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Devis, A., E-mail: adevis@itene.com [Sustainability Divison, Packaging, Transport and Logistics Research Institute, Albert Einstein 1, 46980 Paterna, Valencia (Spain); Cloquell-Ballester, V.A., E-mail: cloquell@dpi.upv.es [Dpto. Proyectos de Ingeniería, Universitat Politècnica de València, Camino de Vera, 46022 Valencia (Spain)

    2014-12-15

    Highlights: • The study compares the recyclability of polymers with and without nanoparticles. • Visual appearance, material quality and mechanical properties are evaluated. • Minor variations in mechanical properties in R-PE and R-PP with nanoparticles. • Slight degradation of R-PET which affect mechanical properties. • Colour deviations in recycled PE, PP and PET in ranges higher that 0.3 units. - Abstract: Packaging is expected to become the leading application for nano-composites by 2020 due to the great advantages on mechanical and active properties achieved with these substances. As novel materials, and although there are some current applications in the market, there is still unknown areas under development. One key issue to be addressed is to know more about the implications of the nano-composite packaging materials once they become waste. The present study evaluates the extrusion process of four nanomaterials (Layered silicate modified nanoclay (Nanoclay1), Calcium Carbonate (CaCO{sub 3}), Silver (Ag) and Zinc Oxide (ZnO) as part of different virgin polymer matrices of polyethylene (PE), Polypropylene (PP) and Polyethyleneterephtalate (PET). Thus, the following film plastic materials: (PE–Nanoclay1, PE–CaCO{sub 3}, PP–Ag, PET–ZnO, PET–Ag, PET–Nanoclay1) have been processed considering different recycling scenarios. Results on recyclability show that for PE and PP, in general terms and except for some minor variations in yellowness index, tensile modulus, tensile strength and tear strength (PE with Nanoclay1, PP with Ag), the introduction of nanomaterial in the recycling streams for plastic films does not affect the final recycled plastic material in terms of mechanical properties and material quality compared to conventional recycled plastic. Regarding PET, results show that the increasing addition of nanomaterial into the recycled PET matrix (especially PET–Ag) could influence important properties of the recycled material, due to a

  6. Recyclability assessment of nano-reinforced plastic packaging.

    Science.gov (United States)

    Sánchez, C; Hortal, M; Aliaga, C; Devis, A; Cloquell-Ballester, V A

    2014-12-01

    Packaging is expected to become the leading application for nano-composites by 2020 due to the great advantages on mechanical and active properties achieved with these substances. As novel materials, and although there are some current applications in the market, there is still unknown areas under development. One key issue to be addressed is to know more about the implications of the nano-composite packaging materials once they become waste. The present study evaluates the extrusion process of four nanomaterials (Layered silicate modified nanoclay (Nanoclay1), Calcium Carbonate (CaCO3), Silver (Ag) and Zinc Oxide (ZnO) as part of different virgin polymer matrices of polyethylene (PE), Polypropylene (PP) and Polyethyleneterephtalate (PET). Thus, the following film plastic materials: (PE-Nanoclay1, PE-CaCO3, PP-Ag, PET-ZnO, PET-Ag, PET-Nanoclay1) have been processed considering different recycling scenarios. Results on recyclability show that for PE and PP, in general terms and except for some minor variations in yellowness index, tensile modulus, tensile strength and tear strength (PE with Nanoclay1, PP with Ag), the introduction of nanomaterial in the recycling streams for plastic films does not affect the final recycled plastic material in terms of mechanical properties and material quality compared to conventional recycled plastic. Regarding PET, results show that the increasing addition of nanomaterial into the recycled PET matrix (especially PET-Ag) could influence important properties of the recycled material, due to a slight degradation of the polymer, such as increasing pinholes, degradation fumes and elongation at break. Moreover, it should be noted that colour deviations were visible in most of the samples (PE, PP and PET) in levels higher than 0.3 units (limit perceivable by the human eye). The acceptance of these changes in the properties of recycled PE, PP and PET will depend on the specific applications considered (e.g. packaging applications are more

  7. Fatigue damage mechanism and failure prevention in fiberglass reinforced plastic

    Directory of Open Access Journals (Sweden)

    Raimundo Carlos Silverio Freire Jr.

    2005-03-01

    Full Text Available Damaging of composite laminates was monitored during fatigue tests, revealing the formation and propagation stages for compressive, tensile, or alternate cyclic loading. Two different laminate stacking sequences, with different number of layers, were tested. The laminates consisted of E-glass fibers reinforced orthoftalic polyester resin (FGRP shaped as mats or (bi-direction woven fabric textile. Preliminary density, calcination tests and static compressive and tensile mechanical tests were carried out. Then, tensile (R = 0.1, compressive (R = 10 and alternate axial (R = - 1 fatigue tests were performed at different maximum stresses. Tensile cyclic loading resulted in crack formation and propagation confirming the findings reported in other studies. On the other hand, damage from alternate and compressive fatigue depicted peculiar features. Less extended damage and better fatigue resistance were observed for the laminate with symmetrically distributed layers.

  8. Advance study of fiber-reinforced self-compacting concrete

    Energy Technology Data Exchange (ETDEWEB)

    Mironova, M., E-mail: mirona@imbm.bas.bg; Ivanova, M., E-mail: magdalena.ivanova@imbm.bas.bg; Naidenov, V., E-mail: valna53@mail.bg [Institute of Mechanics, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bl. 4, Sofia 1113 (Bulgaria); Georgiev, I., E-mail: ivan.georgiev@parallel.bas.bg [Institute of Information and Communication Technologies & Institute of Mathematics and Informatics, Bulgarian Academy of Sciences, Acad. G. Bonchev str., Sofia 1113 (Bulgaria); Stary, J., E-mail: stary@ugn.cas.cz [Institute of Geonics Czech Academy of Sciences, Studentska str., Ostrava 1768 (Czech Republic)

    2015-10-28

    Incorporation in concrete composition of steel macro- and micro – fiber reinforcement with structural function increases the degree of ductility of typically brittle cement-containing composites, which in some cases can replace completely or partially conventional steel reinforcement in the form of rods and meshes. Thus, that can reduce manufacturing, detailing and placement of conventional reinforcement, which enhances productivity and economic efficiency of the building process. In this paper, six fiber-reinforced with different amounts of steel fiber cement-containing self-compacting compositions are investigated. The results of some of their main strength-deformation characteristics are presented. Advance approach for the study of structural and material properties of these type composites is proposed by using the methods of industrial computed tomography. The obtained original tomography results about the microstructure and characteristics of individual structural components make it possible to analyze the effective macro-characteristics of the studied composites. The resulting analytical data are relevant for the purposes of multi-dimensional modeling of these systems. Multifactor structure-mechanical analysis of the obtained with different methods original scientific results is proposed. It is presented a conclusion of the capabilities and effectiveness of complex analysis in the studies to characterize the properties of self-compacting fiber-reinforced concrete.

  9. Advance study of fiber-reinforced self-compacting concrete

    Science.gov (United States)

    Mironova, M.; Ivanova, M.; Naidenov, V.; Georgiev, I.; Stary, J.

    2015-10-01

    Incorporation in concrete composition of steel macro- and micro - fiber reinforcement with structural function increases the degree of ductility of typically brittle cement-containing composites, which in some cases can replace completely or partially conventional steel reinforcement in the form of rods and meshes. Thus, that can reduce manufacturing, detailing and placement of conventional reinforcement, which enhances productivity and economic efficiency of the building process. In this paper, six fiber-reinforced with different amounts of steel fiber cement-containing self-compacting compositions are investigated. The results of some of their main strength-deformation characteristics are presented. Advance approach for the study of structural and material properties of these type composites is proposed by using the methods of industrial computed tomography. The obtained original tomography results about the microstructure and characteristics of individual structural components make it possible to analyze the effective macro-characteristics of the studied composites. The resulting analytical data are relevant for the purposes of multi-dimensional modeling of these systems. Multifactor structure-mechanical analysis of the obtained with different methods original scientific results is proposed. It is presented a conclusion of the capabilities and effectiveness of complex analysis in the studies to characterize the properties of self-compacting fiber-reinforced concrete.

  10. Toxicology and occupational hazards of new materials and processes in metal surface treatment, powder metallurgy, technical ceramics, and fiber-reinforced plastics.

    Science.gov (United States)

    Midtgård, U; Jelnes, J E

    1991-12-01

    Many new materials and processes are about to find their way from the research laboratory into industry. The present paper describes some of these processes and provides an overview of possible occupational hazards and a list of chemicals used or produced in the processes. The technological areas that are considered are metal surface treatment (ion implantation, physical and chemical vapor deposition, plasma spraying), powder metallurgy, advanced technical ceramics, and fiber-reinforced plastics.

  11. Mechanical Properties of a Unidirectional Basalt-Fiber-Reinforced Plastic Under a Loading Simulating Operation Conditions

    Science.gov (United States)

    Lobanov, D. S.; Slovikov, S. V.

    2017-01-01

    The results of experimental investigations of unidirectional composites based on basalt fibers and different marks of epoxy resins are presented. Uniaxial tensile tests were carried out using a specimen fixation technique simulating the operation conditions of structures. The mechanical properties of the basalt-fiber-reinforced plastics (BFRPs) were determined. The diagrams of loading and deformation of BFRP specimens were obtain. The formulations of the composites with the highest mechanical properties were revealed.

  12. The Effects of Weathering on Mechanical Properties of Glass Fiber Reinforced Plastics (Grp Materials

    Directory of Open Access Journals (Sweden)

    H. Abdullah

    2012-08-01

    Full Text Available Glass fiber reinforced plastics composite is extensively used as a structural material for pools, oil pipes and tanks because it has good corrosion resistance properties.  The effects of weathering on the mechanical properties of glass fiber reinforced plastics (GRP in the Sultanate of Oman have been studied.  The tensile and three point bend specimens were exposed to outdoor conditions (open atmosphere in sunlight and tested for various intervals of time.  It was observed that as the exposure time to sunlight, ultraviolet radiation and dust increases the mechanical properties of GRP materials decrease.  The effects of relative humidity (%RH on the mechanical properties were also studied. It was found that as the relative humidity increased in the atmosphere during the exposure time, the tensile strength, flexural strength and modulus of elasticity are lowered. This work has revealed that the decrease in the mechanical properties of GRP under weathering conditions is subjected to atmospheric conditions such as humidity, temperature, ultraviolet radiation and pollutant.Key Words: Weathering, Glass-Fiber Reinforced Plastics, Degradation

  13. Processing of microencapsulated dyes for the visual inspection of fibre reinforced plastics

    Energy Technology Data Exchange (ETDEWEB)

    Hopmann, Ch., E-mail: kerschbaum@ikv.rwth-aachen.de; Kerschbaum, M., E-mail: kerschbaum@ikv.rwth-aachen.de; Küsters, K., E-mail: kerschbaum@ikv.rwth-aachen.de [Institute of Plastics Processing at RWTH Aachen University (IKV), Pontstrasse 49, 52064 Aachen (Germany)

    2014-05-15

    The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture which leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization.

  14. Processing of microencapsulated dyes for the visual inspection of fibre reinforced plastics

    Science.gov (United States)

    Hopmann, Ch.; Kerschbaum, M.; Küsters, K.

    2014-05-01

    The evaluation of damages caused during processing, assembly or usage of fibre reinforced plastics is still a challenge. The use of inspection technology like ultrasonic scanning enables a detailed damage analysis but requires high investments and trained staff. Therefore, the visual inspection method is widely used. A drawback of this method is the difficult identification of barely visible damages, which can already be detrimental for the structural integrity. Therefore an approach is undertaken to integrate microencapsulated dyes into the laminates of fibre reinforced plastic parts to highlight damages on the surface. In case of a damage, the microcapsules rupture which leads to a release of the dye and a visible bruise on the part surface. To enable a wide application spectrum for this technology the microcapsules must be processable without rupturing with established manufacturing processes for fibre reinforced plastics. Therefore the incorporation of microcapsules in the filament winding, prepreg autoclave and resin transfer moulding (RTM) process is investigated. The results show that the use of a carrier medium is a feasible way to incorporate the microcapsules into the laminate for all investigated manufacturing processes. Impact testing of these laminates shows a bruise formation on the specimen surface which correlates with the impact energy level. This indicates a microcapsule survival during processing and shows the potential of this technology for damage detection and characterization.

  15. Energy efficient microwave heating of carbon fibre reinforced plastic; Energieeffiziente Mikrowellentemperierung von kohlenstofffaserverstaerkten Duroplasten

    Energy Technology Data Exchange (ETDEWEB)

    Danilov, Maksim

    2013-07-01

    The polymerization of carbon fiber reinforced thermosetting composites (CFRP) is a dull process step with high energy requirements within the production chain. His improvement would affect the economic and ecological balance of the fiber reinforced materials in a positive way. One possible approach investigated here is tempering of raw materials in a microwave oven. In this work the material to be processed - a carbon fiber-reinforced plastic laminate - is being characterized in the microwave field through electromagnetic and thermal parameters. The relationship between its design parameters (fiber orientation and number of layers), the energy levels (reflection, absorption and transmittance) and the thermal process parameters (temperature gradient achievable) will be established. Afterwards, constructive options will be examined and evaluated which are suitable to install a low-loss (both by means of wave reflections and heat losses) industrial process.

  16. KuDGR- Dual Gridded Carbon Fiber Reinforced Plastic Reflector

    Science.gov (United States)

    Ihle, Alexander; Reichmann, O.; Lori, M.; Nathrath, N.; Pereira, C.; Linke, S.; Rinous, P.

    2014-06-01

    In the frame of an ESA-funded TRP activity HPS GmbH, together with INVENT GmbH and INEGI, has developed an advanced concept for dual gridded reflectors. The target frequency band is the Ku-band requiring high in-orbit thermo-elastic stability. It is a follow-on of the previous KaDGR [1] activity. The concept concerns the polarisation grid of the front and rear reflector. The grids are connected by a full CFRP monolithic peripheral ring. The demonstrator has an overall diameter of 1.4 x 1.2 m and a weight of only 4.23 kg. The design of this concept allows for smaller and larger reflectors.In the following we will present the results of the different development steps and current status of the TRP activity.

  17. Transverse isotropic modeling of the ballistic response of glass reinforced plastic composites

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P.A. [Sandia National Labs., Albuquerque, NM (United States)

    1997-12-31

    The use of glass reinforced plastic (GRP) composites is gaining significant attention in the DoD community for use in armor applications. These materials typically possess a laminate structure consisting of up to 100 plies, each of which is constructed of a glass woven roving fabric that reinforces a plastic matrix material. Current DoD attention is focused on a high strength, S-2 glass cross-weave (0/90) fabric reinforcing a polyester matrix material that forms each ply of laminate structure consisting anywhere from 20 to 70 plies. The resulting structure displays a material anisotropy that is, to a reasonable approximation, transversely isotropic. When subjected to impact and penetration from a metal fragment projectile, the GRP displays damage and failure in an anisotropic manner due to various mechanisms such as matrix cracking, fiber fracture and pull-out, and fiber-matrix debonding. In this presentation, the author will describe the modeling effort to simulate the ballistic response of the GRP material described above using the transversely isotropic (TI) constitutive model which has been implemented in the shock physics code, CTH. The results of this effort suggest that the model is able to describe the delamination behavior of the material but has some difficulty capturing the in-plane (i.e., transverse) response of the laminate due to its cross-weave fabric reinforcement pattern which causes a departure from transverse isotropy.

  18. Advances in modeling plastic waste pyrolysis processes

    Directory of Open Access Journals (Sweden)

    Y. Safadi, J. Zeaiter

    2014-01-01

    Full Text Available The tertiary recycling of plastics via pyrolysis is recently gaining momentum due to promising economic returns from the generated products that can be used as a chemical feedstock or fuel. The need for prediction models to simulate such processes is essential in understanding in depth the mechanisms that take place during the thermal or catalytic degradation of the waste polymer. This paper presents key different models used successfully in literature so far. Three modeling schemes are identified: Power-Law, Lumped-Empirical, and Population-Balance based equations. The categorization is based mainly on the level of detail and prediction capability from each modeling scheme. The data shows that the reliability of these modeling approaches vary with the degree of details the experimental work and product analysis are trying to achieve.

  19. A new framework for cortico-striatal plasticity: behavioural theory meets in vitro data at the reinforcement-action interface

    OpenAIRE

    Gurney, Kevin; Humphries, Mark D.; Redgrave, Peter

    2015-01-01

    Operant learning requires that reinforcement signals interact with action representations at a suitable neural interface. Much evidence suggests that this occurs when phasic dopamine, acting as a reinforcement prediction error, gates plasticity at cortico-striatal synapses, and thereby changes the future likelihood of selecting the action(s) coded by striatal neurons. But this hypothesis faces serious challenges. First, cortico-striatal plasticity is inexplicably complex, depending on spike t...

  20. Nonlocal plasticity effects on fibre debonding in a whisker-reinforced metal

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Tvergaard, Viggo

    2002-01-01

    , in the form of fibre sizes and the length associated with the debonding process, so the nonlocal plasticity model brings in an additional material length. The analyses for metal reinforced by aligned short fibres are used to obtain an understanding of the interaction of the different length scales......Numerical cell-model analyses for the matrix-fibre debonding in a metal matrix composite are used to study the effect of a characteristic material length in the plasticity description of the matrix material deformations. Characteristic material lengths are already present in the model problem...... in the problem. The nonlocal plasticity effect tends to increase the stress level at a given overall strain, which clearly tends to promote the onset of debonding....

  1. Electron processing of fibre-reinforced advanced composites

    Science.gov (United States)

    Singh, Ajit; Saunders, Chris B.; Barnard, John W.; Lopata, Vince J.; Kremers, Walter; McDougall, Tom E.; Chung, Minda; Tateishi, Miyoko

    1996-08-01

    Advanced composites, such as carbon-fibre-reinforced epoxies, are used in the aircraft, aerospace, sporting goods, and transportation industries. Though thermal curing is the dominant industrial process for advanced composites, electron curing of similar composites containing acrylated epoxy matrices has been demonstrated by our work. The main attraction of electron processing technology over thermal technology is the advantages it offers which include ambient temperature curing, reduced curing times, reduced volatile emissions, better material handling, and reduced costs. Electron curing technology allows for the curing of many types of products, such as complex shaped, those containing different types of fibres, and up to 15 cm thick. Our work has been done principally with the AECL's 10 MeV, 1 kW electron accelerator; we have also done some comparative work with an AECL Gammacell 220. In this paper we briefly review our work on the various aspects of electron curing of advanced composites and their properties.

  2. Methods for an investigation of the effect of material components on the mechanical characteristics of glass-fiber-reinforced plastics

    Science.gov (United States)

    Willax, H. O.

    1980-01-01

    The materials used in the production of glass reinforced plastics are discussed. Specific emphasis is given to matrix polyester materials, the reinforcing glass materials, and aspects of specimen preparation. Various methods of investigation are described, giving attention to optical impregnation and wetting measurements and the gravimetric determination of the angle of contact. Deformation measurements and approaches utilizing a piezoelectric device are also considered.

  3. Use of shield support on faces advanced in plastic strata

    Energy Technology Data Exchange (ETDEWEB)

    Pera, F.; Szentai, G.

    1987-01-01

    A new type of rock loading model is presented for shield support on faces advancing in plastic strata. Loading of strata is not independent of the speed of advance. The problem is approached on theoretical bases and is also illustrated by measurements carried out in practice. The interpretation of the active and passive loads is given and the loads are taken into account in different manner.

  4. Somatic and Reinforcement-Based Plasticity in the Initial Stages of Human Motor Learning.

    Science.gov (United States)

    Sidarta, Ananda; Vahdat, Shahabeddin; Bernardi, Nicolò F; Ostry, David J

    2016-11-16

    As one learns to dance or play tennis, the desired somatosensory state is typically unknown. Trial and error is important as motor behavior is shaped by successful and unsuccessful movements. As an experimental model, we designed a task in which human participants make reaching movements to a hidden target and receive positive reinforcement when successful. We identified somatic and reinforcement-based sources of plasticity on the basis of changes in functional connectivity using resting-state fMRI before and after learning. The neuroimaging data revealed reinforcement-related changes in both motor and somatosensory brain areas in which a strengthening of connectivity was related to the amount of positive reinforcement during learning. Areas of prefrontal cortex were similarly altered in relation to reinforcement, with connectivity between sensorimotor areas of putamen and the reward-related ventromedial prefrontal cortex strengthened in relation to the amount of successful feedback received. In other analyses, we assessed connectivity related to changes in movement direction between trials, a type of variability that presumably reflects exploratory strategies during learning. We found that connectivity in a network linking motor and somatosensory cortices increased with trial-to-trial changes in direction. Connectivity varied as well with the change in movement direction following incorrect movements. Here the changes were observed in a somatic memory and decision making network involving ventrolateral prefrontal cortex and second somatosensory cortex. Our results point to the idea that the initial stages of motor learning are not wholly motor but rather involve plasticity in somatic and prefrontal networks related both to reward and exploration.

  5. Stability and reinforcement analysis of rock slope based on elasto-plastic finite element method

    Institute of Scientific and Technical Information of China (English)

    刘耀儒; 武哲书; 常强; 李波; 杨强

    2015-01-01

    The rigid body limit equilibrium method (RBLEM) and finite element method (FEM) are two widely used approaches for rock slope’s stability analysis currently. RBLEM introduced plethoric assumptions; while traditional FEM relied on artificial factors when determining factor of safety (FOS) and sliding surfaces. Based on the definition of structure instability that an elasto-plastic structure is not stable if it is unable to satisfy simultaneously equilibrium condition, kinematical admissibility and constitutive equations under given external loads, deformation reinforcement theory (DRT) is developed. With this theory, plastic complementary energy (PCE) can be used to evaluate the overall stability of rock slope, and the unbalanced force beyond the yield surface could be the identification of local failure. Compared with traditional slope stability analysis approaches, the PCE norm curve to strength reduced factor is introduced and the unbalanced force is applied to the determination of key sliding surfaces and required reinforcement. Typical and important issues in rock slope stability are tested in TFINE(a three-dimensional nonlinear finite element program), which is further applied to several representatives of high rock slope’s stability evaluation and reinforcement engineering practice in southwest of China.

  6. Evolution of the health of concrete structures by electrically conductive GFRP (glass fiber reinforced plastic) composites

    Science.gov (United States)

    Shin, Soon-Gi

    2002-02-01

    The function and performance of self-diagnostic composites embedded in concrete blocks and piles were investigated by bending tests and electrical resistance measurement. Carbon powder (CP) and carbon fiber (CF) were introduced into glass fiber reinforced plastic (GFRP) composites to provide electrical conductivity. The CPGFRP composite displays generally good performance in various bending tests of concrete block and piles compared to the CFGFRP composite. The electrical resistance of the CPGFRP composite increases remarkably at small strains in response to microcrack formation at about 200 μm strain, and can be used to detect smaller deformations before crack formation. The CPGFRP composite shows continuous change in resistance up to a large strain level just before the final fracture for concrete structures reinforced by steel bars. It is concluded that self-diagnostic composites can be used to predict damage and fracture in concrete blocks and piles.

  7. Weathering Characteristics of Wood Plastic Composites Reinforced with Extracted or Delignified Wood Flour

    Directory of Open Access Journals (Sweden)

    Yao Chen

    2016-07-01

    Full Text Available This study investigated weathering performance of an HDPE wood plastic composite reinforced with extracted or delignified wood flour (WF. The wood flour was pre-extracted with three different solvents, toluene/ethanol (TE, acetone/water (AW, and hot water (HW, or sodium chlorite/acetic acid. The spectral properties of the composites before and after artificial weathering under accelerated conditions were characterized by Fourier transform infrared (FTIR spectroscopy, the surface color parameters were analyzed using colorimetry, and the mechanical properties were determined by a flexural test. Weathering of WPC resulted in a surface lightening and a decrease in wood index (wood/HDPE and flexural strength. WPCs that were reinforced with delignified wood flour showed higher ΔL* and ΔE* values, together with lower MOE and MOR retention ratios upon weathering when compared to those with non-extracted control and extracted WF.

  8. Crack Growth Monitoring by Embedded Optical Fibre Bragg Grating Sensors: Fibre Reinforced Plastic Crack Growing Detection

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    This article presents a novel method to asses a crack growing/damage event in fibre reinforced plastic, or adhesive using Fibre Bragg Grating (FBG) sensors embedded in a host material. Different features of the crack mechanism that induce a change in the FBG response were identified. Double...... Cantilever Beams specimens made with glass fibre glued with structural adhesive, were instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. A digital image correlation technique was used to determine the presence of the specific phenomena...

  9. Determination of mechanical properties of some glass fiber reinforced plastics suitable to Wind Turbine Blade construction

    Science.gov (United States)

    Steigmann, R.; Savin, A.; Goanta, V.; Barsanescu, P. D.; Leitoiu, B.; Iftimie, N.; Stanciu, M. D.; Curtu, I.

    2016-08-01

    The control of wind turbine's components is very rigorous, while the tower and gearbox have more possibility for revision and repairing, the rotor blades, once they are deteriorated, the defects can rapidly propagate, producing failure, and the damages can affect large regions around the wind turbine. This paper presents the test results, performed on glass fiber reinforced plastics (GFRP) suitable to construction of wind turbine blades (WTB). The Young modulus, shear modulus, Poisson's ratio, ultimate stress have been determined using tensile and shear tests. Using Dynamical Mechanical Analysis (DMA), the activation energy for transitions that appear in polyester matrix as well as the complex elastic modulus can be determined, function of temperature.

  10. Non-destructive testing of carbon reinforced plastics by means of phase retrieval

    CERN Document Server

    Agour, Mostafa; Kopylow, Christoph v; Bergmann, Ralf B

    2012-01-01

    In this work, the SLM-based phase retrieval system will be used to inspect carbon reinforced plastics samples (CFRP) under applying a thermal load. For this purpose, the system is used to capture a sequence of 8 spatially separated recording planes, where the distance between subsequent planes equals 2 mm. For detecting the hidden failures two sets of intensity observations are recorded. The first set for the initial state and the second set is captured after applying the load. To recover the phase information associated with the two states, the captured intensities have been subjected to an iterative algorithm based on the method of generalized projection.

  11. Anomalous enhancement of drilling rate in carbon fiber reinforced plastic using azimuthally polarized CO2 laser

    Science.gov (United States)

    Endo, Masamori; Araya, Naohiro; Kurokawa, Yuki; Uno, Kazuyuki

    2016-09-01

    We developed an azimuthally polarized pulse-periodic CO2 laser for high-performance drilling applications. We discovered an anomalous enhancement in the drilling rate with the azimuthally polarized beam compared to that with radially or randomly polarized beams. We drilled 0.45 mm-thick carbon fiber reinforced plastic (CFRP) using a focusing lens with a focal length of 50 mm and a numerical aperture (NA) of 0.09. The conditions other than polarization states were identical for all the experiments. The azimuthally polarized beam exhibited a drilling rate more than 10 times greater on average than those of the other two polarizations.

  12. Fiber-Reinforced-Foam (FRF) Core Composite Sandwich Panel Concept for Advanced Composites Technologi

    Science.gov (United States)

    2010-01-01

    Fiber-Reinforced-Foam (FRF) Core Composite Sandwich Panel Concept for Advanced Composites Technologies Project - Preliminary Manufacturing Demonstration Articles for Ares V Payload Shroud Barrel Acreage Structure

  13. Advanced Large Area Plastic Scintillator Project (ALPS): Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, David V.; Reeder, Paul L.; Todd, Lindsay C.; Warren, Glen A.; McCormick, Kathleen R.; Stephens, Daniel L.; Geelhood, Bruce D.; Alzheimer, James M.; Crowell, Shannon L.; Sliger, William A.

    2008-02-05

    The advanced Large-Area Plastic Scintillator (ALPS) Project at Pacific Northwest National Laboratory investigated possible technological avenues for substantially advancing the state-of-the-art in gamma-ray detection via large-area plastic scintillators. The three predominant themes of these investigations comprised the following: * Maximizing light collection efficiency from a single large-area sheet of plastic scintillator, and optimizing hardware event trigger definition to retain detection efficiency while exploiting the power of coincidence to suppress single-PMT "dark current" background; * Utilizing anti-Compton vetoing and supplementary spectral information from a co-located secondary, or "Back" detector, to both (1) minimize Compton background in the low-energy portion of the "Front" scintillator's pulse-height spectrum, and (2) sharpen the statistical accuracy of the front detector's low-energy response prediction as impelmented in suitable energy-windowing algorithms; and * Investigating alternative materials to enhance the intrinsic gamma-ray detection efficiency of plastic-based sensors.

  14. Using Statistical Analysis Software to Advance Nitro Plasticizer Wettability

    Energy Technology Data Exchange (ETDEWEB)

    Shear, Trevor Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-29

    Statistical analysis in science is an extremely powerful tool that is often underutilized. Additionally, it is frequently the case that data is misinterpreted or not used to its fullest extent. Utilizing the advanced software JMP®, many aspects of experimental design and data analysis can be evaluated and improved. This overview will detail the features of JMP® and how they were used to advance a project, resulting in time and cost savings, as well as the collection of scientifically sound data. The project analyzed in this report addresses the inability of a nitro plasticizer to coat a gold coated quartz crystal sensor used in a quartz crystal microbalance. Through the use of the JMP® software, the wettability of the nitro plasticizer was increased by over 200% using an atmospheric plasma pen, ensuring good sample preparation and reliable results.

  15. Aluminium/iron reinforced polyfurfuryl alcohol resin as advanced biocomposites

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2016-07-01

    Full Text Available Aluminium and iron are widely used in construction sectors for the preparation of advanced composites with epoxy resins as matrices. In recent times, there are several reports on the polymerization of polyfufuryl alcohol (PFA a thermoset bioresins from furfuryl alcohol (FA. FA is obtained from waste of sugarcane bagasse. In this work, first the possibility of curing PFA from FA in the presence of aluminium or iron has been explored. Absorbance results from colorimeter/spectrophotometerindicated that the curing of FA to PFA in presence of aluminium started easily while in presence of iron the curing of FA to PFA could not start. Based on the above results, aluminium wire reinforced composites were successfully prepared with three different weight fractions (0.13, 0.09 and 0.07 of aluminium wire. The mechanical properties of these composites were determined theoretically and reported.

  16. Life cycle assessment of biofibres replacing glass fibres as reinforcement in plastics

    Energy Technology Data Exchange (ETDEWEB)

    Corbiere-Nicollier, T.; Gfeller Laban, B.; Jolliet, O. [Laboratory of Ecosystem Management GECOS-EPFL, Swiss Federal Institute of Technology, CH-1015 Lausanne (Switzerland); Lundquist, L.; Leterrier, Y.; Manson, J.A.E. [Composite and Polymer Technology Laboratory, LTC-EPFL, Swiss Federal Institute of Technology Lausanne, EPFL, CH-1015 Lausanne (Switzerland)

    2001-11-01

    This article aims to determine the environmental performance of China reed fibre used as a substitute for glass fibre as reinforcement in plastics and to identify key environmental parameters. A life cycle assessment (LCA) is performed on these two materials for an application to plastic transport pallets. Transport pallets reinforced with China reed fibre prove to be ecologically advantageous if they have a minimal lifetime of 3 years compared with the 5-year lifetime of the conventional pallet. The energy consumption and other environmental impacts are strongly reduced by the use of raw renewable fibres, due to three important factors: (a) the substitution of glass fibre production by the natural fibre production; (b) the indirect reduction in the use of polypropylene linked to the higher proportion of China reed fibre used and (c) the reduced pallet weight, which reduces fuel consumption during transport. Considering the whole life cycle, the polypropylene production process and the transport cause the strongest environmental impacts during the use phase of the life cycle. Since thermoplastic composites are hardly biodegradable, incineration has to be preferred to discharge on landfills at the end of its useful life cycle. The potential advantages of the renewable fibres will be effective only if a purer fibre extraction is obtained to ensure an optimal material stiffness, a topic for further research. China reed biofibres are finally compared with other usages of biomass, biomaterials, in general, can enable a three to ten times more efficient valorisation of biomass than mere heat production or biofuels for transport.

  17. Quantification of defects depth in glass fiber reinforced plastic plate by infrared lock-in thermography

    Energy Technology Data Exchange (ETDEWEB)

    Ranjit, Shrestha; Kim, Won Tae [Kongju National University, Cheonan (Korea, Republic of); Choi, Man Yong [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2016-03-15

    The increasing use of composite materials in various industries has evidenced the need for development of more effective nondestructive evaluation methodologies in order to reduce rejected parts and to optimize production cost. Infrared thermography is a noncontact, fast and reliable non-destructive evaluation technique that has received vast and growing attention for diagnostic and monitoring in the recent years. This paper describes the quantitative analysis of artificial defects in Glass fiber reinforced plastic plate by using Lockin infrared thermography. The experimental analysis was performed at several excitation frequencies to investigate the sample ranging from 2.946 Hz down to 0.019 Hz and the effects of each excitation frequency on defect detachability. The four point method was used in post processing of every pixel of thermal images using the MATLAB programming language. The relationship between the phase contrast with defects depth and area was examined. Finally, phase contrast method was used to calculate the defects depth considering the thermal diffusivity of the material being inspected and the excitation frequency for which the defect becomes visible. The obtained results demonstrated the effectiveness of Lock-in infrared thermography as a powerful measurement technique for the inspection of Glass fiber reinforced plastic structures.

  18. Experimental operation of the production line for carbon fiber-reinforced plastic

    Energy Technology Data Exchange (ETDEWEB)

    Boldin, V.M.; Denezhkin, N.M.; Krivoshchekova, N.P.; Krotova, Z.S.; Yermakov, V.F.

    1979-01-01

    Verifications of the quality of the manufactured tubings established that in physical-mechanical indicators the carbon fiber-reinforced plastic corresponds to the requirements which are made for the material of the timbering rising, operated in the zone of intensive manifestation of mine pressure, and exposed to the effect of a stream of coal transmitted through it. Average data are presented for physical-mechanical properties of the carbon fiber-reinforced plastic according to samples manufactured from the tubings. In 1974-1978 the production line produced over 130,000 tubings, or 6600m of timbering to two type-sizes with inner diameter of 850 and 1090 mm. Experimental operation of the production line indicated that as a whole it is efficient, simple and convenient to operate, and guarantees safe working conditions of the service personnel. Verification and pinpointing of the production parameters for making timbering, as well as generalization of the experience of operating the line made it possible to plan a production line with maximum mechanization and automation of the operations of the production process and increase its productivity two-fold. The production line will be put into operation in 1980 in the experimental shop TsEMM No 4 of the production association ''Prokop'yevskugol'.''

  19. Performance Analysis of a Fiber Reinforced Plastic Oil Cooler Cover Considering the Anisotropic Behavior of the Fiber Reinforced PA66

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2016-09-01

    Full Text Available In this paper, a simulation method based on an orthogonal anisotropic material is proposed. A numerical example using a simple plate is presented to show the difference in the static performance between the orthogonal anisotropic and the isotropic models. Comparing with the tested modal data of a diesel engine oil cooler cover made by glass fiber reinforced polyamide 66 (PA66, the proposed simulation method was confirmed to be much closer to reality than the general isotropic model. After that, a comprehensive performance comparison between the plastic oil cooler covers with the orthogonal anisotropic and the isotropic fiber orientations was carried out including a static deformation and stress analysis under a pressure-temperature coupled load, a forced response analysis, and an acoustic analysis under real operating conditions. The results show that the stress, the deformation, the peak vibration velocity, and the overall sound power level of the orthogonal anisotropic model are different from that obtained with the isotropic model. More importantly, the proposed method can provide a much more detailed frequency content compared to the isotropic model.

  20. Parameters That Effect the Interfacial Stresses in Fibre Reinforced Plastic Laminates Strengthened Rc Beams

    Directory of Open Access Journals (Sweden)

    Barış Sayın

    2010-01-01

    Full Text Available The use of externally bonded fiber-reinforced plastic (FRP laminates for strengthening of reinforced concrete beams has become an effective method. This method has been used because of the advantages of FRP materials such as their high strength-to-weight ratio, good corrosion resistance, and versatility in coping with different sectional shapes and corners. Many studies on this theme have been carried out since the early 1900s. In this study, interfacial stresses of reinforced concrete beams strengthened with FRP effect the parameters will be studied as experimental and numerical. Adhesives used in the beams applied to FRP's thickness, adhesive type and the state of the concrete surface, produced experimental samples are exposed to the bending effect will be studied as a comparative. Afterwards, by using the ANSYS® WB finite element program to model and analyze RC beams by externally bonding FRP will be carried out. Adhesive thickness, adhesive type, the concrete surface will be performed by entering the parameters for analysis of stress can be obtained as a result. Thus, the analytical expressions of stress and normal stress equations will establish should be modified. Finite element analysis and experimental results will be compared, compatibility investigated, the results and recommendations presented by the study be completed.

  1. MWCNTs-reinforced epoxidized linseed oil plasticized polylactic acid nanocomposite and its electroactive shape memory behaviour.

    Science.gov (United States)

    Alam, Javed; Alam, Manawwer; Raja, Mohan; Abduljaleel, Zainularifeen; Dass, Lawrence Arockiasamy

    2014-10-31

    A novel electroactive shape memory polymer nanocomposite of epoxidized linseed oil plasticized polylactic acid and multi-walled carbon nanotubes (MWCNTs) was prepared by a combination of solution blending, solvent cast technique, and hydraulic hot press moulding. In this study, polylactic acid (PLA) was first plasticized by epoxidized linseed oil (ELO) in order to overcome the major limitations of PLA, such as high brittleness, low toughness, and low tensile elongation. Then, MWCNTs were incorporated into the ELO plasticized PLA matrix at three different loadings (2, 3 and 5 wt. %), with the aim of making the resulting nanocomposites electrically conductive. The addition of ELO decreased glass transition temperature, and increased the elongation and thermal degradability of PLA, as shown in the results of differential scanning calorimetry (DSC), tensile test, and thermo gravimetric analysis (TGA). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to observe surface morphology, topography, and the dispersion of MWCNTs in the nanocomposite. Finally, the electroactive-shape memory effect (electroactive-SME) in the resulting nanocomposite was investigated by a fold-deploy "U"-shape bending test. As per the results, the addition of both ELO and MWCNTs to PLA matrix seemed to enhance its overall properties with a great deal of potential in improved shape memory. The 3 wt. % MWCNTs-reinforced nanocomposite system, which showed 95% shape recovery within 45 s at 40 DC voltage, is expected to be used as a preferential polymeric nanocomposite material in various actuators, sensors and deployable devices.

  2. MWCNTs-Reinforced Epoxidized Linseed Oil Plasticized Polylactic Acid Nanocomposite and Its Electroactive Shape Memory Behaviour

    Directory of Open Access Journals (Sweden)

    Javed Alam

    2014-10-01

    Full Text Available A novel electroactive shape memory polymer nanocomposite of epoxidized linseed oil plasticized polylactic acid and multi-walled carbon nanotubes (MWCNTs was prepared by a combination of solution blending, solvent cast technique, and hydraulic hot press moulding. In this study, polylactic acid (PLA was first plasticized by epoxidized linseed oil (ELO in order to overcome the major limitations of PLA, such as high brittleness, low toughness, and low tensile elongation. Then, MWCNTs were incorporated into the ELO plasticized PLA matrix at three different loadings (2, 3 and 5 wt. %, with the aim of making the resulting nanocomposites electrically conductive. The addition of ELO decreased glass transition temperature, and increased the elongation and thermal degradability of PLA, as shown in the results of differential scanning calorimetry (DSC, tensile test, and thermo gravimetric analysis (TGA. Scanning electron microscopy (SEM and atomic force microscopy (AFM were used to observe surface morphology, topography, and the dispersion of MWCNTs in the nanocomposite. Finally, the electroactive-shape memory effect (electroactive-SME in the resulting nanocomposite was investigated by a fold-deploy “U”-shape bending test. As per the results, the addition of both ELO and MWCNTs to PLA matrix seemed to enhance its overall properties with a great deal of potential in improved shape memory. The 3 wt. % MWCNTs-reinforced nanocomposite system, which showed 95% shape recovery within 45 s at 40 DC voltage, is expected to be used as a preferential polymeric nanocomposite material in various actuators, sensors and deployable devices.

  3. Neural plasticity and behavior - sixty years of conceptual advances.

    Science.gov (United States)

    Sweatt, J David

    2016-10-01

    This brief review summarizes 60 years of conceptual advances that have demonstrated a role for active changes in neuronal connectivity as a controller of behavior and behavioral change. Seminal studies in the first phase of the six-decade span of this review firmly established the cellular basis of behavior - a concept that we take for granted now, but which was an open question at the time. Hebbian plasticity, including long-term potentiation and long-term depression, was then discovered as being important for local circuit refinement in the context of memory formation and behavioral change and stabilization in the mammalian central nervous system. Direct demonstration of plasticity of neuronal circuit function in vivo, for example, hippocampal neurons forming place cell firing patterns, extended this concept. However, additional neurophysiologic and computational studies demonstrated that circuit development and stabilization additionally relies on non-Hebbian, homoeostatic, forms of plasticity, such as synaptic scaling and control of membrane intrinsic properties. Activity-dependent neurodevelopment was found to be associated with cell-wide adjustments in post-synaptic receptor density, and found to occur in conjunction with synaptic pruning. Pioneering cellular neurophysiologic studies demonstrated the critical roles of transmembrane signal transduction, NMDA receptor regulation, regulation of neural membrane biophysical properties, and back-propagating action potential in critical time-dependent coincidence detection in behavior-modifying circuits. Concerning the molecular mechanisms underlying these processes, regulation of gene transcription was found to serve as a bridge between experience and behavioral change, closing the 'nature versus nurture' divide. Both active DNA (de)methylation and regulation of chromatin structure have been validated as crucial regulators of gene transcription during learning. The discovery of protein synthesis dependence on the

  4. The test study of the shear strength of the interface between the steel and fiber reinforced plastic in composite guide

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, X.; Guo, J. [Jiaozuo Institute of Technology, Jiaozuo (China)

    2001-02-01

    A new kind of composite guide has been put forward in the light of existing situation that the shaft furniture is corroded seriously. The guide is composed of a steel core which is protected from corrosion by a layer of glass fibre reinforced plastic. The sheer strength of the interface between the steel and the glass fibre reinforced plastic was tested. The test results indicates that the shear strength of the interface withstands the working conditions of the mining shaft, therefore, the performance of the composite materials will not be restricted due to poor shear strength of the interface. 4 refs., 5 figs., 2 tabs.

  5. EFFECT OF UNEQUAL DEFORMATION IN DEVELOPMENT OF ADVANCED PLASTIC PROCESSING TECHNOLOGIES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An effect of unequal deformation in development of advanced plastic processing technologies is researched by studying an in-plane bending process of strip metal under unequal compressing. The research results show the following: If appropriately controlled, unequal plastic deformation can play an important role not only in the improvement of quality of parts obtained by plastic processing technologies, but also in the development of new processes for advanced plastic working technologies. A coordinated growth of unequal plastic deformation can develop the deformation potentiality of material to the full. The degree of unequal plastic deformation can be used as bases for optimization design of processes and dies of plastic forming.

  6. 40 CFR 63.5795 - How do I know if my reinforced plastic composites production facility is a new affected source or...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true How do I know if my reinforced plastic...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic Composites Production What This Subpart Covers §...

  7. A new framework for cortico-striatal plasticity: behavioural theory meets in vitro data at the reinforcement-action interface.

    Directory of Open Access Journals (Sweden)

    Kevin N Gurney

    2015-01-01

    Full Text Available Operant learning requires that reinforcement signals interact with action representations at a suitable neural interface. Much evidence suggests that this occurs when phasic dopamine, acting as a reinforcement prediction error, gates plasticity at cortico-striatal synapses, and thereby changes the future likelihood of selecting the action(s coded by striatal neurons. But this hypothesis faces serious challenges. First, cortico-striatal plasticity is inexplicably complex, depending on spike timing, dopamine level, and dopamine receptor type. Second, there is a credit assignment problem-action selection signals occur long before the consequent dopamine reinforcement signal. Third, the two types of striatal output neuron have apparently opposite effects on action selection. Whether these factors rule out the interface hypothesis and how they interact to produce reinforcement learning is unknown. We present a computational framework that addresses these challenges. We first predict the expected activity changes over an operant task for both types of action-coding striatal neuron, and show they co-operate to promote action selection in learning and compete to promote action suppression in extinction. Separately, we derive a complete model of dopamine and spike-timing dependent cortico-striatal plasticity from in vitro data. We then show this model produces the predicted activity changes necessary for learning and extinction in an operant task, a remarkable convergence of a bottom-up data-driven plasticity model with the top-down behavioural requirements of learning theory. Moreover, we show the complex dependencies of cortico-striatal plasticity are not only sufficient but necessary for learning and extinction. Validating the model, we show it can account for behavioural data describing extinction, renewal, and reacquisition, and replicate in vitro experimental data on cortico-striatal plasticity. By bridging the levels between the single synapse and

  8. A new framework for cortico-striatal plasticity: behavioural theory meets in vitro data at the reinforcement-action interface.

    Science.gov (United States)

    Gurney, Kevin N; Humphries, Mark D; Redgrave, Peter

    2015-01-01

    Operant learning requires that reinforcement signals interact with action representations at a suitable neural interface. Much evidence suggests that this occurs when phasic dopamine, acting as a reinforcement prediction error, gates plasticity at cortico-striatal synapses, and thereby changes the future likelihood of selecting the action(s) coded by striatal neurons. But this hypothesis faces serious challenges. First, cortico-striatal plasticity is inexplicably complex, depending on spike timing, dopamine level, and dopamine receptor type. Second, there is a credit assignment problem-action selection signals occur long before the consequent dopamine reinforcement signal. Third, the two types of striatal output neuron have apparently opposite effects on action selection. Whether these factors rule out the interface hypothesis and how they interact to produce reinforcement learning is unknown. We present a computational framework that addresses these challenges. We first predict the expected activity changes over an operant task for both types of action-coding striatal neuron, and show they co-operate to promote action selection in learning and compete to promote action suppression in extinction. Separately, we derive a complete model of dopamine and spike-timing dependent cortico-striatal plasticity from in vitro data. We then show this model produces the predicted activity changes necessary for learning and extinction in an operant task, a remarkable convergence of a bottom-up data-driven plasticity model with the top-down behavioural requirements of learning theory. Moreover, we show the complex dependencies of cortico-striatal plasticity are not only sufficient but necessary for learning and extinction. Validating the model, we show it can account for behavioural data describing extinction, renewal, and reacquisition, and replicate in vitro experimental data on cortico-striatal plasticity. By bridging the levels between the single synapse and behaviour, our

  9. Laser Cutting of Carbon Fiber Reinforced Plastics - Investigation of Hazardous Process Emissions

    Science.gov (United States)

    Walter, Juergen; Hustedt, Michael; Staehr, Richard; Kaierle, Stefan; Jaeschke, Peter; Suttmann, Oliver; Overmeyer, Ludger

    Carbon fiber reinforced plastics (CFRP) show high potential for use in lightweight applications not only in aircraft design, but also in the automotive or wind energy industry. However, processing of CFRP is complex and expensive due to their outstanding mechanical properties. One possibility to manufacture CFRP structures flexibly at acceptable process speeds is high-power laser cutting. Though showing various advantages such as contactless energy transfer, this process is connected to potentially hazardous emission of respirable dust and organic gases. Moreover, the emitted particles may be fibrous, thus requiring particular attention. Here, a systematic analysis of the hazardous substances emitted during laser cutting of CFRP with thermoplastic and thermosetting matrix is presented. The objective is to evaluate emission rates for the total particulate and gaseous fractions as well as for different organic key components. Furthermore, the influence of the laser process conditions shall be assessed, and first proposals to handle the emissions adequately are made.

  10. Durability of Starch Based Biodegradable Plastics Reinforced with Manila Hemp Fibers

    Directory of Open Access Journals (Sweden)

    Shinji Ochi

    2011-02-01

    Full Text Available The biodegradability of Manila hemp fiber reinforced biodegradable plastics was studied for 240 days in a natural soil and 30 days in a compost soil. After biodegradability tests, weights were measured and both tensile strength tests and microscopic observation were performed to evaluate the biodegradation behavior of the composites. The results indicate that the tensile strength of the composites displays a sharp decrease for up to five days, followed by a gradual decrease. The weight loss and the reduction in tensile strength of biodegradable composite materials in the compost soil are both significantly greater than those buried in natural soil. The biodegradability of these composites is enhanced along the lower portion because this area is more easily attacked by microorganisms.

  11. The importance of material structure in the laser cutting of glass fiber reinforced plastic composites

    Energy Technology Data Exchange (ETDEWEB)

    Caprino, G. (Univ. di Napoli (Italy). Dipt. di Ingegneria dei Materiali e della Produzione); Tagliaferri, V. (Univ. di Salerno (Italy). Istituto di Ingegneria Meccanica); Covelli, L. (IMU-Consiglio Nazionale delle Ricerche, Milano (Italy))

    1995-01-01

    A previously proposed micromechanical formula, aiming to predict the vaporization energy Q[sub v] of composite materials as a function of fiber and matrix properties and fiber volume ratio, was assessed. The experimental data, obtained on glass fiber reinforced plastic panels with different fiber contents cut by a medium power CO[sub 2] cw laser, were treated according to a procedure previously suggested, in order to evaluate Q[sub v]. An excellent agreement was found between experimental and theoretical Q[sub v] values. Theory was then used to predict the response to laser cutting of a composite material with a fiber content varying along the thickness. The theoretical predictions indicated that, in this case, the interpretation of the experimental results may be misleading, bringing to errors in the evaluation of the material thermal properties, or in the prediction of the kerf depth. Some experimental data were obtained, confirming the theoretical findings.

  12. Temperature Dependence of Sound Velocity in High-Strength Fiber-Reinforced Plastics

    Science.gov (United States)

    Nomura, Ryuji; Yoneyama, Keiichi; Ogasawara, Futoshi; Ueno, Masashi; Okuda, Yuichi; Yamanaka, Atsuhiko

    2003-08-01

    Longitudinal sound velocity in unidirectional hybrid composites or high-strength fiber-reinforced plastics (FRPs) was measured along the fiber axis over a wide temperature range (from 77 K to 420 K). We investigated two kinds of high-strength crystalline polymer fibers, polyethylene (Dyneema) and polybenzobisoxazole (Zylon), which are known to have negative thermal expansion coefficients and high thermal conductivities along the fiber axis. Both FRPs had very high sound velocities of about 9000 m/s at low temperatures and their temperature dependences were very strong. Sound velocity monotonically decreased with increasing temperature. The temperature dependence of sound velocity was much stronger in Dyneema-FRP than in Zylon-FRP.

  13. Influence of fibre volume fraction and temperature on fatigue life of glass fibre reinforced plastics

    Directory of Open Access Journals (Sweden)

    Konrad Wegener

    2016-07-01

    Full Text Available The influence of fibre volume fraction and temperature on fatigue life of continuous glass fibre reinforced plastics is investigated in detail. The physical causes of the two effects on the slope of the S-N-curve in fibre direction at R = 0.1 are researched and can be explained with help of micrographs. A new phenomenological approach is presented to model both effects in fibre dominated laminates with different stacking sequences using only the static ultimate strength as an input. Static and fatigue tests of different layups and fibre volume fractions are performed at different temperatures to validate the fatigue life predictions. Additionally it is derived that there is an optimal fibre volume fraction regarding a minimum damage sum. This fibre volume fraction is dependent on a given loading spectra and can be calculated using the phenomenological model.

  14. Copper coated carbon fiber reinforced plastics for high and ultra high vacuum applications

    Science.gov (United States)

    Burri, F.; Fertl, M.; Feusi, P.; Henneck, R.; Kirch, K.; Lauss, B.; Rüttimann, P.; Schmidt-Wellenburg, P.; Schnabel, A.; Voigt, J.; Zenner, J.; Zsigmond, G.

    2014-03-01

    We have used copper-coated carbon fiber reinforced plastic (CuCFRP) for the construction of high and ultra-high vacuum recipients. The vacuum performance is found to be comparable to typical stainless steel used for this purpose. In test recipients we have reached pressures of 2E-8 mbar and measured a desorption rate of 1E-11 mbar*liter/s/cm^2; no degradation over time (2 years) has been found. Suitability for baking has been found to depend on the CFRP production process, presumably on the temperature of the autoclave curing. Together with other unique properties of CuCFRP such as low weight and being nearly non-magnetic, this makes it an ideal material for many high-end vacuum applications.

  15. Dual energy CT inspection of a carbon fibre reinforced plastic composite combined with metal components

    Directory of Open Access Journals (Sweden)

    Daniel Vavrik

    2016-11-01

    Full Text Available This work is focused on the inspection of carbon fibre reinforced plastic composites (CFRP combined with metal components. It is well known that the high absorption of metallic parts degrades the quality of radiographic measurements (contrast and causes typical metal artefacts in X-ray computed tomography (CT reconstruction. It will be shown that these problems can be successfully solved utilizing the dual energy CT method (DECT, which is typically used for the material decomposition of complex objects. In other words, DECT can help differentiate object components with a similar overall attenuation or visualise low attenuation components that are next to high attenuation ones. The application of DECT to analyse honeycomb sandwich panels and CFRP parts joined with metal fasteners will be presented in the article.

  16. Use of pultruded reinforced plastics in energy generation and energy related applications

    Science.gov (United States)

    Anderson, R.

    Applications of pultrusion-formed fiber-reinforced plastics (FRP) in the wind, oil, and coal derived energy industries are reviewed. FRP is noted to be a viable alternative to wood, aluminum, and steel for reasons of availability, price, and weight. Attention is given to the development of FRP wind turbine blades for the DOE 8 kW low cost, high reliability wind turbine program. The blades feature a NACA 23112 profile with a 15 in. chord on the system which was tested at Rocky Flats, CO. Fabricating the blades involved a plus and minus 45 deg roving orientation, a heavy fiber-glass nose piece to assure blade strength, and a separately manufactured foam core. Additional uses for FRP products have been found in the structural members of coal stack scrubbers using a vinyl ester resin in a fire retardant formulation, and as low cost, light weight sucker rods for deep well oil drilling.

  17. Effect of High Velocity Ballistic Impact on Pretensioned Carbon Fibre Reinforced Plastic (CFRP) Plates

    Science.gov (United States)

    Azhar KAMARUDIN, Kamarul; HAMID, Iskandar ABDUL

    2017-01-01

    This work describes an experimental investigation of the pretensioned thin plates made of Carbon Fibre Reinforced Plastic (CFRP) struck by hemispherical and blunt projectiles at various impact velocities. The experiments were done using a gas gun with combination of pretension equipment positioned at the end of gun barrel near the nozzle. Measurements of the initial and residual velocities were taken, and the ballistic limit velocity were calculated for each procedures. The pretension target results in reduction of ballistic limit compared to non-pretension target for both flat and hemispherical projectiles. Target impacted by hemispherical projectile experience split at earlier impact velocity compared to target by flat projectile. C-Scan images analysis technique was used to show target impact damaged by hemispherical and flat projectiles. The damage area was shown biggest at ballistic limit velocity and target splitting occurred most for pretention plate.

  18. Linear and Non-linear Analysis of Fibre Reinforced Plastic Bridge Deck due to Vehicle Loads

    Science.gov (United States)

    Ray, Chaitali; Mandal, Bibekananda

    2015-06-01

    The present work deals with linear and nonlinear static analysis of fibre reinforced plastics composite bridge deck structures using the finite element method. The nonlinear static analysis has been carried out considering geometric nonlinearity. The analysis of bridge deck has been carried out under vehicle load as specified by IRC Class B wheel load classification. The formulation has been carried out using the finite element software package ANSYS 14.0 and the SHELL281 element is used to model the bridge deck. The bridge deck has also been modeled as a plate stiffened with closely spaced hollow box sections and a computer code is developed based on this formulation. The results obtained from the present formulation are compared with those available in the published literature. A parametric study on the stiffened bridge deck has also been carried out with varying dimensions of the stiffeners under vehicle loads.

  19. Copper coated carbon fiber reinforced plastics for high and ultra high vacuum applications

    CERN Document Server

    Burri, F; Feusi, P; Henneck, R; Kirch, K; Lauss, B; Ruettimann, P; Schmidt-Wellenburg, P; Schnabel, A; Voigt, J; Zenner, J; Zsigmond, G

    2013-01-01

    We have used copper-coated carbon fiber reinforced plastic (CuCFRP) for the construction of high and ultra-high vacuum recipients. The vacuum performance is found to be comparable to typical stainless steel used for this purpose. In test recipients we have reached pressures of 2E-8 mbar and measured a desorption rate of 1E-11 mbar*liter/s/cm^2; no degradation over time (2 years) has been found. Suitability for baking has been found to depend on the CFRP production process, presumably on the temperature of the autoclave curing. Together with other unique properties of CuCFRP such as low weight and being nearly non-magnetic, this makes it an ideal material for many high-end vacuum applications.

  20. Cardanol-based thermoset plastic reinforced by sponge gourd fibers (Luffa cylindrica

    Directory of Open Access Journals (Sweden)

    André Leandro da Silva

    2016-02-01

    Full Text Available Abstract A growing global trend for maximum use of natural resources through new processes and products has enhanced studies and exploration of renewable natural materials. In this study, cardanol, a component of the cashew nut shell liquid (CNSL, was used as a building block for the development of a thermosetting matrix, which was reinforced by raw and modified sponge gourd fibers (Luffa cylindrica. DSC and TG results showed that among biocomposites, the one reinforced by sponge gourd fibers treated with NaOH 10 wt% (BF10 had the highest thermal stability, besides the best performance in the Tensile testing, showing good incorporation, dispersion, and adhesion to polymer matrix, observed by SEM. After 80 days of simulated soil experiments, it has been discovered that the presence of treated fiber allowed better biodegradability behavior to biocomposites. The biobased thermoset plastic and biocomposites showed a good potential to several applications, such as manufacturing of articles for furniture and automotive industries, especially BF10.

  1. Spectroscopic study of terahertz reflection and transmission properties of carbon-fiber-reinforced plastic composites

    Science.gov (United States)

    Zhang, Jin; Shi, Changcheng; Ma, Yuting; Han, Xiaohui; Li, Wei; Chang, Tianying; Wei, Dongshan; Du, Chunlei; Cui, Hong-Liang

    2015-05-01

    Carbon-fiber-reinforced plastic (CFRP) composites are widely used in aerospace and concrete structure reinforcement due to their high strength and light weight. Terahertz (THz) time-domain spectroscopy is an attractive tool for defect inspection in CFRP composites. In order to improve THz nondestructive testing of CFRP composites, we have carried out systematic investigations of THz reflection and transmission properties of CFRP. Unidirectional CFRP composites with different thicknesses are measured with polarization directions 0 deg to 90 deg with respect to the fiber direction, in both reflection and transmission modes. As shown in the experiments, CFRP composites are electrically conducting and therefore exhibit a high THz reflectivity. In addition, CFRP composites have polarization-dependent reflectivity and transmissivity for THz radiation. The reflected THz power in the case of parallel polarization is nearly 1.8 times higher than for perpendicular polarization. At the same time, in the transmission of THz wave, a CFRP acts as a Fabry-Pérot cavity resulting from multiple internal reflections from the CFRP-air interfaces. Moreover, from the measured data, we extract the refractive index and absorption coefficient of CFRP composites in the THz frequency range.

  2. CREATION AND STUDY OF THE PROPERTIES OF ORGANIC PLASTICS BASED ON POLYAMIDE, REINFORCED POLYIMIDE FIBERS

    Directory of Open Access Journals (Sweden)

    A. I. Buria

    2014-01-01

    Full Text Available Summary. The rapid development of industry and increase its competitiveness requires the development of new materials, including polymer composites based on polyamides. In order to improve the performance and expand the applications of the polyamide binder is introduced particulate and fibrous fillers. Organic fibers, as compared with other polymers are of good wetting, high bonding strength with the matrix less prone to breakage, high specific strength and stiffness. The aim of the work is the creation and study of the properties of composites based on polyamide - PA-6 aliphatic and aromatic - phenylon C-1, filled polyimide fibers arimid-T. The technology of preparation of polymer compositions comprised of the following steps: mixing, pelletizing, drying and molding. Mixing of the compositions was performed in a rotating electromagnetic field. Under the action of the rotating electromagnetic field, ferromagnetic particles cаme into intensive chaotic motion, which leads to a uniform distribution of fibers in a polymer matrix. Molding samples was performed by compression molding. We study the thermal, physical, mechanical and tribological properties of polymer composites created. It was established that the reinforcement polyamides leads to increased strength characteristics composites. For organic plastics (OР based on the C-1 phenylon reinforced 15% of the mass Arimida-T, yield strength in compression, Rockwell hardness, modulus of elasticity, microhardness higher than the starting polymer at 13; 61, 20 and 68%, respectively. For ОР based on PA-6, the compressive yield stress and break microhardness modulus of elasticity with increasing degree of reinforcement binder increases by 47, 54, 25 and 36%, respectively. The highest wear resistance and low friction have composites based on PA-6 (30 % of the mass аrimida-T and through phenylon C-1 (15 % of the mass оf the fiber. Thermophysical composites research confirmed the presence of

  3. Effect of nanoparticles on tensile, impact and fatigue properties of fibre reinforced plastics

    Indian Academy of Sciences (India)

    R Nagalingam; S Sundaram; B Stanly Jones Retnam

    2010-10-01

    Advanced composite, fibre-reinforced polymer (FRP), has been favoured for certain aerospace, military, marine and automotive applications. Polymer nanocomposites containing layered silicates have attracted much attention. These exhibit increased modulus, decreased thermal expansion coefficient, increased solvent resistance and enhanced ionic conductivity when compared to the polymer alone. Here we have developed eight different combinations of composites FRP with nanoclay (montmorillonite) by layered manufacturing techniques (LM) and measured the mechanical properties. The measurement showed that the tensile strength, impact strength and fatigue life are greatly increased. A plausible explanation for high increase of properties has also been discussed.

  4. Occupational exposure to styrene in the fibreglass reinforced plastic industry: comparison between two different manufacturing processes.

    Science.gov (United States)

    Tranfo, Giovanna; Gherardi, Monica; Paci, E; Gatto, Mariapia; Gordiani, A; Caporossi, Lidia; Capanna, Silvia; Sisto, Renata; Papaleo, B; Fiumalbi, Carla; Garofani, Patrizia

    2012-01-01

    Styrene is used in manufacturing fiberglass reinforced plastics: and occupational exposure was related to neurotoxicology and genotoxicity. The sum of the metabolites mandelic and phenylglyoxylic acids is the ACGIH biomarker for occupational exposure with a BEI of 400 mg/g of creatinine in end shift urine corresponding to a airborne styrene concentration of 85 mg/m3. There are two main molding processes, open and closed, the last more effective at controlling worker's styrene exposure. To compare the open molding process to the compression of fiber reinforced resin foils, a kind of closed molding, monitoring the styrene exposure of workers in two production sites (A and B). Environmental Monitoring was carried out by Radiello samplers and Biological Monitoring by means of the determination of MA and PGA with HPLC/MS/MS in 10 workers at Site A and 14 at Site B. The median values for styrene exposure resulted 31.1 mg/m3 for Site A and 24.4 mg/m for Site B, while the medians for the sum of the two metabolites in the end shift urine were 86.7 e 33.8 mg/g creatinine respectively. There is a significant linear correlation between personal styrene exposure and the excretion of styrene metabolites (R = 0.74). As expected the exposure markers of the workers of the two production sites resulted higher in the open process. The analytical results of both environmental and biological monitoring were all below the occupational exposure limits, confirming the efficacy of the protective devices.

  5. Strategies to improve the mechanical properties of starch-based materials: plasticization and natural fibers reinforcement

    Directory of Open Access Journals (Sweden)

    A. Lopez-Gil

    2014-01-01

    Full Text Available Biodegradable polymers are starting to be introduced as raw materials in the food-packaging market. Nevertheless, their price is very high. Starch, a fully biodegradable and bioderived polymer is a very interesting alternative due to its very low price. However, the use of starch as the polymer matrix for the production of rigid food packaging, such as trays, is limited due to its poor mechanical properties, high hidrophilicity and high density. This work presents two strategies to overcome the poor mechanical properties of starch. First, the plasticization of starch with several amounts of glycerol to produce thermoplastic starch (TPS and second, the production of biocomposites by reinforcing TPS with promising fibers, such as barley straw and grape waste. The mechanical properties obtained are compared with the values predicted by models used in the field of composites; law of mixtures, Kerner-Nielsen and Halpin-Tsai. To evaluate if the materials developed are suitable for the production of food-packaging trays, the TPS-based materials with better mechanical properties were compared with commercial grades of oil-based polymers, polypropylene (PP and polyethylene-terphthalate (PET, and a biodegradable polymer, polylactic acid (PLA.

  6. The electrostatic properties of Fiber-Reinforced-Plastics double wall underground storage gasoline tanks

    Science.gov (United States)

    Li, Yipeng; Liu, Quanzhen; Meng, He; Sun, Lifu; Zhang, Yunpeng

    2013-03-01

    At present Fiber Reinforced Plastics (FRP) double wall underground storage gasoline tanks are wildly used. An FRP product with a resistance of more than 1011 Ω is a static non-conductor, so it is difficult for the static electricity in the FRP product to decay into the earth. In this paper an experimental system was built to simulate an automobile gasoline filling station. Some electrostatic parameters of the gasoline, including volume charge density, were tested when gasoline was unloaded into a FRP double wall underground storage tank. Measurements were taken to make sure the volume charge density in the oil-outlet was similar to the volume charge density in the tank. In most cases the volume charge density of the gasoline was more than 22.7 μC m-3, which is likely to cause electrostatic discharge in FRP double wall underground storage gasoline tanks. On the other hand, it would be hard to ignite the vapor by electrostatic discharge since the vapor pressure in the tanks is over the explosion limit. But when the tank is repaired or re-used, the operators must pay attention to the static electricity and some measurements should be taken to avoid electrostatic accident. Besides the relaxation time of charge in the FRP double wall gasoline storage tanks should be longer.

  7. Microstructure and Mechanical Properties of Warm-Sprayed Titanium Coating on Carbon Fiber-Reinforced Plastic

    Science.gov (United States)

    Ganesan, Amirthan; Takuma, Okada; Yamada, Motohiro; Fukumoto, Masahiro

    2016-04-01

    Polymer materials are increasingly dominating various engineering fields. Recently, polymer-based composite materials' surface performances—in particular, surface in relative motion—have been improved markedly by thermal spray coating. Despite this recent progress, the deposition of high-strength materials—producing a coating thickness of the order of more than 500 μm—remains highly challenging. In the present work, a highly dense and thick titanium coating was successfully deposited onto the carbon fiber-reinforced plastic (CFRP) substrate using a newly developed high-pressure warm spray (WS) system. The coating properties, such as hardness (300 ± 20 HV) and adhesion strength (8.1 ± 0.5 MPa), were evaluated and correlated with the microstructures of the coating. In addition, a wipe-test and in situ particle velocity and temperature measurement were performed to validate the particle deposition behavior as a function of the nitrogen flow rate in the WS system. It was found that the microstructures, deposition efficiency, and mechanical properties of the coatings were highly sensitive to nitrogen flow rates. The coating porosity increased with increasing nitrogen flow rates; however, the highest density was observed for nitrogen flow rate of 1000 standard liters per minute (SLM) samples due to the high fraction of semi-molten particles in the spray stream.

  8. ANALISA TEKNIS DAN EKONOMIS PENGGUNAAN COREMAT UNTUK KONSTRUKSI FRP (FIBERGLASS REINFORCED PLASTIC SANDWICH PADA BADAN KAPAL

    Directory of Open Access Journals (Sweden)

    Parlindungan Manik

    2012-04-01

    Full Text Available Planning of ship construction is make its having good effectivity value and efficiency. Composite as material alternative to changes of steel feedstock and wood has many applied named FRP (fiberglass reinforced plastics single skin. The weakness of this FRP was heavy construction and requires many production time. Therefore, will be checked comparison between single skin with sandwich constructions for shell. In this research, the way for making composite is hand lay up method with three various thickness of skin there are : t, t/2, and t/4. To know strength comparison from the various skin of sandwich with single skin, must be test, consist of tensile test.. The result is analyzed then compared by BKI (Biro Klasifikasi Indonesia rules for the fiberglass ship. Based on the result, indicates that optimization skin thickness of sandwich construction applies Coremat which tensile strength it is equivalent with Single Skin at 2/3t and usage of Sandwich construction causes 23,12 % lighter. In economic analyze, advantage from low weight is compensation of addition 23,12 % DWT. Material cost for Sandwich about 11,35% bigger than Single Skin construction.

  9. Glass fiber reinforced plastics within the fringe and flexure tracker of LINC-NIRVANA

    Science.gov (United States)

    Smajic, Semir; Eckart, A.; Horrobin, M.; Lindhorst, B.; Pott, J.-U.; Rauch, C.; Rost, S.; Straubmeier, C.; Tremou, E.; Wank, I.; Zuther, J.

    2012-07-01

    The Fringe and Flexure Tracking System (FFTS) is meant to monitor and correct atmospheric piston varia­ tion and instrumental vibrations and flexure during near-infrared interferometric image acquisition of LING­ NIRVANA. In close work with the adaptive optics system the FFTS enables homothetic imaging for the Large Binocular Telescope. One of the main problems we had to face is the connection between the cryogenic upper part of the instrument, e.g. detector head, and the lower ambient temperature part. In this ambient temperature part the moving stages are situated that move the detector head in the given field of view (FOV). We show how we solved this problem using the versatile material glass fiber reinforced plastics (GFRP's) and report in what way this material can be worked. We discuss in detail the exquisite characteristics of this material which we use to combine the cryogenic and ambient environments to a fully working system. The main characteristics that we focus on are the low temperature conduction and the tensile strength of the GFRP's. The low temperature conduction is needed to allow for a low heat-exchange between the cryogenic and ambient part whereas the tensile strength is needed to support heavy structures like the baffle motor and to allow for a minimum of flexure for the detector head. Additionally, we discuss the way we attached the GFRP to the remaining parts of the FFTS using a two component encapsulant.

  10. Defect Detection on Carbon Fibre Reinforced Plastics (cfrp) with Laser Generated Lamb Waves

    Science.gov (United States)

    Focke, O.; Huke, P.; Hildebrandt, A.

    2011-06-01

    Standard ultrasound methods using a phased-array or a single transducer are commonly used for non-destructive evaluation (NDE) during manufacturing of carbon fiber reinforced plastics (CFRP) parts and certificated testing schemes were developed for individual parts and geometries. However, most testing methods need direct contact, matching gels and remain therefore time consuming. Laser-Ultrasonics is advantageous due to the contactless measurement technology and high accessibility even on complex parts. Despite the non-destructive testing with body waves, we show that the NDE can be expanded using two-dimensional surface (Lamb) waves for detection of delaminations close to the surface or small deteriorations caused by e.g. impacts. Lamb waves have been excited with a single transducer and with a short-pulse Laser with additionally producing A0-and S0-Lamb waves. The waves were detected with a shearography setup that allows for measuring two-dimensionally the displacement of a surface. Short integration times of the camera were realized using a pulsed ruby laser for illumination. As a consequence to the anisotropy the propagation in different directions exhibits individual characteristics like amplitude, damping and velocity. This has motivated to build up models for the propagation of Lamb waves and to compare them with experimental results.

  11. A composite-appropriate integration method of thick functional components in fibre-reinforced plastics

    Science.gov (United States)

    Filippatos, A.; Höhne, R.; Kliem, M.; Gude, M.

    2016-03-01

    The use of integrated structural health monitoring systems for critical composite parts, such as wind turbine blades, fuselage and wing parts, is an promising approach to guarantee a safe and efficient operational lifetime of such components. Therefore, the integration of thick functional components like sensors, actuators and electronic components is often necessary. An optimal integration of such components should be ensured without material imperfections in the composite structure, i.e. voids and resin rich areas, and failure of the functional components. In this paper, first investigations were undertaken for a basic understanding of the mechanical performance of a fibre reinforced plastic component with integrated functional elements. The influence of different materials and treatment methods for the encapsulation of electronic components was experimentally investigated under static and dynamic loading tests. By means of a parametric finite element model, the effects of an encapsulation and various parameters such as the shape and orientation of the electronic components were examined. Several encapsulation variants were investigated in order to minimise the chance of failure initiations. Based both on experimental and numerical results, a preferred composite integration concept was selected for an electronic board and some first recommendations for an optimal integration were derived.

  12. Standard practice for examination of fiberglass reinforced plastic fan blades using acoustic emission

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice provides guidelines for acoustic emission (AE) examinations of fiberglass reinforced plastic (FRP) fan blades of the type used in industrial cooling towers and heat exchangers. 1.2 This practice uses simulated service loading to determine structural integrity. 1.3 This practice will detect sources of acoustic emission in areas of sensor coverage that are stressed during the course of the examination. 1.4 This practice applies to examinations of new and in-service fan blades. 1.5 This practice is limited to fan blades of FRP construction, with length (hub centerline to tip) of less than 3 m [10 ft], and with fiberglass content greater than 15 % by weight. 1.6 AE measurements are used to detect emission sources. Other nondestructive examination (NDE) methods may be used to evaluate the significance of AE sources. Procedures for other NDE methods are beyond the scope of this practice. 1.7 Units—The values stated in either SI units or inch-pound units are to be regarded separately as sta...

  13. Graphite Nanoplatelet Modified Epoxy Resin for Carbon Fibre Reinforced Plastics with Enhanced Properties

    Directory of Open Access Journals (Sweden)

    Yan Li

    2017-01-01

    Full Text Available A simple approach to deliver graphene or graphite nanoplatelets (GNPs into carbon fibre reinforced plastic (CFRPs to enhance the multifunctional properties of carbon/epoxy laminates was demonstrated. GNPs improved the typically low interlaminar mechanical, thermal, and electrical properties of CFRPs after direct vacuum infusion of GNP doped resin obtained via in situ exfoliation by three-roll milling (TRM. Compared to high shear mixing or probe ultrasonication, TRM produces higher shear rates and stresses to exfoliate and finely disperse GNP particles within an epoxy matrix. This environmentally friendly and industrial scalable process does not require the use of solvents, additives, or chemical treatments. The flexural modulus and interlaminar shear strength (ILSS of CFRPs was increased by 15% and by 18%, respectively, with the addition of 5 wt.% in situ exfoliated GNP in the doped epoxy resin. Out-of-plane electrical and thermal conductivity, at the same filler content, were, respectively, improved by nearly two orders of magnitude and 50%.

  14. Electro-bending characterization of adaptive 3D fiber reinforced plastics based on shape memory alloys

    Science.gov (United States)

    Ashir, Moniruddoza; Hahn, Lars; Kluge, Axel; Nocke, Andreas; Cherif, Chokri

    2016-03-01

    The industrial importance of fiber reinforced plastics (FRPs) is growing steadily in recent years, which are mostly used in different niche products, has been growing steadily in recent years. The integration of sensors and actuators in FRP is potentially valuable for creating innovative applications and therefore the market acceptance of adaptive FRP is increasing. In particular, in the field of highly stressed FRP, structural integrated systems for continuous component parts monitoring play an important role. This presented work focuses on the electro-mechanical characterization of adaptive three-dimensional (3D)FRP with integrated textile-based actuators. Here, the friction spun hybrid yarn, consisting of shape memory alloy (SMA) in wire form as core, serves as an actuator. Because of the shape memory effect, the SMA-hybrid yarn returns to its original shape upon heating that also causes the deformation of adaptive 3D FRP. In order to investigate the influences of the deformation behavior of the adaptive 3D FRP, investigations in this research are varied according to the structural parameters such as radius of curvature of the adaptive 3D FRP, fabric types and number of layers of the fabric in the composite. Results show that reproducible deformations can be realized with adaptive 3D FRP and that structural parameters have a significant impact on the deformation capability.

  15. Optics of carbon fiber-reinforced plastics - A theoretical and an experimental study

    Science.gov (United States)

    Hohmann, Ansgar; ElMaklizi, Ahmed; Foschum, Florian; Voit, Florian; Bergmann, Florian; Simon, Emanuel; Reitzle, Dominik; Kienle, Alwin

    2016-09-01

    Laser processing of carbon fiber-reinforced plastics (CFRP) as well as their design optimization are strongly emerging fields. As the optics of CFRP is still rather unknown, the optical behavior of CFRP was investigated in this study. Different simulation models were implemented to simulate reflectance from CFRP samples as well as distribution and absorption of light within these samples. The methods include an analytical solution of Maxwell's equations and Monte Carlo solutions of the radiative transfer theory. We show that strong inaccurracies occur, if light propagation in CFRP is modeled using the radiative transfer theory. Therefore, the solution of Maxwell's equations is the method of choice for calculation of light propagation in CFRP. Furthermore, measurements of the reflectance of light from CFRP were performed and compared to the simulations for investigation of the optical behavior. Information on the refractive index of carbon fibers was obtained via goniometric measurements. The amount of reflected light was determined as 6.05±0.38% for light polarized parallel to the fiber direction, while it was 3.65±0.41% for light polarized perpendicular to the fiber direction in case of laser-processed CFRP.

  16. Laser cutting of carbon fiber reinforced thermo-plastics (CFRTP) by single-mode fiber laser irradiation

    Science.gov (United States)

    Niino, Hiroyuki; Kawaguchi, Yoshizo; Sato, Tadatake; Narazaki, Aiko; Kurosaki, Ryozo; Muramatsu, Mayu; Harada, Yoshihisa; Anzai, Kenji; Aoyama, Mitsuaki; Matsushita, Masafumi; Furukawa, Koichi; Nishino, Michiteru; Fujisaki, Akira; Miyato, Taizo; Kayahara, Takashi

    2014-03-01

    We report on the laser cutting of carbon fiber reinforced thermo-plastics (CFRTP) with a cw IR fiber laser (single-mode fiber laser, average power: 350 W). CFRTP is a high strength composite material with a lightweight, and is increasingly being used various applications. A well-defined cutting of CFRTP which were free of debris and thermal-damages around the grooves, were performed by the laser irradiation with a fast beam galvanometer scanning on a multiple-scanpass method.

  17. Identification of Damage Types in Carbon Fiber Reinforced Plastic Laminates by a Novel Optical Fiber Acoustic Emission Sensor

    OpenAIRE

    Yu, Fengming; Wu, Qi; Okabe, Yoji; Kobayashi, Satoshi; Saito, Kazuya

    2014-01-01

    International audience; In this research, phase-shifted FBG (PS-FBG) sensor was employed to practical AE detection for carbon fiber reinforced plastic (CFRP) composite laminate. Firstly, we evaluated the characteristics of AE signals detected by this kind of sensor. Secondly, through the experiment and simulation concerning AE source orientation, quantitative information about the standard for discriminating the AE signals due to transverse cracks and delaminations was obtained. Finally, acco...

  18. Strain coordination of quasi-plane-hypothesis for reinforced concrete beam strengthened by epoxy-bonded glass fiber reinforced plastic plate

    Institute of Scientific and Technical Information of China (English)

    ZENG Xian-tao; DING Ya-hong; WANG Xing-guo

    2006-01-01

    The testing of thirteen reinforced concrete (RC) beams strengthened by epoxy-bonded glass fiber reinforced plastic plate (GFRP) shows that the RC beam and the GFRP plate with epoxy bonding on it can work fairly well in coordination to each other. But there is relative slipping between RC beam and GFRP plate. And the strain of GFRP and steel rebar of RC beam satisfies the quasi-plane-hypothesis, that is, the strain of longitudinal fiber that parallels to the neutral axis of plated beam within the scope of effective height (h0) of the cross section is in direct proportion to the distance from the fiber to the neutral axis. The strain of GFRP and steel rebar satisfies the equation: εCFRP = Kεsteel.

  19. Production of Starch Based Bioplastic from Cassava Peel Reinforced with Microcrystalline Celllulose Avicel PH101 Using Sorbitol as Plasticizer

    Science.gov (United States)

    Maulida; Siagian, M.; Tarigan, P.

    2016-04-01

    The production of starch based bioplastics from cassava peel reeinforced with microcrystalline cellulose using sorbitol as plasticizer were investigated. Physical properties of bioplastics were determined by density, water uptake, tensile strength and Fourier Transform Infrared Spectroscopy. Bioplastics were prepared from cassava peel starch plasticized using sorbitol with variation of 20; 25; 30% (wt/v of sorbitol to starch) reinforced with microcrystalline celllulose (MCC) Avicel PH101 fillers with range of 0 to 6% (wt/wt of MCC to starch). The results showed improvement in tensile strength with higher MCC content up to 9, 12 mpa compared to non-reinforced bioplastics. This could be mainly attributed to the strong hydrogen bonds between MCC and starch. On the contrary, the addition of MCC decreased the elongation at break, density and water uptake. Fourier Transform Infrared Spectroscopy showed the functional groups of bioplastics, which the majority of O-H groups were found at the bioplastics with reinforcing filler MCC that represented substantial hydrogen bonds. The highest tensile strength value was obtained for bioplastic with MCC content 6% and sorbitol content 20%. With good adhesion between MCC and starch the production of bioplastics could be widely used as a substitute for conventional plastics with more benefits to the environment.

  20. Plasticization and Reinforcement in a Boron Cage Compound Polyurethane Nanocomposite: A Dielectric Study

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, Dan; Liu, J.; Zhang, X.; Eastwood, E.; Bowler, N.

    2012-09-21

    In order to control and modify the physical properties of nanocomposite systems, it is essential to understand the nano-filler/polymer structure-property relationships. Boron cage compounds (BCCs) are a class of icosahedral, closed cage molecules that are of interest due to their high boron content and inherent neutron absorbing/shielding properties, and because of their ability to act as molecular nano-particles. When the BCC n-hexylcarborane is blended with a polybutadiene (PBD)/polyurethane (PU) segmented copolymer (EN8) an increase in the glass transition (Tg) temperature of the PBD phase (reinforcement) and a decrease in the Tg temperatures of the PU phases (plasticization) are observed. These observations were investigated by examining the dielectric relaxation properties of copolymer samples with and without added n-hexylcarborane (0wt% and 5wt% n-hexylcarborane) using broadband dielectric spectroscopy in the frequency range from 0.01 to 1 MHz and temperature range from -140 to 130 °C. Parametric fitting techniques aided in the identification of two α relaxation processes associated with the glass transitions of the soft PBD phase and the hard urethane phases, and a secondary β relaxation process due to the localized motions of side groups. The conductivities at low frequencies were also identified and modeled. Differential Scanning Calorimetry (DSC) did not indicate the presence of a crystalline component within the copolymer samples, so interfacial polarization (Maxwell-Wagner-Sillars) relaxation is not possible. A relaxation map (Arrhenius diagram) associated with these processes has been developed from the experimental data to elucidate the role of n-hexylcarborane in the molecular dynamics of the system. Values of fitting parameters, calculated Tg values, and a fragility index are also given for comparison. Reduced localized motion of the soft PBD phase, as well as reinforcement of the hard urethane phases is observed upon the introduction of n

  1. Contour scanning of textile preforms using a light-section sensor for the automated manufacturing of fibre-reinforced plastics

    Science.gov (United States)

    Schmitt, R.; Niggemann, C.; Mersmann, C.

    2008-04-01

    Fibre-reinforced plastics (FRP) are particularly suitable for components where light-weight structures with advanced mechanical properties are required, e.g. for aerospace parts. Nevertheless, many manufacturing processes for FRP include manual production steps without an integrated quality control. A vital step in the process chain is the lay-up of the textile preform, as it greatly affects the geometry and the mechanical performance of the final part. In order to automate the FRP production, an inline machine vision system is needed for a closed-loop control of the preform lay-up. This work describes the development of a novel laser light-section sensor for optical inspection of textile preforms and its integration and validation in a machine vision prototype. The proposed method aims at the determination of the contour position of each textile layer through edge scanning. The scanning route is automatically derived by using texture analysis algorithms in a preliminary step. As sensor output a distinct stage profile is computed from the acquired greyscale image. The contour position is determined with sub-pixel accuracy using a novel algorithm based on a non-linear least-square fitting to a sigmoid function. The whole contour position is generated through data fusion of the measured edge points. The proposed method provides robust process automation for the FRP production improving the process quality and reducing the scrap quota. Hence, the range of economically feasible FRP products can be increased and new market segments with cost sensitive products can be addressed.

  2. Advanced Laser Transmission Welding Strategies for Fibre Reinforced Thermoplastics

    Science.gov (United States)

    Wippo, V.; Jaeschke, P.; Brueggmann, M.; Suttmann, O.; Overmeyer, L.

    Laser transmission welding can be used to join endless fibre reinforced thermoplastics. The welding temperature is affected by the heat conduction along carbon fibresand depends on the local orientation of the fibres in the weld seam and the laser welding technique itself. In these investigations the heat development during the welding with quasi-static temperature fields, which is a combination of two laser welding techniques, is evaluated and compared to welding with a homogenized intensity distribution. In order to optimize the temperature distribution over the weld seam width for both linear and curved weld seams, different scanning structures have beenadapted. The experiments were conducted with a diode laser emitting at a wavelength of 940 nm and the process was monitored by aninfrared camera. The used thermoplastics consist of laminates based on unidirectional carbon fibre reinforced polyphenylenesulfide. With the developed scanning structures, a near-homogeneous temperature distribution was generated over the width of the weld seam for curved weld seams, which is not possible by welding with a homogenized laser radiation intensity distribution.

  3. Advanced modelling of concrete deterioration due to reinforcement corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Isgor, O.B. [Carleton Univ., Dept. of Civil and Environmental Engineering, Ottawa, Ontario (Canada); Razaqpur, A.G. [McMaster Univ., Dept. of Civil Engineering, Hamilton, Ontario (Canada)

    2006-06-15

    A comprehensive model is presented for predicting the rate of steel corrosion in concrete structures and the consequent formation and propagation of cracks around the steel reinforcement. The corrosion model considers both the initiation and the propagation stages of corrosion. Processes commencing in the initiation stage, such as the transport of chloride ions and oxygen within the concrete and variation in temperature and moisture, are assumed to continue in the propagation stage while active corrosion is occurring contemporaneously. This allows the model to include the effects of changes in exposure conditions on the corrosion rate and the effects of the corrosion reactions on the transport properties of concrete. The corrosion rates are calculated by applying the finite-element solution of the Laplace equation for electrochemical potential, with appropriate boundary conditions. Because these boundary conditions are nonlinear, a nonlinear solution algorithm is used. The results of the analysis are compared with available test data, and the comparison is found to be satisfactory. (author)

  4. Analysis, design and development of a carbon fibre reinforced plastic knee-ankle-foot orthosis prototype for myopathic patients.

    Science.gov (United States)

    Granata, C; De Lollis, A; Campo, G; Piancastelli, L; Merlini, L

    1990-01-01

    A traditional knee-ankle-foot orthosis (KAFO) for myopathic patients has been studied for the assessment of loads and fatigue resistance. Starting from this basis a thermoplastic matrix carbon fibre reinforced plastic composite (CFRP) KAFO has been developed in order to reduce the weight. A finite-element simulation programme for deformation analysis was used to compare the behaviour of conventional and CFRP orthosis. There were no breakages either of the prototype or of its parts. The CFRP orthosis allows a weight reduction of more than 40 per cent.

  5. Laser drilling of carbon fiber reinforced plastics (CFRP) by picosecond laser pulses: comparative study of different drilling tools

    Science.gov (United States)

    Herrmann, T.; Stolze, M.; L'huillier, J.

    2014-03-01

    Carbon fiber reinforced plastic (CFRP) as a lightweight material with superior properties is increasingly being used in industrial manufacturing. Using ultrashort laser pulses can improve the quality in cutting or drilling applications, but at high power levels it is more complicated to maintain the accuracy and precision in CFRP drilling. According to the application requirements for the extent of the heat affected zone, the geometric precision and the productivity different drilling tools can be used. Therefore we report on the application of three different beam delivery systems to drilling processes of CFRP: Galvanometer scanner, trepanning head and diffractive optical elements.

  6. Investigation on short-term burst pressure of plastic pipes reinforced by cross helically wound steel wires

    Institute of Scientific and Technical Information of China (English)

    Jin-yang ZHENG; Yong-jian GAO; Xiang LI; Xiu-feng LIN; Yu-bin LU; Yan-cong ZHU

    2008-01-01

    Plastic pipes reinforced by cross helically wound steel wires (PSP), which have exhibited excellent mechanical performance, consist of inner polyethylene (PE) layer, winding layer and outer PE layer. The winding layer is composed of two monolayers where steel wires are cross helically wound. An analytical procedure is developed to predict the short-term burst pressure of PSP as the monolayer is assumed to be elastic and orthotropic. The 3D anisotropic elasticity and Maximum Stress Failure Criterion are employed in the formulation of the elasticity problem. Good agreement between the theoretical results and the experimental data shows that the proposed approach can well predict the short-term burst pressure of PSP.

  7. The Application of Plastics Stabilizaters in Unsatured Polyster Glass Fiber Reinforced Plastic (GFRP) Composites%塑料稳定剂在玻璃纤维增强不饱和聚酯树脂中的应用

    Institute of Scientific and Technical Information of China (English)

    王玉民; 宁培森; 丁著明

    2011-01-01

    Recent advances in the application of plastics stabilizaters including ultraviolet absorbent, hindered amine light stabilizers (HALS) and antioxidant in unsatured polyster glass fiber reinforced plastic (GFRP) composites were reviewed. The results of some research papers showed the effect is not good when using single stabilizer,the combined use of main and auxilary antioxidant has the better effect on anti-ageing of GFRP.%综述了塑料稳定剂(包括紫外线吸收剂、受阻胺光稳定剂和抗氧剂等)在不饱和聚酯玻璃纤维增强塑料(GFRP)上的应用研究情况。一些研究结果表明:只使用单一的稳定剂效果不佳,必须配合使用稳定剂,才能取得较好的防老化效果。

  8. Final LDRD report : advanced plastic scintillators for neutron detection.

    Energy Technology Data Exchange (ETDEWEB)

    Vance, Andrew L.; Mascarenhas, Nicholas; O' Bryan, Greg; Mrowka, Stanley

    2010-09-01

    This report summarizes the results of a one-year, feasibility-scale LDRD project that was conducted with the goal of developing new plastic scintillators capable of pulse shape discrimination (PSD) for neutron detection. Copolymers composed of matrix materials such as poly(methyl methacrylate) (PMMA) and blocks containing trans-stilbene (tSB) as the scintillator component were prepared and tested for gamma/neutron response. Block copolymer synthesis utilizing tSBMA proved unsuccessful so random copolymers containing up to 30% tSB were prepared. These copolymers were found to function as scintillators upon exposure to gamma radiation; however, they did not exhibit PSD when exposed to a neutron source. This project, while falling short of its ultimate goal, demonstrated the possible utility of single-component, undoped plastics as scintillators for applications that do not require PSD.

  9. Properties of wood-plastic composites (WPCs) reinforced with extracted and delignified wood flour

    Science.gov (United States)

    Yao Chen; Nicole M. Stark; Mandla A. Tshabalala; Jianmin Gao; Yongming Fan

    2014-01-01

    The water sorption and mechanical properties of wood-plastic composites (WPCs) made of extracted and delignified wood flour (WF) has been investigated. WF was prepared by extraction with the solvent systems toluene/ethanol (TE), acetone/water (AW), and hot water (HW), and its delignification was conducted by means of sodium chlorite/acetic acid (AA) solution. A 2 4...

  10. Moisture Performance of wood-plastic composites reinforced with extracted and delignified wood flour

    Science.gov (United States)

    Yao Chen; Nicole M. Stark; Mandla A. Tshabalala; Jianmin Gao; Yongming Fan

    2014-01-01

    This study investigated the effect of using extracted and delignified wood flour on water sorption properties of wood–plastic composites. Wood flour (WF) extraction was performed with three solvent systems: toluene/ethanol (TE), acetone/water (AW), and hot water (HW); delignification was conducted using sodium chlorite/acetic acid solution. A 24 full-factorial...

  11. Testing of containers made of glass-fiber reinforced plastic with the aid of acoustic emission analysis

    Science.gov (United States)

    Wolitz, K.; Brockmann, W.; Fischer, T.

    1979-01-01

    Acoustic emission analysis as a quasi-nondestructive test method makes it possible to differentiate clearly, in judging the total behavior of fiber-reinforced plastic composites, between critical failure modes (in the case of unidirectional composites fiber fractures) and non-critical failure modes (delamination processes or matrix fractures). A particular advantage is that, for varying pressure demands on the composites, the emitted acoustic pulses can be analyzed with regard to their amplitude distribution. In addition, definite indications as to how the damages occurred can be obtained from the time curves of the emitted acoustic pulses as well as from the particular frequency spectrum. Distinct analogies can be drawn between the various analytical methods with respect to whether the failure modes can be classified as critical or non-critical.

  12. Study of Surface Roughness Characteristics of Drilled Hole in Glass Fiber Reinforced Plastic (GFRP by CNC Milling

    Directory of Open Access Journals (Sweden)

    Shubham.

    2016-02-01

    Full Text Available Now-a-days glass fiber-reinforced plastics (GFRP are always applicable in variety of engineering applications. It is used in aerospace, automotive and aircraft industries due to their well known properties. Milling of GFRP composite materials is very difficult due to its heterogeneity and the number of troubles like as surface delamination during machining affects uniqueness of the material and the machining parameters. Present paper focuses the experimental details to find out delamination factor on GFRP composite laminates by using Taguchi‟s DOE L9 orthogonal array. The main objective of the present work is to optimize the process parameters in the drilling of GFRP composite using Taguchi DOE and to find the significance of each process parameter using ANOVA. As far as the effect of input factors are considered, the factors drilled material and spindle speed both have nearly predominant influence on the delamination factor of drilled holes on GFRP composite by using CNC milling process.

  13. Characterization and Effects of Fiber Pull-Outs in Hole Quality of Carbon Fiber Reinforced Plastics Composite

    Directory of Open Access Journals (Sweden)

    Sina Alizadeh Ashrafi

    2016-10-01

    Full Text Available Hole quality plays a crucial role in the production of close-tolerance holes utilized in aircraft assembly. Through drilling experiments of carbon fiber-reinforced plastic composites (CFRP, this study investigates the impact of varying drilling feed and speed conditions on fiber pull-out geometries and resulting hole quality parameters. For this study, hole quality parameters include hole size variance, hole roundness, and surface roughness. Fiber pull-out geometries are quantified by using scanning electron microscope (SEM images of the mechanically-sectioned CFRP-machined holes, to measure pull-out length and depth. Fiber pull-out geometries and the hole quality parameter results are dependent on the drilling feed and spindle speed condition, which determines the forces and undeformed chip thickness during the process. Fiber pull-out geometries influence surface roughness parameters from a surface profilometer, while their effect on other hole quality parameters obtained from a coordinate measuring machine is minimal.

  14. The influence of porosity on ultrasound attenuation in carbon fiber reinforced plastic composites using the laser-ultrasound spectroscopy

    Science.gov (United States)

    Karabutov, A. A.; Podymova, N. B.; Belyaev, I. O.

    2013-11-01

    Wideband acoustic spectroscopy with a laser ultrasound source for quantitative analysis of the effect of porosity on the attenuation coefficient of longitudinal acoustic waves in carbon fiber reinforced plastic (CFRP) composite materials was experimentally implemented. The samples under study had different bulk-porosity levels (up to 10%), which were determined using X-ray computer tomography. A resonance ultrasound attenuation peak associated with the one-dimensional periodicity of the layered composite structure was observed for all samples. The absolute value of the resonance-peak maximum and its width depend on the local concentration of microscopic isolated pores and extended delaminations in the sample structure. The obtained empirical relationships between these parameters of the frequency dependence of the ultrasound attenuation coefficient and the type of inhomogeneities and their volume concentration can be used for rapid evaluation of the structural quality of CFRP composites.

  15. The Role of Plastic Surgeons in Advancing Development Global.

    Science.gov (United States)

    Broer, P Niclas; Jenny, Hillary E; Ng-Kamstra, Joshua S; Juran, Sabrina

    2016-05-01

    In September 2015, the international community came together to agree on the 2030 Agenda for Sustainable Development, a plan of action for people, the planet, and prosperity. Ambitious and far-reaching as they are, they are built on three keystones: the elimination of extreme poverty, fighting climate change, and a commitment to fighting injustice and inequality. Critical to the achievement of the Agenda is the global realization of access to safe, affordable surgical and anesthesia care when needed. The landmark report by the Lancet Commission on Global Surgery estimated that between 28 and 32 percent of the global burden of disease is amenable to surgical treatment. However, as many as five billion people lack access to safe, timely, and affordable surgical care, a burden felt most severely in low- and middle-income countries (LMICs). Surgery, and specifically plastic surgery, should be incorporated into the international development and humanitarian agenda. As a community of care providers dedicated to the restoration of the form and function of the human body, plastics surgeons have a collective opportunity to contribute to global development, making the world more equitable and helping to reduce extreme poverty. As surgical disease comprises a significant burden of disease and surgery can be delivered in a cost-effective manner, surgery must be considered a public health priority.

  16. Surface topography of machined fibre reinforced plastics obtained by stylus instruments and optical profilometers

    DEFF Research Database (Denmark)

    Eriksen, Else; Hansen, Hans Nørgaard

    1998-01-01

    introduced. They use another working principle to obtain the same parameters, but the settings of most of the measuring variables are not standardized. The present study has investigated aspects that have to be taken into account when the roughness of short fibre reinforced thermoplastics is measured...... identical values, whereas significantly higher roughnesses were measured with one of the two optical instruments. The optical instruments were identical but with different settings of the control parameters, which resulted in large deviations between the values measured. Some of the differences between...... by stylus instruments and by optical profilometers. The measurements were performed on machined surfaces with three distinct different roughness levels. The materials were two thermoplastics, polyoxymethylene and polypropylene, reinforced with short glass fibres. The two stylus instruments gave almost...

  17. Evaluation of a local exhaust system used in the manufacture of small parts made of reinforced plastic.

    Science.gov (United States)

    Lazure, L P

    2000-09-01

    Fiber-reinforced plastics are used to manufacture a large variety of products, particularly for the transportation sector. Hand lay-up molding and projection molding are the main methods of manufacture. The users of these processes are exposed to appreciable emissions of styrene; in Quebec, more than 3000 workers work in this industry. A statistical analysis of styrene concentrations measured over a five-year period by the Institut de recherche en santé et en sécurité du travail (IRSST, Occupational Health and Safety Research Institute) reveals that for all of the main manufacturing sectors involved, between 40 percent and 78 percent of the results exceed the exposure standard of 50 ppm. This study evaluated the effectiveness of a ventilated table in controlling worker exposure to styrene and acetone in a shop that manufactures fiber-reinforced plastics parts. The evaluated local extraction system consists of a ventilated table with a surface area of 1.2 m x 1.2 m. During molding, the styrene emissions are exhausted through the ventilated table as well as through the slots in a lateral hood. Replacement air, introduced vertically through a supply air shower located above the worker, limits the diffusion of contaminants toward the worker's breathing zone. The reduction in worker exposure to styrene and acetone during hand lay-up molding was measured in the breathing zone for two sizes of molds. The results show that exhaust ventilation reduced the styrene concentrations by 91 percent and that the introduction of replacement air increased the efficiency of the ventilated table to 96 percent. The evaluation performed indicates that the ventilated table adequately controls worker exposure to styrene and acetone during the molding of small components.

  18. Quality Assessment of Glass Reinforced Plastic Ship Hulls in Naval Applications. Course XIII-A.

    Science.gov (United States)

    1985-06-01

    Fiber Reinforced Epoxy Matrix Composite Materials’, Material Science Corporation , NADC Report #76228-30, January, 1978. 41. Griffith, *The Phenomena...Materials," Material Sciences Corporation , PA., August, 1979. 100 44. Shivakumar, K.N. and Whitcomb, J.D., ’Buckling of a Sublaminate in a Quasi...Dimeo nspectionim ure .e,:t.- INSPECION REUIREMETS FR CMPSIE ATRLe Prssr Oretto ueIseto a iaeIseto .............. emertue ecrd Gorn~ibii Cot r t Pr

  19. 浅述玻璃钢制品质量控制%Research on the Quality Control of Fibre Reinforced Plastic Product

    Institute of Scientific and Technical Information of China (English)

    陈瑛卿

    2012-01-01

      Fibre-reinforced plastic (FRP) (also fibre-reinforced polymer) is a composite material made of a polymer matrix reinforced with fibres, which with light quality and high intensity. At present, the integrated quality control system of fibre reinforced plastic technics still not been established in China, to insure the product quality of fibre reinforced plastic, some measures must be taken from the technical training of perspnnel, quality control of raw materials, process control of manufacturing and quality control of final product.%  玻璃钢是一种高性能的纤维增强树脂基复合材料,轻质高强。目前我国的玻璃钢工业尚未建立起完整的质量控制体系,为了确保玻璃钢产品的质量,必须从人员的技术培训、原材料的质量把关,制造过程的工艺控制和成品控制等几方面入手。

  20. Standard practice for acoustic emission examination of pressurized containers made of fiberglass reinforced plastic with balsa wood cores

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers guidelines for acoustic emission (AE) examinations of pressurized containers made of fiberglass reinforced plastic (FRP) with balsa cores. Containers of this type are commonly used on tank trailers for the transport of hazardous chemicals. 1.2 This practice is limited to cylindrical shape containers, 0.5 m [20 in.] to 3 m [120 in.] in diameter, of sandwich construction with balsa wood core and over 30 % glass (by weight) FRP skins. Reinforcing material may be mat, roving, cloth, unidirectional layers, or a combination thereof. There is no restriction with regard to fabrication technique or method of design. 1.3 This practice is limited to containers that are designed for less than 0.520 MPa [75.4 psi] (gage) above static pressure head due to contents. 1.4 This practice does not specify a time interval between examinations for re-qualification of a pressure container. 1.5 This practice is used to determine if a container is suitable for service or if follow-up NDT is needed before that...

  1. Rigid-Plastic Dynamic Response of Reinforced Concrete Bridge Pier Impacted by Automobile

    Institute of Scientific and Technical Information of China (English)

    ZHENG Xiaoning; DIAO Bo; YE Yinghua

    2006-01-01

    Bridge piers are impacted by autos sometimes.The pier usually has not been destroyed after once impact by auto.But there are few research on damage which will affect pier's capability,and most relative studies have focused the problems on piers impacted by vessels.The methods involve mainly sutra experience theory,numerical analysis,and experimental method.Owing to the complicacy of the bridge pier impacted by a vessel,there are few research derived with the sutra mechanics model and the piers impacted by autos.The dynamic response is studied here under the assumption of the rigid-plastic small-deformation for the pier impacted by auto.According to the Parkes beam model,the rigid-plastic theoretical solution is deduced.The final deformation is calculated by a practical example for the pier impacted by auto.

  2. Advanced postbuckling and imperfection sensitivity of the elastic-plastic Shanley-Hutchinson model column

    DEFF Research Database (Denmark)

    Christensen, Claus Dencker; Byskov, Esben

    2008-01-01

    The postbuckling behavior and imperfection sensitivity of the Shanley-Hutchinson plastic model column introduced by Hutchinson in 1973 are examined. The study covers the initial, buckled state and the advanced postbuckling regime of the geometrically perfect realization as well as its sensitivity...

  3. Research Advances: Paper Batteries, Phototriggered Microcapsules, and Oil-Free Plastic Production

    Science.gov (United States)

    King, Angela G.

    2010-01-01

    Chemists continue to work at the forefront of materials science research. Recent advances include application of bioengineering to produce plastics from renewable biomass instead of petroleum, generation of paper-based batteries, and development of phototriggerable microcapsules for chemical delivery. In this article, the author provides summaries…

  4. Multiscale carbon nanotube-carbon fiber reinforcement for advanced epoxy composites.

    Science.gov (United States)

    Bekyarova, E; Thostenson, E T; Yu, A; Kim, H; Gao, J; Tang, J; Hahn, H T; Chou, T-W; Itkis, M E; Haddon, R C

    2007-03-27

    We report an approach to the development of advanced structural composites based on engineered multiscale carbon nanotube-carbon fiber reinforcement. Electrophoresis was utilized for the selective deposition of multi- and single-walled carbon nanotubes (CNTs) on woven carbon fabric. The CNT-coated carbon fabric panels were subsequently infiltrated with epoxy resin using vacuum-assisted resin transfer molding (VARTM) to fabricate multiscale hybrid composites in which the nanotubes were completely integrated into the fiber bundles and reinforced the matrix-rich regions. The carbon nanotube/carbon fabric/epoxy composites showed approximately 30% enhancement of the interlaminar shear strength as compared to that of carbon fiber/epoxy composites without carbon nanotubes and demonstrate significantly improved out-of-plane electrical conductivity.

  5. Mechanical properties of carbon fiber reinforced plastics and their response to a radiation environment

    Science.gov (United States)

    Spieβberger, S. M.; Humer, K.; Tschegg, E. K.; Weber, H. W.; Noma, K.; Iwasaki, Y.

    "TORAYCA T300 3K" is a two and a half dimensional woven carbon fiber reinforced epoxy which was developed for various applications including cryogenics. "Scaling" experiments in tension, in the shear-mode (mode II) and in the crack-opening-mode (mode I) were made at room and low temperature, in order to establish suitable sample geometries for irradiation experiments. Moreover, the interlaminar and the intralaminar shear strength as well as the ultimate tensile strength were investigated after irradiation at 340 K with a reactor spectrum up to a fast neutron fluence of 5 × 10 22 m -2 ( E > 0.1 MeV). The irradiated material was measured at 77 K and acoustic emission (AE) investigations were made for the tensile and the mode II samples.

  6. Experimental investigation of fibre reinforced plastics with hybrid layups under high-velocity impact loads

    Directory of Open Access Journals (Sweden)

    Marco Romano

    2014-07-01

    Full Text Available This paper deals with experimental investigations concerning energy dissipation capacity of different kinds of reinforcement fibres in monolithic and hybrid layups under high-velocity impact loads. The investigated kinds of fibres are carbon, glass and basalt fibres. Therefore test panels, using the same thermoset resin, were built up and cured by autoclave processing. The fibre volume content of the test panels has been determined. Furthermore the influence of a separating layer at selected positions in the hybrid stacked panels was investigated. The results show the influence and the energy dissipation capacity of each single kind of fibre and the enhanced properties for the hybrid layups by hybrid stacking sequences and the use of a separating core material.

  7. Assessment of the exit defects in carbon fibre-reinforced plastic plates caused by drilling

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Houjiang; Zhang Liangchi [Sydney Univ. (Australia). Dept. of Mechanical and Mechatronic Engineering; Chen Wuyi; Chen Dingchang [Beijing Univ. of Aeronautics and Astronautics, BJ (China). Dept. of Manufacturing Engineering

    2001-07-01

    This paper investigates the formation of the exit defects in carbon fibre-reinforced plates and characterizes their features in terms of drilling conditions. It was found that spalling and fuzzing are the major mechanisms of exit defects. The spalling, consisting of a main region and a secondary region, is caused by chisel and cutting edge actions, in which the former plays a key role. The fuzzing, however, exists in the cutting region where the included angle between the fibre direction of the surface layer and that of the cutting speed is acute. A severer spalling damage corresponds to a high spindle speed, a large feed rate and a great thrust force. Some empirical relationships, including a dimensionless formula, were developed for assessing the characteristic dimension of the spalling damage based on the known drilling conditions. (orig.)

  8. Ratcheting deformation of advanced 316 steel under creep-plasticity condition

    Energy Technology Data Exchange (ETDEWEB)

    Kawashima, Fumiko; Ishikawa, Akiyoshi; Asada, Yasuhide [Tokai Univ., Tokyo (Japan). Dept. of Mechanical Engineering

    1998-11-01

    Tension-torsion biaxial ratcheting tests have been conducted with Advanced 316 Steel (316FR Steel) at 650 C under a cyclic strain rate of 10{sup -3} to 10{sup -5} s{sup -1}. Accumulation of ratcheting strain has been measured. Accumulated ratchet strain has shown to be much larger than predicted based on a usual method of the linear superposition of strains due to creep and plasticity. The result shows there observed the creep-plasticity interaction in the observation. (orig.)

  9. Smart Natural Fiber Reinforced Plastic (NFRP) Composites Based On Recycled Polypropylene in The Presence Kaolin

    Science.gov (United States)

    Suharty, N. S.; Ismail, H.; Diharjo, K.; Handayani, D. S.; Lestari, W. A.

    2017-07-01

    Composites contain double filler material which act as reinforcement and flame retardants of recycled polypropylene (rPP)/kaolin(Kao)/palm oil empty bunch fiber (PEBF) have been succesfully prepared. The composites were synthesized through reactively solution method, using coupling agent PP-g-AA and compatibilizer DVB. The effect of double filler [Kao/PEBF] were investigated flexural strength (FS), inflammability, and morphology. Mechanical testing result in accordance to ASTM D790, the FS of rPP/DVB/PP-g-AA/Kao+ZB/PEBF composite was 48% higher than that of rPP matrix. Moreover, flexural modulus (FM) was significantly improved by 56% as compared to that of rPP matrix. The scanning electron images (SEM) shown good dispersion of [Ka/PEBF] and good filler-matrix interaction. The inflammability testing result which is tested using ASTM D635, showed that the flame resistance of rPP/DVB/PP-g-AA/Kao+ZB/PEBF composite was improve by increasing of time to ignition (TTI) about 857% and burning rate (BR) decreasing to 66% compared to the raw material rPP matrix. In the same time, the addition of 20% (w/w) PEBF as a second filler to form rPP/DVB/PP-g-AA/Kao+ZB/PEBF composites (F5) is able to increase: the FS by 17.5%, the FM by 19%, the TTI by 7.6% and the BR by 3.7% compared to the composite without PEBF (F2).

  10. FIQUE FIBER AN ALTERNATIVE FOR REINFORCED PLASTICS. INFLUENCE OF SURFACE MODIFICATION

    Directory of Open Access Journals (Sweden)

    MARIO FERNANDO MUÑOZ VELEZ

    2014-12-01

    Full Text Available In this paper are studied the physicochemical, mechanical and thermal properties of the natural fique fibers, that can be used as reinforcement of polymeric matrices. The fibers were subjected to superficial modifications from chemical treatments which are conventionally used to promote the compatibility of natural fibers (hydrophilics with matrices of polymeric nature (hydrophobics. The superficial modification process of the fibers was carried out by alkalinization treatment with NaOH, followed by grafting of a coupling agent type silane and then a pre-impregnation with polyethylene. By running FTIR tests, it was possible to observe functional typical groups of native fibers and confirmed the proper execution of the superficial modifications proposed; in the same way, the thermal characterization by TGA allowed to demonstrate the loss of hemicellulose and lignin, that were removed with alkaline treatment, and the appearance of a new transition due to the polyethylene deposited subsequently with the pre-impregnate treatment. Finally, it was found that the alkaline treatment conditioned the mechanical properties of the treated fibers, being negligible the influence of silanization and the pre-impregnation in this characterization.

  11. Scanning tone burst eddy-current thermography (S-TBET) for NDT of carbon fiber reinforced plastic (CFRP) components

    Energy Technology Data Exchange (ETDEWEB)

    Libin, M. N.; Maxfield, B. W.; Balasubramanian, Krishnan [Centre for Nondestructive Evaluation, Indian Institute of Technology Madras, Chennai 600036 (India)

    2014-02-18

    Tone Burst Eddy Current technique uses eddy current to apply transient heating inside a component and uses a conventional IR camera for visualization of the response to the transient heating. This technique has been earliest demonstrated for metallic components made of AL, Steel, Stainless Steel, etc., and for detection of cracks, corrosion and adhesive dis-bonds. Although, not nearly as conducting as metals, the Carbon Fibre Reinforced Plastic (CFRP) material absorbs measurable electromagnetic radiation in the frequency range above 10 kHz. When the surface temperature is observed on the surface that is being heated (defined as the surface just beneath and slightly to one side of the heating coil), the surface temperature increases with increasing frequency because the internal heating increases with frequency. A 2-D anisotropic transient Eddy current heating and thermal conduction model has been developed that provides a reasonable description of the processes described above. The inherent anisotropy of CFRP laminates is included in this model by calculating the heating due to three superimposed, tightly coupled isotropic layers having a specified ply-layup. The experimental apparatus consists of an induction heating coil and an IR camera with low NETD and high frame rates. The coil is moved over the sample using a stepper motor controlled manipulator. The IR data recording is synchronized with the motion control to provide a movie of the surface temperature over time. Several components were evaluated for detection of impact damage, location of stiffeners, etc. on CFRP components.

  12. Clinical application of carbon fibre reinforced plastic leg orthosis for polio survivors and its advantages and disadvantages.

    Science.gov (United States)

    Hachisuka, K; Makino, K; Wada, F; Saeki, S; Yoshimoto, N; Arai, M

    2006-08-01

    A prospective study was carried out on the clinical application and features of a carbon fibre reinforced plastic leg orthosis (carbon orthosis) for polio survivors. The subjects comprised 9 polio survivors, and 11 carbon knee-ankle-foot orthoses (KAFOs) were prescribed, fabricated, and checked out at the authors' post-polio clinic. Walking was classified based on the functional ambulatory category, and the features of walking with a carbon orthosis were self-evaluated by using a visual analogue scale. The period from modelling a cast to completion was 55 +/- 25 days; the weight of a carbon KAFO was 27.8% lighter than that of the ordinary KAFO; the standard carbon KAFO was 50% more expensive than the ordinary KAFO. The carbon KAFO remained undamaged for at least 2 years. It improved the scores in the functional ambulation categories, but there was no difference between walking with an ordinary and with a carbon KAFO. The self-evaluation of walking with a carbon KAFO revealed that the subjects using a carbon KAFO were satisfied with their carbon KAFO. The carbon KAFO is lightweight, durable, slim and smart, and is positively indicated for polio survivors.

  13. Energy-related application of composite material. Carbon fiber reinforced plastics (CFRP); Enerugi kanren yoto to CFRP

    Energy Technology Data Exchange (ETDEWEB)

    Higuchi, T. [Toray Industries, Tokyo (Japan)

    2000-01-15

    Carbon fiber reinforced plastics (CFRP) with advantages such as high strength, high relative elastic modulus, high chemical stability, and excellent thermal/electric properties, is widely used in aviation/space, sports, and industries. This paper takes up CNG tank, flywheel, and windmill blade, as examples of energy-related application development. For the purpose of weight reduction of CNG car, big three car manufacturers of the U.S. and Honda adopted CNG tank. Flywheel with CFRP rotor can store 3.8 times energy compared with that of steel. Windmill blade used in windmill power generation is mostly made of 3 blades and presently GFRP is used, but CFRP will become a main stream when the windmill is scaled up. In the future, it is necessary to reduce the cost of carbon fiber and its treatment process, as well as to solve the targets such as standardization of design, recognition by users, and verification in environmental use, and to develop further applications. (NEDO)

  14. Impacts of the manufacturing process using fiberglass reinforced plastic composite on the environment and occupational health: the automotive industry case

    Directory of Open Access Journals (Sweden)

    Cíntia Madureira Orth

    2012-06-01

    Full Text Available The production of fiberglass reinforced plastic composite parts may cause serious damages to the health of workers and/or the environment, especially due to the generation of process trimmings, noise level and gas emission.  In view of that, this essay aims at assessing the main impacts of the Molding and Finish processes of an automotive plant on the environment and occupational health. It was observed that the open molding method adopted by the studied plant is the main cause of the generation of residues and that the waste of raw materials as trimmings may reach up to 30%. The final destination of those trimmings, which represent 45% of all the residues generated by the factory, is the industrial landfill. It was also observed that, due to the use of open molds, the levels of styrene and fiber dust were above the tolerance limits, presenting risks to the health of the workers.  Therefore, the studied company should consider the possibility of adopting less aggressive technologies, such as that used in closed molds. The reduction of the negative impacts of the productive processes in their source should be part of the company’s policy. Furthermore, the prevention must be continuous and improved every day.

  15. Studies of print-through and reflectivity of x-ray mirrors using thin carbon-fiber-reinforced plastic

    Science.gov (United States)

    Sugita, Satoshi; Awaki, Hisamitsu; Yoshioka, Kenya; Ogi, Keiji; Kunieda, Hideyo; Matsumoto, Hironori; Miyazawa, Takuya; Mitsuishi, Ikuyuki; Iwase, Toshihiro; Saji, Shigetaka; Tachibana, Sasagu; Maejima, Masato; Yoshikawa, Shun; Shima, Naoki; Ishikawa, Takashi; Hamada, Takayoshi; Ishida, Naoki; Akiyama, Hiromichi; Kishimoto, Kazuaki; Utsunomiya, Shin; Kamiya, Tomohiro; Uesugi, Kentaro; Suzuki, Yoshio

    2016-01-01

    We fabricated x-ray mirrors from carbon-fiber-reinforced plastic with a tightly nested design for x-ray satellites, using a replication method for the surfaces. We studied the effects of print-through on the mirror surface as a function of curing temperature. With room temperature curing, the root-mean-square value of the surface error was 0.8 nm. The reflectivity was measured using 8-keV x-rays, and the roughness was calculated as 0.5 nm by model fitting-comparable to that of the ASTRO-H/HXT mirror. We verified the long-term stability of the mirror surface over 6 months. We fabricated Wolter type-I quadrant-shell mirrors with a diameter of 200 mm and performed x-ray measurements at BL20B2 in the SPring-8 synchrotron radiation facility. We obtained reflection images of the mirrors using a 20-keV x-ray spot beam with a slit size of 10×1 mm in the radial and circumferential directions, respectively. The averaged half-power diameter (HPD) of the images in one mirror was 1.2 arc min in the circumferential center of the mirror and 3.0 arc min at the edge. In the spot images with a smaller slit size of 10×0.2 mm, we achieved an HPD of 0.38 arc min in the best case.

  16. Scanning tone burst eddy-current thermography (S-TBET) for NDT of carbon fiber reinforced plastic (CFRP) components

    Science.gov (United States)

    Libin, M. N.; Maxfield, B. W.; Balasubramanian, Krishnan

    2014-02-01

    Tone Burst Eddy Current technique uses eddy current to apply transient heating inside a component and uses a conventional IR camera for visualization of the response to the transient heating. This technique has been earliest demonstrated for metallic components made of AL, Steel, Stainless Steel, etc., and for detection of cracks, corrosion and adhesive dis-bonds. Although, not nearly as conducting as metals, the Carbon Fibre Reinforced Plastic (CFRP) material absorbs measurable electromagnetic radiation in the frequency range above 10 kHz. When the surface temperature is observed on the surface that is being heated (defined as the surface just beneath and slightly to one side of the heating coil), the surface temperature increases with increasing frequency because the internal heating increases with frequency. A 2-D anisotropic transient Eddy current heating and thermal conduction model has been developed that provides a reasonable description of the processes described above. The inherent anisotropy of CFRP laminates is included in this model by calculating the heating due to three superimposed, tightly coupled isotropic layers having a specified ply-layup. The experimental apparatus consists of an induction heating coil and an IR camera with low NETD and high frame rates. The coil is moved over the sample using a stepper motor controlled manipulator. The IR data recording is synchronized with the motion control to provide a movie of the surface temperature over time. Several components were evaluated for detection of impact damage, location of stiffeners, etc. on CFRP components.

  17. Studies of the moisture absorption of thin carbon fiber reinforced plastic substrates for x-ray mirrors

    Science.gov (United States)

    Sugita, Satoshi; Awaki, Hisamitsu; Kurihara, Daichi; Yoshioka, Kenya; Nomura, Mizuki; Ogi, Keiji; Tomita, Yuuki; Mita, Tomoki; Kunieda, Hideyo; Matsumoto, Hironori; Miyazawa, Takuya; Mitsuishi, Ikuyuki; Iwase, Toshihiro; Maejima, Masato; Shima, Naoki; Ishikawa, Takashi; Hamada, Takayoshi; Ishida, Naoki; Akiyama, Hiromichi; Kishimoto, Kazuaki; Utsunomiya, Shin; Kamiya, Tomohiro

    2015-07-01

    We study a lightweight x-ray mirror with a carbon fiber reinforced plastic (CFRP) substrate for next-generation x-ray satellites. For tightly nested x-ray mirrors, such as those on the Suzaku and ASTRO-H telescopes, CFRP is the suitable substrate material because it has a higher strength-to-weight ratio and forming flexibility than those of metals. In flat CFRP substrate fabrication, the surface waviness has a root mean square (RMS) of ˜1 μm in the best products. The RMS approximately reaches a value consistent with the RMS of the mold used for the forming. We study the effect of moisture absorption using accelerated aging tests in three environments. The diffusivity of the CFRP substrate at 60°C and at relative humidity of 100% is ˜9.7×10-4 mm2.h-1, and the acceleration rate to the laboratory environment was 180 times higher. We also develop co-curing functional sheets with low water-vapor transmissivity on the CFRP substrate. Co-curing the sheets successfully reduced the moisture absorption rate by 440 times compared to the un-co-cured substrate. Details of the CFRP substrate fabrication and moisture absorption tests are also reported.

  18. Quick Preparation of Moisture-Saturated Carbon Fiber-Reinforced Plastics and Their Accelerated Ageing Tests Using Heat and Moisture

    Directory of Open Access Journals (Sweden)

    Masao Kunioka

    2016-06-01

    Full Text Available A quick method involving the control of heat and water vapor pressure for preparing moisture-saturated carbon fiber-reinforced plastics (CFRP, 8 unidirectional prepreg layers, 1.5 mm thickness, epoxy resin has been developed. The moisture-saturated CFRP sample was obtained at 120 °C and 0.2 MPa water vapor in 72 h by this method using a sterilizer (autoclave. The bending strength and viscoelastic properties measured by a dynamic mechanical analysis (DMA remained unchanged during repetitive saturation and drying steps. No degradation and molecular structural change occurred. Furthermore an accelerated ageing test with two ageing factors, i.e., heat and moisture was developed and performed at 140–160 °C and 0.36–0.62 MPa water vapor pressure by using a sealed pressure-proof stainless steel vessel (autoclave. The bending strength of the sample decreased from 1107 to 319 MPa at 160 °C and 0.63 MPa water vapor pressure in 9 days. Degraded samples were analyzed by DMA. The degree of degradation for samples was analyzed by DMA. CFRP and degraded CFRP samples were analyzed by using a surface and interfacial cutting analysis system (SAICAS and an electron probe micro-analyzer (EPMA equipped in a scanning electron microscope.

  19. Recovery of carbon fibres and production of high quality fuel gas from the chemical recycling of carbon fibre reinforced plastic wastes

    OpenAIRE

    Yildirir, E; Onwudili, JA; Williams, PT

    2014-01-01

    A solvolysis process to depolymerize the resin fraction of carbon fibre reinforced plastic waste to recover carbon fibre, followed by hydrothermal gasification of the liquid residual product to produce fuel gas was investigated using batch reactors. The depolymerisation reactions were carried out in ethylene glycol and ethylene glycol/water mixtures at near-critical conditions of the two solvents. With ethylene glycol alone the highest resin removal of 92.1% was achieved at 400 °C. The additi...

  20. Constructing Novel Fiber Reinforced Plastic (FRP) Composites through a Biomimetic Approach: Connecting Glass Fiber with Nanosized Boron Nitride by Polydopamine Coating

    OpenAIRE

    XueMei Wen; ZaoZao Xiao; Tao Jiang; Jian Li; Wei Zhang; Lei Zhang; Huaiqi Shao

    2013-01-01

    A biomimetic method was developed to construct novel fiber reinforced plastic (FRP) composites. By mimicking mussel adhesive proteins, a monolayer of polydopamine was coated on glass fiber (GF) surface. The polydopamine-treated GF (D-GF) adsorbed boron nitride (BN) nanoparticles, while obtaining micronano multiscale hybrid fillers BN-D-GF. Scanning electron microscopy (SEM) results showed that the strong interfacial interaction brought by the polydopamine benefits the loading amount as well ...

  1. Study on "dry process" to prepare reinforced fluoro plastic%增强氟塑料干法制备工艺研究

    Institute of Scientific and Technical Information of China (English)

    白龙腾; 姜潮

    2012-01-01

    对生产增强氟塑料的原材料P202和FR104两种聚四氟乙烯树脂性能进行了对比,采用“干法”制备工艺并对工艺参数进行改进,生产出FS-20d和FS-35d增强氟塑料。生产制品测试结果表明:“干法”制备工艺配方稳定、生产工艺稳定,制品的耐磨性能、耐高温性能、致密性、均匀性和相分散性均优于“湿法”制备工艺制品。%The properties of two kinds of polyterafluoroethylene resins (P202 and FR104) for preparing the reinforced fluoro plastic were compared. The "dry process" to prepare the reinforced fluoro plastic was chosen to improve the process parameters, and adopted to produce two new kinds of reinforced fluoro plastic (FS-20d, FS-35d). The test results of the final products indicate that the preparation process formula and production process of "dry process" are stable, and the wear-resis- ting property, high temperature resistance, compactness, uniformity and phase dispersion of the new products prepared with "dry process" are better than the products yield by "wet process" .

  2. Effect of Specimen Size on the Tensile Strength Behavior of the Plastic Waste Fiber Reinforced Soil – Lime – Rice Husk Ash Mixtures

    Directory of Open Access Journals (Sweden)

    Muntohar A.S.

    2011-01-01

    Full Text Available Improvement of tensile strength in fiber reinforced soil is an important research topic. A study has been undertaken to investigate the strength of stabilized clay-soil reinforced with randomly distributed discrete plastic waste fibers by carrying out split tensile strength test. In this study, the clay soil was stabilized with lime and rice husk ash mixtures. The main purpose of this research is to investigate the effect of specimen size to the tensile strength behavior. Testing procedure was formulated using extended ASTM C496 standard. The laboratory investigation results showed that split-tensile strength of reinforced specimens increased with increase in size. The limitations of the dataset indicate that specimen size of 70 mm in diameter is the threshold to produce reasonable representative strengths.

  3. Fibre-reinforced plastic composites - Determination of the in-plane shear stress/shear strain response, including the in-plane shear modulus and strength, by the plus or minus 45 degree tension test method

    CERN Document Server

    International Organization for Standardization. Geneva

    1997-01-01

    Fibre-reinforced plastic composites - Determination of the in-plane shear stress/shear strain response, including the in-plane shear modulus and strength, by the plus or minus 45 degree tension test method

  4. Advanced postbuckling and imperfection sensitivity of the elastic-plastic Shanley-Hutchinson model column

    DEFF Research Database (Denmark)

    Christensen, Claus Dencker; Byskov, Esben

    2008-01-01

    The postbuckling behavior and imperfection sensitivity of the Shanley-Hutchinson plastic model column introduced by Hutchinson in 1973 are examined. The study covers the initial, buckled state and the advanced postbuckling regime of the geometrically perfect realization as well as its sensitivity...... and the solution to an actual problem is determined by an asymptotic expansion involving hyperbolic trial functions (instead of polynomials) which fulfill general boundary conditions at bifurcation and infinity. The method provides an accurate estimate of the maximum load even if it occurs in an advanced...

  5. Hierarchical fiber-optic delamination detection system for carbon fiber reinforced plastic structures

    Science.gov (United States)

    Minakuchi, Shu; Banshoya, Hidehiko; Shingo, Ii; Takeda, Nobuo

    2012-10-01

    This study develops a delamination detection system by extending our previous approach for monitoring surface cracks in a large-scale composite structure. In the new system, numerous thin glass capillaries are embedded into a composite structure, and internal pressure in the built-in capillary sensors, based on comparative vacuum monitoring (CVM), is maintained as a vacuum. When delamination is induced, the capillary sensors located within the delaminated area are breached, and atmospheric air flows into the capillaries. The consequent pressure change within the capillaries is then converted into axial strain in a surface-mounted optical fiber through a transducing mechanism, which is connected to the capillaries. By monitoring the strain distribution along the optical fiber, it is possible to identify a transducing mechanism in which the pressure change occurred and thus to specify the location of the delamination. This study begins by establishing a novel sensor embedding/extracting method. The airflow characteristic in the capillary sensors is then comprehensively evaluated, determining the basic performance of the new system. The proposed detection technique is validated by taking a step-by-step approach, and finally the hierarchical fiber-optic delamination detection system is demonstrated. A further advance to be combined with a self-healing concept is also discussed.

  6. The extrinsic influence of carbon fibre reinforced plastic laminates to strengthen steel structures

    Indian Academy of Sciences (India)

    A K Patnaik; C L Bauer; T S Srivatsan

    2008-06-01

    The intrinsic advantages of strengthening the steel-based structures by the use of fibre reinforced plastic (FRP) material have not yet been fully exploited. In this paper, a succinct overview of recent studies made to enhance the strength of steel beams using FRP laminates is presented. The results presented and discussed in this paper were obtained by closely studying the behaviour of steel beams strengthened with carbon FRP material. An attempt is made to succinctly summarise the findings for two different types of strengthening of the steel beams using carbon FRP laminates. The first type of beams focuses on enhancing the strength of steel in flexure while the second focuses on increasing the shear strength of the beams. Three beams were designed so as to cause them to fail in flexure. Of the beams studied, two were strengthened using carbon FRP strips attached to the tension flange. One of the beams was tested to facilitate comparison of their behaviour to the two beams which are strengthened in flexure. Three other beams were designed such that they failed predominantly in shear. Of these three, two were strengthened with carbon FRP strips attached to the webs while the third beam was used as a control beam for the purpose of drawing comparisons. Preliminary results revealed a noticeable increase in the strength for both the flexure strengthened beams and the beams strengthened in shear. The observed increase in shear strength of the beams was 26% while the increase in strength for the beams tested in flexure was 15%. This study convincingly shows that it is possible to strengthen steel beams using carbon FRP laminates in both flexure and in shear.

  7. Comparative effects of pyrolytic products of fiber reinforced plastic and wood shavings on the respiratory variables in mice.

    Science.gov (United States)

    Kumar, Pravin; Deb, Utsab; Gautam, Anshoo; Vijayaraghavan, R; Ratna, Debdatta; Chakraborty, B C

    2010-08-01

    Comparative inhalation toxicity studies of pyrolytic products (smoke) from synthetic polymer, fiberglass reinforced plastic (FRP) and teak wood shavings were carried out in male Swiss albino mice. The breathing pattern and the respiratory variables were monitored using a computer program that recognizes the modifications of the respiratory pattern. Exposure to the smoke from both the polymers caused a concentration dependent decrease in normal breathing and an increase in sensory irritation measure. The acute lethal concentration 50 values for a 15 min static inhalation exposure to the smoke from FRP and teak wood shavings were found to be > 200.00 and 62.99 g/m(3), respectively. Hence the inhalation toxicity of smoke from FRP sample on a mass basis is approximately one-third that of the smoke from teak wood. The concentration of smoke causing 50% respiratory depression of the exposed animals were found to be 6.877 and 0.106 g/m(3) for FRP and teak wood samples, respectively. Thus the sensory irritancy of the smoke from FRP sample is approximately 65 times lesser than the smoke from teak wood. The higher sensory irritancy potential of wood smoke as compared to FRP smoke may be caused by a greater number of submicron particles (size range of 2 micron and less) and greater percentage of gases present in wood smoke as compared to FRP smoke. Thus in case of accidental fires, synthetic polymers like FRP may be a safer choice for structural parts and interiors than the natural wood.

  8. 加强筋地膜加工装置的设计与试验%Development of Reinforced Plastic Processing Device to Strengthen

    Institute of Scientific and Technical Information of China (English)

    蒋建云; 王旭峰; 胡灿; 孟祥营; 陈超

    2014-01-01

    为了防治地膜受风沙作用破损及提高残膜回收率,研制成功一种加强筋塑料地膜和加工机械。为了提高效率,降低成本,设计了一种加强筋地膜加工装置,与现有棉花覆膜播种机配套使用。同时,对该装置和加强筋地膜加工机械进行加工试验对比分析,结果表明,该装置结构简单、便于维修,有效提高了加强筋加工效率,降低了成本,并能正常进行棉花覆膜播种,且残膜回收率高,达到95.3%。经过棉花种植成本计算分析,加强筋地膜有很好的经济效益,可以大面积推广。%For prevention and control of mulch sand damage and residual film recovery ,our previous successfully devel-oped a kind of reinforced plastic film and processing machinery ,in order to improve efficiency ,reduce cost , this paper de-signed a kind of reinforced plastic processing equipment ,with the existing cotton coated machine supporting the use .And on the device and reinforced plastic processing machinery processing experiment was carried out comparative analysis , the results show that the device has simple structure ,easy maintenance ,effective reinforcement processing efficiency ,reduces the cost, at the same time,it can be carried out as normal and cotton coated seed .After membrane recycling residue test , residual film recovery rate is high ,at 95.3%, after cotton cultivation cost calculation and analysis ,reinforced plastic has good economic benefit ,can large area promotion .

  9. Improving the Wear Resistance of Moulds for the Injection of Glass Fibre–Reinforced Plastics Using PVD Coatings: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Francisco Silva

    2017-02-01

    Full Text Available It is well known that injection of glass fibre–reinforced plastics (GFRP causes abrasive wear in moulds’ cavities and runners. Physical vapour deposition (PVD coatings are intensively used to improve the wear resistance of different tools, also being one of the most promising ways to increase the moulds’ lifespan, mainly when used with plastics strongly reinforced with glass fibres. This work compares four different thin, hard coatings obtained using the PVD magnetron sputtering process: TiAlN, TiAlSiN, CrN/TiAlCrSiN and CrN/CrCN/DLC. The first two are monolayer coatings while the last ones are nanostructured and consist of multilayer systems. In order to carry out the corresponding tribological characterization, two different approaches were selected: A laboratorial method, using micro-abrasion wear tests based on a ball-cratering configuration, and an industrial mode, analysing the wear resistance of the coated samples when inserted in a plastic injection mould. As expected, the wear phenomena are not equivalent and the results between micro-abrasion and industrial tests are not similar due to the different means used to promote the abrasion. The best wear resistance performance in the laboratorial wear tests was attained by the TiAlN monolayer coating while the best performance in the industrial wear tests was obtained by the CrN/TiAlCrSiN nanostructured multilayer coating.

  10. Graphite-Fiber-Reinforced Plastic Pressure Hull Mod 2 for the Advanced Unmanned Search System Vehicle

    Science.gov (United States)

    1988-08-01

    Weight Factor 4 Steel ( HY80 ) 0.283 80 280 1.25 Steel (HY130) 0.283 130 460 1.25 Aluminum (7075-T6) 0.10 73 730 1.25 Titanium (GAL-4V) 0.16 125 780 1.25...1 2, and 3. A quick glance at the numbers is sufficient to recogrnize that high-strength steel doexs not meet the rigid requirements. Stated simply...the poor weight-to- strength ratio will sink deep-submergence vehicles constructed from steel . Other metallic materials, like high-strength aluminum or

  11. FRP reinforcement of timber structures

    OpenAIRE

    Schober, Kay-Uwe; Harte, Annette M.; Kliger, Robert; Jockwer, Robert; Xu, Qingfeng; Chen, Jian-fei

    2015-01-01

    Timber engineering has advanced over recent decades to offer an alternative to traditional materials and methods. The bonding of fibre reinforced plastics (FRP) with adhesives to timber structures for repair and strengthening has many advantages. However, the lack of established design rules has strongly restrained the use of FRP strengthening in many situations, where these could be a preferable option to most traditional techniques. A significant body of research has been carried out in rec...

  12. Comprehensive Application of Steel Reinforced Concrete Jacking Pipe and Sand Glass Fiber Reinforced Plastic Pipe%钢筋混凝土管顶管与夹砂玻璃钢管的综合应用

    Institute of Scientific and Technical Information of China (English)

    李之国

    2009-01-01

    该文介绍了采用DN2200钢筋混凝土管作为穿越管道进行顶管施工,然后在钢筋混凝土管内安装DNl800承插式夹砂玻璃钢管相结合的施工方法.此施工方法可有效地解决埋深较大的市政污水压力管道工程的施工技术问题.现供从事市政污水压力管道工程施工的同行参考.%The article introduces the construction of jacking pipe by using DN2200 steel reinforced concrete pipe as the crossing pipe, and the construction method of then installing DN1800 socket-and-spigot sand glass fiber reinforced plastic pipe into the steel reinforced concrete pipe. This construction method can efficiently solve the construction technical problems of the deeper embedded municipal sewage pressure pipe, which can provide the reference for the construction of the municipal sewage pressure pipe.

  13. Experimental Study on Drilling Glass Fiber Reinforced Plastics%玻璃纤维增强复合材料钻削试验研究

    Institute of Scientific and Technical Information of China (English)

    宋中权; 程寓; 高超; 金浩

    2011-01-01

    选用S刃钻尖TIN涂层麻花钻对玻璃纤维增强复合材料进行了孔加工试验,并用扫描电子显微镜对孔壁表面进行了微观观察,分析了玻璃纤维破坏机理和切削表面微观结构特征.试验结果表明,S刃钻尖与普通钻尖麻花钻相比,可以有效减小钻削轴向力,减少分层缺陷的发生.因此,S刃钻尖麻花钻适用于玻璃纤维增强复合材料的加工,具有广泛的应用前景.%Drilling trials were carried out on glass fiber reinforced plastics with twist drill which had S shaped drill tip coated by TIN and the ground surfaces of drilled holes were observed by using scanning electron microscope ( SEM ), the fracture mechanism of glass fiber and the microscopic charaeteristics of ground surfaces were analyzed. The experimental results show that twist drill with S shaped drill tip offers less drilling thrust force and delamination fracture campared with conventional twist drills. Therefore,twist drill with S shaped drill tip is suitable for drilling glass fiber reinforced plastics and has a wide application prospect.

  14. Society of the plastic industry process emission initiatives

    Science.gov (United States)

    Mcdermott, Joseph

    1994-01-01

    At first view, plastics process emissions research may not seem to have much bearing on outgassing considerations relative to advanced composite materials; however, several parallel issues and cross currents are of mutual interest. The following topics are discussed: relevance of plastics industry research to aerospace composites; impact of clean air act amendment requirements; scope of the Society of the Plastics Industry, Inc. activities in thermoplastic process emissions and reinforced plastics/composites process emissions; and utility of SPI research for advanced polymer composites audiences.

  15. An Assessment of the Compressive Strength of Glass Reinforced Plastic Waste Filled Concrete for Potential Applications in Construction

    Directory of Open Access Journals (Sweden)

    Asokan Pappu

    2010-03-01

    Full Text Available

    Efforts were made to recycle Glass reinforced plastic (GRP waste powder in concrete products and assess its compressive strength to comply with British Standards for use in construction applications. More than 90 GRP waste-filled concrete specimens were

  16. Quasi-plane-hypothesis of strain coordination for RC beams seismically strengthened with externally-bonded or near-surface mounted fiber reinforced plastic

    Science.gov (United States)

    Ren, Zhenhua; Zeng, Xiantao; Liu, Hanlong; Zhou, Fengjun

    2013-03-01

    The application of fiber reinforced plastic (FRP), including carbon FRP and glass FRP, for structural repair and strengthening has grown due to their numerous advantages over conventional materials such as externally bonded reinforcement (EBR) and near-surface mounted (NSM) strengthening techniques. This paper summarizes the results from 21 reinforced concrete beams strengthened with different methods, including externally-bonded and near-surface mounted FRP, to study the strain coordination of the FRP and steel rebar of the RC beam. Since there is relative slipping between the RC beam and the FRP, the strain of the FRP and steel rebar of the RC beam satisfy the quasi-plane-hypothesis; that is, the strain of the longitudinal fiber that parallels the neutral axis of the plated beam within the scope of the effective height ( h 0) of the cross section is in direct proportion to the distance from the fiber to the neutral axis. The strain of the FRP and steel rebar satisfies the equation: ɛ FRP= βɛ steel, and the value of β is equal to 1.1-1.3 according to the test results.

  17. Experimental study of Electro-Plastic Effect on Advanced High Strength Steels

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xun; Lan, Shuhuai; Ni, Jun, E-mail: junni@umich.edu

    2013-10-10

    Application of Advanced High Strength Steels (AHSS) into vehicle structures calls for innovative manufacturing processes. In terms of reducing deformation resistance through external energy, Electro-Plastic Effect (EPE) provides a potential alternative to traditional thermal softening phenomenon. In this work, effectiveness of EPE on one group of AHSS, Transformation Induced Plasticity (TRIP) Steel, was evaluated. It was found that EPE cannot be effectively initiated until the current density reaches a threshold value between 7.4 A/mm{sup 2} and 11.4 A/mm{sup 2}. Besides, the softening phenomenon is more distinct at larger strains. Underlying mechanisms are explained from perspectives of dislocation multiplication, gliding and mechanical twinning. The inevitable Joule heating phenomenon associated with current was suppressed with forced air cooling and the temperature distribution inside the tensile specimen was numerically calculated with a coupled Finite Element Model. Effectiveness of EPE rather than thermal softening or expansion was further proved with the larger flow stress reduction under higher current density and shorter pulses at same temperature increase. Hollomon equation was adopted to model the observed stress strain relationships. Since material properties of TRIP steels are directly related to the phase transformation from retained austenite into martensite, volume fraction of retained austenite was quantitatively measured by X-ray Diffraction (XRD). It was found that the applied current retarded martensitic transformation process. Metallographic analysis was further performed and phenomena of change of grain structures and phase distribution were hardly observable.

  18. Use of Advanced Plastic Materials in Nigeria: Performance Assessment of Expanded Polystyrene Building Technology System

    Directory of Open Access Journals (Sweden)

    Anthony Nkem Ede (PhD

    2016-08-01

    Full Text Available The provision of affordable residential houses for the masses in the developing nations has been a mirage over the years and the future does not portend good as the cost of adopting conventional concrete material technologies is escalating while so many environmental issues like climate change are being raised in the recent times.To circumvent this poor housing provision trend, some innovative construction materials and technologies are being introduced to facilitate unique modular designs, reduction of labour, decline in the depletion of exhaustible materials,savings of time and fund. One of such materials is the expanded polystyrene. The introduction of advanced plastic materials and in particular the expanded polystyrene building technologies in the Nigerian constructionindustry will be a very useful and brilliant initiative that will aid the reduction of cost of construction and facilitate access to affordable houses for the masses.This researchaims at studying the applications of this innovative plastic material in the Nigerian building industry with special regard to the performance perception by the clients and the end users. A building estate where expanded polystyrene building technology has been predominantly used in Abuja is considered as a case study. Questionnaires were distributed among clients and residents of the building estate and statistical tools were used to analyse the data collected. Great satisfaction verified among the clients and residents and the high ranking performance confirmed for recyclability, reliability, versatility and moisture resistance of EPS building products all herald a great future for the applications of this advanced building products in the Nigerian building industry.

  19. A study on the effect of halloysite nanoparticle addition on the strength of glass fiber reinforced plastic

    Science.gov (United States)

    Kim, Yun-Hae; Park, Soo-Jeong; Lee, Jin-Woo; Moon, Kyung-Man

    2015-03-01

    Halloysite nanotube, which has been used in the polymer, has been spotlighted as a useful functional materials in the improvement of mechanical properties. In the current study, we established the optimal nanoparticle dispersion and analyzed the mechanical characteristics and the behavior of composites reinforced by HNTs have been synthesized by dispersing HNTs to the unsaturated polyester resin (UPR) and their mechanical characteristics, especially the tensile strength, interlaminar shear strength have been analyzed. Additionally, the reinforcement effect and its variation according to the amount of HNTs was also studied.

  20. Surface Crack Detection for Carbon Fiber Reinforced Plastic Materials Using Pulsed Eddy Current Based on Rectangular Differential Probe

    Directory of Open Access Journals (Sweden)

    Jialong Wu

    2014-01-01

    Full Text Available Aiming at the surface defect inspection of carbon fiber reinforced composite, the differential and the direct measurement finite element simulation models of pulsed eddy current flaw detection were built. The principle of differential pulsed eddy current detection was analyzed and the sensitivity of defect detection was compared through two kinds of measurements. The validity of simulation results was demonstrated by experiments. The simulation and experimental results show that the pulsed eddy current detection method based on rectangular differential probe can effectively improve the sensitivity of surface defect detection of carbon fiber reinforced composite material.

  1. 玻璃纤维增强连续塑料复合管道的应用性能%Performances of fiberglass reinforced composite plastic pipeline

    Institute of Scientific and Technical Information of China (English)

    夏平原; 李诗春; 陈斌

    2013-01-01

    Characterized by light weight,superior corrosion resistance,high pressure-beating capacities,longer extension,flexibility,easiness in fabrication,energy conservation and higher safety factors,fiberglass reinforced composite plastic pipeline of high-performance flexible composite pipe with multi-layer structures will gradually replace steel pipe for development and transportation of hydrocarbons due to their overall low costs.Through a model,the mechanical property of fiberglass reinforced composite plastic pipe is analyzed.In addition,six types of fiberglass reinforced composite plastic pipes have been produced and explosion tested in accordance with different design requirements.Research results show that actual bursting pressures are basically the same with designed theoretical pressure with pressure extent of 5.5 to 25 MPa.These products can fulfill requirements presented by actual production process.%玻璃纤维增强连续塑料复合管是一种多层结构高性能柔性复合管,具有质量轻、抗腐蚀能力强、承压能力强、制作长度长、可弯曲、施工简易、维护方便、节能环保、使用安全系数高的优点,因此整体使用成本较低,有望逐步取代钢制管道,用于石油天然气的开采和输送.建模分析了玻璃纤维增强连续塑料复合管的力学性能,根据不同要求设计了6种玻璃纤维增强连续塑料复合管道,并实施爆破试验,结果表明:实际爆破压力与理论设计压力基本相同,压力范围为5.5~25 MPa,可以满足实际生产需求.

  2. A plastic network approach to model calving glacier advance and retreat

    Science.gov (United States)

    Ultee, Lizz; Bassis, Jeremy N.

    2017-03-01

    Calving glaciers contribute substantially to sea level rise, but they are challenging to represent in models. Fine resolution is required for continental-scale models to accurately resolve calving dynamics and in many cases glacier geometry is too complicated to be adequately reflected by more simplified models. Flowline models are able to resolve flow along the main branch of a glacier, but many of those in current use either ignore tributaries entirely or parameterize their effect using a measure of “equivalent width”. Here we present a simple method to simulate terminus advance and retreat for an interacting network of glacier branches, based on a model extending Nye’s 1953 perfect plastic flow approximation to calving glaciers. We apply the method to case studies of four marine-terminating glaciers: Jakobshavn Isbræ and Helheim Glacier of Greenland, and Columbia and Hubbard Glaciers of Alaska. Given bed topography and upstream elevation history, our method reproduces observed patterns of terminus advance and retreat in all cases, as well as centerline profiles for all branches.

  3. Advanced Nanocomposite Coatings of Fusion Bonded Epoxy Reinforced with Amino-Functionalized Nanoparticles for Applications in Underwater Oil Pipelines

    Directory of Open Access Journals (Sweden)

    Patricia A. Saliba

    2016-01-01

    Full Text Available The performance of fusion-bonded epoxy coatings can be improved through advanced composite coatings reinforced with nanomaterials. Hence, in this study a novel organic-inorganic nanocomposite finish was designed, synthesized, and characterized, achieved by adding γ-aminopropyltriethoxysilane modified silica nanoparticles produced via sol-gel process in epoxy-based powder. After the curing process of the coating reinforced with nanoparticles, the formation of a homogenous novel nanocomposite with the development of interfacial reactions between organic-inorganic and inorganic-inorganic components was observed. These hybrid nanostructures produced better integration between nanoparticles and epoxy matrix and improved mechanical properties that are expected to enhance the overall performance of the system against underwater corrosion.

  4. Modification of carbon fabrics by radio-frequency capacitive discharge at low pressure to regulate mechanical properties of carbon fiber reinforced plastics based on it

    Science.gov (United States)

    Garifullin, A. R.; Krasina, I. V.; Skidchenko, E. A.; Shaekhov, M. F.; Tikhonova, N. V.

    2017-01-01

    To increase the values of mechanical properties of carbon fiber (CF) composite materials used in sports equipment production the method of radio-frequency capacitive (RFC) low-pressure plasma treatment in air was proposed. Previously it was found that this type of modification allows to effectively regulate the surface properties of fibers of different nature. This treatment method differs from the traditional ones by efficiency and environmental friendliness as it does not require the use of aggressive, environmentally hazardous chemicals. In this paper it was established that RFC low-pressure air plasma treatment of carbon fabrics enhances the interlaminar shear strength (ILSS) of carbon fiber reinforced plastic (CFRP). As a result of experimental studies of CF by Fourier Transform Infrared (FTIR) spectroscopy method it was proved that after radio-frequency capacitive plasma treatment at low pressure in air the oxygen-containing functional groups is grafted on the surface. These groups improve adhesion at the interface “matrix-fiber”.

  5. Simulator trials to determine the wear of the combination aluminium oxide ceramic-carbon fibre reinforced plastic (CFRP) used as an insert in a hip socket.

    Science.gov (United States)

    Scheller, G; Schwarz, M; Früh, H J; Jani, L

    1999-01-01

    Hip simulator trials were conducted to determine the initial wear between alumina femoral heads and carbon fibre reinforced plastic (CFRP, CAPROMAN) insert in a titanium socket. A force of 2500 N and a frequency of 0.857 H were applied. Using surface and sphericity measurement techniques, the amount of wear was determined. After 500,000 cycles, the centre of the head had moved by 10 microm into the insert, and the average radius increased by 2 microm. After 1 million cycles, the additional changes were less than 1 microm. Based on an examination of retrieved implants (wear rate: 6.1 microm/year) and based on the simulator results, the combination alumina-CFRP inserts could be approved for total hip replacement.

  6. Open fibre reinforced plastic (FRP) flat plate collector (FPC) and spray network systems for augmenting the evaporation rate of tannery effluent (soak liquor)

    Energy Technology Data Exchange (ETDEWEB)

    Srithar, K. [Department of Mechanical Engineering, Thiagarajar College of Engineering, Madurai 625 015 (India); Mani, A. [Department of Mechanical Engineering, Indian Institute of Technology, Madras, Chennai 600 036 (India)

    2007-12-15

    Presently, tanneries in Tamilnadu, India are required to segregate the effluent of soaking and pickling sections from other wastewater streams and send it to shallow solar pans for evaporation to avoid land pollution. A large area of solar pans is required for evaporating the water in the effluent at salt concentration in the range of 4-5%. An experimental study has been made by using fibre reinforced plastic flat plate collector (FRP-FPC) and spray system in a pilot plant with a capacity to handle 5000 l per day, which increases the evaporation rate. After increasing the salt concentration level to near saturation limit, the concentrated liquid was sent to conventional solar pans for its continued evaporation and recovery of salt. In this improved system, the rate of evaporation was found to be 30-40% more than that in the conventional solar pans. The performance is compared with the theoretically simulated performance. (author)

  7. New Advanced Source Identification Algorithm (ASIA-NEW) for radiation monitors with plastic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Stavrov, Andrei; Yamamoto, Eugene [Rapiscan Systems, Inc., 14000 Mead Street, Longmont, CO, 80504 (United States)

    2015-07-01

    Radiation Portal Monitors (RPM) with plastic detectors represent the main instruments used for primary border (customs) radiation control. RPM are widely used because they are simple, reliable, relatively inexpensive and have a high sensitivity. However, experience using the RPM in various countries has revealed the systems have some grave shortcomings. There is a dramatic decrease of the probability of detection of radioactive sources under high suppression of the natural gamma background (radiation control of heavy cargoes, containers and, especially, trains). NORM (Naturally Occurring Radioactive Material) existing in objects under control trigger the so-called 'nuisance alarms', requiring a secondary inspection for source verification. At a number of sites, the rate of such alarms is so high it significantly complicates the work of customs and border officers. This paper presents a brief description of new variant of algorithm ASIA-New (New Advanced Source Identification Algorithm), which was developed by the authors and based on some experimental test results. It also demonstrates results of different tests and the capability of a new system to overcome the shortcomings stated above. New electronics and ASIA-New enables RPM to detect radioactive sources under a high background suppression (tested at 15-30%) and to verify the detected NORM (KCl) and the artificial isotopes (Co-57, Ba-133 and other). New variant of ASIA is based on physical principles and does not require a lot of special tests to attain statistical data for its parameters. That is why this system can be easily installed into any RPM with plastic detectors. This algorithm was tested for 1,395 passages of different transports (cars, trucks and trailers) without radioactive sources. It also was tested for 4,015 passages of these transports with radioactive sources of different activity (Co-57, Ba-133, Cs-137, Co-60, Ra-226, Th-232) and these sources masked by NORM (K-40) as well

  8. Anterior cruciate ligament repair with LARS (ligament advanced reinforcement system: a systematic review

    Directory of Open Access Journals (Sweden)

    Machotka Zuzana

    2010-12-01

    Full Text Available Abstract Background Injury to the anterior cruciate ligament (ACL of the knee is common. Following complete rupture of the ACL, insufficient re-vascularization of the ligament prevents it from healing completely, creating a need for reconstruction. A variety of grafts are available for use in ACL reconstruction surgery, including synthetic grafts. Over the last two decades new types of synthetic ligaments have been developed. One of these synthetic ligaments, the Ligament Advanced Reinforcement System (LARS, has recently gained popularity. The aim of this systematic review was to assess the current best available evidence for the effectiveness of the LARS as a surgical option for symptomatic, anterior cruciate ligament rupture in terms of graft stability, rehabilitation time and return to pre-injury function. Method This systematic review included studies using subjects with symptomatic, ACL ruptures undergoing LARS reconstruction. A range of electronic databases were searched in May 2010. The methodological quality of studies was appraised with a modified version of the Law critical appraisal tool. Data relating to study characteristics, surgical times, complication rates, outcomes related to knee stability, quality of life, function, and return to sport as well as details of rehabilitation programs and timeframes were collected. Results This review identified four studies of various designs, of a moderate methodological quality. Only one case of knee synovitis was reported. Patient satisfaction with LARS was high. Graft stability outcomes were found to be inconsistent both at post operative and at follow up periods. The time frames of rehabilitation periods were poorly reported and at times omitted. Return to pre-injury function and activity was often discussed but not reported in results. Conclusions There is an emerging body of evidence for LARS with comparable complication rates to traditional surgical techniques, and high patient

  9. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics......In a fibre-reinforced polymer (FRP) structure designed using the emerging damage tolerance and structural health monitoring philosophy, sensors and models that describe crack propagation will enable a structure to operate despite the presence of damage by fully exploiting the material’s mechanical...... a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG) sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored...

  10. Surface Crack Detection for Carbon Fiber Reinforced Plastic Materials Using Pulsed Eddy Current Based on Rectangular Differential Probe

    OpenAIRE

    Jialong Wu; Deqiang Zhou; Jun Wang

    2014-01-01

    Aiming at the surface defect inspection of carbon fiber reinforced composite, the differential and the direct measurement finite element simulation models of pulsed eddy current flaw detection were built. The principle of differential pulsed eddy current detection was analyzed and the sensitivity of defect detection was compared through two kinds of measurements. The validity of simulation results was demonstrated by experiments. The simulation and experimental results show that the pulsed ed...

  11. Constructing Novel Fiber Reinforced Plastic (FRP Composites through a Biomimetic Approach: Connecting Glass Fiber with Nanosized Boron Nitride by Polydopamine Coating

    Directory of Open Access Journals (Sweden)

    XueMei Wen

    2013-01-01

    Full Text Available A biomimetic method was developed to construct novel fiber reinforced plastic (FRP composites. By mimicking mussel adhesive proteins, a monolayer of polydopamine was coated on glass fiber (GF surface. The polydopamine-treated GF (D-GF adsorbed boron nitride (BN nanoparticles, while obtaining micronano multiscale hybrid fillers BN-D-GF. Scanning electron microscopy (SEM results showed that the strong interfacial interaction brought by the polydopamine benefits the loading amount as well as dispersion of the nano-BN on GF’s surface. The BN-D-GF was incorporated into epoxy resin to construct “FRP nanocomposites.” The morphology, dynamic mechanical and thermal characteristics of the FRP nanocomposites were analyzed. SEM morphology revealed that BN-D-GF heterogeneous dispersed in epoxy matrix. There was good adhesion between the polymer matrix and the BN-D-GF filler. The dynamic modulus and mechanical loss were studied using dynamic mechanical analysis (DMA. Compared with neat epoxy and untreated GF reinforced composites, BN-D-GF/epoxy and D-GF/epoxy systems showed improved mechanical properties. The thermal conductivity, Shore D hardness, and insulation properties were also enhanced.

  12. Plastic Bridge

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Already ubiquitous in homes and cars, plastic is now appearing inbridges. An academic-industrial consortium based at the University ofCalifornia in San Diego is launching a three-year research program aimed atdeveloping the world’s first plastic highway bridge, a 450-foot span madeentirely from glass-,carbon,and polymer-fiber-reinforced composite mate-rials, the stuff of military aircraft. It will cross Interstate 5 to connect thetwo sides of the school’s campus.

  13. Development on Anti-ageing of Unsaturated Polyester Glass Fiber Reinforced Plastic (GFRP) Composites%以不饱和聚酯树脂为基的玻璃钢复合材料防老化研究进展

    Institute of Scientific and Technical Information of China (English)

    王玉民; 郭振宇; 宁培森; 丁著明

    2011-01-01

    综述了不饱和聚酯树脂基玻璃钢复合材料(GFRP)防老化方面的最近研究进展,包括GFRP表面新型涂层及树脂的添加剂(紫外线吸收剂、受阻胺光稳定剂和抗氧剂等).结果表明,只使用单一的稳定剂效果不佳,必须将抗氧剂和其他添加剂(例如某些环氧化合物)并用,才能取得较好的效果.%Recent advances in anti-ageing of unsatured polyester glass fiber reinforced plastic (GFRP) were reviewed in this paper, including novel coating of GFRP and adding various stabilizers, such as ultraviolet absorbent,hindered amine light stabilizers(HALS) and antioxidant. The results showed the effect was not good using single stabilizer. The combined use of Main and side antioxidant and other additives (e. g. some epoxy compounds) had the best Effect on maintaining anti-ageing of GFRP

  14. Th1/Th17 Plasticity Is a Marker of Advanced β Cell Autoimmunity and Impaired Glucose Tolerance in Humans

    Science.gov (United States)

    Reinert-Hartwall, Linnea; Honkanen, Jarno; Salo, Harri M.; Nieminen, Janne K.; Luopajärvi, Kristiina; Härkönen, Taina; Veijola, Riitta; Simell, Olli; Ilonen, Jorma; Peet, Aleksandr; Tillmann, Vallo; Knip, Mikael; Knip, Mikael; Koski, Katriina; Koski, Matti; Härkönen, Taina; Ryhänen, Samppa; Hämäläinen, Anu-Maaria; Ormisson, Anne; Peet, Aleksandr; Tillmann, Vallo; Ulich, Valentina; Kuzmicheva, Elena; Mokurov, Sergei; Markova, Svetlana; Pylova, Svetlana; Isakova, Marina; Shakurova, Elena; Petrov, Vladimir; Dorshakova, Natalya V.; Karapetyan, Tatyana; Varlamova, Tatyana; Ilonen, Jorma; Kiviniemi, Minna; Alnek, Kristi; Janson, Helis; Uibo, Raivo; Salum, Tiit; von Mutius, Erika; Weber, Juliane; Ahlfors, Helena; Kallionpää, Henna; Laajala, Essi; Lahesmaa, Riitta; Lähdesmäki, Harri; Moulder, Robert; Nieminen, Janne; Ruohtula, Terhi; Vaarala, Outi; Honkanen, Hanna; Hyöty, Heikki; Kondrashova, Anita; Oikarinen, Sami; Harmsen, Hermie J. M.; De Goffau, Marcus C.; Welling, Gjalt; Alahuhta, Kirsi; Virtanen, Suvi M.

    2015-01-01

    Upregulation of IL-17 immunity and detrimental effects of IL-17 on human islets have been implicated in human type 1 diabetes. In animal models, the plasticity of Th1/Th17 cells contributes to the development of autoimmune diabetes. In this study, we demonstrate that the upregulation of the IL-17 pathway and Th1/Th17 plasticity in peripheral blood are markers of advanced β cell autoimmunity and impaired β cell function in human type 1 diabetes. Activated Th17 immunity was observed in the late stage of preclinical diabetes in children with β cell autoimmunity and impaired glucose tolerance, but not in children with early β cell autoimmunity. We found an increased ratio of IFN-γ/IL-17 expression in Th17 cells in children with advanced β cell autoimmunity, which correlated with HbA1c and plasma glucose concentrations in an oral glucose tolerance test, and thus impaired β cell function. Low expression of Helios was seen in Th17 cells, suggesting that Th1/Th17 cells are not converted thymus-derived regulatory T cells. Our results suggest that the development of Th1/Th17 plasticity may serve as a biomarker of disease progression from β cell autoantibody positivity to type 1 diabetes. These data in human type 1 diabetes emphasize the role of Th1/Th17 plasticity as a potential contributor to tissue destruction in autoimmune conditions. PMID:25480564

  15. Auto-reinforce Magnetic Flywheel as Recent Advancement of Automobile Flywheel

    Directory of Open Access Journals (Sweden)

    Akbar Ahmad Radikal

    2014-07-01

    Full Text Available A new feature for flywheel energy storage device is proposed, considering the deficiencies on existing technology. This feature is introduced as auto-reinforce performance which means an ability to recover the kinetic energy after speed-down occurred as impact of sudden loading or sudden braking. The performance will significantly keep longer the stored energy of a flywheel device. This novel concept of flywheel is engineered by installing a number of Permanent Magnets (PM. The magnetism configuration such magnetic strength, magnetic energy density, pole direction, geometry, and dimension are influential parameters to its performance. By executing Finite Element Magnetic Modeling, it is possible to predict the design parameters such magnetic force and magnetic torque. Finally by evaluating these mechanical parameters, the key performance of this device such as percentage of energy reinforcement and percentage of discharge elongation can be predicted for prototyping references.

  16. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation.

    Science.gov (United States)

    Pereira, G F; Mikkelsen, L P; McGugan, M

    2015-01-01

    In a fibre-reinforced polymer (FRP) structure designed using the emerging damage tolerance and structural health monitoring philosophy, sensors and models that describe crack propagation will enable a structure to operate despite the presence of damage by fully exploiting the material's mechanical properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics: the damage mechanism (delamination of FRP), the structural health monitoring technology (fibre Bragg gratings to detect delamination), and the finite element method model of the structure that incorporates these concepts into a final and integrated damage-monitoring concept. A novel method for assessing a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG) sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored by the end-user. Conjointly, a novel model for sensor output prediction (virtual sensor) was developed using this FBG sensor crack monitoring concept and implemented in a finite element method code. The monitoring method was demonstrated and validated using glass fibre double cantilever beam specimens instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. The digital image correlation technique was used to validate the model prediction by correlating the specific sensor response caused by the crack with the developed model.

  17. Crack Detection in Fibre Reinforced Plastic Structures Using Embedded Fibre Bragg Grating Sensors: Theory, Model Development and Experimental Validation.

    Directory of Open Access Journals (Sweden)

    G F Pereira

    Full Text Available In a fibre-reinforced polymer (FRP structure designed using the emerging damage tolerance and structural health monitoring philosophy, sensors and models that describe crack propagation will enable a structure to operate despite the presence of damage by fully exploiting the material's mechanical properties. When applying this concept to different structures, sensor systems and damage types, a combination of damage mechanics, monitoring technology, and modelling is required. The primary objective of this article is to demonstrate such a combination. This article is divided in three main topics: the damage mechanism (delamination of FRP, the structural health monitoring technology (fibre Bragg gratings to detect delamination, and the finite element method model of the structure that incorporates these concepts into a final and integrated damage-monitoring concept. A novel method for assessing a crack growth/damage event in fibre-reinforced polymer or structural adhesive-bonded structures using embedded fibre Bragg grating (FBG sensors is presented by combining conventional measured parameters, such as wavelength shift, with parameters associated with measurement errors, typically ignored by the end-user. Conjointly, a novel model for sensor output prediction (virtual sensor was developed using this FBG sensor crack monitoring concept and implemented in a finite element method code. The monitoring method was demonstrated and validated using glass fibre double cantilever beam specimens instrumented with an array of FBG sensors embedded in the material and tested using an experimental fracture procedure. The digital image correlation technique was used to validate the model prediction by correlating the specific sensor response caused by the crack with the developed model.

  18. Laser cutting plastic materials

    Energy Technology Data Exchange (ETDEWEB)

    Van Cleave, R.A.

    1980-08-01

    A 1000-watt CO/sub 2/ laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. Applications for laser cutting described include fiberglass-reinforced laminates, Kevlar/epoxy composites, fiberglass-reinforced phenolics, nylon/epoxy laminates, ceramics, and disposable tooling made from acrylic.

  19. 新FRP技术加固钢筋混凝土矩形柱改善延性的试验研究%Experimental study on ductility improvement of reinforced concrete rectangular columns retrofitted with a new fiber reinforced plastics method

    Institute of Scientific and Technical Information of China (English)

    刘涛; 冯伟; 张智梅; 欧阳煜

    2008-01-01

    Reinforced concrete (RC) columns lacking adequately detailed transverse reinforcement do not possess the necessaryductility to dissipate seismic energy during a major earthquake without severe strength degradation. In this paper, a newretrofit method, which utilized fiber-reinforced plastics (FRP) confinement mechanism and anchorage of embedded bars, wasdeveloped aiming to retrofit non-ductile large RC rectangular columns to prevent the damage of the plastic hinges. CarbonFRP (CFRP) sheets and glass FRP (GFRP) bars were used in this test, and five scaled RC columns were tested to examinethe function of this new method for improving the ductility of columns. Responses of columns were examined before andafter being retrofitted. Test results indicate that this new composite method can be very effective to improve the anti-seismicbehavior of non-ductile RC columns compared with normal CFRP sheets retrofitted column.

  20. Self-expanding plastic stent removed after radiochemotherapy for advanced esophageal cancer.

    Science.gov (United States)

    Laquière, A; Grandval, P; Heresbach, D; Prat, F; Arpurt, J P; Bichard, P; D'Halluin, P-N; Berthillier, J; Boustière, C; Laugier, R

    2014-01-01

    Endoscopic evaluation after chemoradiotherapy (CR) is impossible with an esophageal stent in place. The main study objective was to evaluate self-expanding plastic stent (SEPS) removal post-CR. Secondary end-points were the improvement of dysphagia and patients' quality of life. From October 2008 to March 2011, 20 dysphagic patients who suffered from advanced esophageal cancer were enrolled in a multicenter, prospective study. SEPS was inserted prior to CR and then removed endoscopically. SEPS efficiency (dysphagia score) and tolerance, as well as the patients' quality of life (European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire validated for the esophagus), were monitored. Continuous variables were compared using a paired t-test analysis for matched data. A P-value of less than 0.05 was considered statistically significant. Twenty patients (15 men and 5 women), aged 61.5 years (±9.88) (range 43-82 years), with adenocarcinoma (n = 12) and squamous cell carcinoma (n = 8), were enrolled. SEPS were successfully inserted in all patients (100%). There was one perforation and three episodes of migration. All of these complications were medically treated. The mean dysphagia score at the time of stent placement was 2.79 (0.6). Mean dysphagia scores obtained on day 1 and day 30 post-SEPS placement were 0.7 (0.9) (P cancer. Early stenting by SEPS prior to and during CR may reduce dysphagia and improve quality of oral alimentation. © 2013 Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

  1. Thermal expansion behavior of co-extruded wood-plastic composites with glass-fiber reinforced shells

    Directory of Open Access Journals (Sweden)

    Runzhou Huang

    2012-11-01

    Full Text Available Coextruded wood-plastic composites (WPCs with glass-fiber (GF filled shells were manufactured, and their thermal expansion behavior was studied. A three-dimensional finite element model (FEM considering differential properties of both shell and core layers was developed to predict the linear coefficient of thermal expansion (LCTE of the material. It was shown that the LCTE values varied with composite structure and composition (i.e., core-shell thicknesses and materials. The use of GF-filled shells helped lower overall composite LCTE values. The imbalance of shell and core LCTE, and their moduli led to complex stress fields within a given composite system. The FEM predicted a trend of LCTE change with varying composite structures, which was in good agreement with the experimental data. This study provides for the first time a finite element modeling technique to optimize raw material composition and composite structure for optimizing thermal expansion behavior of co-extruded WPCs.

  2. The impact of advancing age on postoperative outcomes in plastic surgery.

    Science.gov (United States)

    Shih, Kevin; De Oliveira, Gildasio S; Qin, Charles; Kim, John Y

    2015-11-01

    Age has been shown to be an independent predictor of complications in general surgery patients. In contrast, the effect of age on outcomes after plastic surgery has yet to be confirmed or refuted. The objective of the current investigation was to evaluate a possible association between age and postoperative outcomes after plastic surgery. The 2005-2012 NSQIP database was retrospectively reviewed for all patients undergoing plastic surgery. Patients ≥60 years with procedures under the category of plastic surgery in NSQIP were selected for analysis. The primary outcome of interest was 30-day overall complication rates. Multivariate regression models were constructed to control for potential perioperative confounders. Of the 2,320,920 patients captured in the NSQIP database, 36,819 patients underwent plastic surgery and met inclusion criteria. The incidence of unadjusted overall complications increased with age with an overall complication rate of 9.0% in patients plastic surgery. Medical complications and mortality were more likely in extremes of age (>80 years). Age alone should not be included as a decisional factor in patients plastic surgery.

  3. Recent advances in understanding the reinforcing ability and mechanism of carbon nanotubes in ceramic matrix composites

    Science.gov (United States)

    Estili, Mehdi; Sakka, Yoshio

    2014-12-01

    Since the discovery of carbon nanotubes (CNTs), commonly referred to as ultimate reinforcement, the main purpose for fabricating CNT-ceramic matrix composites has been mainly to improve the fracture toughness and strength of the ceramic matrix materials. However, there have been many studies reporting marginal improvements or even the degradation of mechanical properties. On the other hand, those studies claiming noticeable toughening measured using indentation, which is an indirect/unreliable characterization method, have not demonstrated the responsible mechanisms applicable to the nanoscale, flexible CNTs; instead, those studies proposed those classical methods applicable to microscale fiber/whisker reinforced ceramics without showing any convincing evidence of load transfer to the CNTs. Therefore, the ability of CNTs to directly improve the macroscopic mechanical properties of structural ceramics has been strongly questioned and debated in the last ten years. In order to properly discuss the reinforcing ability (and possible mechanisms) of CNTs in a ceramic host material, there are three fundamental questions to our knowledge at both the nanoscale and macroscale levels that need to be addressed: (1) does the intrinsic load-bearing ability of CNTs change when embedded in a ceramic host matrix?; (2) when there is an intimate atomic-level interface without any chemical reaction with the matrix, could one expect any load transfer to the CNTs along with effective load bearing by them during crack propagation?; and (3) considering their nanometer-scale dimensions, flexibility and radial softness, are the CNTs able to improve the mechanical properties of the host ceramic matrix at the macroscale when individually, intimately and uniformly dispersed? If so, how? Also, what is the effect of CNT concentration in such a defect-free composite system? Here, we briefly review the recent studies addressing the above fundamental questions. In particular, we discuss the new

  4. Recent advances in understanding the reinforcing ability and mechanism of carbon nanotubes in ceramic matrix composites

    Science.gov (United States)

    Estili, Mehdi; Sakka, Yoshio

    2014-01-01

    Since the discovery of carbon nanotubes (CNTs), commonly referred to as ultimate reinforcement, the main purpose for fabricating CNT–ceramic matrix composites has been mainly to improve the fracture toughness and strength of the ceramic matrix materials. However, there have been many studies reporting marginal improvements or even the degradation of mechanical properties. On the other hand, those studies claiming noticeable toughening measured using indentation, which is an indirect/unreliable characterization method, have not demonstrated the responsible mechanisms applicable to the nanoscale, flexible CNTs; instead, those studies proposed those classical methods applicable to microscale fiber/whisker reinforced ceramics without showing any convincing evidence of load transfer to the CNTs. Therefore, the ability of CNTs to directly improve the macroscopic mechanical properties of structural ceramics has been strongly questioned and debated in the last ten years. In order to properly discuss the reinforcing ability (and possible mechanisms) of CNTs in a ceramic host material, there are three fundamental questions to our knowledge at both the nanoscale and macroscale levels that need to be addressed: (1) does the intrinsic load-bearing ability of CNTs change when embedded in a ceramic host matrix?; (2) when there is an intimate atomic-level interface without any chemical reaction with the matrix, could one expect any load transfer to the CNTs along with effective load bearing by them during crack propagation?; and (3) considering their nanometer-scale dimensions, flexibility and radial softness, are the CNTs able to improve the mechanical properties of the host ceramic matrix at the macroscale when individually, intimately and uniformly dispersed? If so, how? Also, what is the effect of CNT concentration in such a defect-free composite system? Here, we briefly review the recent studies addressing the above fundamental questions. In particular, we discuss the new

  5. Effect of cellulose reinforcement on the properties of organic acid modified starch microparticles/plasticized starch bio-composite films.

    Science.gov (United States)

    Teacă, Carmen-Alice; Bodîrlău, Ruxanda; Spiridon, Iuliana

    2013-03-01

    The present paper describes the preparation and characterization of polysaccharides-based bio-composite films obtained by the incorporation of 10, 20 and 30 wt% birch cellulose (BC) within a glycerol plasticized matrix constituted by the corn starch (S) and chemical modified starch microparticles (MS). The obtained materials (coded as MS/S, respectively MS/S/BC) were further characterized. FTIR spectroscopy and X-ray diffraction were used to evidence structural and crystallinity changes in starch based films. Morphological, thermal, mechanical, and water resistance properties were also investigated. Addition of cellulose alongside modified starch microparticles determined a slightly improvement of the starch-based films water resistance. Some reduction of water uptake for any given time was observed mainly for samples containing 30% BC. Some compatibility occurred between MS and BC fillers, as evidenced by mechanical properties. Tensile strength increased from 5.9 to 15.1 MPa when BC content varied from 0 to 30%, while elongation at break decreased significantly.

  6. Machinability of drilling T700/LT-03A carbon fiber reinforced plastic (CFRP) composite laminates using candle stick drill and multi-facet drill

    Science.gov (United States)

    Wang, Cheng-Dong; Qiu, Kun-Xian; Chen, Ming; Cai, Xiao-Jiang

    2015-03-01

    Carbon Fiber Reinforced Plastic (CFRP) composite laminates are widely used in aerospace and aircraft structural components due to their superior properties. However, they are regarded as difficult-to-cut materials because of bad surface quality and low productivity. Drilling is the most common hole making process for CFRP composite laminates and drilling induced delamination damage usually occurs severely at the exit side of drilling holes, which strongly deteriorate holes quality. In this work, the candle stick drill and multi-facet drill are employed to evaluate the machinability of drilling T700/LT-03A CFRP composite laminates in terms of thrust force, delamination, holes diameter and holes surface roughness. S/N ratio is used to characterize the thrust force while an ellipse-shaped delamination model is established to quantitatively analyze the delamination. The best combination of drilling parameters are determined by full consideration of S/N ratios of thrust force and the delamination. The results indicate that candle stick drill will induce the unexpected ellipse-shaped delamination even at its best drilling parameters of spindle speed of 10,000 rpm and feed rate of 0.004 mm/tooth. However, the multi-facet drill cutting at the relative lower feed rate of 0.004 mm/tooth and lower spindle speed of 6000 rpm can effectively prevent the delamination. Comprehensively, holes quality obtained by multi-facet drill is much more superior to those obtained by candle stick drill.

  7. [Survey of carbon fiber reinforced plastic orthoses and occupational and medical problems based on a questionnaire administered to companies involved in the manufacture of prosthetics and orthotics].

    Science.gov (United States)

    Kaneshiro, Yuko; Furuta, Nami; Makino, Kenichiro; Wada, Futoshi; Hachisuka, Kenji

    2011-09-01

    We surveyed carbon fiber reinforced plastic orthoses (carbon orthoses) and their associated occupational and medical problems based on a questionnaire sent to 310 companies which were members of the Japan Orthotics and Prosthetics Association. Of all the companies, 232 responded: 77 of the 232 companies dealt with ready-made carbon orthoses, 52 dealt with fabricated custom-made orthoses, and 155 did not dealt with carbon orthoses. Although the total number of custom-made carbon ortheses in Japan was 829/ 5 years, there was a difference by region, and one company fabricated only 12 (per 5 years) custom-made carbon orthoses on average. The advantages of the carbon orthosis were the fact that it was "light weight", "well-fitted", had a "good appearance", and "excellent durability", while the disadvantages were that it was "expensive", "high cost of production", of "black color", and required a "longer time for completion", and "higher fabrication techniques". From the standpoint of industrial medicine, "scattering of fine fragments of carbon fibers", "itching on the skin" and "health hazards" were indicated in companies that manufacture the orthosis. In order to make the carbon orthosis more popular, it is necessary to develop a new carbon material that is easier to fabricate at a lower cost, to improve the fabrication technique, and to resolve the occupational and medical problems.

  8. Non-contact characterization of hybrid aluminium/carbon-fibre-reinforced plastic sheets using multi-frequency eddy-current sensors

    Science.gov (United States)

    Yin, W.; Li, X.; Withers, P. J.; Peyton, A. J.

    2010-10-01

    The characterization of hybrid aluminium/carbon-fibre-reinforced plastic (CFRP) sheets using multi-frequency eddy-current sensors is presented in this paper. Both air-cored circular sensors and highly directional ferrite-cored sensors are designed for bulk conductivity measurements and directionality characterization. An analytical model describing the interaction of the circular sensors with the hybrid planar structure is developed. Finite element (FE) models that take into account the anisotropicity of CFRP have also been proposed. Both models are in good agreement with experimental results. The features of the sensor output signals are analysed and explained. It is proved that an anisotropic model (tensor expression for conductivity) is appropriate for the CFRP materials under investigation. A formula to link the bulk conductivity with the conductivity tensor is proposed and verified. Lift-off effects are also discussed. It is believed that this is amongst the first published reports of using eddy-current techniques for characterizing the hybrid aluminium/CFRP material.

  9. Damage evaluation of fiber reinforced plastic-confined circular concrete-filled steel tubular columns under cyclic loading using the acoustic emission technique

    Science.gov (United States)

    Li, Dongsheng; Du, Fangzhu; Ou, Jinping

    2017-03-01

    Glass-fiber reinforced plastic (GFRP)-confined circular concrete-filled steel tubular (CCFT) columns comprise of concrete, steel, and GFRP and show complex failure mechanics under cyclic loading. This paper investigated the failure mechanism and damage evolution of GFRP–CCFT columns by performing uniaxial cyclic loading tests that were monitored using the acoustic emission (AE) technique. Characteristic AE parameters were obtained during the damage evolution of GFRP–CCFT columns. Based on the relationship between the loading curve and these parameters, the damage evolution of GFRP–CCFT columns was classified into three stages that represented different damage degrees. Damage evolution and failure mode were investigated by analyzing the b-value and the ratio of rise time to waveform amplitude and average frequency. The damage severity of GFRP–CCFT columns were quantitatively estimated according to the modified index of damage and NDIS-2421 damage assessment criteria corresponding to each loading step. The proposed method can explain the damage evolution and failure mechanism for GFRP–CCFT columns and provide critical warning information for composite structures.

  10. Advanced WC-Co cermet composites with reinforcement of TiCN prepared by extended thermal plasma route

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, B. [Centre for Advanced Materials Processing, Central Mechanical Engineering Research Institute, Mahatma Gandhi Avenue, Durgapur 713 209, West Bengal (India)], E-mail: bnmondal@rediffmail.com; Das, P.K. [Central Glass and Ceramic Research Institute, Kolkata (India); Singh, S.K. [Institute of Minerals and Materials Technology (IIMT), Bhubeneswar (India)

    2008-12-20

    The synthesis of titanium carbonitride (TiCN) powders by thermal plasma using extended arc thermal plasma reactor and the effect of TiCN reinforcement for the development of advanced WC-Co cermets has been studied with respect to hardness and fracture toughness. These classes of materials are being investigated for future application in wear-resistant seals, cutting tools, etc. Metallurgical reactions and microstructural developments during sintering of cermets and functionally graded cemented carbonitrides are being investigated by analytical methods such as differential thermal analysis/thermo-gravimetric analysis, X-ray diffraction and analytical Scanning electron microscopy with energy dispersive X-ray spectroscopy. By an in-depth understanding of the complex phase reactions and the mechanisms that govern the sintering process and metallurgical reactions, new cermets and different types of functionally graded cemented carbonitrides with desired microstructures and properties have been attempted to develop. The significant improvement of micro-hardness was observed with optimal concentration of TiCN reinforcement addition in WC-Co system without sacrificing much fracture toughness value of the composite cermets.

  11. Basic failure mechanisms in advanced composites. [composed of epoxy resins reinforced with carbon fibers

    Science.gov (United States)

    Mazzio, V. F.; Mehan, R. L.; Mullin, J. V.

    1973-01-01

    The fundamental failure mechanisms which result from the interaction of thermal cycling and mechanical loading of carbon-epoxy composites were studied. This work was confined to epoxy resin uniderictionally reinforced with HTS carbon fibers, and consists of first identifying local fiber, matrix and interface failure mechanisms using the model composite specimen containing a small number of fibers so that optical techniques can be used for characterization. After the local fracture process has been established for both mechanical loading and thermal cycling, engineering composite properties and gross fracture modes are then examined to determine how the local events contribute to real composite performance. Flexural strength in high fiber content specimens shows an increase in strength with increased thermal cycling. Similar behavior is noted for 25 v/o material up to 200 cycles; however, there is a drastic reduction after 200 cycles indicating a major loss of integrity probably through the accumulation of local cleavage cracks in the tensile region.

  12. The Use of Fibre Reinforced Composites (Frcs in Periodontal Splinting & the Natural Tooth Pontic (NTP in the Management of Advanced Periodontal Disease

    Directory of Open Access Journals (Sweden)

    Ian Kerr

    2013-12-01

    Full Text Available This article uses a series of case studies to examine the use of fibre reinforced composite splints in the management of advanced gum disease that has led to mobility and imminent exfoliation of teeth. The case studies show the various techniques for producing a durable aesthetic splint and how to use these principles in the production of a natural tooth pontic.

  13. Synthesis of cellulose nanofiber composites for mechanical reinforcement and other advanced applications

    Science.gov (United States)

    Xu, Xuezhu

    Cellulose nanofibers from bioresources have attracted intensive research interest in recent years due to their unique combination of properties including high strength and modulus, low density, biocompatibility/biodegradability and rich surface chemistry for functionalization. The nanofibers have been widely studied as nanoreinforcements in polymer nanocomposites; while the nanocomposite research is still very active, new research directions of using the nanofibers for hydrogels/aerogels, template for nanoparticle synthesis, scaffold, carbon materials, nanopaper, etc. have emerged. In this Ph.D. thesis, fundamental studies and application developments are performed on three types of cellulose nanofibers, i.e. cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs) and bacterial cellulose (BC). First CNCs and CNFs are systematically compared in terms of their effects on the mechanical properties, crystallization and failure behavior of the nanocomposites, which provides a guideline for the design of cellulose nanofiber reinforced composites. Second, CNFs and BC are used to develop core-shell carbon fibers and flexible carbon aerogels for energy storage applications. This part is focused on developing nanocarbon materials with multi-scale features. Lastly, hybrid CNC/CNF nanopaper with superior optical, mechanical, and electrical properties is developed and its application is demonstrated on a LED device.

  14. Synthesis of high performance ceramic fibers by chemical vapor deposition for advanced metallics reinforcing

    Science.gov (United States)

    Revankar, Vithal; Hlavacek, Vladimir

    1991-01-01

    The chemical vapor deposition (CVD) synthesis of fibers capable of effectively reinforcing intermetallic matrices at elevated temperatures which can be used for potential applications in high temperature composite materials is described. This process was used due to its advantage over other fiber synthesis processes. It is extremely important to produce these fibers with good reproducible and controlled growth rates. However, the complex interplay of mass and energy transfer, blended with the fluid dynamics makes this a formidable task. The design and development of CVD reactor assembly and system to synthesize TiB2, CrB, B4C, and TiC fibers was performed. Residual thermal analysis for estimating stresses arising form thermal expansion mismatch were determined. Various techniques to improve the mechanical properties were also performed. Various techniques for improving the fiber properties were elaborated. The crystal structure and its orientation for TiB2 fiber is discussed. An overall view of the CVD process to develop CrB2, TiB2, and other high performance ceramic fibers is presented.

  15. Two-surface plasticity Model and Its Application to Spring-back Simulation of Automotive Advanced High Strength Steel Sheets

    Science.gov (United States)

    Park, Taejoon; Seok, Dong-Yoon; Lee, Chul-Hwan; Noma, Nobuyasu; Kuwabara, Toshihiko; Stoughton, Thomas B.; Chung, Kwansoo

    2011-08-01

    A two-surface isotropic-kinematic hardening law was developed based on a two-surface plasticity model previously proposed by Lee et al., (2007, Int. J. Plast. 23, 1189-1212). In order to properly represent the Bauschinger and transient behaviors as well as permanent softening during reverse loading with various pre-strains, both the inner yield surface and the outer bounding surface expand (isotropic hardening) and translate (kinematic hardening) in this two-surface model. As for the permanent softening, both the isotropic hardening and the kinematic hardening evolution of the outer bounding surface were modified by introducing softening parameters. The numerical formulation was also developed based on the incremental plasticity theory and the developed constitutive law was implemented into the commercial finite element program, ABAQUS/Explicit and ABAQUS/Standard using the user-defined material subroutines. In this work, a dual phase (DP) steel was considered as an advanced high strength steel sheet and uni-axial tension tests and uni-axial tension-compression-tension tests were performed for the characterization of the material property. For a validation purpose, the developed two-surface plasticity model was applied to the 2-D draw bending test proposed as a benchmark problem of the NUMISHEET 2011 conference and successfully validated with experiments.

  16. New advanced electrochemical techniques for on site measurements of reinforcement corrosion

    Directory of Open Access Journals (Sweden)

    Andrade, C.

    2001-12-01

    Full Text Available Measurement techniques of reinforcement corrosion are scarcely researched if compared with the increasing number of publications in the subject. However, numerous possibilities and challenges remain without being explored. In present paper mention is made to some of the present possibilities of electrochemical techniques, either on-site or in the laboratory. Concerning on-site techniques it is commented the possibilities and limitations of present methods of measuring Polarization Resistance, Rp. Particular attention is given to the need to use a modulated guardring with sensors controlling this modulation to obtain accurate values of the corrosion rate. After, description of the basis of new techniques related to the measurements of the passivation state in cathodically protected structures, is made. The basis of a new method of measuring corrosion without the need to touch the metal is also presented. Regarding the use of embedded sensors, the experience until now shows the difficulty of interpretation of the data collected, due to the important influence of ambient temperature. Finally, some comments are presented on the need of joint work of material and structural specialists.

    Las técnicas de medida de la corrosión en hormigón armado se investigan muy poco en comparación con el creciente número de publicaciones sobre este tema. Sin embargo, existen muchas posibilidades y retos que todavía no han sido exploradas. En el presente artículo se descubren algunas de las presentes posibilidades de las técnicas electroquímicas, tanto in-situ como en laboratorio. En cuanto a las técnicas in situ se refiere, se comentan las posibilidades y limitaciones de los métodos actuales de medida de la Resistencia de Polarización, Rp. Se presta particular atención ante la necesidad de utilizar un anillo de guarda modulado con sensores que controlen esta modulación para obtener valores adecuados de velocidad de corrosión. Después se

  17. 火灾下钢筋混凝土构件的弹塑性本构模型%An Elasto-plastic Constitutive Model for Reinforced Concrete Members Exposed to Fire

    Institute of Scientific and Technical Information of China (English)

    苏娟; 王振清; 徐辉; 白丽丽

    2011-01-01

    Based on the elastic-plastic theory, it is considered that the material properties changed with temperature. The incremental constitutive equations of elastic-plastic structure of reinforced concrete members under high temperature are obtained with the J2 theory of flowing and a finite element program was developed. This proposed model possesses clear physics meaning and it is such a standard formulation that it is feasible for numerical application. It was found out that numerical results were in good agreement with the current ones for the material constitutive equations of elastic-plastic material. The developed program can be used for analysis on fire resistance of reinforced concrete structure under high temperature.%在弹塑性理论的基础上,考虑了材料性能随温度的变化,应用J2流动理论导出了高温下钢筋混凝土构件弹塑性增量本构模型,编制了该模型的有限元求解程序.该模型具有明确的物理意义,表达形式规范,便于数值手段实现.数值计算结果与现有的试验模型基本吻合.

  18. Overcoming maladaptive plasticity through plastic compensation

    Directory of Open Access Journals (Sweden)

    Matthew R.J. MORRIS, Sean M. ROGERS

    2013-08-01

    Full Text Available Most species evolve within fluctuating environments, and have developed adaptations to meet the challenges posed by environmental heterogeneity. One such adaptation is phenotypic plasticity, or the ability of a single genotype to produce multiple environmentally-induced phenotypes. Yet, not all plasticity is adaptive. Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution, much less is known about maladaptive plasticity. However, maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments. This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity, two of which involve genetic changes (standing genetic variation, genetic compensation and two of which do not (standing epigenetic variation, plastic compensation. Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity. In particular, plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence. We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change [Current Zoology 59 (4: 526–536, 2013].

  19. Overcoming maladaptive plasticity through plastic compensation

    Institute of Scientific and Technical Information of China (English)

    Matthew R.J.MORRIS; Sean M.ROGERS

    2013-01-01

    Most species evolve within fluctuating environments,and have developed adaptations to meet the challenges posed by environmental heterogeneity.One such adaptation is phenotypic plasticity,or the ability of a single genotype to produce multiple environmentally-induced phenotypes.Yet,not all plasticity is adaptive.Despite the renewed interest in adaptive phenotypic plasticity and its consequences for evolution,much less is known about maladaptive plasticity.However,maladaptive plasticity is likely an important driver of phenotypic similarity among populations living in different environments.This paper traces four strategies for overcoming maladaptive plasticity that result in phenotypic similarity,two of which involve genetic changes (standing genetic variation,genetic compensation) and two of which do not (standing epigenetic variation,plastic compensation).Plastic compensation is defined as adaptive plasticity overcoming maladaptive plasticity.In particular,plastic compensation may increase the likelihood of genetic compensation by facilitating population persistence.We provide key terms to disentangle these aspects of phenotypic plasticity and introduce examples to reinforce the potential importance of plastic compensation for understanding evolutionary change.

  20. Computational fluid dynamics analysis of a twisted airfoil shaped two-bladed H-Darrieus rotor made from fibreglass reinforced plastic (FRP

    Directory of Open Access Journals (Sweden)

    Rajat Gupta, Sukanta Roy, Agnimitra Biswas

    2010-11-01

    Full Text Available H-Darrieus rotor is a lift type device having two to three blades designed as airfoils. The blades are attached vertically to the central shaft through support arms. The support to vertical axis helps the rotor maintain its shape. In this paper, Computational Fluid Dynamics (CFD analysis of an airfoil shaped two-bladed H-Darrieus rotor using Fluent 6.2 software was performed. Based on the CFD results, a comparative study between experimental and computational works was carried out. The H-Darrieus rotor was 20cm in height, 5cm in chord and twisted with an angle of 30° at the trailing end. The blade material of rotor was Fiberglass Reinforced Plastic (FRP. The experiments were earlier conducted in a subsonic wind tunnel for various height-to-diameter (H/D ratios. A two dimensional computational modeling was done with the help of Gambit tool using unstructured grid. Realistic boundary conditions were provided for the model to have synchronization with the experimental conditions. Two dimensional steady-state segregated solver with absolute velocity formulation and cell based grid was considered, and a standard k-epsilon viscous model with standard wall functions was chosen. A first order upwind discretization scheme was adopted for pressure velocity coupling of the flow. The inlet velocities and rotor rotational speeds were taken from the experimental results. From the computational analysis, power coefficient (Cp and torque coefficient (Ct values at ten different H/D ratios namely 0.85, 1.0, 1.10, 1.33, 1.54, 1.72, 1.80, 1.92, 2.10 and 2.20 were calculated in order to predict the performances of the twisted H-rotor. The variations of Cp and Ct with tip speed ratios were analyzed and compared with the experimental results. The standard deviations of computational Cp and Ct from experimental Cp and Ct were obtained. From the computational analysis, the highest values of Cp and Ct were obtained at H/D ratios of 1.0 and 1.54 respectively. The

  1. The effect of acute swim stress and training in the water maze on hippocampal synaptic activity as well as plasticity in the dentate gyrus of freely moving rats: revisiting swim-induced LTP reinforcement.

    Science.gov (United States)

    Tabassum, Heena; Frey, Julietta U

    2013-12-01

    Hippocampal long-term potentiation (LTP) is a cellular model of learning and memory. An early form of LTP (E-LTP) can be reinforced into its late form (L-LTP) by various behavioral interactions within a specific time window ("behavioral LTP-reinforcement"). Depending on the type and procedure used, various studies have shown that stress differentially affects synaptic plasticity. Under low stress, such as novelty detection or mild foot shocks, E-LTP can be transformed into L-LTP in the rat dentate gyrus (DG). A reinforcing effect of a 2-min swim, however, has only been shown in (Korz and Frey (2003) J Neurosci 23:7281-7287; Korz and Frey (2005) J Neurosci 25:7393-7400; Ahmed et al. (2006) J Neurosci 26:3951-3958; Sajikumar et al., (2007) J Physiol 584.2:389-400) so far. We have reinvestigated these studies using the same as well as an improved recording technique which allowed the recording of field excitatory postsynaptic potentials (fEPSP) and the population spike amplitude (PSA) at their places of generation in freely moving rats. We show that acute swim stress led to a long-term depression (LTD) in baseline values of PSA and partially fEPSP. In contrast to earlier studies a LTP-reinforcement by swimming could never be reproduced. Our results indicate that 2-min swim stress influenced synaptic potentials as well as E-LTP negatively.

  2. Developments in Plasticity Approach to Shear

    DEFF Research Database (Denmark)

    Hoang, Cao Linh; Nielsen, Mogens Peter

    1999-01-01

    The paper deals with plastic methods applied to shear design of reinforced concrete beams. Emphasis is put on the recently developed crack sliding model applicable to non-shear reinforced and lightly shear reinforced beams and slabs. The model, which is an upper bound plasticity approach, takes...

  3. 整形外科新进展与发展设想%Recent advancements and prospects of plastic surgery

    Institute of Scientific and Technical Information of China (English)

    邢新

    2011-01-01

    目的 综述国内外整形外科研究现状和发展动态,提出未来我军整形外科的发展方向、目标和重点.方法 在PubMed、Medline和中文生物医学期刊文献数据库(CMCC)中检索近5年发表的相关文献并进行综述,同时对军队整形外科近5年来取得的成就进行统计调查.结果 近5年来,整形外科在基础研究和临床治疗方面都取得了可喜进展,在战创伤早期救治中的作用和地位也得到重视和认可;我军整形外科在慢性创面修复、皮肤软组织爆炸伤及海水浸泡伤的损伤机制和防治方法 、战创伤面部畸形救治新技术、同种异体面部复合组织移植等方面取得了令人瞩目的成就.结论未来我军整形外科的发展应以战创伤组织缺损和畸形的修复与重建作为主要研究方向,重点开展组织工程、同种异体复合组织移植、干细胞治疗、异常瘢痕形成机制等科研工作,以解决严重面部毁损伤、广泛性胸腹壁全层缺损、慢性溃疡以及异常瘢痕等临床治疗难题,同时应注重发挥专业特长,积极参与战创伤的早期救治.%Objective To summarize the recent advancements and developmentalprospects of plastic surgery worldwide, and to describe the future directions, aims, and highlights of Chinese military plastic surgery. Methods Relevant articles published in the last five years were retrieved through a search in PubMed, Medline, and CMCC. A statistical survey was conducted to summarize the achievements obtained by the Chinese military plastic surgery unit in the last five years. Results Considerable progress has been achieved in both clinical treatment and basic research of plastic surgery in the past five years. Its important role in the early treatment of combat injury and trauma has been recognized and emphasized Chinese military plastic surgery has achieved considerable accomplishments in the last five years, especially in chronic wound repair; mechanism

  4. 功能性玻璃钢在烟气排放控制工程中的应用%Application of Functional Glass Fiber Reinforced Plastics in Flue Gas Emission Control Engineering

    Institute of Scientific and Technical Information of China (English)

    贺朝铸; 赵丰; 吴斐; 许凯奇; 黄楠

    2014-01-01

    The paper presents the several common use equipment antisepsis programs in lfue gas emission control en-gineering of power plant;explicates the development on the compound material antisepsis program of functional glass ifber reinforced plastics and application prospect in the antisepsis ifeld of wet lfue gas.%介绍了火电厂烟气排放控制工程中几种常用的设备防腐方案,阐述了功能性玻璃钢复合材料防腐方案的发展和在湿烟气防腐领域的应用前景。

  5. Recent advances in ecological genomics: from phenotypic plasticity to convergent and adaptive evolution and speciation.

    Science.gov (United States)

    Landry, Christian R; Aubin-Horth, Nadia

    2014-01-01

    Biological diversity emerges from the interaction between genomes and their environment. Recent conceptual and technological developments allow dissecting these interactions over short and long time-scales. The 16 contributions to this book by leaders in the field cover major recent progresses in the field of Ecological Genomics. Altogether, they illustrate the interplay between the life-history and genomic architecture of organisms, how the interaction of the environment and the genome is shaping phenotypic variation through phenotypic plasticity, how the process of adaptation may be constrained and fueled by internal and external features of organisms and finally, how species formation is the result of intricate interactions between genomes and the ecological conditions. These contributions also show how fundamental questions in biology transcend the boundaries of kingdoms, species and environments and illustrate how integrative approaches are powerful means to answer the most important and challenging questions in ecology and evolution.

  6. Comparison of biocompatibility and adsorption properties of different plastics for advanced microfluidic cell and tissue culture models.

    Science.gov (United States)

    van Midwoud, Paul M; Janse, Arnout; Merema, Marjolijn T; Groothuis, Geny M M; Verpoorte, Elisabeth

    2012-05-01

    Microfluidic technology is providing new routes toward advanced cell and tissue culture models to better understand human biology and disease. Many advanced devices have been made from poly(dimethylsiloxane) (PDMS) to enable experiments, for example, to study drug metabolism by use of precision-cut liver slices, that are not possible with conventional systems. However, PDMS, a silicone rubber material, is very hydrophobic and tends to exhibit significant adsorption and absorption of hydrophobic drugs and their metabolites. Although glass could be used as an alternative, thermoplastics are better from a cost and fabrication perspective. Thermoplastic polymers (plastics) allow easy surface treatment and are generally transparent and biocompatible. This study focuses on the fabrication of biocompatible microfluidic devices with low adsorption properties from the thermoplastics poly(methyl methacrylate) (PMMA), polystyrene (PS), polycarbonate (PC), and cyclic olefin copolymer (COC) as alternatives for PDMS devices. Thermoplastic surfaces were oxidized using UV-generated ozone or oxygen plasma to reduce adsorption of hydrophobic compounds. Surface hydrophilicity was assessed over 4 weeks by measuring the contact angle of water on the surface. The adsorption of 7-ethoxycoumarin, testosterone, and their metabolites was also determined after UV-ozone treatment. Biocompatibility was assessed by culturing human hepatoma (HepG2) cells on treated surfaces. Comparison of the adsorption properties and biocompatibility of devices in different plastics revealed that only UV-ozone-treated PC and COC devices satisfied both criteria. This paper lays an important foundation that will help researchers make informed decisions with respect to the materials they select for microfluidic cell-based culture experiments.

  7. Fiber-reinforced ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Belcheva, D. [Technological University `Prof. A. Zlatarov`, Bourgas (Bulgaria); Lubchev, L.; Jelezkov, G.; Georgiev, W.

    1995-03-01

    The possibilities for preparation of reinforced composite materials were studied. Test specimens based on different types of alumina matrices, plasticized with formaldehyde oligomer and polyvinyl alcohol, and reinforced with carbon and mullite fibers were prepared and investigated. The results confirmed that reinforced composite materials with valuable properties such as high thermal shock resistance, chemical resistance and mechanical strength can be produced. The density of technical alumina materials is lower, compared with that of pure alumina. The density can also be influenced by the type and quantity of the plasticizers used. By increasing the fiber content, the density of the material decreases. The shrinkage is influcenced by the type and the quantity of the reinforcing material. (orig.)

  8. Characteristics of bone tunnel changes after anterior cruciate ligament reconstruction using Ligament Advanced Reinforcement System artificial ligament

    Institute of Scientific and Technical Information of China (English)

    HUANG Jian-ming; LIU Hao-yuan; CHEN Feng-rong; JIAN Guo-jian; CHEN Qi; WANG Zi-min; KANG Yi-fan

    2012-01-01

    Background There are different materials used for anterior cruciate ligament(ACL)reconstruction.It has been reported that both autologous grafts and allografts used in ACL reconstruction can cause bone tunnel enlargement.This study aimed to observe the characteristics of bone tunnel changes and possible causative factors following ACL reconstruction using Ligament Advanced Reinforcement System(LARS)artificial ligament.Methods Forty-three patients underwent ACL reconstruction using LARS artificial ligament and were followed up for 3 years.X-ray and CT examinations were performed at 1,3,6,12,24,and 36 months after surgery,to measure the width of tibial and femoral tunnels.Knee function was evaluated according to the Lysholm scoring system.The anterior and posterior stability of the knee was measured using the KT-1000 arthrometer.Results According to the Peyrache grading method,grade 1 femoral bone tunnel enlargement was observed in three cases six months after surgery.No grade 2 or grade 3 bone tunnel enlargement was found.The bone tunnel enlargement in the three cases was close to the articular surface with an average tunnel enlargement of(2.5±0.3)mm.Forty cases were evaluated as grade 0.The average tibial and femoral tunnel enlargements at the last follow-up were(0.8±0.3)and(1.1±0.3)mm,respectively.There was no statistically significant difference in bone tunnel width changes at different time points(P>0.05).X-ray and CT measurements were consistent.Conclusions There was no marked bone tunnel enlargement immediately following ACL reconstruction using LARS artificial ligament.Such enlargement may,however,result from varying grafting factors involving the LARS artificial ligament or from different fixation methods.

  9. Testing of molded high temperature plastic actuator road seals for use in advanced aircraft hydraulic systems

    Science.gov (United States)

    Waterman, A. W.; Huxford, R. L.; Nelson, W. G.

    1976-01-01

    Molded high temperature plastic first and second stage rod seal elements were evaluated in seal assemblies to determine performance characteristics. These characteristics were compared with the performance of machined seal elements. The 6.35 cm second stage Chevron seal assembly was tested using molded Chevrons fabricated from five molding materials. Impulse screening tests conducted over a range of 311 K to 478 K revealed thermal setting deficiencies in the aromatic polyimide molding materials. Seal elements fabricated from aromatic copolyester materials structurally failed during impulse cycle calibration. Endurance testing of 3.85 million cycles at 450 K using MIL-H-83283 fluid showed poorer seal performance with the unfilled aromatic polyimide material than had been attained with seals machined from Vespel SP-21 material. The 6.35 cm first stage step-cut compression loaded seal ring fabricated from copolyester injection molding material failed structurally during impulse cycle calibration. Molding of complex shape rod seals was shown to be a potentially controllable technique, but additional molding material property testing is recommended.

  10. Filling a Plastic Bag with Carbon Dioxide: A Student-Designed Guided-Inquiry Lab for Advanced Placement and College Chemistry Courses

    Science.gov (United States)

    Lanni, Laura M.

    2014-01-01

    A guided-inquiry lab, suitable for first-year general chemistry or high school advanced placement chemistry, is presented that uses only inexpensive, store-bought materials. The reaction of sodium bicarbonate (baking soda) with aqueous acetic acid (vinegar), under the constraint of the challenge to completely fill a sealable plastic bag with the…

  11. Filling a Plastic Bag with Carbon Dioxide: A Student-Designed Guided-Inquiry Lab for Advanced Placement and College Chemistry Courses

    Science.gov (United States)

    Lanni, Laura M.

    2014-01-01

    A guided-inquiry lab, suitable for first-year general chemistry or high school advanced placement chemistry, is presented that uses only inexpensive, store-bought materials. The reaction of sodium bicarbonate (baking soda) with aqueous acetic acid (vinegar), under the constraint of the challenge to completely fill a sealable plastic bag with the…

  12. Calculation of a Tunnel Cross Section Subjected to Fire – with a New Advanced Transient Concrete Model for Reinforced Structures

    Directory of Open Access Journals (Sweden)

    U. Schneider

    2009-01-01

    Full Text Available The paper presents the structural application of a new thermal induced strain model for concrete – the TIS-Model. An advanced transient concrete model (ATCM is applied with the material model of the TIS-Model. The non-linear model comprises thermal strain, elastic strain, plastic strain and transient temperature strains, and load history modelling of restraint concrete structures subjected to fire.The calculations by finite element analysis (FEA were done using the SAFIR structural code. The FEA software was basically new with respect to the material modelling derived to use the new TIS-Model (as a transient model considers thermal induced strain. The equations of the ATCM consider a lot of capabilities, especially for considering irreversible effects of temperature on some material properties. By considering the load history during heating up, increasing load bearing capacity may be obtained due to higher stiffness of the concrete. With this model, it is possible to apply the thermal-physical behaviour of material laws for calculation of structures under extreme temperature conditions.A tunnel cross section designed and built by the cut and cover method is calculated with a tunnel fire curve. The results are compared with the results of a calculation with the model of the Eurocode 2 (EC2-Model. The effect of load history in highly loaded structures under fire load will be investigated.A comparison of this model with the ordinary calculation system of Eurocode 2 (EC2 shows that a better evaluation of the safety level was achieved with the new model. This opens a space for optimizing concrete structure design with transient temperature conditions up to 1000 °C. 

  13. Advanced 3D textile composites reinforcements meso F.E analyses based on X-ray computed tomography

    Science.gov (United States)

    Naouar, Naim; Vidal-Salle, Emmanuelle; Boisse, Philippe

    2016-10-01

    Meso-FE modelling of 3D textile composites is a powerful tool, which can help determine mechanical properties and permeability of the reinforcements or composites. The quality of the meso FE analyses depends on the quality of the initial model. A direct method based on X-ray tomography imaging is introduced to determine finite element models based on the real geometry of 3D composite reinforcements. The method is particularly suitable regarding 3D textile reinforcements for which internal geometries are numerous and complex. The approach used for the separation of the yarns in different directions is specialized because the fibres flow in three-dimensional space. An analysis of the image's texture is performed. A hyperelastic model developed for fibre bundles is used for the simulation of the deformation of the 3D reinforcement.

  14. 有机磷阻燃剂对阻燃玻璃钢性能的影响%EFFECTS OF ORGANOPHOSPHORUS RETARDANT ON PERFORMANCES OF FLAME RETARDANT FIBER REINFORCED PLASTICS

    Institute of Scientific and Technical Information of China (English)

    王志涛; 丁辛; 罗永康; 奚国防

    2012-01-01

    在阻燃型玻璃钢复合材料结构件的制作中,反应型阻燃不饱和聚酯树脂由于粘度太大,不适合真空辅助树脂传递模塑工艺(VARTM).采用添加液体有机磷阻燃剂甲基磷酸二甲酯(DMMP)的方法,降低树脂粘度以满足VARTM工艺性能要求,并进一步提高其阻燃性.结果表明,当DMMP添加量为12%时,树脂粘度降低50.3%,适合VARTM工艺;其浇铸体氧指数可达31.6%,制得的玻璃钢试样氧指数达37.0%,垂直燃烧分级达到Ⅴ-0级,玻璃钢复合材料力学性能无明显降低.%During the process of making structure components of flame retardant fiberglass reinforced plastic composite materials, the viscosity of unsaturated polyester resin with reactive flame retardant groups is too large to be used in Vacuum-Assisted Resin Transfer Molding (VARTM) process. In this paper, a large amount of tests were conducted by the way of adding flame retardant of dimethyl methyl phosphate ( DMMP) so as to make the resin fit for VARTM processing properties requirements as well as increase its flame retardant properties to a higher level. The results showed that, when the content of DMMP was 12% , the resin could be provided with lower viscosity with a reduction of 50. 3% , making it possible for the resin to be used in vacuum import process. When the content of DMMP reached 12% , LOI of the casting body reached 31.6, with LOI of glass fiber reinforced plastic of 37. 0% , the vertical burning classification of which reached V-0 level without significant drop on mechanical properties of fiberglass reinforced plastics.

  15. 46 CFR 160.035-8 - Construction of fibrous glass reinforced plastic (F.R.P.), oar-, hand-, and motor-propelled...

    Science.gov (United States)

    2010-10-01

    ...) Plastic lifeboats shall comply with the general requirements for the construction and arrangement of steel... finish, and there shall be no protruding surface fibers, open voids, pits, cracks, bubbles or blisters... tackiness, and shall show no tendency to delaminate, peel, or craze in any overlay. The laminate shall...

  16. Oxygen consumption, oxygen cost and physiological cost index in polio survivors: a comparison of walking without orthosis, with an ordinary or a carbon-fibre reinforced plastic knee-ankle-foot orthosis.

    Science.gov (United States)

    Hachisuka, Kenji; Makino, Kenichiro; Wada, Futoshi; Saeki, Satoru; Yoshimoto, Nami

    2007-10-01

    To examine, for polio survivors, whether walking with a carbon-fibre reinforced plastic knee-ankle-foot orthosis (carbon KAFO) is more efficient than walking with an ordinary KAFO or without an orthosis. Consecutive sample. Post-polio clinic, University Hospital of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan. Eleven polio survivors who had a carbon KAFO prescribed at the post-polio clinic. A carbon KAFO was prescribed, fabricated and inspected. Oxygen consumption, oxygen cost and physiological cost index. An ordinary KAFO weighed 1403 g (standard deviation(SD) 157 g), whereas a carbon KAFO weighed 992 g (SD 168 g). Subjects walking with a carbon KAFO showed a tendency to increase step length, and to increase speed significantly compared with walking without an orthosis and with an ordinary KAFO (paired t-test, p KAFO (-9%, -14%, -15%; paired t-test, p KAFO was objectively better than those without an orthosis or with an ordinary KAFO.

  17. HEPHAISTOS - energy efficiency and innovation by microwave technology for the industrial production of polymers and reinforced plastics; HEPHAISTOS - Energieeffizienz und Innovation durch Mikrowellentechnik fuer die industrielle Produktion von polymeren Verbundwerkstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Feher, L.; Stanculovic, S.; Akhtar, J.; Nuss, V.; Seitz, T.; Zoeller, C.; Layer, S.; Dittrich, J. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Hochleistungsimpuls- und Mikrowellentechnik

    2007-07-01

    High mobility and resources consumption today characterize a global, export-oriented economy. Increasing scarcity of resources and energy, however, will influence the cost structure of products, services, locations, and mobility. Provident, innovative developments give rise to new, resources-efficient production processes, systems, and materials. For some years now, innovative approaches have been pursued by to opening up energy-efficient applications with microwaves by technology transfer to industry. By this work, an innovative modular microwave system line HEPHAISTOS with very homogeneous field distributions has been developed. Several industrial installations have been realized and taken into service at the new HEPHAISTOS-Experimental Centre (HEC) to develop highly efficient sophisticated processes actually targeted at avionic CFRP (Carbon Fibre Reinforced Plastics) structures. (orig.)

  18. Nanoscaled boehmites' modes of action in a polymer and its carbon fiber reinforced plastic under compression load; Wirkungsweisen nanoskaliger Boehmite in einem Polymer und seinem Kohlenstofffaserverbund unter Druckbelastung

    Energy Technology Data Exchange (ETDEWEB)

    Arlt, Christine

    2011-07-01

    Increasing ecological awareness as well as quality and safety demands, which are present, for instance, in the aerospace and automotive sectors, lead to the need to use more sophisticated and more effective materials. For that purpose, laminates of carbon fiber reinforced plastic (CFRP), which are manufactured by injection technology, are reinforced with boehmite particles. This doping strengthens the laminates, whose original properties are weaker than prepregs. Besides the shear strength, compression strength and the damage tolerance, the mode of action of the nanoparticles in resin and in CRFP is also analyzed. It thereby reveals that the hydroxyl groups and even more a taurine modification of the boehmites' surface after the elementary polymer morphology. Consequently a new flow and reaction comportment, lower glass transition temperatures and shrinkage, as well as a changed mechanical behavior occur. Due to a structural upgrading of the matrix (higher shear stiffness, reduced residual stress), a better fiber-matrix adhesion, and differing crack paths, the boehmite nanoparticles move the degradation barrier of the material to higher loadings, thus resulting in considerably upgraded new CFRP. (orig.)

  19. 高炉喷吹废塑料的先进技术%Establishment of Advanced Recycling Technology for Waste Plastics in Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    王颖

    2012-01-01

    废塑料循环利用技术对于全球环境保护和社会发展都是一个非常重要的课题。JFE制钢公司为了将废塑料作为高炉的还原剂,通过热模燃烧实验;研究了废塑料的燃烧气化率。经过研究,为了改善粗粒废塑料的燃烧性,开发了同时喷吹煤粉或/和天然气的技术,为了提高废塑料的燃烧和气化率及炉内透气性,JFE开发出将废塑料与碳酸钙(CaC03)复合造粒技术。另外,JFE还研究了废塑料精细粉碎技术。此技术已经应用在实际生产中。%The establishment of technology for recycling waste plastics is a highly important issue for global environmental conservation and the society. JFE Steel has pursued the effective use of waste plastics as a reducing agent for injection into blast furnaces, and conducted hot model experiments to study the combustion and gasification behaviour of waste plastics. On the basis of this basic investigation, advanced technologies that can further improve the combustion and gasification efficiency of waste plastics even with low strength has been developed; i.e. in order to improve combustibility of fine waste plastics, technology for simultaneous injection of such plastics with pulverized coal and/or natural gas has been developed. For improved the strength of plastics, technology for combined agglomeration of waste plastics with CaC03 has been developed. In addition, technology for fine crushing of waste plastics has been studied on the basis of new ideas, and this technology has been applied in actual plant operation. These technologies have been successfully applied in actual blast furnaces, contributing to lowering the reducing agent rate.

  20. Carbon fibre reinforced plastic knee-ankle-foot orthosis with a partially flexible thigh cuff: a modification for comfort while sitting on a toilet seat.

    Science.gov (United States)

    Hachisuka, K; Arai, K; Arai, M

    2007-06-01

    At the request of a polio survivor, a partially flexible thigh cuff made of leather and canvas for a carbon KAFO was devised to allow the wearer to feel more comfortable while sitting on a toilet seat. The original, acrylic resin, thigh cuff was partially excised to make an opening (15x10 cm), which was stuffed with rubber sponge, and was sealed with leather and canvas. The opening's surround was vertically and horizontally reinforced with carbon fibres. This modification provided relief to the polio survivor from the discomfort previously experienced while sitting on a toilet seat, and satisfied her needs in daily life.

  1. 'Process-structure characteristic' - correlation of cast fibre-reinforced plastics; ''Prozess-Gefuege-Eigenschaft'' - Korrelation gegossener Faserverbundwerkstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Mathes, M. [ACCESS e.V. Materialwissenschaften, Aachen (Germany); Hofmann, S.; Neussl, E. [Technische Hochschule Aachen (Germany). Lehrstuhl fuer das Gesamte Giessereiwesen und Giesserei-Institut

    1999-07-01

    Metal matrix composites are not sufficiently reliable for full-scale industrial application. The reasons for their widely divergent mechanical characteristics - especially strength - are not sufficiently known. The distribution of the ceramic fibres in the metal matrix is highly important for the desired reinforcing effect. The authors interpreted microscopic polished sections of test pieces produced by different methods and attempted to define parameters describing the distribution of fibres in the matrix. Their macroscopic analyses focused on the position and shape of the reinforced areas and their microscopic analyses on the relative positions of the individual fibres. It is shown that this type of analysis provides reliable information on the material characteristics. [German] Technisches Hindernis fuer eine industrielle Nutzung der Metall-Matrix-Verbundwerkstoffe ist bisher die noch nicht ausreichende Zuverlaessigkeit. Ursachen fuer die extrem hohe Streuung gemessener mechanischer Kennwerte, insbesondere der Festigkeiten, koennen nach dem derzeitigen Kenntnisstand nur unzureichend geklaert werden. Die Verteilung der keramischen Fasern in der metallischen Grundmatrix hat im Hinblick auf den angestrebten Verstaerkungseffekt eine signifikante Bedeutung. Aus mikroskopischen Schliffbildern von unter verschiedenen Bedingungen hergestellten Proben werden verschiedene, die Verteilung der Fasern in der Matrix beschreibende Parameter ermittelt. Makroskopisch wird Lage und Auspraegung der verstaerkten Bereiche und mikroskopisch die genaue Lage der Einzelfasern zueinander analysiert. Bereits anhand weniger und unterschiedlich prozessierter Proben laesst sich eindeutig erkennen, dass sich die tatsaechlichen Werkstoffeigenschaften mit Hilfe schneller bildanalytischer Methoden wesentlich genauer vorhersagen lassen. (orig./AKF)

  2. Surface modification of nano-silica on the ligament advanced reinforcement system for accelerated bone formation: primary human osteoblasts testing in vitro and animal testing in vivo.

    Science.gov (United States)

    Li, Mengmeng; Wang, Shiwen; Jiang, Jia; Sun, Jiashu; Li, Yuzhuo; Huang, Deyong; Long, Yun-Ze; Zheng, Wenfu; Chen, Shiyi; Jiang, Xingyu

    2015-05-07

    The Ligament Advanced Reinforcement System (LARS) has been considered as a promising graft for ligament reconstruction. To improve its biocompatibility and effectiveness on new bone formation, we modified the surface of a polyethylene terephthalate (PET) ligament with nanoscale silica using atom transfer radical polymerization (ATRP) and silica polymerization. The modified ligament is tested by both in vitro and in vivo experiments. Human osteoblast testing in vitro exhibits an ∼21% higher value in cell viability for silica-modified grafts compared with original grafts. Animal testing in vivo shows that there is new formed bone in the case of a nanoscale silica-coated ligament. These results demonstrate that our approach for nanoscale silica surface modification on LARS could be potentially applied for ligament reconstruction.

  3. Advanced X-Ray Inspection of Reinforced Carbon Composite Materials on the Orbiter Leading Edge Structural Subsystem (LESS)

    Science.gov (United States)

    Hernandez, Jose M.; Berry, Robert F.; Osborn, Robin; Bueno, Clifford; Osterlitz, Mark; Mills, Richard; Morris, Philip; Phalen, Robert; McNab, Jim; Thibodeaux, Tahanie; Thompson, Kyle

    2004-01-01

    The post return-to-flight (RTF) inspection methodology for the Orbiter Leading Edge Structural Subsystem (LESS) is currently being defined. Numerous NDT modalities and techniques are being explored to perform the flight-to-flight inspections of the reinforced carbon/carbon (RCC) composite material for impact damage, general loss of mass in the bulk layers, or other anomalous conditions that would pose risk to safe return upon re-entry. It is possible to have an impact upon ascent that is not visually observable on the surface, yet causes internal damage. Radiographic testing may be a useful NDT technique for such occurrences. The authors have performed radiographic tests on full-sized mock samples of LESS hardware with embedded image quality phantoms. Digitized radiographic film, computed radiography and flat panel digital real-time radiography was acquired using a GE Eresco 200 x-ray tube, and Se-75 and Yb-169 radioisotopes.

  4. Finite difference analysis of an advance core pre-reinforcement system for Toulon’s south tube

    Institute of Scientific and Technical Information of China (English)

    Fethi Kitchah; Sadok Benmebarek

    2016-01-01

    The stability of shallow tunnels excavated in full face has been a major challenge to the scientific community for a long time. In recent years, new techniques based on the installation of a pre-reinforcement system ahead of the tunnel face were developed to control the deformations and sur-face settlements induced by the excavation and to ensure the sustainability of the tunnel in the long term. In this paper, a finite difference numerical simulation was conducted to study the behaviors and effects of two pre-reinforcement systems, i.e. the face bolting and the umbrella arch system installed in a section of southern Toulon tunnel in France. For this purpose, two approaches were taken and compared:a two-dimensional (2D) approach based on the convergence-confinement method, and a three-dimensional (3D) approach taking into account the complete modeling of the tunnel. A 2D numerical back-analysis was performed to identify the geomechanical parameters that offer satis-factory agreement with the measurement results. The limit of this method lies in the exact choice of the stress relaxation ratioλ. To overcome this uncertainty, a 3D model was developed, which permitted to study the influence of different pre-support systems on the reaction of ground mass. Both 2D and 3D numerical approaches have been fitted to measurements recorded in a section of the Toulon tunnel and the very satisfactory correspondence has allowed validating the simulations. The results show that the 3D numerical analysis with a full discretization of the inclusions seems unquestionably the most reliable approach.

  5. Topology optimization of reinforced concrete structures

    DEFF Research Database (Denmark)

    Amir, Oded

    Recent advances regarding topology optimization procedures of reinforced concrete structures are presented. We discuss several approaches to the challenging problem of optimizing the distribution of concrete and steel reinforcement. In particular, the consideration of complex nonlinear constitutive...

  6. 预制夹芯保温墙体FRP连接件应用进展%STATE-OF-THE-ART OF FIBER REINFORCED PLASTIC CONNECTORS IN PRECAST CONCRETE SANDWICH WALL PANELS

    Institute of Scientific and Technical Information of China (English)

    杨佳林; 薛伟辰

    2012-01-01

    Precast concrete sandwich wall panel is a new type of insulation wall which performs well both in structural bearing and thermal insulation. It is consisted of internal and external concrete wall-board, insulating layers and connectors, etc. According to different material, connector can be divided into three categories: common reinforced connector, alloy metal connector and fiber reinforced plastic ( FRP) connector. FRP connector has the property of low thermal conductivity, good durability and high strength. Which can decrease the heat transfer coefficient of sandwich wall panel, and has bright foreground in engineering applications. This paper introduces classification,research and application, standards and specifications of FRP connector, and offers the prospect for research trend of FRP connector in future.%预制混凝土夹芯保温墙体是集承载与保温一体化的新型预制保温墙体,该墙体由内外层混凝土墙板、中间保温层及连接件等组成.按照材料的不同,连接件主要分为普通钢筋连接件、金属合金连接件和纤维塑料(FRP)连接件三种.FRP连接件具有导热系数低、耐久性好、强度高的特点,可有效降低墙体的传热系数,具有广阔的工程应用前景.本文介绍了预制混凝土夹芯保温墙体FRP连接件分类、国内外研究与应用进展和技术规范情况,并对今后FRP连接件研究工作进行了展望.

  7. 木塑复合材料用增容剂研究进展%Advance in Research of Compatibilizer for Wood-Plastic Composite

    Institute of Scientific and Technical Information of China (English)

    刘昊; 许宏武; 刘宛宜; 沈力; 张美秀; 王野

    2015-01-01

    The advance in research of compatibilizer for wood-plastic composite was illustrated,which included the applications of copolymer compatibilizer,coupling compatibilizer and compound compatibilizer. The research prospect of the compatibilizer was expected.%介绍木塑复合材料用增容剂的研究进展,包括共聚型增容剂、偶联剂型增容剂、复合型增容剂的应用情况,并对木塑复合材料增容剂的研究前景进行了展望.

  8. Plastic Surgery

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Plastic Surgery KidsHealth > For Teens > Plastic Surgery Print A A ... forehead lightened with a laser? What Is Plastic Surgery? Just because the name includes the word "plastic" ...

  9. Plasticity Approach to Shear Design

    DEFF Research Database (Denmark)

    Hoang, Cao Linh; Nielsen, Mogens Peter

    1998-01-01

    The paper presents some plastic models for shear design of reinforced concrete beams. Distinction is made between two shear failure modes, namely web crushing and crack sliding. The first mentioned mode is met in beams with large shear reinforcement degrees. The mode of crack sliding is met in no...... in uncracked concrete. Good agree between theory and tests has been found.Keywords: dsign, plasticity, reinforced concrete, reinforcement, shear, web crushing.......The paper presents some plastic models for shear design of reinforced concrete beams. Distinction is made between two shear failure modes, namely web crushing and crack sliding. The first mentioned mode is met in beams with large shear reinforcement degrees. The mode of crack sliding is met in non......-shear reinforced beams as well as in lightly shear reinforced beams. For such beams the shear strength is determined by the recently developed crack sliding model. This model is based upon the hypothesis that cracks can be transformed into yield lines, which have lower sliding resistance than yield lines formed...

  10. Th1/Th17 plasticity is a marker of advanced β cell autoimmunity and impaired glucose tolerance in humans

    NARCIS (Netherlands)

    Reinert-Hartwall, Linnea; Honkanen, Jarno; Salo, Harri M; Nieminen, Janne K; Luopajärvi, Kristiina; Härkönen, Taina; Veijola, Riitta; Simell, Olli; Ilonen, Jorma; Peet, Aleksandr; Tillmann, Vallo; Knip, Mikael; Vaarala, Outi; Harmsen, Hermanus

    2015-01-01

    Upregulation of IL-17 immunity and detrimental effects of IL-17 on human islets have been implicated in human type 1 diabetes. In animal models, the plasticity of Th1/Th17 cells contributes to the development of autoimmune diabetes. In this study, we demonstrate that the upregulation of the IL-17 pa

  11. Silica reinforced triblock copolymer gels

    DEFF Research Database (Denmark)

    Theunissen, E.; Overbergh, N.; Reynaers, H.

    2004-01-01

    The effect of silica and polymer coated silica particles as reinforcing agents on the structural and mechanical properties of polystyrene-poly(ethylene/butylene)-polystyrene (PS-PEB-PS) triblock gel has been investigated. Different types of chemically modified silica have been compared in order...... a viscoclastic rubber to a plastic fluid and from a plastic fluid to a viscoelastic liquid are shifted to more elevated temperatures when silica is added to the triblock copolymer gel. (C) 2004 Elsevier Ltd. All rights reserved....

  12. 2010年我国工程塑料应用进展%ADVANCE IN THE ENGINEERING PLASTICS APPLICATION OF CHINA IN 2010

    Institute of Scientific and Technical Information of China (English)

    闫烨; 杨超

    2011-01-01

    根据2010年国内公开发表的文献,综述了我国工程塑料及改性塑料在机车车辆、电子电器、环保抗菌、机械设备、建材、军事及航天装备、薄膜、医疗用品等领域的应用情况及研究进展,并介绍了以上领域内塑料新产品的开发、性能评价和使用效果.指出2010年我国工程塑料新产品的开发应用重点是机车车辆、电子电器、薄膜等领域.%According to the public articles at home in 2010, the application of the engineering plastics and modified plastics in the fields of vehicles, electrics and electronics, environmental protection and antibiosis, mechanical equipment, building materials,military and space flight equipment, films, medical supplies, etc. and the research advance were presented. The development, performance evaluation and use effect of the new products of plastics in the above-mentioned rields were also summarized. It was pointed out that the key research and application fields in 2010 were vehicles, electrics and electronics, film, etc.

  13. Structural Engineering Properties of Fibre Reinforced Concrete Based On Recycled Glass Fibre Polymer (GFRP)

    OpenAIRE

    Adetiloye A; Ephraim M. E

    2015-01-01

    Glass fibre reinforced plastics (GFRP) based on resin recovered from recycling plastic waste has been shown to possess mechanical properties satisfying normative requirements. This paper investigates the flexural behavior of concrete beams reinforced with GFRP produced from resin recovered from recycled plastic wastes. A total of twelve of beams of sizes 150 ×150 ×900mm and 100 × 100 × 500mm reinforced with GFRP made from recycled glass fibre reinforced polymer was tested. The fle...

  14. The Thickness Design Calculation should be Paid Attention to during the Manufacture of Glass Fiber Reinforced Plastic Tank%玻璃钢储罐生产应重视厚度的设计计算

    Institute of Scientific and Technical Information of China (English)

    谢春良; 骆立刚

    2014-01-01

    Although the quantity of glass fiber reinforced plastic ( FRP) tank increases every year, the quality has not been improved simultaneously, the reasons mostly being insufficient wall thickness and low quality of internal and external surfaces arising from the negligence to relevant quality standards and the insufficient attention to tank thickness design calculation of manufacturing enterprises. Emphasizes the importance of the thickness design calculation of FRP tank and discusses the calculation method, which aims to help improve the quality of FRP tanks and therefore avoid potential accidents due to inferior tank quality.%我国玻璃钢储罐用量逐年增加,但其产品质量并没有同步提升。存在的主要问题是储罐壁厚不足和内外表面质量不符合要求等。原因在于设备制造企业对相关标准的忽视和对玻璃钢储罐厚度设计计算的不重视。强调了玻璃钢储罐厚度设计计算的重要性,并论述了其设计计算方法,以期对提高玻璃钢储罐产品质量及消除事故隐患有所帮助。

  15. Plastics recycling: challenges and opportunities

    National Research Council Canada - National Science Library

    Jefferson Hopewell; Robert Dvorak; Edward Kosior

    2009-01-01

    .... Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public...

  16. 复合材料力矩管扭转性能的研究%A Study on the Torsional Properties of Glass Fibre Reinforced Plastic Tubes

    Institute of Scientific and Technical Information of China (English)

    吴非; 王翔; 蔡浩鹏; 朱泉尧

    2011-01-01

    Glass fiber reinforced epoxy resin tubes were made by wet filament winding process with different winding angles in this paper and the influence of torsion properties of composite with different winding angles were also discussed in order to practical application. The factors which effect the torsion performance of tubes were analyzed by testing the buckling torque and compared with theoretical value in this paper. As shown in the research, the failure model of winding tube was in-plane shear buckling,with the increase of winding angles between 25°to 60°, the shear behavior of composite tube was gradually weakened, and the thickness was decreased accompanied with delamination after buckling. The torsion performance was best when the winding angles achieved to 25°, the maximum torque reached 118 N·m,and the corresponding shear strength was also up to 209 MPa.%为了研究缠绕角度对玻璃纤维增强复合材料管(GFRP)扭转性能的影响和给在实际应用中提供依据,本文研究采用湿法缠绕成型工艺制得了具有不同缠绕角度的GFRP管.通过测试缠绕管的破坏扭矩来分析影响复合材料缠绕管扭转性能的各项因素,并与理论计算值进行了比较.研究结果表明,缠绕管扭转破坏的主要形式为面内剪切破坏.当缠绕角度在25°至60°范围内变化时,随着缠绕角度的增大,复合材料缠绕管的壁厚逐渐减小,抗剪性能逐渐减弱且扭转破坏形式有分层情况出现.当缠绕角是25°时,缠绕管的抗扭性能最佳,最大扭矩为118N·m,对应的扭转强度为209 MPa.

  17. Recent advances in high performance poly(lactide): From ``green'' plasticization to super-tough materials via (reactive) compounding

    Science.gov (United States)

    Kfoury, Georgio; Raquez, Jean-Marie; Hassouna, Fatima; Odent, Jérémy; Toniazzo, Valérie; Ruch, David; Dubois, Philippe

    2013-12-01

    Due to its origin from renewable resources, its biodegradability, and recently, its industrial implementation at low costs, poly(lactide) (PLA) is considered as one of the most promising ecological, bio-sourced and biodegradable plastic materials to potentially and increasingly replace traditional petroleum derived polymers in many commodity and engineering applications. Beside its relatively high rigidity (high tensile strength and modulus compared with many common thermoplastics such as poly(ethylene terephthalate) (PET), high impact poly(styrene) (HIPS) and poly(propylene) (PP)), PLA suffers from an inherent brittleness, which can limit its applications especially where mechanical toughness such as plastic deformation at high impact rates or elongation is required. Therefore, the curve plotting stiffness vs. impact resistance and ductility must be shifted to higher values for PLA-based materials, while being preferably fully bio-based and biodegradable upon the application. This review aims to establish a state of the art focused on the recent progresses and preferably economically viable strategies developed in the literature for significantly improve the mechanical performances of PLA. A particular attention is given to plasticization as well as to impact resistance modification of PLA in the case of (reactive) blending PLA-based systems.

  18. Recent advances in high performance poly(lactide): from "green" plasticization to super-tough materials via (reactive) compounding.

    Science.gov (United States)

    Kfoury, Georgio; Raquez, Jean-Marie; Hassouna, Fatima; Odent, Jérémy; Toniazzo, Valérie; Ruch, David; Dubois, Philippe

    2013-01-01

    Due to its origin from renewable resources, its biodegradability, and recently, its industrial implementation at low costs, poly(lactide) (PLA) is considered as one of the most promising ecological, bio-sourced and biodegradable plastic materials to potentially and increasingly replace traditional petroleum derived polymers in many commodity and engineering applications. Beside its relatively high rigidity [high tensile strength and modulus compared with many common thermoplastics such as poly(ethylene terephthalate) (PET), high impact poly(styrene) (HIPS) and poly(propylene) (PP)], PLA suffers from an inherent brittleness, which can limit its applications especially where mechanical toughness such as plastic deformation at high impact rates or elongation is required. Therefore, the curve plotting stiffness vs. impact resistance and ductility must be shifted to higher values for PLA-based materials, while being preferably fully bio-based and biodegradable upon the application. This review aims to establish a state of the art focused on the recent progresses and preferably economically viable strategies developed in the literature for significantly improve the mechanical performances of PLA. A particular attention is given to plasticization as well as to impact resistance modification of PLA in the case of (reactive) blending PLA-based systems.

  19. Recent advances in high performance poly(lactide: From green plasticization to super-tough materials via (reactive compounding

    Directory of Open Access Journals (Sweden)

    Georgio eKfoury

    2013-12-01

    Full Text Available Due to its origin from renewable resources, its biodegradability, and recently, its industrial implementation at low costs, poly(lactide (PLA is considered as one of the most promising ecological, bio-sourced and biodegradable plastic materials to potentially and increasingly replace traditional petroleum derived polymers in many commodity and engineering applications. Beside its relatively high rigidity (high tensile strength and modulus compared with many common thermoplastics such as poly(ethylene terephthalate (PET, high impact poly(styrene (HIPS and poly(propylene (PP, PLA suffers from an inherent brittleness, which can limit its applications especially where mechanical toughness such as plastic deformation at high impact rates or elongation is required. Therefore, the curve plotting stiffness vs. impact resistance and ductility must be shifted to higher values for PLA-based materials, while being preferably fully bio-based and biodegradable upon the application.This review aims to establish a state of the art focused on the recent progresses and preferably economically viable strategies developed in the literature for significantly improve the mechanical performances of PLA. A particular attention is given to plasticization as well as to impact resistance modification of PLA in the case of (reactive blending PLA-based systems.

  20. 纳米纤维素增强木塑复合材料的性能研究%Properties of Wood Plastic Composite Reinforced by Cellulose Nanofibers

    Institute of Scientific and Technical Information of China (English)

    李晶晶; 宋湛谦; 李大纲; 商士斌; 郭勇

    2015-01-01

    The poplar cellulose nanofibers ( CNF ) were extracted from poplar flour and used to reinforce the wood flour/high density polyethylene ( HDPE ) composite by physical pretreatment method and polyethylene oxide ( PEO ) dispersion agent method. Then the wood flour/HDPE/CNF composites were prepared by extruding molding. The effect of dispersion and reinforcement of CNF in the wood flour/HDPE/CNF composites was investigated by a comparioson of two pretreatment methods using compounding method as control . The results indicated that CNF with a diameter of several hundred nanometers could be achieved successfully after the effectively removing of the lignin and hemicellulose of poplar by chemical and mechanical treatments. SEM images showed that an ideal dispersion of CNF in the HDPE matrix of the the wood flour/HDPE/CNF composites could be obtained by using these two pretreatment methods. CNF were entangled with wood flour and HDPE matrix forming a three-dimensional network structure, and the fracture mode of the composites became the ductile fracture. The bending strength and elastic modulus of the wood flour/HDPE/CNF composites prepared with the two pretreatment methods were improved evidently. The bending strengths of the composites by the physical pretreatment method and the PEO dispersion agent method were 43. 3 and 38. 7Mpa,which was increased by 36. 2% and 21. 7% respectively compared to the control 31. 8 MPa. The elastic modulus of the composites were 3 342 and 3 008 MPa with these two pretreatment methods, increasing by 48. 9% and 34. 1%than the control 2 243 MPa. The bending strength and elastic modulus of the composites with the physical pretreatment method were higher than those of the composites with the PEO dispersion agent method. This indicated that the physical pretreatment method was an environmental friendly and effective method.%以杨木粉为原料制备出纳米纤维素( CNF),然后采用物理预处理法和聚氧化乙烯( PEO)分散剂法利

  1. Comparison of Biocompatibility and Adsorption Properties of Different Plastics for Advanced Microfluidic Cell and Tissue Culture Models

    NARCIS (Netherlands)

    van Midwoud, Paul M.; Janse, Arnout; Merema, M.T.; Groothuis, Geny M. M.; Verpoorte, Elisabeth

    2012-01-01

    Microfluidic technology is providing new routes toward advanced cell and tissue culture models to better understand human biology and disease. Many advanced devices have been made from poly(dimethylsiloxane) (PDMS) to enable experiments, for example, to study drug metabolism by use of precision cut

  2. Comparison of Biocompatibility and Adsorption Properties of Different Plastics for Advanced Microfluidic Cell and Tissue Culture Models

    NARCIS (Netherlands)

    van Midwoud, Paul M.; Janse, Arnout; Merema, M.T.; Groothuis, Geny M. M.; Verpoorte, Elisabeth

    2012-01-01

    Microfluidic technology is providing new routes toward advanced cell and tissue culture models to better understand human biology and disease. Many advanced devices have been made from poly(dimethylsiloxane) (PDMS) to enable experiments, for example, to study drug metabolism by use of precision cut

  3. Technology and future prospects for lightweight plastic vehicle structures

    Energy Technology Data Exchange (ETDEWEB)

    Stodolsky, F.; Cuenca, R.M.; Bonsignore, P.V.

    1997-08-01

    The state of the technology and the materials and processing issues of using plastics in vehicle body applications (structural and semistructural) were assessed. Plastics are significantly lighter in weight, more easily fabricated into complex shapes, and more corrosion resistance than sheet steel, high-strength steel, or aluminum. However, at their current stage of development, plastics are deficient in one or more necessary properties: heat resistance and dimensional stability, stiffness and tensile strength, toughness, and impact resistance. To upgrade their physical properties for automotive chassis/body applications, plastics need to be compounds with suitable reinforcing fibers. As a short-term approach, the material of choice is a composite structure made with low-cost glass-fiber reinforcement, such as that made in the resin-transfer-molding (RTM) process and used in the body of the Dodge Viper. However, RTM technology based on thermosets requires a processing cycle time that is too long for large production runs. Adaptation of RTM to the formation of thermoplastic composite bodies could have a significant advantage over thermoset technology. Cyclic oligomers, which are precursors to thermoplastic matrix polymers, show promise for this application. Farther on the horizon are advanced composites compounds with the much more expensive (but stronger and stiffer) carbon-fiber reinforcement. However, significant price reductions of precursor materials and advances in processing and fabrication would be needed. Other materials holding promise are liquid crystal polymers (LCP) and LCP blends with other polymers (molecular composites). However, the cost of monomers and the subsequent polymerization technology also remains a considerable drawback to the widespread and increasing acceptance of LCPs.

  4. 33 CFR 183.552 - Plastic encased fuel tanks: Installation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Plastic encased fuel tanks... § 183.552 Plastic encased fuel tanks: Installation. (a) Each fuel tank encased in cellular plastic foam or in fiber reinforced plastic must have the connections, fittings, and labels accessible...

  5. Numerical study on deformation and failure of reinforced sand

    Institute of Scientific and Technical Information of China (English)

    PENG Fang-le; LI Jian-zhong; Tatsuoka Fumio

    2005-01-01

    In order to investigate the deformation and failure of reinforced sand, and the reinforcing mechanism of flexible and rigid reinforcement, a set of plane strain compression tests of dense Toyoura reinforced sand with planar reinforcement of a wide range of stiffness were analysed by a nonlinear finite element method. The analysis was incorporated into an energy-based elasto-plastic constitutive model for sand to develop a stress path-independent work-hardening parameter based on the modified plastic strain energy concept. Numerical results indicate that the global stress-strain relations of sand specimens are reinforced by using relatively flexible and rigid reinforcement, and an unreinforced sand specimen can be reasonably simulated by the current finite element method. It is also found that the reinforcing mechanism and progressive failure with a development of shear bands in reinforced sand can be reasonably examined by the finite element method.

  6. Advances of honeybee lifespan plasticity%蜜蜂寿命可塑性研究进展

    Institute of Scientific and Technical Information of China (English)

    管翠; 刘亭亭; 颜伟玉; 曾志将

    2011-01-01

    Honey bees (Apis mellifera ) are eusocial insects that exhibit striking caste-specific differences in lifespan.Queens live, on average, for 1 -2 years whereas workers live, on average, 30 -40 days in the breeding season and 90200 days in the winter. This seasonal variation in worker lifespans indicates that honeybee lifespans are plastic. Because queens and workers are fundamentally the same genetic. This plasticity is probably controlled by environmental, rather than genetic factors. In addition, workers have reverted behavioral ontogeny, and this peculiarity is indicative of reverted ageing. In order to elucidate plasticity in the ageing of honey bees, here we review recent findings about aging in honeybees over the past few years, focusing on knowledge of ageing at different life history stages.%蜜蜂是一种完全社会化的昆虫,它们在寿命方面表现出了显著的级型差异.蜂王的平均寿命是1~2年,而工蜂在生产季节平均寿命是30~40 d,越冬季节平均寿命是90~200d,显然蜜蜂寿命有可塑性.这种可塑性是由环境因素控制,因为蜂王和工蜂的遗传基础是一致的.另外工蜂任务可以发生逆转,这意味着老化的逆转.本文综述了近年来一些老化研究,从老化知识的不同层面来阐明蜜蜂老化可塑性.

  7. Micromechanics of plastic deformation and phase transformation in a three-phase TRIP-assisted advanced high strength steel: Experiments and modeling

    Science.gov (United States)

    Srivastava, Ankit; Ghassemi-Armaki, Hassan; Sung, Hyokyung; Chen, Peng; Kumar, Sharvan; Bower, Allan F.

    2015-05-01

    The micromechanics of plastic deformation and phase transformation in a three-phase advanced high strength steel are analyzed both experimentally and by microstructure-based simulations. The steel examined is a three-phase (ferrite, martensite and retained austenite) quenched and partitioned sheet steel with a tensile strength of ~980 MPa. The macroscopic flow behavior and the volume fraction of martensite resulting from the austenite-martensite transformation during deformation were measured. In addition, micropillar compression specimens were extracted from the individual ferrite grains and the martensite particles, and using a flat-punch nanoindenter, stress-strain curves were obtained. Finite element simulations idealize the microstructure as a composite that contains ferrite, martensite and retained austenite. All three phases are discretely modeled using appropriate crystal plasticity based constitutive relations. Material parameters for ferrite and martensite are determined by fitting numerical predictions to the micropillar data. The constitutive relation for retained austenite takes into account contributions to the strain rate from the austenite-martensite transformation, as well as slip in both the untransformed austenite and product martensite. Parameters for the retained austenite are then determined by fitting the predicted flow stress and transformed austenite volume fraction in a 3D microstructure to experimental measurements. Simulations are used to probe the role of the retained austenite in controlling the strain hardening behavior as well as internal stress and strain distributions in the microstructure.

  8. Advanced Micromechanical Model for Transformation-Induced Plasticity Steels with Application of In-Situ High-Energy X-Ray Diffraction Method

    Science.gov (United States)

    Choi, K. S.; Liu, W. N.; Sun, X.; Khaleel, M. A.; Ren, Y.; Wang, Y. D.

    2008-12-01

    Compared to other advanced high-strength steels, transformation-induced plasticity (TRIP) steels exhibit better ductility at a given strength level and can be used to produce complicated automotive parts. This enhanced formability comes from the transformation of retained austenite to martensite during plastic deformation. In this study, as a first step in predicting optimum processing parameters in TRIP steel productions, a micromechanical finite element model is developed based on the actual microstructure of a TRIP 800 steel. The method uses a microstructure-based representative volume element (RVE) to capture the complex deformation behavior of TRIP steels. The mechanical properties of the constituent phases of the TRIP 800 steel and the fitting parameters describing the martensite transformation kinetics are determined using the synchrotron-based in-situ high-energy X-ray diffraction (HEXRD) experiments performed under a uniaxial tensile deformation. The experimental results suggest that the HEXRD technique provides a powerful tool for characterizing the phase transformation behavior and the microstress developed due to the phase-to-phase interaction of TRIP steels during deformation. The computational results suggest that the response of the RVE well represents the overall macroscopic behavior of the TRIP 800 steel under deformation. The methodology described in this study may be extended for studying the effects of the various processing parameters on the macroscopic behaviors of TRIP steels.

  9. A Survey on Key Technologies for Carbon Fiber-reinforced Plastics with Applications to Automobile Lightening%面向汽车轻量化应用的碳纤维复合材料关键技术

    Institute of Scientific and Technical Information of China (English)

    宋燕利; 杨龙; 郭巍; 华林

    2016-01-01

    轻量化技术已成为汽车实现节能、减排的重要途径,碳纤维复合材料为汽车轻量化提供了重要材料基础。由于材料特性与制造工艺的特殊性与复杂性,采用碳纤维复合材料实现汽车轻量化时需要克服多项关键技术。结合汽车产品特点,从低成本碳纤维技术、材料-结构-性能一体化技术、高效成型技术、多材料连接技术、循环利用技术几个方面阐述了碳纤维复合材料在汽车轻量化应用中的关键技术,展望了未来汽车用碳纤维复合材料的发展趋势。%Lightweight has become an important way to achieve energy saving and emission reduction for auto-mobile and carbon fiber-reinforced plastics (CFRP)has provided a significant material foundation for automobile ligh-tening.Due to particularity and complexity of material properties and manufacturing processes,the application of CFRP to vehicle lightening still faces several crucial technological challenges.In this paper,the key technologies aimed at these issues,including low cost carbon fiber,structure-function integration,highly efficient molding,multi-mate-rial connection,and recycling,are analyzed and summarized combining with the automobile features.The future de-velopment prospect of CFRP for automobile application is also put forward.

  10. Research on Installation Construction Techniques of Subsea Socket Type Fiberglass Reinforced Plastic Pipelines%海底承插式玻璃钢管道安装施工工艺研究

    Institute of Scientific and Technical Information of China (English)

    上育平; 寇君淑; 房海勃; 李明亮

    2014-01-01

    The installation of large diameter glass reinforced plastic pipes(FRP)under the sea is affected by sea waves , tidal range ,ocean current and seabed geology and so on ,so the construction is difficult with high risks .According to the installation engineering characteristics of large diameter FRP pipes in Sihanouk ,Kampuchea power plant ,the Hough joints were assembled onshore and then the socket joints were connected subsea .During the installation of FRP ,it is very important to control the installation accuracy of the joints ,as well as the construction quality of subsea pipe connection and sealing .The construction result is satisfactory ,which provides some referential value for tsimilar engineering pro-jects .%海底大直径玻璃钢管安装受海上风浪、潮差、海流及海床地质等因素影响,操作技术难度大,操作风险极高。针对柬埔寨西哈努克市火电厂海底大直径玻璃钢管安装工程的特点,采用岸上哈夫接头拼装,水下承插接头安装的施工方法进行安装。在施工中,重点控制岸上接头安装精度、水下管道连接与密封工艺施工质量,取得了很好的效果。本工程施工质量控制措施可为类似工程施工提供重要的技术参考。

  11. 涂层钻头钻削碳纤维复合材料的轴向力研究%Study of drilling thrust force of coated drills in drilling the carbon fiber reinforced plastic

    Institute of Scientific and Technical Information of China (English)

    魏良耀; 程寓

    2013-01-01

    不同刀具材料对碳纤维复合材料的加工有较大的影响.通过合理选择钻头的基体材料和涂层材料,基于正交试验综合分析不同涂层材料、主轴转速及进给速度对钻削轴向力的影响.试验结果表明,涂层材料对轴向力的影响最大,涂层钻头的钻削轴向力比无涂层YG6X钻头小很多,类金刚石涂层(DLC)钻头最小.TiAIN和TiCN涂层钻头都有不同程度的磨损,DLC钻头的耐磨性和加工质量都远远高于其他涂层.%Different tool materials have a greater impact on the processing of carbon fiber reinforced plastic. Through the reasonable choice of substrate material and coating materials of the drill, based on the orthogonal experiment and comprehensive analysis of the coating materials, different spindle speeds and feed drilling speeds on the effect of the thrust force. The results show that coating material is the biggest influencing factor for drilling thrust force, compared to the uncoated drill bits, the thrust force of the coating drill is much smaller, and the least is DLC drill. TiAIN and TiCN coating drill both have different degrees of wear. The wear resistance and processing quality of the diamond-like-coating ( DLC) drill are far higher than other coatings.

  12. Digital Measurement System for Fiber-Reinforced Plastic In-Plane Compression Testing%纤维增强塑料面内压缩性能试验数字测量系统

    Institute of Scientific and Technical Information of China (English)

    谷瑞; 张涛; 王振清

    2011-01-01

    In-plane compression is an important aspect of material characterization. However, eccentricity must be controlled within a certain range in order to guarantee the validity and accuracy. In this article, the digital measuring system for in-plane compression testing of the fiber-reinforced plastic was discussed. Special fixture, AD620 instru- mentation amplifiers and high accuracy and fast data acquisition board AMPCI-9101 in the system were used and a special software application was made. Experiments under the instruction where the eccentricity is below 0.1 were made, which is an achieved good result.%面内压缩性能是表征材料的重要方面。而对于面内压缩来说,为了保证试验的有效性和准确性,需要保证载荷的偏心率在一定范围内。讨论了针对纤维增强塑料面内压缩设计的数字测量系统。为了达到测量和控制精度,应用了特制夹具、专门的AD620仪表放大器和高精度快速数据采集板AMPCI-9101,来保证传力的准确性和测量的准确性,并且编写特殊的软件。依据操作流程进行试验,使得偏心率小于0.1,达到了良好的效果。

  13. Design of macro-synthetic fibre reinforced concrete pipes

    OpenAIRE

    Fuente, Albert de la; Escariz, Renata Campos; Figueiredo,Antonio Domingues de; Aguado, Antonio

    2013-01-01

    This paper presents an experimental campaign in which concrete pipes were manufactured using plastic fibres as the sole reinforcement material. In this regard, it has been demonstrated that the use of plastic fibres is compatible with pipe production systems, and that, when subjected to the crushing test (CT), plastic fibre reinforced pipes yield strength classes that are attractive in terms of the growth of this material in the concrete pipe industry. Moreover, the results obtained from b...

  14. Continuous jute fibre reinforced laminated paper composite and reinforcement-fibre free paper laminate

    Indian Academy of Sciences (India)

    B B Verma

    2009-12-01

    Plastic bags create a serious environmental problem. The proposed jute fibre reinforced laminated paper composite and reinforcement-fibre free paper laminate may help to combat the war against this pollutant to certain extent. The paper laminate, without reinforcement fibre, exhibited a few fold superiority in tensile properties than single paper strip. The studies further show that an appreciable improvement in tensile properties can be achieved by introducing continuous jute fibre in paper laminates.

  15. The Experimental Study of Concrete Beams Reinforced with Different Types of Bars Carrying Capacity

    OpenAIRE

    Benin Andrey; Semenov Sergey; Ekaterina Bogdanova

    2016-01-01

    The results of experimental study on concrete beams reinforced with glass fiber reinforced plastic (GFRP) bars are presented and compared with steel reinforced concrete beams and beams reinforced with steel and GFRP bars together. Three series of reinforced beams were tested in the flexure. The experimental data are showed that possible area in which GFRP bar possesses potential to employ is secondary reinforcement in concrete structures.

  16. The Experimental Study of Concrete Beams Reinforced with Different Types of Bars Carrying Capacity

    Directory of Open Access Journals (Sweden)

    Benin Andrey

    2016-01-01

    Full Text Available The results of experimental study on concrete beams reinforced with glass fiber reinforced plastic (GFRP bars are presented and compared with steel reinforced concrete beams and beams reinforced with steel and GFRP bars together. Three series of reinforced beams were tested in the flexure. The experimental data are showed that possible area in which GFRP bar possesses potential to employ is secondary reinforcement in concrete structures.

  17. Plasticity theory

    CERN Document Server

    Lubliner, Jacob

    2008-01-01

    The aim of Plasticity Theory is to provide a comprehensive introduction to the contemporary state of knowledge in basic plasticity theory and to its applications. It treats several areas not commonly found between the covers of a single book: the physics of plasticity, constitutive theory, dynamic plasticity, large-deformation plasticity, and numerical methods, in addition to a representative survey of problems treated by classical methods, such as elastic-plastic problems, plane plastic flow, and limit analysis; the problem discussed come from areas of interest to mechanical, structural, and

  18. Study of variation of thermal diffusivity of advanced composite materials of E-glass fibre reinforced plastic (GFRP) in temperature range 5–300 K

    Indian Academy of Sciences (India)

    Kalobaran Das; S M Kamaruzzaman; Tapas Ranjan Middya; Siddhartha Datta

    2009-02-01

    Modified Angstrom method is applied to study the variation of thermal diffusivity of plain woven fabric composite in closed cycle cryo-refrigerator (CCR) based set up in the temperature range 5–300 K. The set up used is plug in type and its small size offers portability. The set up works without use of any liquid cryogen. The temperature versus thermal diffusivity curve shows three distinct regions viz. 5–30 K, 30–120 K and 120–300 K. In the first region thermal diffusivity varies exponentially and rapidly. In the second region thermal diffusivity changes exponentially but relatively slowly than that in the first region. In the last region the change in thermal diffusivity with temperature is exponential in nature but very slow.

  19. Plastic Jellyfish.

    Science.gov (United States)

    Moseley, Christine

    2000-01-01

    Presents an environmental science activity designed to enhance students' awareness of the hazards of plastic waste for wildlife in aquatic environments. Discusses how students can take steps to reduce the effects of plastic waste. (WRM)

  20. ADVANCE OF IMPROVEMENT RESEARCH OF GLASS FIBER REINFORCED POLYAMIDE 66%玻璃纤维增强尼龙66改性研究进展

    Institute of Scientific and Technical Information of China (English)

    李跃文

    2017-01-01

    Advance of improvement research on toughening,flame retardancy,solvent resistance,abrasion resistance,interphase property,compounding and preparation technology of glass fiber (GF) reinforced polyamide 66 (PA66) was expounded.The toughness of PA66/GF composites could be improved via adding toughner,but the compatibility between toughner and PA66 had to be increased.Microencapsulation red phosphorus and P-N type flame retardant had fine inflaming retarding effect for GF/PA66 composites.Surface covering treatment of red phosphorus was necessary,because of bad compatibility between it and PA66 and its amaranth.Solvent resistance of the composites could be enhanced via adding low polarity resin and using anti-hydrolysis GF.Friction and wear resistance of the composites was improved when they were mixed with self lubricating resin and wear resistant filler.The interfacial structure between GF and PA66 could be improved by coupling or infiltration treatment of GF.Its mechanical property was enhanced when suitable other fillers were added into the composites,as a result of synergistic effect between GF and the fillers.After appropriate technological method of composite was selected,and the process parameters were optimized,the retention length of GF increased,resulting of improvement of mechanical property of the composites.%阐述了玻璃纤维增强尼龙66在增韧改性、阻燃改性、耐溶剂改性、耐磨改性、界面改性、复合改性和制备工艺改进等方面的研究进展.指出玻璃纤维增强尼龙66目前常用的增韧方法是与弹性体和高韧性聚烯烃共混,而阻燃改性的有效手段是添加微胶囊化红磷和P-N型阻燃剂.

  1. Real breakthrough in detection of radioactive sources by portal monitors with plastic detectors and New Advanced Source Identification Algorithm (ASIA-New)

    Energy Technology Data Exchange (ETDEWEB)

    Stavrov, Andrei; Yamamoto, Eugene [Rapiscan Systems, Inc., 14000 Mead Street, Longmont, CO, 80504 (United States)

    2015-07-01

    Radiation Portal Monitors (RPM) with plastic detectors represent the main instruments used for primary border (customs) radiation control. RPM are widely used because they are simple, reliable, relatively inexpensive and have a high sensitivity. However, experience using the RPM in various countries has revealed the systems have some grave shortcomings. There is a dramatic decrease of the probability of detection of radioactive sources under high suppression of the natural gamma background (radiation control of heavy cargoes, containers and, especially, trains). NORM (Naturally Occurring Radioactive Material) existing in objects under control trigger the so-called 'nuisance alarms', requiring a secondary inspection for source verification. At a number of sites, the rate of such alarms is so high it significantly complicates the work of customs and border officers. This paper presents a brief description of new variant of algorithm ASIA-New (New Advanced Source Identification Algorithm), which was developed by the Rapiscan company. It also demonstrates results of different tests and the capability of a new system to overcome the shortcomings stated above. New electronics and ASIA-New enables RPM to detect radioactive sources under a high background suppression (tested at 15-30%) and to verify the detected NORM (KCl) and the artificial isotopes (Co- 57, Ba-133 and other). New variant of ASIA is based on physical principles, a phenomenological approach and analysis of some important parameter changes during the vehicle passage through the monitor control area. Thanks to this capability main advantage of new system is that this system can be easily installed into any RPM with plastic detectors. Taking into account that more than 4000 RPM has been installed worldwide their upgrading by ASIA-New may significantly increase probability of detection and verification of radioactive sources even masked by NORM. This algorithm was tested for 1,395 passages of

  2. Performances and economy comparison analysis of different fiber reinforced wood-plastic composite formwork%不同纤维增强木塑复合模板性能与经济性对比

    Institute of Scientific and Technical Information of China (English)

    孙胜伟; 罗健林; 刘文清; 李秋义; 胡小川; 高嵩; 韩鹏

    2013-01-01

    Employing different surfactants modification,vibromill or ultrasonic treatment dispersion tecnnique,chrysotile asbestos fiber(CAF),polyvinyl alcohol fiber(PVAF),basalt fiber(BF) with different loading was pre-dispersed in water,mixed with the wood flour,and then compounded to the molting polypropylene by a mixing roll,respectively.Subsequently,3 kinds of fiber reinforced wood-plastic composite sheets (CAF/WPC,PVAF/WPC,BF/WPC) were formed by hot-press method.The tensile,flexural,impact and wear-resisting performances of the corresponding composite were studied by dumb-bell sample tensile testing,three-point bending,pendulum impact and rotary abrasion method,respectively,as well as the economy comparison of three sorts of the composite serving as formwork.Results show,the tensile,flexural,impact,wear-resisting properties and single cost saving as formwork of the CAF/WPC,PVAF/WPC,BF/WPC with 10 wt% fiber addition,increases 66.6%,48.4%,36.3%,68.9%,67.33%.33.2%,54.3%,38.8%,81.8%,63.47%.44.2%,24.7%,9.3%,85.6%,60.93%,respectively.Obviously,the quality and cheap CAF addition can bring forth both good improvement on the comprehensive performance of the WPC as formwork,and the least increased cost,which has a good prospect of application in fresh water formwork field.%结合不同表面活性剂改性、振动磨或超声波处理工艺分别将温石棉纤维(CAF)、聚乙烯醇纤维(PVAF)、玄武岩纤维(BF)预分散在水中,与木粉混杂后辊炼到熔融聚丙烯(PP)中,热压成型3种纤维增强木塑复合材料(CAF/WPC、PVAF/WPC、BF/WPC).通过哑铃形试样拉伸法、三点弯曲法、摆锤冲击法、旋转磨耗法分别表征其拉伸、弯曲、冲击和耐磨性能,并对3种材料用作建筑模板的经济性进行对比分析.结果表明,相比于空白WPC,掺有10%(质量百分比)各纤维的CAF/WPC、PVAF/WPC、BF/WPC的拉伸、弯曲、冲击强度、耐磨性能与单次折算节约费分别提高了66.6

  3. American Society of Plastic Surgeons

    Science.gov (United States)

    ... PRS PRS GO PSN PSEN GRAFT Contact Us Cosmetic Surgery New procedures and advanced technologies offer plastic surgery ... David Berman MD 14 Pidgeon Hill Drive Berman Cosmetic Surgery & S... Sterling, VA 20165 Website Franklin Richards MD Suite ...

  4. Behavior and Performance of GFRP Reinforced Concrete Columns with Various Types of Stirrups

    OpenAIRE

    Woraphot Prachasaree; Sitthichai Piriyakootorn; Athawit Sangsrijun; Suchart Limkatanyu

    2015-01-01

    Fiber reinforced polymer (FRP) composites are gaining acceptance in concrete structural applications due to their high ratio of strength/stiffness to self-weight and corrosion resistance. This study focused on the structural behavior and the performance of concrete columns internally reinforced with glass fiber reinforced plastic (GFRP) rebars. Twelve series of concrete columns with varied longitudinal reinforcement, cross section, concrete cover, and type of lateral reinforcement were tested...

  5. Plasticity modeling & computation

    CERN Document Server

    Borja, Ronaldo I

    2013-01-01

    There have been many excellent books written on the subject of plastic deformation in solids, but rarely can one find a textbook on this subject. “Plasticity Modeling & Computation” is a textbook written specifically for students who want to learn the theoretical, mathematical, and computational aspects of inelastic deformation in solids. It adopts a simple narrative style that is not mathematically overbearing, and has been written to emulate a professor giving a lecture on this subject inside a classroom. Each section is written to provide a balance between the relevant equations and the explanations behind them. Where relevant, sections end with one or more exercises designed to reinforce the understanding of the “lecture.” Color figures enhance the presentation and make the book very pleasant to read. For professors planning to use this textbook for their classes, the contents are sufficient for Parts A and B that can be taught in sequence over a period of two semesters or quarters.

  6. On monolithic stability and reinforcement analysis of high arch dams

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Monolithic stability safety and reinforcement based on monolithic stability are very important for arch dam design.In this paper,the issue is addressed based on deformation reinforcement theory.In this approach,plastic complementary energy norm can be taken as safety Index for monolithic stability.According to deformation reinforcement theory,the areas where unbalanced force exists require reinforcement,and the required reinforcement forces are just the unbalanced forces with opposite direction.Results show that areas with unbalanced force mainly concentrate in dam-toes,dam-heels and faults.

  7. McGrath-5型视频喉镜引导气管导管不同前端塑形角度对肥胖患者经口气管插管的效果比较%Comparison of different front plastic angle with reinforced plastic endotracheal tube guidance by McGrath -5 video laryngoscope for orotracheal intubation in obesity

    Institute of Scientific and Technical Information of China (English)

    严峰; 李军; 王浩杰; 沈荣荣; 费莉

    2015-01-01

    Objective To compare the different front plastic angle with reinforced plastic endotracheal tube guidance by McGrath -5 video laryngoscope for orotracheal intubation in obesity.Methods 1 20 cases with obesity undergoing general anesthesia,ASA gradeⅠ -Ⅲ who planned intubation guidance by McGrath -5 video laryngo-scope,were randomly divided into three group according to different front plastic angle for endotracheal tube:group A (catheter 60°),group B(catheter 75°),C group(catheter 90°),40 cases in each group.General information and air-way evaluation indexes such as Mallampati classification,the degree of open mouth,neck circumference,thyromental distance,atlanto -occipital joint stretch degree preoperatively were recorded.C /L classification with laryngoscopic exposure,the successful rate of first intubation,time of first intubation,cases of second intubation,the incidence of blood stained catheter and postoperative sore throat and hoarseness were recorded also.Results There were no signif-icant differences of patients with general information and airway evaluating indexes such as Mallampati classification, the degree of open mouth,neck circumference,thyromental distance,atlanto -occipital joint stretch degree among three groups(P >0.05).The successful rate of catheter alignment glottal was 97.5% in group B,which was signifi-cantly higher than that of group A(80.0%)and group C(85.0%)(χ2 =8.36,P 0.05).Conclusion McGrath -5 video laryngoscope which guided endotracheal tube with front plastic angle at 75°degree has highest success rate of intubation,shortest intubation time,least compli-cation and is suitable for the application of tracheal intubation in obese patients.%目的:比较 McGrath-5型视频喉镜引导加强型气管导管不同前端塑形角度对肥胖患者经口气管插管效果的影响。方法选取肥胖患者120例,ASA 分级Ⅰ~Ⅲ级,用 McGrath-5型视频喉镜插管,气管导管前端塑形一定角度,按数字

  8. 46 CFR 160.010-5 - Buoyant apparatus with plastic foam buoyancy.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Buoyant apparatus with plastic foam buoyancy. 160.010-5... Vessels § 160.010-5 Buoyant apparatus with plastic foam buoyancy. (a) Buoyant apparatus with plastic foam buoyancy must have a plastic foam body with an external protective covering. The body may be reinforced...

  9. Chemical properties of reinforcing fiberglass in aggressive media

    Directory of Open Access Journals (Sweden)

    Avdeeva Arina

    2016-01-01

    Full Text Available In this article describe reinforced fiberglass. Fiberglass – fiber or complex yarn, formed from glass. The main application area of fiberglass and fiberglass textile materials is their use as reinforcing elements of fiberglass plastics and composites. For its consideration, conducted laboratory tests were conducted. As a result of the research was chosen the best of the characteristics of fiberglass.

  10. Shear strength of non-shear reinforced concrete elements

    DEFF Research Database (Denmark)

    Hoang, Cao linh

    1997-01-01

    The paper deals with the plastic shear strength of non shear reinforced T-beams.The influence of an un-reinforced flange on the shear capacity is investigated by considering a failure mechanism involving crack sliding in the web and a kind of membrane action over an effective width of the flange...

  11. 静电纺纳米纤维增强复合材料的研究进展∗%Advances in composites reinforced with electrospun nanofibers

    Institute of Scientific and Technical Information of China (English)

    杨海贞; 蔡志江

    2015-01-01

    静电纺丝是制备纳米纤维的一种高效方法。介绍了静电纺CNT增强复合材料、静电纺纤维素纳米纤维增强复合材料、静电纺PA 6纳米纤维增强复合材料和静电纺PAN/PMMA纳米纤维增强复合材料的研究进展及其潜在的应用领域,并展望了静电纺纳米纤维增强复合材料的发展前景。%Electrospinning is an effective method for fabricating nanofibers. The research progress and potential applications of composites reinforced with electrospun CNT, cellulose, PA 6 and PAN/PMMA nanofibers were introduced. Prospect of composites reinforced with electrospun nanofibers also was described.

  12. Probabilistic Durability Analysis in Advanced Engineering Design

    Directory of Open Access Journals (Sweden)

    A. Kudzys

    2000-01-01

    Full Text Available Expedience of probabilistic durability concepts and approaches in advanced engineering design of building materials, structural members and systems is considered. Target margin values of structural safety and serviceability indices are analyzed and their draft values are presented. Analytical methods of the cumulative coefficient of correlation and the limit transient action effect for calculation of reliability indices are given. Analysis can be used for probabilistic durability assessment of carrying and enclosure metal, reinforced concrete, wood, plastic, masonry both homogeneous and sandwich or composite structures and some kinds of equipments. Analysis models can be applied in other engineering fields.

  13. REINFORCED COMPOSITE PANEL

    DEFF Research Database (Denmark)

    2003-01-01

    A composite panel having front and back faces, the panel comprising facing reinforcement, backing reinforcement and matrix material binding to the facing and backing reinforcements, the facing and backing reinforcements each independently comprising one or more reinforcing sheets, the facing...... by matrix material, the facing and backing reinforcements being interconnected to resist out-of-plane relative movement. The reinforced composite panel is useful as a barrier element for shielding structures, equipment and personnel from blast and/or ballistic impact damage....

  14. REINFORCED COMPOSITE PANEL

    DEFF Research Database (Denmark)

    2003-01-01

    A composite panel having front and back faces, the panel comprising facing reinforcement, backing reinforcement and matrix material binding to the facing and backing reinforcements, the facing and backing reinforcements each independently comprising one or more reinforcing sheets, the facing rein...... by matrix material, the facing and backing reinforcements being interconnected to resist out-of-plane relative movement. The reinforced composite panel is useful as a barrier element for shielding structures, equipment and personnel from blast and/or ballistic impact damage....

  15. Spring forward of woven fabric reinforced composites

    NARCIS (Netherlands)

    Wijskamp, Sebastiaan; Lamers, E.A.D.; Akkerman, Remko

    2002-01-01

    Continuous-fibre-reinforced plastic products are usually formed at elevated temperatures. They exhibit distortions when they are cooled to room temperature and released from the mould. For example, the enclosed angle of an L-shaped product decreases, see Fig. 1. This effect is known as

  16. Strength of Cracked Reinforced Concrete Disks

    DEFF Research Database (Denmark)

    Hoang, Cao Linh; Nielsen, Mogens Peter

    1999-01-01

    The paper deals with models, based on the theory of plasticity, to be used in strength assessments of reinforced concrete disks suffering from different kinds of cracking. Based on the assumption that the sliding strength of concrete is reduced in sections where cracks are located, solutions...

  17. Plastics Technology.

    Science.gov (United States)

    Barker, Tommy G.

    This curriculum guide is designed to assist junior high schools industrial arts teachers in planning new courses and revising existing courses in plastics technology. Addressed in the individual units of the guide are the following topics: introduction to production technology; history and development of plastics; safety; youth leadership,…

  18. ANALYSIS FOR BENDING CAPACITY OF REFORCED CONCRETE BEAMS MULTIPLE STRENGTHENED WITH NEAR-SURFACE MOUNTEDCARBON FIBER REINFORCED PLASTIC BAR AND PRE-STRESSED HELICAL RIB BAR%复合内嵌碳纤维筋预应力螺旋肋钢筋加固混凝土梁承载力分析

    Institute of Scientific and Technical Information of China (English)

    任振华; 曾宪桃; 周丰峻

    2012-01-01

    RC beams can be strengthened with Carbon Fiber Reinforced Plastic (CFRP) and pre-stressed Helical Rib Bar ( HRB) that are inserted into the concrete cover of tensile region in the concrete beams , which can effectively improve force performance of the beams . In order to analyze the failure form, ultimate state and normal section bearing capacity of RC beams composites strengthened with near-surface mounted carbon fiber reinforced plastic bar and pre-stressed helical rib bar , the bearing capacity equation of strengthened beams corresponding to different failure modes was supplied by analyzing force in each stage of beams in pre-stress state, bearing capacity calculating and limit state. In order to inspect and verify the rationality and the reliability of the conclusions and the veracity of the equation, the flexural experimental studies were tested on seven concrete beams strengthened with near-surface mounted carbon fiber reinforced plastic bar and pre-stressed helical rib bar. The results indicate that the failure modes and limit state of strengthened beams are reasonable, the equation can veraciously calculate the bend capacity of strengthened beams.%用碳纤维筋和预应力螺旋肋钢筋共同嵌入到混凝土梁受拉区保护层中对混凝土梁进行加固,能更有效地改善混凝土梁的受力性能.为更有效地分析复合内嵌碳纤维筋预应力螺旋肋钢筋加固混凝土梁的破坏形态、极限状态及正截面承载力,通过对预应力状态下梁各阶段受力情况分析、承载力计算及界限状态的判别,提出了加固混凝土梁对应不同破坏形态下承载力的计算公式.为验证所得分析结论的合理性和可靠性及计算公式的准确性,对7根碳纤维筋预应力螺旋肋钢筋加固的混凝土梁进行弯曲试验,结果表明,被加固梁的破坏形态、极限状态分析是合理的,所提出的计算公式能准确计算加固梁抗弯承载能力.

  19. Basal Reinforced Piled Embankments

    NARCIS (Netherlands)

    Van Eekelen, S.J.M.

    2015-01-01

    A basal reinforced piled embankment consists of a reinforced embankment on a pile foundation. The reinforcement consists of one or more horizontal layers of geosynthetic reinforcement (GR) installed at the base of the embankment. The design of the GR is the subject of this thesis. A basal reinforce

  20. Basal Reinforced Piled Embankments

    NARCIS (Netherlands)

    Van Eekelen, S.J.M.

    2015-01-01

    A basal reinforced piled embankment consists of a reinforced embankment on a pile foundation. The reinforcement consists of one or more horizontal layers of geosynthetic reinforcement (GR) installed at the base of the embankment. The design of the GR is the subject of this thesis. A basal reinforce

  1. FOAM CONCRETE REINFORCEMENT BY BASALT FIBRES

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2012-10-01

    Full Text Available The authors demonstrate that the foam concrete performance can be improved by dispersed reinforcement, including methods that involve basalt fibres. They address the results of the foam concrete modeling technology and assess the importance of technology-related parameters. Reinforcement efficiency criteria are also provided in the article. Dispersed reinforcement improves the plasticity of the concrete mix and reduces the settlement crack formation rate. Conventional reinforcement that involves metal laths and rods demonstrates its limited application in the production of concrete used for thermal insulation and structural purposes. Dispersed reinforcement is preferable. This technology contemplates the infusion of fibres into porous mixes. Metal, polymeric, basalt and glass fibres are used as reinforcing components. It has been identified that products reinforced by polypropylene fibres demonstrate substantial abradability and deformability rates even under the influence of minor tensile stresses due to the low adhesion strength of polypropylene in the cement matrix. The objective of the research was to develop the type of polypropylene of D500 grade that would demonstrate the operating properties similar to those of Hebel and Ytong polypropylenes. Dispersed reinforcement was performed by the basalt fibre. This project contemplates an autoclave-free technology to optimize the consumption of electricity. Dispersed reinforcement is aimed at the reduction of the block settlement in the course of hardening at early stages of their operation, the improvement of their strength and other operating properties. Reduction in the humidity rate of the mix is based on the plasticizing properties of fibres, as well as the application of the dry mineralization method. Selection of optimal parameters of the process-related technology was performed with the help of G-BAT-2011 Software, developed at Moscow State University of Civil Engineering. The authors also

  2. Plasticity Approach to HSC Shear Wall Design

    DEFF Research Database (Denmark)

    Liu, Lunying; Nielsen, Mogens Peter

    1998-01-01

    The paper describes a simple theory for determining the ultimate strength of shear walls. It is based on application of the theory of perfectly plastic materials. When applied to concrete the theoretical solutions must be modified by inserting into the solutions a reduced compressive strength...... to 140 MPa and reinforcement yield strengths up to 1420 MPa. The work was carried out as a Ph.D. study by the first author, the second author supervising the study.Keywords: shear wall, plasticity, strut and tie, load-carrying capacity, concrete, reinforcement....

  3. Shear Capacity of Steel and Polymer Fibre Reinforced Concrete Beams

    DEFF Research Database (Denmark)

    Kragh-Poulsen, Jens C.; Hoang, Cao Linh; Goltermann, Per

    2011-01-01

    This paper deals with the application of a plasticity model for shear strength estimation of fibre reinforced concrete beams without stirrups. When using plastic theory to shear problems in structural concrete, the so-called effective strengths are introduced, usually determined by calibrating...... the plastic solutions with tests. This approach is, however, problematic when dealing with fibre reinforced concrete (FRC), as the effective strengths depend also on the type and the amount of fibres. In this paper, it is suggested that the effective tensile strength of FRC can be determined on the basis...

  4. Plastic analysis of the lateral effective width of cantilever slabs of reinforced concrete box-girders%基于塑性分析的钢筋混凝土箱梁悬臂板横向受力有效分布宽度

    Institute of Scientific and Technical Information of China (English)

    方志; 郑辉; 刘双阳

    2012-01-01

    目前国内外相关设计规范中关于行车道板横向受力有效分布宽度的取值是基于弹性理论分析结果确定的,不能体现塑性阶段行车道板横向受力特点。通过对2个钢筋混凝土箱梁模型上的4块悬臂板进行荷载试验,得出悬臂板极限荷载和塑性铰线分布形式,并运用塑性分析方法,推导钢筋混凝土箱梁悬臂板在局部荷载作用下塑性有效分布宽度的计算公式。试验结果和理论分析比较表明:悬臂板的塑性有效分布宽度与荷载作用位置及单位板宽正、负极限弯矩值相关;满足构造配筋要求的箱梁悬臂板进行极限状态设计时,建议采用简化的三折线破坏模式进行塑性横向有效分布宽度计算,取正铰线扩散角为45°,负铰线扩散角为60°;荷载作用于悬臂板边缘时基于塑性的横向有效分布宽度是基于弹性分析的1.58倍。%According to the current design code specifications home and abroad, the values of effective width are mostly based on the results of elasticity theory, which cannot represent the characteristics of effective width in the plastic stage. The ultimate load capacity of cantilever slab and the distribution form of plastic yield-lines were acquired through loading experiments of four cantilever slabs of two reinforced concrete box-girders. The formula for calculating the effective width of the slabs under patch load was derived from plastic analysis. By comparing the experimental results with that of theoretical analysis, it is found that the plastic effective width depends on the load-bearing position and both the positive and negative values of ultimate moment, in addition, the simplified tri-linear mode could effectively determine the ultimate strength and plastic effective width of the slabs with at least the minimum reinforcement, and the desirable calculation plastic spread angle is 45~ for the positive yield-line, 60~ for the negative yield

  5. Debonding failure and size effects in micro reinforced composites

    DEFF Research Database (Denmark)

    Legarth, Brian Nyvang; Niordson, Christian Frithiof

    2010-01-01

    Failure in micro-reinforced composites is investigated numerically using the strain-gradient plasticity theory of Gudmundson [Gudmundson, P., 2004. A unified treatment of strain gradient plasticity. Journal of the Mechanics and Physics of Solids 52 (6) 1379–1406] in a plane strain visco......-plastic formulation. Bi-axially loaded unit cells are used and failure is modeled using a cohesive zone at the reinforcement interface. During debonding a sudden stress drop in the overall average stress–strain response is observed. Adaptive higher-order boundary conditions are imposed at the reinforcement interface...... for realistically modeling the restrictions on moving dislocations as debonding occurs. It is found that the influence of the imposed higher-order boundary conditions at the interface is minor. If strain-gradient effects are accounted for a void with a smooth shape develops at the reinforcement interface while...

  6. 废旧塑料在复合材料领域中回用技术的研究进展%Research Advances in the Recycling Technologies of Waste Plastics in Composites Field

    Institute of Scientific and Technical Information of China (English)

    张效林; 王汝敏; 王志彤; 冯冰; 付钰

    2011-01-01

    介绍了国内外废旧塑料现状以及废旧塑料在复合材料领域利用新进展,综述了废旧塑料在植物纤维/废旧塑料复合材料、废纸/废塑料复合材料、木塑复合发泡材料、可生物降解塑料复合材料及其他复合材料领域的再利用技术新进展,并分析了废旧塑料在复合材料领域回收再利用技术的发展趋势,提出应进一步探讨不同种类废旧塑料对复合材料力学性能及植物纤维/废旧塑料界面相容性的影响.%The present research status and category of printing and packaging waste plastic are introduced,and research advances in the recycling technology of different kind of waste plastic in composite material field such as plant fibre/recycled thermoplastic composites, wastepaper/thermoplastic polymer composites, wood-plastic foaming composites, eco-friendly biodegradable composites and other composites are discussed. Development trend of the recycling technology of waste plastic in composite material field is pointed out. And further more, research area such as the effect of different waste plastics on the composites interface compatibility is proposed.

  7. Plastic bronchitis

    National Research Council Canada - National Science Library

    Singhi, Anil Kumar; Vinoth, Bharathi; Kuruvilla, Sarah; Sivakumar, Kothandam

    2015-01-01

    Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics...

  8. Passive Control Reinforced Concrete Frame Mechanism with High Strength Reinforcements and Its Potential Benefits Against Earthquakes

    Institute of Scientific and Technical Information of China (English)

    Asad Ullah Qazi; YE Lieping; LU Xinzheng

    2006-01-01

    Severe earthquakes continue to cause major catastrophes. Many devices in active, hybrid, and semi-active structural control systems which are used as controllable force devices are costly to build and maintain. The passive control reinforced concrete frame (PCRCF) reinforced with high strength steel only in the columns presented here provides structural systems more resistance to lateral earthquake loadings at comparatively lower cost. The effectiveness is demonstrated by a nonlinear static analysis using fiber model for a single story single bay frame. The study shows that the use of high performance steel in columns prevents formation of plastic hinges at the critical column base sections and failures are always initiated by reinforcement yielding at the beam ends. Furthermore, after experiencing severe lateral drift, the passive control design has small residual displacements compared to ordinary reinforced concrete frames. PCRCF rehabilitation and strengthening can be achieved more easily as compared with ordinary reinforced concrete frame.

  9. Plastic Fishes

    CERN Multimedia

    Trettnak, Wolfgang

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness. The slideshow below gives you a taste of the artworks by Wolfgang Trettnak and Margarita Cimadevila.

  10. Modification research of halogen free flame retardant glass fiber reinforced PA66 engineering plastics%无卤阻燃玻纤增强PA66工程塑料的改性研究

    Institute of Scientific and Technical Information of China (English)

    刘裕红

    2016-01-01

    PA66 is the most widely used in the production of PA, the largest species,but there are relatively easy combustion,easy blistering,burning from the shortcomings, which limit its further application in various fields.At present,the research on the modification of PA66 mainly focus on two aspects enhancement and flame retardant,glass fiber reinforced PA66 of PA66 reinforced modified the most widely used products,this paper studies different flame retardant on the flame retardant performance of glass fiber reinforced PA66 and toughening agent on halogen-free flame-retardant glass fiber reinforced effect of comprehensive performance of PA66.The results are as follows: red phosphorus flame retardant masterbatch and MCA compound synergistic flame retardant according to a certain quality, less dosage of flame retardant and excellent flame retardant effect; maleic anhydride grafted POE on halogen-free flame-retardant glass fiber reinforced PA66 system has a good toughening effect.%PA66是PA产品中产量最大、应用最广的品种,但存在较易燃烧、燃烧时容易起泡、滴落的缺点,极大的限制了其在各领域的进一步推广应用.目前,对PA66的改性研究主要集中在增强和阻燃两方面,玻纤增强PA66是对PA66增强改性使用最广泛的产品,本文研究不同阻燃剂对玻纤增强PA66阻燃性能的影响和增韧剂用量对无卤阻燃玻纤增强PA66综合性能的影响.研究结果为:红磷阻燃母粒和MCA按一定质量份进行复配协效阻燃,阻燃剂用量少且阻燃效果优异;马来酸酐接枝POE对无卤阻燃玻纤增强PA66体系有良好的增韧效果.

  11. Machining fiber-reinforced composites

    Science.gov (United States)

    Komanduri, Ranga

    1993-04-01

    Compared to high tool wear and high costs of tooling of fiber-reinforced composites (FRCs), noncontact material-removal processes offer attractive alternative. Noncontact machining methods can also minimize dust, noise, and extensive plastic deformation and consequent heat generation associated with conventional machining of FRCs, espacially those with an epoxy matrix. The paper describes the principles involved in and the details of machining of FRCs by laser machining, water jet-cutting and abrasive water jet-cutting, and electrical discharge machining of composites, as well as the limitations of each method.

  12. GREEN PLASTIC: A NEW PLASTIC FOR PACKAGING

    OpenAIRE

    Mr. Pankaj Kumar*, Sonia

    2016-01-01

    This paper gives a brief idea about a new type of plastic called as bio-plastic or green plastic. Plastic is used as a packaging material for various products, but this plastic is made up of non renewable raw materials. There are various disadvantages of using conventional plastic like littering, CO2 production, non-degradable in nature etc. To overcome these problems a new type of plastic is discovered called bio-plastic or green plastic. Bio-plastic is made from renewable resources and also...

  13. Construction technology of soft foundation reinforcement with plastic drainage plates for Minjiang River flood dike%闽江防洪堤软土地基塑料排水板加固施工技术

    Institute of Scientific and Technical Information of China (English)

    周婉真

    2015-01-01

    The author discussed the engineering geological conditions of Fuzhou section(1st-stage)of Minjiang River Flood Protection Project and the working principle of soft foundation treatment with plastic drainage plates. An introduction was made on the material of plastic drainage plate, the construction machine, technical program, monitoring method and construction quality control measures.%论述了闽江防洪工程福州段(一期)工程的工程地质情况及塑料排水板处理软土地基的工作原理。介绍了塑料排水板的材料、施工机械、工艺流程、监测方法和施工质量控制措施。

  14. Graphene oxide capturing surface-fluorinated TiO2 nanosheets for advanced photocatalysis and the reveal of synergism reinforce mechanism.

    Science.gov (United States)

    Dai, Kai; Lu, Luhua; Liu, Qi; Zhu, Guangping; Liu, Qinzhuang; Liu, Zhongliang

    2014-02-07

    Surface-fluorinated TiO2 (F-TiO2) nanosheets with exposed (001) facets were synthesized from a scalable hydrothermal treatment assisted by a specific stabilization effect of fluorine ions on the (001) facets. Assembly of F-TiO2 on graphene oxide (GO) sheets into GO/F-TiO2 hybrid in aqueous solution was further achieved by making use of the surfactant role of GO. Photocatalytic properties of GO/F-TiO2 hybrid were evaluated under 365 nm UV light irradiation for photodegradation of methylene blue (MB). An optimal GO content has been determined to be 3 wt%, and the corresponding apparent pseudo-first-order rate constant Kapp is 0.0493 min(-1), 3 times and 4 times more than that of pure TiO2 nanosheets and commercial P25 photocatalyst, respectively. To reveal the synergism reinforce mechanism of GO/F-TiO2 hybrid, photo absorption, surface absorption, and the photoelectrochemical current properties have been intensively studied. We found that enhanced electron-hole separation has been the key issue for the reinforcement of photocatalytic performance. F-TiO2 with exposed (001) facet has stronger electron-hole separation resulting in a higher photoelectrochemical current than that of P25 photocatalyst. Moreover, hybridization of F-TiO2 with GO could further increase the photoelectrochemical current and the largest current for the optimal weight fraction of GO is in good accordance with the photocatalysis performance. The GO/F-TiO2 interface junction that favors the electron-hole separation was attributed to the photoelectrochemical current enhancement.

  15. In-plane shear test of fibre reinforced concrete panels

    DEFF Research Database (Denmark)

    Solgaard, Anders Ole Stubbe; Stang, Henrik; Goltermann, Per

    2008-01-01

    contributes to the investigation of fibers as reinforcement in panels with experimental results and a consistent approach to material characterization and modeling. The proposed model draws on elements from the classical yield line theory of rigid, perfectly plastic materials and the theory of fracture......The present paper concerns the investigation of polymer Fiber Reinforced Concrete (FRC) panels subjected to in-plane shear. The use of fibers as primary reinforcement in panels is a new application of fiber reinforcement, hence test methods, design bases and models are lacking. This paper...

  16. Plasticity and beyond microstructures, crystal-plasticity and phase transitions

    CERN Document Server

    Hackl, Klaus

    2014-01-01

    The book presents the latest findings in experimental plasticity, crystal plasticity, phase transitions, advanced mathematical modeling of finite plasticity and multi-scale modeling. The associated algorithmic treatment is mainly based on finite element formulations for standard (local approach) as well as for non-standard (non-local approach) continua and for pure macroscopic as well as for directly coupled two-scale boundary value problems. Applications in the area of material design/processing are covered, ranging from grain boundary effects in polycrystals and phase transitions to deep-drawing of multiphase steels by directly taking into account random microstructures.

  17. Imaging brain plasticity after trauma

    Institute of Scientific and Technical Information of China (English)

    Zhifeng Kou; Armin Iraji

    2014-01-01

    The brain is highly plastic after stroke or epilepsy;however, there is a paucity of brain plasticity investigation after traumatic brain injury (TBI). This mini review summarizes the most recent evidence of brain plasticity in human TBI patients from the perspective of advanced magnetic resonance imaging. Similar to other forms of acquired brain injury, TBI patients also demonstrat-ed both structural reorganization as well as functional compensation by the recruitment of other brain regions. However, the large scale brain network alterations after TBI are still unknown, and the ifeld is still short of proper means on how to guide the choice of TBI rehabilitation or treat-ment plan to promote brain plasticity. The authors also point out the new direction of brain plas-ticity investigation.

  18. [The history of plastic surgery in Israel].

    Science.gov (United States)

    Wiser, Itay; Scheflan, Michael; Heller, Lior

    2014-09-01

    The medical institutions in the country have advanced together with the development of the state of Israel. Plastic surgery, which has progressed significantly during the 20th century, has also grown rapidly in the new state. The arrival of Jewish plastic surgeons from all over the world with the knowledge and experience gained in their countries of origin, as well as the need for reconstructive surgical treatment for many combat injured soldiers, also contributed to the development of plastic surgery. This review tells the story of plastic surgery in Israel, since its foundation until nowadays. This article reviews the work of the founders of plastic surgery in Israel, indicating significant milestones in its development, and clinical and scientific contribution to the international plastic surgery profession. Moreover, the article describes the current condition of the field of plastic surgery in Israel and presents the trends and the future challenges facing the next generation of plastic surgery in Israel.

  19. Modelling of Rotational Capacity in Reinforced Linear Elements

    DEFF Research Database (Denmark)

    Hestbech, Lars; Hagsten, Lars German; Fisker, Jakob

    2011-01-01

    The Capacity Design Method forms the basis of several seismic design codes. This design philosophy allows plastic deformations in order to decrease seismic demands in structures. However, these plastic deformations must be localized in certain zones where ductility requirements can be documented ...... as the effect of shear cracking on the length of the plastic zone.......The Capacity Design Method forms the basis of several seismic design codes. This design philosophy allows plastic deformations in order to decrease seismic demands in structures. However, these plastic deformations must be localized in certain zones where ductility requirements can be documented...... reinforced concrete elements. The model is taking several important parameters into account. Empirical values is avoided which is considered an advantage compared to previous models. Furthermore, the model includes force variations in the reinforcement due to moment distributions and shear as well...

  20. Basal Reinforced Piled Embankments

    NARCIS (Netherlands)

    Van Eekelen, S.J.M.

    2015-01-01

    A basal reinforced piled embankment consists of a reinforced embankment on a pile foundation. The reinforcement consists of one or more horizontal layers of geosynthetic reinforcement (GR) installed at the base of the embankment. The design of the GR is the subject of this thesis. A basal

  1. The Reinforcement Hierarchy

    Science.gov (United States)

    Forness, Steven R.

    1973-01-01

    Reinforcement hierarchy implies movement along a continuum from top to bottom, from primitive levels of reinforcement to more sophisticated levels. Unless it is immediately obvious that a child cannot function without the use of lower-order reinforcers, we should approach him as though he responds to topmost reinforcers until he demonstrates…

  2. Plastic condoms.

    Science.gov (United States)

    1968-01-01

    Only simple equipment, simple technology and low initial capital investment are needed in their manufacture. The condoms can be made by people who were previously unskilled or only semi-skilled workers. Plastic condoms differ from those made of latex rubber in that the nature of the plastic film allows unlimited shelf-life. Also, the plastic has a higher degree of lubricity than latex rubber; if there is a demand for extra lubrication in a particular market, this can be provided. Because the plastic is inert, these condoms need not be packaged in hermetically sealed containers. All these attributes make it possible to put these condoms on the distributors' shelves in developing countries competitively with rubber condoms. The shape of the plastic condom is based on that of the lamb caecum, which has long been used as luxury-type condom. The plastic condom is made from plastic film (ethylene ethyl acrilate) of 0.001 inch (0.0254 mm.) thickness. In addition, a rubber ring is provided and sealed into the base of the condom for retention during coitus. The advantage of the plastic condom design and the equipment on which it is made is that production can be carried out either in labour-intensive economy or with varying degrees of mechanization and automation. The uniform, finished condom if made using previously untrained workers. Training of workers can be done in a matter of hours on the two machines which are needed to produce and test the condoms. The plastic film is provided on a double wound roll, and condom blanks are prepared by means of a heat-sealing die on the stamping machine. The rubber rings are united to the condom blanks on an assembly machine, which consists of a mandrel and heat-sealing equipment to seal the rubber ring to the base of the condom. Built into the assembly machine is a simple air-testing apparatus that can detect the smallest pinhole flaw in a condom. The manufacturing process is completed by unravelling the condom from the assembly

  3. Deformation reinforcement theory and its application to high arch dams

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper,the deformation reinforcement theory(DRT) proposed by the authors is elaborated with a new definition of instability that an elasto-plastic structure is not stable if it cannot satisfy simultaneously equilibrium condition,kinematical admissibility and constitutive equations under the prescribed loading.Starting from the definition,a proof is established to the principle of minimum plastic complementary energy for failured structures.It is revealed that the principle of mini-mum plastic complementary energy results in relaxed constitutive equations,especially,yield conditions.It is demonstrated with case studies that many key issues in arch dam design,e.g.,global stability,dam-toe reinforcement,dam-toe cracking,dam-abut-ment reinforcement,can be well solved within the framework of the deformation reinforcement theory.The structural global stability can be described by the curve of the plastic complementary energy vs overloading factor.The unbalanced-forces obtained by elasto-plastic FEM can be used as the basis of analysis of global stability,dam-heel cracking,dam-toe anchorage and reinforcement of faults of high arch dams and their foundations.

  4. Plastic Bronchitis.

    Science.gov (United States)

    Rubin, Bruce K

    2016-09-01

    Plastic bronchitis is an uncommon and probably underrecognized disorder, diagnosed by the expectoration or bronchoscopic removal of firm, cohesive, branching casts. It should not be confused with purulent mucous plugging of the airway as seen in patients with cystic fibrosis or bronchiectasis. Few medications have been shown to be effective and some are now recognized as potentially harmful. Current research directions in plastic bronchitis research include understanding the genetics of lymphatic development and maldevelopment, determining how abnormal lymphatic malformations contribute to cast formation, and developing new treatments. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Plastics recycling: challenges and opportunities.

    Science.gov (United States)

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-07-27

    Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3-4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

  6. Plastics recycling: challenges and opportunities

    Science.gov (United States)

    Hopewell, Jefferson; Dvorak, Robert; Kosior, Edward

    2009-01-01

    Plastics are inexpensive, lightweight and durable materials, which can readily be moulded into a variety of products that find use in a wide range of applications. As a consequence, the production of plastics has increased markedly over the last 60 years. However, current levels of their usage and disposal generate several environmental problems. Around 4 per cent of world oil and gas production, a non-renewable resource, is used as feedstock for plastics and a further 3–4% is expended to provide energy for their manufacture. A major portion of plastic produced each year is used to make disposable items of packaging or other short-lived products that are discarded within a year of manufacture. These two observations alone indicate that our current use of plastics is not sustainable. In addition, because of the durability of the polymers involved, substantial quantities of discarded end-of-life plastics are accumulating as debris in landfills and in natural habitats worldwide. Recycling is one of the most important actions currently available to reduce these impacts and represents one of the most dynamic areas in the plastics industry today. Recycling provides opportunities to reduce oil usage, carbon dioxide emissions and the quantities of waste requiring disposal. Here, we briefly set recycling into context against other waste-reduction strategies, namely reduction in material use through downgauging or product reuse, the use of alternative biodegradable materials and energy recovery as fuel. While plastics have been recycled since the 1970s, the quantities that are recycled vary geographically, according to plastic type and application. Recycling of packaging materials has seen rapid expansion over the last decades in a number of countries. Advances in technologies and systems for the collection, sorting and reprocessing of recyclable plastics are creating new opportunities for recycling, and with the combined actions of the public, industry and governments it

  7. Mixed plastics recycling technology

    CERN Document Server

    Hegberg, Bruce

    1995-01-01

    Presents an overview of mixed plastics recycling technology. In addition, it characterizes mixed plastics wastes and describes collection methods, costs, and markets for reprocessed plastics products.

  8. Ties between ageing plasticity and reproductive physiology in honey bees (Apis mellifera) reveal a positive relation between fecundity and longevity as consequence of advanced social evolution.

    Science.gov (United States)

    Rueppell, Olav; Aumer, Denise; Moritz, Robin Fa

    2016-08-01

    Honey bees (Apis mellifera) are the best studied model of ageing among the social insects. As in other social insects, the reproductive queen far outlives her non-reproductive workers despite developing from the same genome in the same colony environment. Thus, the different social roles of the two female castes are critical for the profound phenotypic plasticity. In several special cases, such as the reproductive workers of Apis mellifera capensis, within-caste plasticity enables further studies of the fecundity-longevity syndrome in honey bees. At present, molecular evidence suggests that a reorganization of physiological control pathways may facilitate longevity of reproductive individuals. However, the social role and social environment of the different colony members are also very important and one of the key future questions is how much social facilitation versus internal regulation is responsible for the positive association between fecundity and longevity in honey bees.

  9. Recent advances in high performance poly(lactide): from “green” plasticization to super-tough materials via (reactive) compounding

    Science.gov (United States)

    Kfoury, Georgio; Raquez, Jean-Marie; Hassouna, Fatima; Odent, Jérémy; Toniazzo, Valérie; Ruch, David; Dubois, Philippe

    2013-01-01

    Due to its origin from renewable resources, its biodegradability, and recently, its industrial implementation at low costs, poly(lactide) (PLA) is considered as one of the most promising ecological, bio-sourced and biodegradable plastic materials to potentially and increasingly replace traditional petroleum derived polymers in many commodity and engineering applications. Beside its relatively high rigidity [high tensile strength and modulus compared with many common thermoplastics such as poly(ethylene terephthalate) (PET), high impact poly(styrene) (HIPS) and poly(propylene) (PP)], PLA suffers from an inherent brittleness, which can limit its applications especially where mechanical toughness such as plastic deformation at high impact rates or elongation is required. Therefore, the curve plotting stiffness vs. impact resistance and ductility must be shifted to higher values for PLA-based materials, while being preferably fully bio-based and biodegradable upon the application. This review aims to establish a state of the art focused on the recent progresses and preferably economically viable strategies developed in the literature for significantly improve the mechanical performances of PLA. A particular attention is given to plasticization as well as to impact resistance modification of PLA in the case of (reactive) blending PLA-based systems. PMID:24790960

  10. Plastic fish

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    In terms of weight, the plastic pollution in the world’s oceans is estimated to be around 300,000 tonnes. This plastic comes from both land-based and ocean-based sources. A lecture at CERN by chemist Wolfgang Trettnak addressed this issue and highlighted the role of art in raising people’s awareness.   Artwork by Wolfgang Trettnak. Packaging materials, consumer goods (shoes, kids’ toys, etc.), leftovers from fishing and aquaculture activities… our oceans and beaches are full of plastic litter. Most of the debris from beaches is plastic bottles. “PET bottles have high durability and stability,” explains Wolfgang Trettnak, a chemist by education and artist from Austria, who gave a lecture on this topic organised by the Staff Association at CERN on 26 May. “PET degrades very slowly and the estimated lifetime of a bottle is 450 years.” In addition to the beach litter accumulated from human use, rivers bring several ki...

  11. Plastic zonnecellen

    NARCIS (Netherlands)

    Roggen, Marjolein

    1998-01-01

    De zonnecel van de toekomst is in de maak. Onderzoekers van uiteenlopend pluimage werken eendrachtig aan een plastic zonnecel. De basis is technisch gelegd met een optimale, door invallend licht veroorzaakte, vorming van ladingdragers binnen een composiet van polymeren en buckyballs. Nu is het zaak

  12. Self Healing Fibre-reinforced Polymer Composites: an Overview

    Science.gov (United States)

    Bond, Ian P.; Trask, Richard S.; Williams, Hugo R.; Williams, Gareth J.

    Lightweight, high-strength, high-stiffness fibre-reinforced polymer composite materials are leading contenders as component materials to improve the efficiency and sustainability of many forms of transport. For example, their widespread use is critical to the success of advanced engineering applications, such as the Boeing 787 and Airbus A380. Such materials typically comprise complex architectures of fine fibrous reinforcement e.g. carbon or glass, dispersed within a bulk polymer matrix, e.g. epoxy. This can provide exceptionally strong, stiff, and lightweight materials which are inherently anisotropic, as the fibres are usually arranged at a multitude of predetermined angles within discrete stacked 2D layers. The direction orthogonal to the 2D layers is usually without reinforcement to avoid compromising in-plane performance, which results in a vulnerability to damage in the polymer matrix caused by out-of-plane loading, i.e. impact. Their inability to plastically deform leaves only energy absorption via damage creation. This damage often manifests itself internally within the material as intra-ply matrix cracks and inter-ply delaminations, and can thus be difficult to detect visually. Since relatively minor damage can lead to a significant reduction in strength, stiffness and stability, there has been some reticence by designers for their use in safety critical applications, and the adoption of a `no growth' approach (i.e. damage propagation from a defect constitutes failure) is now the mindset of the composites industry. This has led to excessively heavy components, shackling of innovative design, and a need for frequent inspection during service (Richardson 1996; Abrate 1998).

  13. Plastic Surgery Statistics

    Science.gov (United States)

    ... PSN PSEN GRAFT Contact Us News Plastic Surgery Statistics Plastic surgery procedural statistics from the American Society of Plastic Surgeons. Statistics by Year Print 2016 Plastic Surgery Statistics 2015 ...

  14. Conditioned reinforcement and information theory reconsidered.

    Science.gov (United States)

    Shahan, Timothy A; Cunningham, Paul

    2015-03-01

    The idea that stimuli might function as conditioned reinforcers because of the information they convey about primary reinforcers has a long history in the study of learning. However, formal application of information theory to conditioned reinforcement has been largely abandoned in modern theorizing because of its failures with respect to observing behavior. In this paper we show how recent advances in the application of information theory to Pavlovian conditioning offer a novel approach to conditioned reinforcement. The critical feature of this approach is that calculations of information are based on reductions of uncertainty about expected time to primary reinforcement signaled by a conditioned reinforcer. Using this approach, we show that previous failures of information theory with observing behavior can be remedied, and that the resulting framework produces predictions similar to Delay Reduction Theory in both observing-response and concurrent-chains procedures. We suggest that the similarity of these predictions might offer an analytically grounded reason for why Delay Reduction Theory has been a successful theory of conditioned reinforcement. Finally, we suggest that the approach provides a formal basis for the assertion that conditioned reinforcement results from Pavlovian conditioning and may provide an integrative approach encompassing both domains.

  15. Advances of bio-plastics in food packaging application%食品包装用生物塑料研究进展

    Institute of Scientific and Technical Information of China (English)

    何江川; 张睿; 王颖

    2011-01-01

    在白色污染和石油危机日趋严重的今天,具有生态友好特征和可持续性的生物基质-生物分解塑料有望替代 部分石油基塑料成为一种新型基础原材料,在农业、包装、生物医用等领域已开始显示出巨大的市场潜力.本文介绍 了聚乳酸、淀粉基塑料、聚羟基烷酸酯等几类最有可能率先实现产业化并用于食品包装材料的生物基质-生物分解塑 料,对其在食品包装材料应用方面所具有的优势和存在的问题进行了评价,并对目前国内外在这几类材料的生产和应 用技术及产业化等方面的最新进展进行了归纳.%Biomass- based biodegradable plastics characteristic of ecological concern and sustainability are expected to become a novel category of basic raw materials in a wide range of potential applications such as agriculture, packaging and biomedical ,when white pollution and oil crisis are increasingly serious today. The main categories of biomass- based biodegradable plastics, including poly( lactic acid), starch-based plastics and poly hydroxylalkanoates were introduced,which may most probably take the lead to be commercialized and used for food packaging. Their advantage and shortage in the application of food packaging were commented. The latest development of the manufacturing and applying techniques of these materials together with their industrialization status throughout the world was overviewed.

  16. Clincal report on arthroscopic reconstruction of anterior cruciate ligament using ligament advanced reinforcement system%关节镜下人工韧带重建前交叉韧带临床研究

    Institute of Scientific and Technical Information of China (English)

    董伟强; 尹知训; 白波; 郭志勇

    2011-01-01

    目的 总结关节镜下先进韧带加强系统(LARS,ligament advanced reinforcement system)人工韧带在膝关节前交叉韧带(ACL,anterior cruciate ligament)重建中的早期疗效及注意事项.方法 2006年1月-2010年8月,对15例膝关节ACL损伤患者行关节镜下LARS人工韧带重建术.结果 术后患者均随访9~24个月,平均15个月,术后膝关节不稳症状消失,屈伸活动度为O°~135°;术后14例前抽屉试验、Lanchman试验和轴移试验均为阴性,1例出现可疑Lanchman试验和前抽屉试验阳性;Lysholm膝关节均分为(86.40±2.14)分,与术前比较差异有显著性(P<0.05).结论 LARS人工韧带重建ACL早期效果满意;术中应尽量保留较多的韧带残端和使用准确的等长重建方法.%Objective To explore the operative techniques and preliminary clinical effect of arthroscopic reconstruction of anterior cruciate ligament (ACL) using ligament advanced reinforcement system (LARS).Methods From Jan.2006 to Aug.2010,15 patients with ACL rupture were treated with LARS under arthroscopic observation.All were males,aged 23.0-53.0 years old.All patients had unstable feeling in their knees.The anterior drawer test,Lanchan test and pivot shift test were positive.The average Lyshlom scores was (43.30 ± 1.32).Results All the patients were regular followed up for 9 to 36 months (15 months at average).All the patients feel their knees with no more unstability.The pivot shift test showed 15 case(-); the anterior drawer test and Lanchan test showed 14 case(-),(I) case( ± ).Lysholm scores was (86.40:±:2.14)(P < 0.05) with significant difl`erences with that before operation.Conclusion ACL arthroscopic reconstruction with the use of LARS artificial ligaments leads to rapid recovery and satisfactory clinical efficacy.

  17. Plastic bronchitis

    Directory of Open Access Journals (Sweden)

    Anil Kumar Singhi

    2015-01-01

    Full Text Available Plastic bronchitis, a rare but serious clinical condition, commonly seen after Fontan surgeries in children, may be a manifestation of suboptimal adaptation to the cavopulmonary circulation with unfavorable hemodynamics. They are ominous with poor prognosis. Sometimes, infection or airway reactivity may provoke cast bronchitis as a two-step insult on a vulnerable vascular bed. In such instances, aggressive management leads to longer survival. This report of cast bronchitis discusses its current understanding.

  18. Starch composites reinforced by bamboo cellulosic crystals.

    Science.gov (United States)

    Liu, Dagang; Zhong, Tuhua; Chang, Peter R; Li, Kaifu; Wu, Qinglin

    2010-04-01

    Using a method of combined HNO(3)-KClO(3) treatment and sulfuric acid hydrolysis, bamboo cellulose crystals (BCCs) were prepared and used to reinforce glycerol plasticized starch. The structure and morphology of BCCs were investigated using X-ray diffraction, electron microscopy, and solid-state (13)C NMR. Results showed that BCCs were of typical cellulose I structure, and the morphology was dependent on its concentration in the suspension. BCC of 50-100 nm were assembled into leaf nervations at low concentration (i.e. 0.1 wt.% of solids), but congregated into a micro-sized "flower" geometry at high concentration (i.e. 10.0 wt.% of solids). Tensile strength and Young's modulus of the starch/BCC composite films (SBC) were enhanced by the incorporation of the crystals due to reinforcement of BCCs and reduction of water uptake. BCCs at the optimal 8% loading level exhibited a higher reinforcing efficiency for plasticized starch plastic than any other loading level.

  19. Strength and durability of mixed glass-fibre-reinforced laminates

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Ya.; Limonov, V.A.; Mikel`son, M.; Tamuzh, V. [Inst. Mekhaniki Polimerov AN Latvii, Riga (Russian Federation)

    1994-01-01

    For unidirectional fabric-reinforced and mixed fiber glass plastics the results of static and fatigue tests are presented. Elastic and strength properties have been determined using plain and tubular specimens. Combination of unidirectional and glass fabric reinforcing layers is found to increase considerably torsional strength at inconsiderable decrease of tensile and compression strength. Results of layer-by-layer failure analysis agree well with experimental data. 12 refs.

  20. Diagonal Cracking and Shear Strength of Reinforced Concrete Beams

    DEFF Research Database (Denmark)

    Zhang, Jin-Ping

    1997-01-01

    found by the usual plastic theory, a physical explanation is given for this phenomenon and a way to estimate the shear capacity of reinforced concrete beams, based on the theory of plasticity, is described. The theoretical calculations are shown to be in fairly good agreement with test results from......The shear failure of non-shear-reinforced concrete beams with normal shear span ratios is observed to be governed in general by the formation of a critical diagonal crack. Under the hypothesis that the cracking of concrete introduces potential yield lines which may be more dangerous than the ones...

  1. Management of Reinforcement Corrosion

    DEFF Research Database (Denmark)

    Küter, André; Geiker, Mette Rica; Møller, Per

    Reinforcement corrosion is the most important cause for deterioration of reinforced concrete structures, both with regard to costs and consequences. Thermodynamically consistent descriptions of corrosion mechanisms are expected to allow the development of innovative concepts for the management...... of reinforcement corrosion....

  2. Partial Planning Reinforcement Learning

    Science.gov (United States)

    2012-08-31

    This project explored several problems in the areas of reinforcement learning , probabilistic planning, and transfer learning. In particular, it...studied Bayesian Optimization for model-based and model-free reinforcement learning , transfer in the context of model-free reinforcement learning based on

  3. Variable Resolution Reinforcement Learning.

    Science.gov (United States)

    1995-04-01

    Can reinforcement learning ever become a practical method for real control problems? This paper begins by reviewing three reinforcement learning algorithms... reinforcement learning . In addition to exploring state space, and developing a control policy to achieve a task, partigame also learns a kd-tree partitioning of

  4. Fundamentals of the theory of plasticity

    CERN Document Server

    Kachanov, L M

    2004-01-01

    Intended for use by advanced engineering students and professionals, this volume focuses on plastic deformation of metals at normal temperatures, as applied to strength of machines and structures. 1971 edition.

  5. Vascular plasticity in cerebrovascular disorders

    DEFF Research Database (Denmark)

    Edvinsson, Lars I H; Povlsen, Gro Klitgaard

    2011-01-01

    Cerebral ischemia remains a major cause of morbidity and mortality with little advancement in subacute treatment options. This review aims to cover and discuss novel insight obtained during the last decade into plastic changes in the vasoconstrictor receptor profiles of cerebral arteries and micr...

  6. Cellular plasticity and tumor therapy resistance:research advances%细胞可塑性与肿瘤治疗耐药的研究进展

    Institute of Scientific and Technical Information of China (English)

    陈亚琼; 刘卫; 彭晖

    2014-01-01

    Drug resistance,tumor relapse and metastasis remain the main obstacles to the success of cancer treatments. Chemotherapies,targeted therapies and immunotherapies can successfully achieve remissions in cancer patients,but durable responses are rare. Although the mechanisms of diverse therapies vary,plasticity alteration of tumor and immune cells in response to therapy-induced tumor tissue injury and inflammation contributes to the development of drug resistance. This review summarizes research progress in the adaptive phenotypic plasticity of tumor cells and immune cells during tumor progression as well as the successful combination of targeted therapy and immunotherapy in cancer treatment to tackle resistance.%肿瘤的耐药、复发和转移是肿瘤治疗的首要难题。化疗、靶向治疗和免疫治疗对肿瘤患者效果显著,但持续时间短暂。尽管不同治疗方式下耐药性产生的机制各异,但由多种治疗手段引起肿瘤组织损伤和炎症共同介导的细胞可塑性的改变是肿瘤耐药产生的主要原因。本文综述了肿瘤细胞和免疫细胞可塑性改变对肿瘤发展的影响,以及联合免疫治疗和靶向治疗逆转肿瘤耐药的研究进展。

  7. Advances in the diagnosis and treatment of children with plastic bronchitis%儿童塑型性支气管炎诊疗进展

    Institute of Scientific and Technical Information of China (English)

    张雪

    2013-01-01

    儿童塑型性支气管炎是一种较罕见的疾病,病因不明,起病隐匿,进展快,症状重,诊断和治疗难度大,病死率高.儿童塑型支气管炎被认为与某些疾病包括支气管哮喘、囊性纤维病、伴发急性胸部综合征的镰状细胞病、先天性心脏病以及各种呼吸道细菌性和病毒性感染有一定关系.关于儿童塑型性支气管炎的诊断和治疗目前仍较困难,临床医生应该警惕该病,做到早期诊断、早期治疗.%Children with plastic bronchitis,characterized by unknown origin,insidious onset,rapid progress,severe symptom and high mortality,is a relatively rare disease.Also,it is difficult to diagnose and treat with plastic bronchitis characterized by marked airway obstruction,via the formation of large gelatinous or rigid airway cast.It is associated with certain diseases including bronchial asthma,cystic fibrosis,accompanied with acute chest syndrome with sickle cell disease,congenital heart disease and bacterial and viral respiratory infection.Clinicians should be aware of this disease,and early bronchoscopy should be intervened.

  8. Soil Reinforcement Techniques

    Directory of Open Access Journals (Sweden)

    Prashant Patil

    2016-08-01

    Full Text Available In many activities concerned with the use of soil, the physical properties like Stiffness, Compressibility and Strength are some of the few important parameters to be considered. Of the many methods involved in improvement of soil properties, soil reinforcement is method concerned with increase of strength properties of soil. In soil reinforcement, the reinforcements or resisting element are of different materials and of various forms depending upon the intended use. The reinforcement can be provided permanently or temporarily to increase strength of adjacent structures. The present topic of discussion involves different materials, forms and applications of soil reinforcement

  9. Microelectronics plastic molded packaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.R. [Ktech Corp., Albuquerque, NM (United States); Palmer, D.W.; Peterson, D.W. [Sandia National Lab., Albuquerque, NM (United States)] [and others

    1997-02-01

    The use of commercial off-the-shelf (COTS) microelectronics for nuclear weapon applications will soon be reality rather than hearsay. The use of COTS for new technologies for uniquely military applications is being driven by the so-called Perry Initiative that requires the U.S. Department of Defense (DoD) to accept and utilize commercial standards for procurement of military systems. Based on this philosophy, coupled with several practical considerations, new weapons systems as well as future upgrades will contain plastic encapsulated microelectronics. However, a conservative Department of Energy (DOE) approach requires lifetime predictive models. Thus, the focus of the current project is on accelerated testing to advance current aging models as well as on the development of the methodology to be used during WR qualification of plastic encapsulated microelectronics. An additional focal point involves achieving awareness of commercial capabilities, materials, and processes. One of the major outcomes of the project has been the definition of proper techniques for handling and evaluation of modern surface mount parts which might be used in future systems. This program is also raising the familiarity level of plastic within the weapons complex, allowing subsystem design rules accommodating COTS to evolve. A two year program plan is presented along with test results and commercial interactions during this first year.

  10. 碳纤维复合材料的智能复合反射镜技术研究%Research on Smart Mirror based on Carbon Fiber Reinforced Plastics

    Institute of Scientific and Technical Information of China (English)

    王志

    2013-01-01

    With the enlargement of aperture of optical telescope,reducing largely the mass of mirror and simplifying the support structure were getting more and more important,as a new and effective option,the CFRP (Carbon Fiber Re-inforeed Plastics) smart mirror was provided. Firstly, the constitution of smart mirror and the theory of active surface correction were introduced. Then the models of surface correction and optimization were provided. Secondly,the fabrica-tion of CFRP composite mirror and optical manufacture were introduced in detail. Thirdly, the optical measure method of Hartmann was provided for the smart mirror. So this smart mirror will have important value to the development of space-based and ground-based telescope.%随着望远镜光学口径的不断增大,为了最大限度地降低光学镜面重量,精简镜面支撑结构,提出了基于CFRP复合材料的智能反射镜技术,从技术层面分析了该技术的可行性及发展前景。文章具体从智能反射镜组成和主动面形校正原理出发,推导了智能反射镜面形校正模型的建立及面形优化的数学模型,对复合反射镜镜体的制备工艺、加工方法以及哈特曼波前检测技术进行了详细的介绍。深入开展该项技术研究对空间和地面大口径望远镜的发展具有的重要的意义。

  11. MEASURING AND MODELING OF THE MECHANICAL PROPERTIES OF COMPOSITE BEARING PAD MADE OF PLASTIC MATRIX AND FINE BRONZE ELASTIC SPRINGS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The viscoelastic properties of the normal PTFE plastic and strengthened PTFE plastic for bearing pad are measured. The mechanical properties of the composite material for bearing pad, which is made of the aforementioned plastics as matrix reinforced by fine bronze elastic springs, are modeled and relaxation modulus of the material are presented. The difference between these two kinds of PTFE is studied. The results show that the complex modulus of PTFE plastics for bearing pad is higher than that of normal PTFE plastics.

  12. Supercritical Water Process for the Chemical Recycling of Waste Plastics

    Science.gov (United States)

    Goto, Motonobu

    2010-11-01

    The development of chemical recycling of waste plastics by decomposition reactions in sub- and supercritical water is reviewed. Decomposition reactions proceed rapidly and selectively using supercritical fluids compared to conventional processes. Condensation polymerization plastics such as PET, nylon, and polyurethane, are relatively easily depolymerized to their monomers in supercritical water. The monomer components are recovered in high yield. Addition polymerization plastics such as phenol resin, epoxy resin, and polyethylene, are also decomposed to monomer components with or without catalysts. Recycling process of fiber reinforced plastics has been studied. Pilot scale or commercial scale plants have been developed and are operating with sub- and supercritical fluids.

  13. Ceramic susceptor for induction bonding of metals, ceramics, and plastics

    Science.gov (United States)

    Fox, Robert L.; Buckley, John D.

    1991-01-01

    A thin (.005) flexible ceramic susceptor (carbon) was discovered. It was developed to join ceramics, plastics, metals, and combinations of these materials using a unique induction heating process. Bonding times for laboratory specimens comparing state of the art technology to induction bonding were cut by a factor of 10 to 100 times. This novel type of carbon susceptor allows for applying heat directly and only to the bondline without heating the entire structure, supports, and fixtures of a bonding assembly. The ceramic (carbon film) susceptor produces molten adhesive or matrix material at the bond interface. This molten material flows through the perforated susceptor producing a fusion between the two parts to be joined, which in many instances has proven to be stronger than the parent material. Bonding can be accomplished in 2 minutes on areas submitted to the inductive heating. Because a carbon susceptor is used in bonding carbon fiber reinforced plastics and ceramics, there is no radar signature or return making it an ideal process for joining advanced aerospace composite structures.

  14. 基于 VARTM 工艺的纤维增强复合材料携行箱的研制%Development of Portable Box with Mixed-fiber Reinforced Plastic Based on VARTM Technique

    Institute of Scientific and Technical Information of China (English)

    龚水莲; 田阳

    2015-01-01

    Because of the rapid change in the battle field , high mobility of the system is required , which means the portable box to load and protect the electronic equipment is required to be lightweight .According to the lightweight requirement , the vacuum assisted resin transfer molding ( VARTM) technique is studied and a kind of portable box made of carbon fiber and Kevlar as the reinforced composite material is developed in this paper . The effectiveness and feasibility of this VARTM technique for the portable box with integral shaping method are verified .Due to the advantages of light weight , high intensity , rapid molding , efficient production , low cost and excellent environmental adaptation , this portable box is of high value and has a bright future .%为适应战场环境的快速变化,要求系统具有高机动性能,也要求用来装载和保护电子设备的携行箱更加轻量化。文中针对轻量化需求,采用高强度、高模量的碳纤维材料和耐冲击性能好的芳纶材料作为增强复合材料,研究真空辅助树脂传递模塑( Vacuum Assisted Resin Transfer Molding ,VARTM)整体成型工艺,研制了轻型复合材料携行箱,并对携行箱VARTM 工艺成型的有效性及可行性进行了验证。采用该工艺制作的携行箱具有重量轻、强度高、成型快速、生产效率高、制造成本低、环境适应性强等优点,具有较高的工程价值和发展前景。

  15. Habituation of reinforcer effectiveness

    Directory of Open Access Journals (Sweden)

    David R Lloyd

    2014-01-01

    Full Text Available In this paper we propose an integrative model of habituation of reinforcer effectiveness (HRE that links behavioral and neural based explanations of reinforcement. We argue that habituation of reinforcer effectiveness (HRE is a fundamental property of reinforcing stimuli. Most reinforcement models implicitly suggest that the effectiveness of a reinforcer is stable across repeated presentations. In contrast, an HRE approach predicts decreased effectiveness due to repeated presentation. We argue that repeated presentation of reinforcing stimuli decreases their effectiveness and that these decreases are described by the behavioral characteristics of habituation (McSweeney and Murphy, 2009;Rankin et al., 2009. We describe a neural model that postulates a positive association between dopamine neurotransmission and HRE. We present evidence that stimulant drugs, which artificially increase dopamine neurotransmission, disrupt (slow normally occurring HRE and also provide evidence that stimulant drugs have differential effects on operant responding maintained by reinforcers with rapid vs. slow HRE rates. We hypothesize that abnormal HRE due to genetic and/or environmental factors may underlie some behavioral disorders. For example, recent research indicates that slow-HRE is predictive of obesity. In contrast ADHD may reflect ‘accelerated-HRE’. Consideration of HRE is important for the development of effective reinforcement based treatments. Finally, we point out that most of the reinforcing stimuli that regulate daily behavior are non-consumable environmental/social reinforcers which have rapid-HRE. The almost exclusive use of consumable reinforcers with slow-HRE in pre-clinical studies with animals may have caused the importance of HRE to be overlooked. Further study of reinforcing stimuli with rapid-HRE is needed in order to understand how habituation and reinforcement interact and regulate behavior.

  16. Punishment Insensitivity and Impaired Reinforcement Learning in Preschoolers

    Science.gov (United States)

    Briggs-Gowan, Margaret J.; Nichols, Sara R.; Voss, Joel; Zobel, Elvira; Carter, Alice S.; McCarthy, Kimberly J.; Pine, Daniel S.; Blair, James; Wakschlag, Lauren S.

    2014-01-01

    Background: Youth and adults with psychopathic traits display disrupted reinforcement learning. Advances in measurement now enable examination of this association in preschoolers. The current study examines relations between reinforcement learning in preschoolers and parent ratings of reduced responsiveness to socialization, conceptualized as a…

  17. 橡胶增韧塑料机理研究进展%Advance in research on mechanisms for rubber-toughening of plastics

    Institute of Scientific and Technical Information of China (English)

    王荣伟

    2012-01-01

    The mechanisms for deformation behaviors of rubber-toughened plastics are summarized in terms of their evolution, limitations and relationship with the failure behaviors of glassy polymer matrices. The difference between craze and crack is explained in detail using many experimental evidences in literature. In particular, Souheng Wu's quantitative method is systematically explained, which is derived from this yielding-crazing competition theory and reveals the quantitative relationship between molecular chain parameters of the matrices and morphological parameters of the dispersed rubber phase. In addition, Wu's view is emphasized that chain parameters of the matrices control the intrinsic brittleness and toughness of both matrix and its blend with rubber, and determine the favorable morphology of rubber phase as well.%介绍了橡胶增韧塑料机理演进及其与不同链结构基体树脂断裂行为的关系,描述了银纹和裂缝区别,详细地介绍了不同基体树脂的分子链参数与橡胶分散相形态参数的定量关系,同时强调基体树脂的链参数既控制聚合物/橡胶共混物的本征韧性,又决定了橡胶分散相的适宜形态.

  18. Structural Engineering Properties of Fibre Reinforced Concrete Based On Recycled Glass Fibre Polymer (GFRP

    Directory of Open Access Journals (Sweden)

    Adetiloye A

    2015-04-01

    Full Text Available Glass fibre reinforced plastics (GFRP based on resin recovered from recycling plastic waste has been shown to possess mechanical properties satisfying normative requirements. This paper investigates the flexural behavior of concrete beams reinforced with GFRP produced from resin recovered from recycled plastic wastes. A total of twelve of beams of sizes 150 ×150 ×900mm and 100 × 100 × 500mm reinforced with GFRP made from recycled glass fibre reinforced polymer was tested. The flexural test results yielded lower ultimate load, lower stiffness and larger deflections at the same load when compared with the control steel reinforced beam. However, the ultimate flexural strength of beams, reinforced with GFRP from recycled resin was at least four times higher than that of the control unreinforced beam. This is in agreement, quantitatively and qualitatively, with the trend of these parameters in GFRP reinforced concrete based on virgin resins. The results therefore confirm the applicability for structural uses of GFRP reinforcement made from recycled plastic waste, with the accompanying benefits of wealth creation, value addition and environmental sustainability.

  19. Effect of Moisture Absorption Behavior on Mechanical Properties of Basalt Fibre Reinforced Polymer Matrix Composites

    OpenAIRE

    Amuthakkannan Pandian; Manikandan Vairavan; Winowlin Jappes Jebbas Thangaiah; Marimuthu Uthayakumar

    2014-01-01

    The study of mechanical properties of fibre reinforced polymeric materials under different environmental conditions is much important. This is because materials with superior ageing resistance can be satisfactorily durable. Moisture effects in fibre reinforced plastic composites have been widely studied. Basalt fibre reinforced unsaturated polyester resin composites were subjected to water immersion tests using both sea and normal water in order to study the effects of water absorption behavi...

  20. A review of plastic waste biodegradation.

    Science.gov (United States)

    Zheng, Ying; Yanful, Ernest K; Bassi, Amarjeet S

    2005-01-01

    With more and more plastics being employed in human lives and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. This review looks at the technological advancement made in the development of more easily biodegradable plastics and the biodegradation of conventional plastics by microorganisms. Additives, such as pro-oxidants and starch, are applied in synthetic materials to modify and make plastics biodegradable. Recent research has shown that thermoplastics derived from polyolefins, traditionally considered resistant to biodegradation in ambient environment, are biodegraded following photo-degradation and chemical degradation. Thermoset plastics, such as aliphatic polyester and polyester polyurethane, are easily attacked by microorganisms directly because of the potential hydrolytic cleavage of ester or urethane bonds in their structures. Some microorganisms have been isolated to utilize polyurethane as a sole source of carbon and nitrogen source. Aliphatic-aromatic copolyesters have active commercial applications because of their good mechanical properties and biodegradability. Reviewing published and ongoing studies on plastic biodegradation, this paper attempts to make conclusions on potentially viable methods to reduce impacts of plastic waste on the environment.

  1. LARS人工韧带同时重建前、后交叉韧带%Reconstruction of both the anterior cruciate ligament and posterior cruciate ligament with ligament advanced reinforcement system artificial ligament transplantation under knee arthroscopy

    Institute of Scientific and Technical Information of China (English)

    尚平; 贺宪; 江永发; 刘志祥; 才忠民; 杨俊龙

    2007-01-01

    目的 探讨关节镜下LARS(Ligament Advanced Reinforcement System,LARS)人工韧带同时重建前(Anterior cruciate ligament,ACL)、后交叉韧带(posterior cruciate ligament,PCL)的方法和临床疗效.方法 从2006年1月至2007年4月,用LARS人工韧带同时重建ACL、PCL2例.应用Lysholm功能评分表评估膝关节功能,采用抽屉实验检查膝关节前后松弛度.结果 2例均获得随访,随访时间分别为8月、3月.2例患者术后患膝关节不稳定症状消失,胫骨后坠征阴性,前、后抽屉试验阴性.膝关节功能评估采用Lysholm功能评分标准,术前平均分别为45.6±7.6分,术后平均为80.3±9.1分.结论 关节镜下应用LARS人工韧带同时重建ACL、PCL可更好地恢复膝关节的稳定性,且创伤小,并发症少,近期疗效满意,但远期效果仍需进一步观察.

  2. Reinforcement Learning: A Tutorial.

    Science.gov (United States)

    1997-01-01

    The purpose of this tutorial is to provide an introduction to reinforcement learning (RL) at a level easily understood by students and researchers in...provides a simple example to develop intuition of the underlying dynamic programming mechanism. In Section (2) the parts of a reinforcement learning problem... reinforcement learning algorithms. These include TD(lambda) and both the residual and direct forms of value iteration, Q-learning, and advantage learning

  3. Mechanically reinforced glass beams

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Olesen, John Forbes

    2007-01-01

    to breakage without any warning or ductility, which can be catastrophic if no precautions are taken. One aspect of this issue is treated here by looking at the possibility of mechanically reinforcing glass beams in order to obtain ductile failure for such a structural component. A mechanically reinforced...... the mechanical behavior of the beam is explained. Finally, some design criterions for reinforced glass beams are discussed....

  4. Finite element modelling of fibre-reinforced brittle materials

    NARCIS (Netherlands)

    Kullaa, J.

    1997-01-01

    The tensile constitutive behaviour of fibre-reinforced brittle materials can be extended to two or three dimensions by using the finite element method with crack models. The three approaches in this study include the smeared and discrete crack concepts and a multi-surface plasticity model. The tensi

  5. Aspects of Robust Computational Modeling for Plain and Reinforced Concrete

    NARCIS (Netherlands)

    Feenstra, F.H.; De Borst, R.

    1993-01-01

    The problems commonly encountered in the numerical analysis of reinforced structures are often related to biaxial stress states in the structure. In this study this problem is solved with the formulation of a composite plasticity model which describes both cracking and crushing of concrete within th

  6. Rip-Stop Reinforced Thin Film Sun Shield Structure Project

    Data.gov (United States)

    National Aeronautics and Space Administration — During a proposed Phase I and Phase II program, PSI will advance the TRL from 3 to 6 for the ripstop reinforcement of thin film membranes used for large deployable...

  7. Recycling of Plastic

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde

    2011-01-01

    Plastic is produced from fossil oil. Plastic is used for many different products. Some plastic products like, for example, wrapping foil, bags and disposable containers for food and beverage have very short lifetimes and thus constitute a major fraction of most waste. Other plastic products like......, good strength and long durability. Recycling of plastic waste from production is well-established, while recycling of postconsumer plastic waste still is in its infancy. This chapter describes briefly how plastic is produced and how waste plastic is recycled in the industry. Quality requirements...

  8. Finite-size effects in a model for plasticity of amorphous composites

    DEFF Research Database (Denmark)

    Tyukodi, Botond; Lemarchand, Claire; Hansen, Jesper Schmidt

    2016-01-01

    We discuss the plastic behavior of an amorphous matrix reinforced by hard particles. A mesoscopic depinning-like model accounting for Eshelby elastic interactions is implemented. Only the effect of a plastic disorder is considered. Numerical results show a complex size dependence of the effective...... flow stress of the amorphous composite. In particular, the departure from the mixing law shows opposite trends associated to the competing effects of the matrix and the reinforcing particles, respectively. The reinforcing mechanisms and their effects on localization are discussed. Plastic strain...... is shown to gradually concentrate on the weakest band of the system. This correlation of the plastic behavior with the material structure is used to design a simple analytical model. The latter nicely captures reinforcement size effects in (logN/N)1/2, where N is the linear size of the system, observed...

  9. Fly ash-reinforced thermoplastic starch composites

    Energy Technology Data Exchange (ETDEWEB)

    Ma, X.F.; Yu, J.G.; Wang, N. [Tianjin University, Tianjin (China). School of Science

    2007-01-02

    As a by-product from the combustion of pulverized coal, fly ash was, respectively, used as the reinforcement for formamide and urea-plasticized thermoplastic starch (FUPTPS) and glycerol-plasticized thermoplastic starch (GPTPS). The introduction of fly ash improved tensile stress from 4.56 MPa to 7.78 MPa and Youngs modulus increased trebly from 26.8 MPa to 84.6 MPa for fly ash-reinforced FUPTPS (A-FUPTPS), while tensile stress increased from 4.55 MPa to 12.86 MPa and Youngs modulus increased six times from 76.4 MPa to 545 MPa for fly ash-reinforced GPTPS (A-GPTPS). X-ray diffractograms illustrated that fly ash destroyed the formation of starch ordered crystal structure, so both A-GPTPS and FUPTPS could resist the starch re-crystallization (retrogradation). Also fly ash improved water resistance of TPS. As shown by rheology, during the thermoplastic processing, the extruder screw speed effectively adjusted the flow behavior of A-FUPTPS, while the increasing of the processing temperature effectively ameliorated the flow behavior of A-GPTPS. However, superfluous ash contents (e.g., 20 wt%) worsened processing fluidity and resulted in the congregation of fly ash in FUPTPS matrix (tested by SEM) rather than in GPTPS matrix. This congregation decreased the mechanical properties and water resistance of the materials.

  10. Geotehnical Properties of Plastic Stabilized Lateritic Soil

    OpenAIRE

    Akinola Johnson Olarewaju

    2016-01-01

    Stabilization is the combination of soils and additives to change its properties and remain in its stable compacted state without undergoing any change under effect of exposure to weather and traffic. Soil stabilization through the reinforced soil construction is an efficient and reliable technique for improving the strength and stability of soils. The lateritic soil used in this study was taken along Papa-Ilaro road Ajegunle at Abalabi, Ogun State, Nigeria and the solid plastic wastes were t...

  11. Punching shear capacity of reinforced concrete slabs with headed shear studs

    DEFF Research Database (Denmark)

    Hoang, Linh Cao; Pop, Anamaria

    2015-01-01

    Punching shear in slabs is analogous to shear in beams. Despite this similarity, current design codes provide distinctly different methods for the design of shear reinforcement in the two situations. For example, the Eurocode method for beam shear design is founded on the theory of rigid plasticity....... To design shear reinforcement in slabs, on the other hand, the engineer must settle for an empirical equation. The aim of the study reported is to demonstrate that it is possible in a simple manner to design shear reinforcement in slabs based on the same rigid-plasticity foundation as for beam shear design...

  12. Response Analysis for Steel Reinforced Concrete Frame Structures under Earthquake Load

    OpenAIRE

    Hua Wei; Jiye Zhang; Haijun Wang

    2013-01-01

    In order to understand the whole process of the steel reinforced concrete frame structure from elastic to elasto-plastic cracking gradually, damage until the collapse, the elasto-plastic finite element analysis theory and ETABS structural analysis software were used, then the spatial three-dimensional truss system model of frame structures was established. Based on the analysis of the elasto-plastic response for the frame structure under one-dimensional and two-dimensional earthquake load, th...

  13. Continuous Reinforced Concrete Beams

    DEFF Research Database (Denmark)

    Hoang, Cao Linh; Nielsen, Mogens Peter

    1996-01-01

    This report deals with stress and stiffness estimates of continuous reinforced concrete beams with different stiffnesses for negative and positive moments e.g. corresponding to different reinforcement areas in top and bottom. Such conditions are often met in practice.The moment distribution...

  14. Hierarchical Multiagent Reinforcement Learning

    Science.gov (United States)

    2004-01-25

    In this paper, we investigate the use of hierarchical reinforcement learning (HRL) to speed up the acquisition of cooperative multiagent tasks. We...introduce a hierarchical multiagent reinforcement learning (RL) framework and propose a hierarchical multiagent RL algorithm called Cooperative HRL. In

  15. "Reinforcement" in behavior theory.

    Science.gov (United States)

    Schoenfeld, W N

    1978-01-01

    In its Pavlovian context, "reinforcement" was actually a descriptive term for the functional relation between an unconditional and a conditional stimulus. When it was adopted into operant conditioning, "reinforcement" became the central concept and the key operation, but with new qualifications, new referents, and new expectations. Some behavior theorists believed that "reinforcers" comprise a special and limited class of stimuli or events, and they speculated about what the essential "nature of reinforcement" might be. It is now known that any stimulus can serve a reinforcing function, with due recognition of such parameters as subject species characteristics, stimulus intensity, sensory modality, and schedule of application. This paper comments on these developments from the standpoint of reflex behavior theory.

  16. Vascular plasticity in cerebrovascular disorders

    DEFF Research Database (Denmark)

    Edvinsson, Lars I H; Povlsen, Gro Klitgaard

    2011-01-01

    Cerebral ischemia remains a major cause of morbidity and mortality with little advancement in subacute treatment options. This review aims to cover and discuss novel insight obtained during the last decade into plastic changes in the vasoconstrictor receptor profiles of cerebral arteries and micr......Cerebral ischemia remains a major cause of morbidity and mortality with little advancement in subacute treatment options. This review aims to cover and discuss novel insight obtained during the last decade into plastic changes in the vasoconstrictor receptor profiles of cerebral arteries...... therapeutic target for prevention of vasoconstrictor receptor upregulation after stroke. Together, those findings provide new perspectives on the pathophysiology of ischemic stroke and point toward a novel way of reducing vasoconstriction, neuronal cell death, and thus neurologic deficits after stroke....

  17. Controlling floor heave of extraction opening by reinforcing sides and roof

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-jun

    2005-01-01

    The effect of reinforcing roof, sides and floor corners to control floor heave of extraction opening was analyzed, It was proved by engineering practice and numerical simulation that reinforcing any part of surrounding rock have certainly control effect for floor heave, in the basis of this, the new way that roof, sides and floor corners were reinforced to control floor heave was put forward. Contrasting control result of reinforcing floor with this, it is determined that reinforcing is more suitable to control floor heave of extraction opening than reinforcing floor when advancing abutment pressure is in some range.

  18. Reinforcement learning improves behaviour from evaluative feedback

    Science.gov (United States)

    Littman, Michael L.

    2015-05-01

    Reinforcement learning is a branch of machine learning concerned with using experience gained through interacting with the world and evaluative feedback to improve a system's ability to make behavioural decisions. It has been called the artificial intelligence problem in a microcosm because learning algorithms must act autonomously to perform well and achieve their goals. Partly driven by the increasing availability of rich data, recent years have seen exciting advances in the theory and practice of reinforcement learning, including developments in fundamental technical areas such as generalization, planning, exploration and empirical methodology, leading to increasing applicability to real-life problems.

  19. Fundamentals of fibre-reinforced soil engineering

    CERN Document Server

    Shukla, Sanjay Kumar

    2017-01-01

    This book is intended to serve as a one-stop reference on fibre-reinforced soils. Over the past 30-35 years, the engineering behaviour of randomly distributed/oriented fibre-reinforced soil, also called simply fibre-reinforced soil, has been investigated in detail by researchers and engineers worldwide. Waste fibres (plastic waste fibres, old tyre fibres, etc.) create disposal and environmental problems. Utilization of such fibres in construction can help resolve these concerns. Research studies and some field applications have shown that the fibres can be utilized in large quantities in geotechnical and civil engineering applications in a cost-effective and environmentally friendly manner. This book covers a complete description of fibres, their effects when included within a soil or other similar materials such as the fly ash, and their field applications. It gives a detailed view of fibre-reinforced soil engineering. The book will be useful to students, professional, and researchers alike, and can also ser...

  20. Applications and Properties of Fibre Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Amit Rai1 ,

    2014-05-01

    Full Text Available In conventional concrete, micro-cracks develop before structure is loaded because of drying shrinkage and other causes of volume change. When the structure is loaded, the micro cracks open up and propagate because of development of such micro-cracks, results in inelastic deformation in concrete. Fibre reinforced concrete (FRC is cementing concrete reinforced mixture with more or less randomly distributed small fibres. In the FRC, a numbers of small fibres are dispersed and distributed randomly in the concrete at the time of mixing, and thus improve concrete properties in all directions. The fibers help to transfer load to the internal micro cracks. FRC is cement based composite material that has been developed in recent years. It has been successfully used in construction with its excellent flexural-tensile strength, resistance to spitting, impact resistance and excellent permeability and frost resistance. It is an effective way to increase toughness, shock resistance and resistance to plastic shrinkage cracking of the mortar. These fibers have many benefits. Steel fibers can improve the structural strength to reduce in the heavy steel reinforcement requirement. Freeze thaw resistance of the concrete is improved. Durability of the concrete is improved to reduce in the crack widths. Polypropylene and Nylon fibers are used to improve the impact resistance. Many developments have been made in the fiber reinforced concrete.

  1. A new dedicated finite element for push-over analysis of reinforced concrete shear wall systems

    Directory of Open Access Journals (Sweden)

    Delal Doğru ORMANCI

    2016-06-01

    Full Text Available In this study, a finite element which has been analyzed based on anisotropic behavior of reinforced shear walls is developed. Element stiffness matrices were varied based on whether the element is in the tension or the compression zone of the cross-section. Nonlinear behavior of reinforced shear wall model is investigated under horizontal loads. This behavior is defined with a similar approach to plastic hinge assumption in frame structures that the finite element behaves lineer elastic between joints and plastic deformations are concentrated on joints as vertical plastic displacements. According to this acceptance, plastic behavior of reinforced shear wall occurs when the vertical strain reaches elastic strain limit. In the definition of finite element, displacement functions are chosen considering that the partition of shear walls just at floor levels, are enough for solution. Results of this study are compared with the solution obtained from a different computer programme and experimental results.

  2. Flow modelling of steel fibre reinforced self-compacting concrete

    DEFF Research Database (Denmark)

    Svec, Oldrich

    Concrete is one of the most widely used materials in the world. Ordinary concrete composition makes the material strong in compression yet weak and brittle in tension. Steel reinforced concrete successfully eliminates the weak tensile properties of the ordinary concrete. Steel fibres dispersed...... in concrete can efficiently substitute or supplement conventional steel reinforcement, such as reinforcement bars. Ordinary concrete composition further makes the material stiff and non-flowable. Self-compacting concrete is an alternative material of low yield stress and plastic viscosity that does flow...... and fills the formwork with a little or no effort. Steel fibre reinforced self-compacting concrete is a logical combination of the two types of concrete. The combination nevertheless creates several challenges. It has been observed by many authors that steel fibres orient and distribute according...

  3. AN FE ANALYSIS OF REINFORCED SUBGRADE UNDER AUTOMOBILE LOADING

    Institute of Scientific and Technical Information of China (English)

    YAN Shuwang; ZHANG Xinqiang; LIU Run

    2004-01-01

    An FE analysis procedure was presented to predict the behavior of soil-geogrid interaction under automobile loading. The dynamic interactions between the transverse bars, the longitudinal ribs and the soil were simulated by a system consisting of nonlinear springs, dashpots and masses, to study the deformation properties of the reinforced soil. The equivalent stiffness and damping ratios could be determined with the shaking table. The dynamic responses of a reinforced subgrade were analyzed with the 3D finite element approach. This approach is programmed and applied to analyze the soil-geogrid interaction under dynamic loading. The comparative analysis of the response of the reinforced subgrade and that of the subgrade without reinforcement shows that the geogrid placed at the bottom of the base layer may effectively reduce the accumulative plastic deformation due to the cyclic automobile loading.

  4. Strength of Cracked Reinforced Concrete Disks

    DEFF Research Database (Denmark)

    Hoang, Cao Linh; Nielsen, Mogens Peter

    1999-01-01

    The paper deals with models, based on the theory of plasticity, to be used in strength assessments of reinforced concrete disks suffering from different kinds of cracking. Based on the assumption that the sliding strength of concrete is reduced in sections where cracks are located, solutions...... for the shear strength of disks with initial cracks and disks suffering from isotropic cracking are presented. Furthermore, in the case of isotropicly cracked disks subjected to arbitrary in-plane loading, a general yield condition is derived....

  5. Tracks of cosmic rays in plastics.

    Science.gov (United States)

    Fleischer, R L; Price, P B; Walker, R M; Filz, R C; Fukui, K; Friedlander, M W; Holeman, E; Rajan, R S; Tamhane, A S

    1967-01-13

    Cosmic ray nuclei have been observed with the use of plastic trackdetecting solids in satellites and high-altitude balloon flights. Nuclear emulsions in the stacks of plastic sheets allowed the positive identification of cosmic raynuclei as light as nitrogen. The most striking new information was the failure to observe relativistic iron nuclei, a result which has led to an advance in the understanding of track registration criteria.

  6. Continuous Reinforced Concrete Beams

    DEFF Research Database (Denmark)

    Hoang, Cao Linh; Nielsen, Mogens Peter

    1996-01-01

    This report deals with stress and stiffness estimates of continuous reinforced concrete beams with different stiffnesses for negative and positive moments e.g. corresponding to different reinforcement areas in top and bottom. Such conditions are often met in practice.The moment distribution...... at the limit state of serviceability is in some simple cases determined by setting up the statical and the compatibility conditions.With these moment distributions, the maximum deflection and the reinforcement stresses at the span middle and at a support are calculated.The results are compared with results...

  7. Algorithms for Reinforcement Learning

    CERN Document Server

    Szepesvari, Csaba

    2010-01-01

    Reinforcement learning is a learning paradigm concerned with learning to control a system so as to maximize a numerical performance measure that expresses a long-term objective. What distinguishes reinforcement learning from supervised learning is that only partial feedback is given to the learner about the learner's predictions. Further, the predictions may have long term effects through influencing the future state of the controlled system. Thus, time plays a special role. The goal in reinforcement learning is to develop efficient learning algorithms, as well as to understand the algorithms'

  8. Reinforcing the mineral layer

    Energy Technology Data Exchange (ETDEWEB)

    Pishchulin, V.V.; Kuntsevich, V.I.; Seryy, A.M.; Shirokov, A.P.

    1980-05-15

    A way of reinforcing the mineral layer includes drilling holes and putting in anchors that are longer than the width of the layer strip being extracted. It also includes shortening the anchors as the strip is mined and reinforcing the remaining part of the anchor in the mouth of the hole. To increase the productivity and safety of the work, the anchors are shortened by cutting them as the strip is mined and are reinforced through wedging. The device for doing this has auxilliary lengthwise grooves in the shaft located along its length at an interval equal to the width of the band being extracted.

  9. Formability of tufted 3-dimensional composite reinforcement

    Science.gov (United States)

    Liu, Ling Shan; Wang, Peng; Legrand, Xavier; Soulat, Damien

    2016-10-01

    In the aerospace industry, more and more complex preform for composite parts are needed. Traditionally, laminated reinforcement is largely used as the method. The development of tufting technology has now advanced to a stage whereby it can be employed to produce the 3D textile composite reinforcements. Because the tufting technology is user-friendly, in this study, the tufting parameters (tufting density, tufting length, tufting yarn orientations…) are varied, in order to improve the understanding of formability of the tufted 3D fabric during manufacturing, in particular the influence of the tufting yarns, the present work is performed to analyse the preforming behaviours of tufted 3D reinforcement in the hemispherical stamping process. The preforming behaviours are also compared with the ones of the multilayered forming. Interply sliding and winkling phenomenon during forming are fully influenced by tufting yarns on the material draw-in, by the orientations of tufting yarn, …

  10. Laser based metal and plastics joining for lightweight design

    Science.gov (United States)

    Kahmann, Max; Quentin, Ulf; Kirchhoff, Marc; Brockmann, Rüdiger; Löffler, Klaus

    2015-03-01

    One of the most important issues in automotive industry is lightweight design, especially since the CO2 emission of new cars has to be reduced by 2020. Plastic and fiber reinforced plastics (e.g. CFRP and GFRP) receive besides new manufacturing methods and the employment of high-strength steels or non-ferrous metals increasing interest. Especially the combination of different materials such as metals and plastics to single components exhausts the entire potential on weight reduction. This article presents an approach based on short laser pulses to join such dissimilar materials in industrial applications.

  11. Plastic flow in a composite : a comparison of nonlocal continuum and discrete dislocation predictions

    NARCIS (Netherlands)

    Bassani, J.L.; Needleman, A.; Giessen, E. van der

    2001-01-01

    A two-dimensional model composite with elastic reinforcements in a crystalline matrix subject to macroscopic shear is considered using both discrete dislocation plasticity and a nonlocal continuum crystal plasticity theory. Only single slip is permitted in the matrix material. The discrete dislocati

  12. Plasticity dependent damage evolution in composites with strain-gradient effects

    DEFF Research Database (Denmark)

    Legarth, Brian Nyvang

    2015-01-01

    A unit cell approach is adopted to numerically analyze the effect of reinforcement size on fracture evolution in metal matrix composites. The matrix material shows plastic size-effects and is modeled by an anisotropic version of the single parameter strain-gradient (higher-order) plasticity model...

  13. Recycling of Plastic

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde

    2011-01-01

    Plastic is produced from fossil oil. Plastic is used for many different products. Some plastic products like, for example, wrapping foil, bags and disposable containers for food and beverage have very short lifetimes and thus constitute a major fraction of most waste. Other plastic products like......, for example, gutters, window frames, car parts and transportation boxes have long lifetimes and thus appear as waste only many years after they have been introduced on the market. Plastic is constantly being used for new products because of its attractive material properties: relatively cheap, easy to form......, good strength and long durability. Recycling of plastic waste from production is well-established, while recycling of postconsumer plastic waste still is in its infancy. This chapter describes briefly how plastic is produced and how waste plastic is recycled in the industry. Quality requirements...

  14. safety of carbon fibre reinforced plastic hollow sections in compression

    African Journals Online (AJOL)

    ADMINUSER

    2014-01-06

    Jan 6, 2014 ... make them ideal for widespread applications in construction worldwide. .... adhesive between CFRP and steel/concrete may be affected by various ...... 201, pp 2528-2539. [16] Fawzia, S and Kabir, M. H., “A Review on.

  15. Jute fibre reinforced plastic: evaluation of application based properties

    Directory of Open Access Journals (Sweden)

    J. B. Sajin

    2015-01-01

    Full Text Available A fibre extracted from jute is a budding component identified for its potential application in composites. It is imperative to evaluate the parametric and property based features to determine its suitability. In this research study, considering the possible application of the fibre composites, the aptness of these fibres are examined with respect to their physical, mechanical [by layered manufacturing technique(LM] and thermal properties. This study focuses on evaluating the properties and behaviour of raw Jute fibres and NaOH surface treated fibres. Subsequently, the fibres are subjected to thermo-gravimetry tests. The outcome of the thermal analysis clearly indicates that the temperature peak shifts to a higher region in the treated fibre compared to raw fibre. The overall observation strongly emphasize that the physical properties and the thermal behaviour of jute fibre are enhanced after surface treatments which makes it more feasible for its application in composite structures.

  16. Use of Fiber Reinforced Plastics in the Marine Industry

    Science.gov (United States)

    1990-09-06

    applications. * More high-heat polyethylene terephthalate PET materials. • A polyphenylene sulfide sulfone grade for underhood use. • Long-steel-fiber...phenolics, melamines , silicones, dallyl phtalate, some epoxies. Molds Single- or multiple-cavity hardened and chrome plated molds, usually cored for steam or...aldehyde, particularly of non-volatile material Portion remaining as phenol with formaldehyde . Used in high- solid under specific conditions short of decom

  17. Advances in the Study of Aging and Anti-aging of Long Glass Fiber Reinforced Composites%长玻纤增强复合材料老化研究进展及防老化研究

    Institute of Scientific and Technical Information of China (English)

    左晓玲; 张道海; 罗兴; 吴斌; 郝智; 郭建兵

    2013-01-01

    综述了以热塑性材料为基体树脂的长玻纤增强复合材料结构分析,阐述了长玻纤增强热塑性复合材料在湿热、热氧、光氧条件下有可能的老化机理.最后提出了几点长玻纤增强热塑性复合材料防老化的建议措施.%The structure analysis of thermoplastic materials for the matrix resin of long glass fiber reinforced composites was summarized, the possible aging mechanisms of long glass fiber reinforced thermoplastic composites in hygrotherma, thermal oxidation and light conditions were elaborated. Finally several measures in anti-aging research for long glass fiber reinforced thermoplastic composites were proposed.

  18. Mechanical Properties of Welded Deformed Reinforcing Steel Bars

    Directory of Open Access Journals (Sweden)

    Ghafur H. Ahmed

    2015-05-01

    Full Text Available Reinforcement strength, ductility and bendability properties are important components in design of reinforced concrete members, as the strength of any member comes mainly from reinforcement. Strain compatibility and plastic behaviors are mainly depending on reinforcement ductility. In construction practice, often welding of the bars is required. Welding of reinforcement is an instant solution in many cases, whereas welding is not a routine connection process. Welding will cause deficiencies in reinforcement bars, metallurgical changes and re-crystallization of microstructure of particles. Weld metal toughness is extremely sensitive to the welding heat input that decreases both of its strength and ductility. For determining the effects of welding in reinforcement properties, 48 specimens were tested with 5 different bar diameters, divided into six groups. Investigated parameters were: properties of un-welded bars; strength, ductility and density of weld metal; strength and ductility reduction due to heat input for bundled bars and transverse bars; welding effect on bars’ bending properties; behavior of different joint types; properties of three weld groove shapes also the locations and types of failures sections. Results show that, strength and elongation of the welded bars decreased by (10-40% and (30-60% respectively. Cold bending of welded bars and groove welds shall be prevented.

  19. The Plastic Tension Field Method

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    . The emphasis is attached to the presentation of a design method based on the diagonal tension field theory. Also, how to determine the load-carrying capacity of a given steel plate girder with transverse web stiffeners, is briefly presented. The load-carrying capacity may be predicted by applying both...... method. The method is based on the theory of plasticity and is analogous to the so-called diagonal compression field method developed for reinforced concrete beams with transverse stirrups, which is adopted in the common European concrete code (Eurocode 2). Many other theories have been developed......, but the method presented differs from these theories by incorporating the strength of the transverse stiffeners and by the assumption that the tensile bands may pass the transverse stiffeners, which often is observed in tests. Other methods have only dealt with a single web field between two stiffeners...

  20. Reinforcement Lernen mit Regularisierungsnetzwerken

    OpenAIRE

    Jung, Tobias

    2007-01-01

    Die Arbeit behandelt das Problem der Skalierbarkeit von Reinforcement Lernen auf hochdimensionale und komplexe Aufgabenstellungen. Unter Reinforcement Lernen versteht man dabei eine auf approximativem Dynamischen Programmieren basierende Klasse von Lernverfahren, die speziell Anwendung in der Künstlichen Intelligenz findet und zur autonomen Steuerung simulierter Agenten oder realer Hardwareroboter in dynamischen und unwägbaren Umwelten genutzt werden kann. Dazu wird mittels Regression aus Sti...

  1. Reinforcement learning in scheduling

    Science.gov (United States)

    Dietterich, Tom G.; Ok, Dokyeong; Zhang, Wei; Tadepalli, Prasad

    1994-01-01

    The goal of this research is to apply reinforcement learning methods to real-world problems like scheduling. In this preliminary paper, we show that learning to solve scheduling problems such as the Space Shuttle Payload Processing and the Automatic Guided Vehicle (AGV) scheduling can be usefully studied in the reinforcement learning framework. We discuss some of the special challenges posed by the scheduling domain to these methods and propose some possible solutions we plan to implement.

  2. Covert Reinforcement: A Partial Replication.

    Science.gov (United States)

    Ripstra, Constance C.; And Others

    A partial replication of an investigation of the effect of covert reinforcement on a perceptual estimation task is described. The study was extended to include an extinction phase. There were five treatment groups: covert reinforcement, neutral scene reinforcement, noncontingent covert reinforcement, and two control groups. Each subject estimated…

  3. Design of collimation frame structure for lunar-based extreme ultraviolet camera based on carbon fiber reinforced plastics%基于碳纤维复合材料的月基极紫外相机照准架结构设计

    Institute of Scientific and Technical Information of China (English)

    王智

    2012-01-01

    为了减少月基极紫外相机的质量并保证相机的二维转动机构在卫星发射、地月变轨及月表着陆过程中受到大量级振动冲击以及月表超大温差环境下能正常工作,设计并研制了基于碳纤维复合材料(CFRP)的照准架结构。首先,设计了基于金属材料和CFRP的不同照准架结构,通过有限元法对不同材料的照准架进行分析对比,证明了CFRP照准架的优越性。温度和力学验证试验表明:基于CFRP的照准架质量小于其它材料的照准架,其刚度和热稳定性能满足极紫外相机环境适应性的要求。%To lighten the weight of a lunar-based Extreme Ultraviolet(EUV) camera and to ensure the function of the collimation frame structure of the EUV camera under the conditions of the large level vibration caused by satellite launching, earth-moon orbit transfer, moon landing and the large temperature difference on the lunar surface, a collimation frame structure based on Carbon Fiber Reinforced Plastics(CFRP) is designed. Firstly, different collimation frames are designed based on metal materials and the CFRP, and the superiority of the collimation frame based on the CFRP is verified by finite element analysis. Finally, the experiments on tem- peratures and mechanics are performed, and the experiment results show that CFRP collimation frame has a lighter weight and its stiffness and thermal stability meet the requirements of environmental adaptation.

  4. Caracterização de tubo e adesivo utilizados em tubulações de plástico reforçado com fibras de vidro aplicados em plataformas marítimas Characterization of pipes and adhesives of glassfiber reinforced plastics used in offshore platforms

    Directory of Open Access Journals (Sweden)

    Maikon C. R. Pessanha

    2008-03-01

    Full Text Available Na indústria de exploração e produção de petróleo, principalmente no setor offshore, os plásticos reforçados por fibras de vidro (PRFV têm apresentado grande destaque. Isso se deve à intrínseca capacidade destes de resistir à corrosão em ambientes salinos, bem como serem materiais que apresentam elevada resistência mecânica específica. O presente trabalho buscou caracterizar tubo e adesivo utilizados em plataformas marítimas. Para tanto, as técnicas utilizadas foram: espectroscopia na região do infravermelho com transformada de Fourier (FTIR, análise termogravimétrica (TGA, análise termodinâmico-mecânica (DMTA e temperatura de amolecimento de Vicat. Amostras do tubo de PRFV e dos componentes do adesivo (denominados de A e B foram estudadas individualmente. Além disso, foram confeccionadas misturas, em massa, nas seguintes proporções: 40%A-60%B, 50%A-50%B e 60%A-40%B. Foi possível determinar a composição e a estrutura química dos materiais, além do comportamento mecânico à degradação térmica. Foi verificado que adesivo e tubo apresentaram desempenho satisfatório à temperatura ambiente quanto à degradação e à rigidez. Por outro lado, quando submetido ao calor, principalmente os adesivos, apresentaram queda brusca de desempenho.Glassfiber reinforced plastics (GFRP have been applied in the offshore industry owing to their high resistance to corrosion and high specific mechanical strength. The present work aimed at characterizing pipes and adhesives used in offshore platforms in order to evaluate the thermo-mechanical performance of these materials. The techniques used were: Fourier transform infrared spectroscopy (FTIR, thermogravimetry analysis (TGA, dynamic mechanical thermal analysis (DMTA and Vicat softening temperature. Specimens of GFRP pipe and adhesive components (referred to as A and B were evaluated individually. The adhesive samples were made in the following ratios (% weight: 40%A-60%B, 50%A-50

  5. 77 FR 54930 - Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A Subsidiary of Plastics...

    Science.gov (United States)

    2012-09-06

    ... Employment and Training Administration Carlyle Plastics and Resins, Formerly Known as Fortis Plastics, A... plastic parts. New information shows that Fortis Plastics is now called Carlyle Plastics and Resins. In... of Carlyle Plastics and Resins, formerly known as Fortis Plastics, a subsidiary of...

  6. Optimal reinforcing of reticular structures Optimal reinforcing of reticular structures

    Directory of Open Access Journals (Sweden)

    Juan Santiago Mejía

    2006-12-01

    Full Text Available This article presents an application of Genetic Algorithms (GA and Finite Element Analysis (FEA to solve a structural optimisation problem on reticular plastic structures. Structural optimisation is used to modify the original shape by placing reinforcements at optimum locations. As a result, a reduction in the maximum stress by 14,70% for a structure with a final volume increase of 8,36% was achieved. This procedure solves the structural optimisation problem by adjusting the original mold and thereby avoiding the re-construction of a new one.Este artículo presenta una aplicación de Algoritmos Genéticos (GA y Análisis por Elementos Finitos (FEA a la solución de un problema de optimización estructural en estructuras reticulares plásticas. Optimización estructurales usada para modificar la forma original colocando refuerzos en posiciones óptimas. Como resultado se obtuvo una reducción en el esfuerzo máximo de 14,70% para una estructura cuyo volumen original aumento en 8,36%. Este procedimiento soluciona el problema de optimización estructural ajustando el molde original y evitando la manufactura de un nuevo molde.

  7. VISUAL REINFORCEMENT IN FIGHTING COCKS.

    Science.gov (United States)

    THOMPSON, T I

    1964-01-01

    Fighting cocks were conditioned to emit a key-pecking response on a fixed ratio reinforcement schedule leading to the visual image of another fighting cock. In addition, the relative reinforcing properties of the visual reinforcer were compared with food and water reinforcers in a three-choice, non-reversible option situation. The relative reinforcing effects of mirror presentation and another rooster visually presented through a window, were compared. The mirror maintained a relatively lower response output.

  8. Carbon nanotube reinforced metal binder for diamond cutting tools

    DEFF Research Database (Denmark)

    Sidorenko, Daria; Mishnaevsky, Leon; Levashov, Evgeny

    2015-01-01

    of grain size of the structural constituents of the binder, what in turn leads to the improved simultaneously hardness, Young modulus, plastic extension, bending strength and performances of the metallic binders. Comparing service properties of diamond end-cutting drill bits with and without MWCNT one......The potential of carbon nanotube reinforcement of metallic binders for the improvement of quality and efficiency of diamond cutting wheels is studied. The effect of multi-walled carbon nanotube (MWCNT) reinforcement on the mechanical properties i.e. hardness, Young modulus, strength and deformation...

  9. Mechanical recycling of continuous fiber-reinforced thermoplastic sheets

    Science.gov (United States)

    Moritzer, Elmar; Heiderich, Gilmar

    2016-03-01

    This contribution examines possible material recycling of offcuts generated during the production of continuous-fiber-reinforced composite sheets. These sheets consist of a polyamide 6 matrix and glass fiber fabric. In the initial step, the offcut is shredded to obtain particles; following that, the particles are processed in a twin-screw process to produce fiber-reinforced plastic pellets with varying fiber contents. These pellets are intended for use in injection molding processes as a substitution for new raw materials. This investigation centers on the mechanical properties which can be achieved with the recycled material after both the twin-screw process and injection molding.

  10. Recycled fishing nets as reinforcement of existing concrete structures

    DEFF Research Database (Denmark)

    Sigvardsen, Nina Marie; Bonnerup, Amanda Helena; Ottosen, Lisbeth M.

    2016-01-01

    Large amounts of fishing nets are discarded every year polluting the oceans with plastic fibers on a global scale. Due to the big fishing industry in Greenland, an alternative use for discarded fishing nets would have a decreasing effect on the amount of marine litter in the Arctic. A use...... for discarded fishing nets could be as fiber-reinforced polymer (FRP) composites for near surface mounted reinforcement (NSMR). NSMR prolongs the lifetime of existing structures, and thus reduces the amount of materials transported to Greenland, reducing CO2-emission and expenses. The effect of NSMR FRP bars...

  11. Reinforcement signalling in Drosophila; dopamine does it all after all.

    Science.gov (United States)

    Waddell, Scott

    2013-06-01

    Reinforcement systems are believed to drive synaptic plasticity within neural circuits that store memories. Recent evidence from the fruit fly suggests that anatomically distinct dopaminergic neurons ultimately provide the key instructive signals for both appetitive and aversive learning. This dual role for dopamine overturns the previous model that octopamine signalled reward and dopamine punishment. More importantly, this anatomically segregated double role for dopamine in reward and aversion mirrors that emerging in mammals. Therefore, an antagonistic organization of distinct reinforcing dopaminegic neurons is a conserved feature of brains. It now seems crucial to understand how the dopaminergic neurons are controlled and what the released dopamine does to the underlying circuits to convey opposite valence.

  12. Our plastic age

    National Research Council Canada - National Science Library

    Richard C. Thompson; Shanna H. Swan; Charles J. Moore; Frederick S. vom Saal

    2009-01-01

    Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production...

  13. Weinig plastic in vissenmaag

    NARCIS (Netherlands)

    Foekema, E.M.

    2012-01-01

    Waar de magen van sommige zeevogels vol plastic zitten, lijken vissen in de Noordzee nauwelijks last te hebben van kunststofafval. Onderzoekers die plastic resten zochten in vissenmagen vonden ze in elk geval nauwelijks.

  14. Ear Plastic Surgery

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Ear Plastic Surgery Ear Plastic Surgery Patient Health Information ... they may improve appearance and self-confidence. Can Ear Deformities Be Corrected? Formation of the ear during ...

  15. Geotehnical Properties of Plastic Stabilized Lateritic Soil

    Directory of Open Access Journals (Sweden)

    Akinola Johnson Olarewaju

    2016-09-01

    Full Text Available Stabilization is the combination of soils and additives to change its properties and remain in its stable compacted state without undergoing any change under effect of exposure to weather and traffic. Soil stabilization through the reinforced soil construction is an efficient and reliable technique for improving the strength and stability of soils. The lateritic soil used in this study was taken along Papa-Ilaro road Ajegunle at Abalabi, Ogun State, Nigeria and the solid plastic wastes were taken from different locations in Ilaro. The plastics were grounded into pellets and substituted with laterite at 10%, 15%, 20%, 25% and 30% for compaction test and at 5%, 10%, 15%, 20%, 25% and 30% for California bearing ration (CBR test. The tests conducted in line with BS 1377 (1990 are the specific gravity, compaction and CBR. From the results, it was also observed that plastic pellets reduce the bulk densities and dry densities in the same proportion as the percentage water content increases. From the results, it is hereby suggested that plastic pellets could be mixed with lateritic material around underground pipes to mitigate the effects of accidental explosions. Consequently, environmental risk and hazards caused by plastic wastes and accidental explosions could be greatly reduced.

  16. Biodegradability of Plastics

    OpenAIRE

    Yutaka Tokiwa; Calabia, Buenaventurada P.; Charles U. Ugwu; Seiichi Aiba

    2009-01-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical ...

  17. Behavior of reinforced concrete beams reinforced with GFRP bars

    Directory of Open Access Journals (Sweden)

    D. H. Tavares

    Full Text Available The use of fiber reinforced polymer (FRP bars is one of the alternatives presented in recent studies to prevent the drawbacks related to the steel reinforcement in specific reinforced concrete members. In this work, six reinforced concrete beams were submitted to four point bending tests. One beam was reinforced with CA-50 steel bars and five with glass fiber reinforced polymer (GFRP bars. The tests were carried out in the Department of Structural Engineering in São Carlos Engineering School, São Paulo University. The objective of the test program was to compare strength, reinforcement deformation, displacement, and some anchorage aspects between the GFRP-reinforced concrete beams and the steel-reinforced concrete beam. The results show that, even though four GFRP-reinforced concrete beams were designed with the same internal tension force as that with steel reinforcement, their capacity was lower than that of the steel-reinforced beam. The results also show that similar flexural capacity can be achieved for the steel- and for the GFRP-reinforced concrete beams by controlling the stiffness (reinforcement modulus of elasticity multiplied by the bar cross-sectional area - EA and the tension force of the GFRP bars.

  18. Preference for 50% reinforcement over 75% reinforcement by pigeons.

    Science.gov (United States)

    Gipson, Cassandra D; Alessandri, Jérôme J D; Miller, Holly C; Zentall, Thomas R

    2009-11-01

    When pigeons are given a choice between an initial-link alternative that results in either a terminal-link stimulus correlated with 100% reinforcement or a stimulus correlated with 0% reinforcement (overall 50% reinforcement) and another initial-link alternative that always results in a terminal-link stimulus correlated with 100% reinforcement, some pigeons show a preference for the initial-link alternative correlated with 50% reinforcement. Using this procedure, in Experiment 1, we found a relatively modest preference for 100% over 50% reinforcement. In Experiment 2, we decreased the reinforcement density for the second initial-link alternative to 75% and found a significant preference for the 50% reinforcement initial-link alternative. It may be that this "maladaptive" behavior results from a positive contrast between the expectation of reinforcement correlated with the 50% reinforcement initial-link alternative and the terminal-link stimulus correlated with 100% reinforcement. But apparently, the complementary negative contrast does not develop between the expectation of reinforcement correlated with the 50% reinforcement initial-link alternative and the terminal-link stimulus correlated with 0% reinforcement that often follow. Such paradoxical choice may account for certain human appetitive risk-taking behavior (e.g., gambling) as well.

  19. Tensile behavior and tension stiffening of reinforced concrete

    Energy Technology Data Exchange (ETDEWEB)

    Choun, Young Sun; Seo, Jeong Moon

    2001-03-01

    For the ultimate behavior analysis of containment buildings under severe accident conditions, a clear understanding of tensile behaviors of plain and reinforced concrete is necessary. Nonlinear models for tensile behaviors of concrete are also needed. This report describe following items: tensile behaviors of plain concrete, test results of reinforced concrete panels in uniaxial and biaxial tension, tension stiffening. The tensile behaviors of reinforced concrete are significantly influenced by the properties of concrete and reinforcing steel. Thus, for a more reliable evaluation of tensile behavior and ultimate pressure capacity of a reinforced or prestressed concrete containment building, an advanced concrete model which can be considered rebar-concrete interaction effects should be developed. In additions, a crack behavior analysis method and tension stiffening models, which are based on fracture mechanics, should be developed. The model should be based on the various test data from specimens considering material and sectional properties of the containment building.

  20. Chemical Recycle of Plastics

    Directory of Open Access Journals (Sweden)

    Sara Fatima

    2014-11-01

    Full Text Available Various chemical processes currently prevalent in the chemical industry for plastics recycling have been discussed. Possible future scenarios in chemical recycling have also been discussed. Also analyzed are the effects on the environment, the risks, costs and benefits of PVC recycling. Also listed are the various types of plastics and which plastics are safe to use and which not after rcycle

  1. Plastic value chains

    DEFF Research Database (Denmark)

    Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin

    2014-01-01

    Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example...

  2. 关节镜下人工韧带加强系统重建前交叉韧带%Arthroscopic reconstruction of the anterior cruciate ligament using ligament advanced reinforcement system artificial ligament

    Institute of Scientific and Technical Information of China (English)

    陈明; 董启榕

    2008-01-01

    背景:由于人工韧带新材料生产工艺的改进,减少了人工韧带使用后由于材料疲劳而出现的断裂,以及因组织相容性问题出现滑膜炎等并发症的问题,使人工韧带应用更为广泛.目的:评估关节镜下应用人工韧带加强系统(Ligament Advanced Reinforcement System,LARS)重建膝关节前交叉韧带后的组织相容性反应及其临床效果.设计:完全随机临床设计.单位:苏州大学附属第二医院骨科.对象:2005-06/2006-06苏州大学附属第二医院骨科因膝关节前交叉韧带损伤行关节镜下LARS重建人工韧带的手术患者32例,男27例,女13例,平均年龄21岁,均为运动损伤.所有患者术前MRI均显示前交叉韧带损伤并发半月板损伤:患者对治疗内容知情同意.方法:对32例膝关节前交叉韧带损伤患者行关节镜下LARS人工韧带重建.重建韧带应用LARS人工韧带加强系统,由法国LARS公司生产(证书:CE0459,IS09002-EN46002).人工韧带材型为PET-聚对苯二甲酸乙二醇酯,L021201(左膝),L021202(右膝),模仿人体韧带的解剖结构和生物力学原理设计而成[AC120 2BL(左膝),AC120 2BR(右膝).国食药监械(进)字2004第3460468号].所有韧带重建均由苏州大学附属第二医院骨科同一组有10年以上资质的医生以同样的技术标准完成,由同一高年资的具有博士生导师、主任医师职称的医生主持,参与手术的医生符合卫生部相关上岗职称规定.治疗及实验方案经医院伦理委员会批准.主要观察指标:①观察人工韧带与患者的生物相容性.②对患者进行平均24个月随访,以Lysholm进行膝关节功能评分,以Tegner评分反映患者主观满意度.结果:32例患者均完成随访:完成18,20,24,28,30个月随访者分别为3,7,8,12,2例.①人工韧带生物相容性观察:患者随访结束时均未出现疼痛,急、慢性滑膜炎,以及韧带断裂和活动明显受限等并发症.②膝关节活动功

  3. Size-effects on yield surfaces for micro reinforced composites

    DEFF Research Database (Denmark)

    Azizi, Reza; Niordson, Christian Frithiof; Legarth, Brian Nyvang

    2011-01-01

    of the plastic strain tensor appear as free variables in addition to the displacement variables. Non-conventional boundary conditions are applied at material interfaces to model a constraint on plastic flow due to dislocation blocking. Unit cell calculations are carried out under generalized plane strain...... conditions. The homogenized response of a material with cylindrical reinforcing fibers is analyzed for different values of the internal material length scale and homogenized yield surfaces are presented. While the main focus is on initial yield surfaces, subsequent yield surfaces are also presented...

  4. Biodegradability of plastics.

    Science.gov (United States)

    Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

    2009-08-26

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  5. Plastic value chains

    DEFF Research Database (Denmark)

    Baxter, John; Wahlstrom, Margareta; Zu Castell-Rüdenhausen, Malin

    2014-01-01

    Optimizing plastic value chains is regarded as an important measure in order to increase recycling of plastics in an efficient way. This can also lead to improved awareness of the hazardous substances contained in plastic waste, and how to avoid that these substances are recycled. As an example......, plastics from WEEE is chosen as a Nordic case study. The project aims to propose a number of improvements for this value chain together with representatives from Nordic stakeholders. Based on the experiences made, a guide for other plastic value chains shall be developed....

  6. Biodegradability of Plastics

    Directory of Open Access Journals (Sweden)

    Yutaka Tokiwa

    2009-08-01

    Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  7. Journal of CHINA PLASTICS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Journal of CHINA PLASTICS was authorized and approved by The State Committee of Science and Technology of China and The Bureau of News Press of China, and published by The China Plastics Processing Industry Association,Beijing Technology and Business University and The Institute of Plastics Processing and Application of Light Industry, distributed worldwide. Since its birth in 1987, CHINA PLASTICS has become a leading magazine in plastics industry in China, a national Chinese core journal and journal of Chinese scientific and technological article statistics. It is covered by CA.

  8. Carbon fiber reinforced thermoplastic composites for future automotive applications

    Science.gov (United States)

    Friedrich, K.

    2016-05-01

    After a brief introduction to polymer composite properties and markets, the state of the art activities in the field of manufacturing of advanced composites for automotive applications are elucidated. These include (a) long fiber reinforced thermoplastics (LFT) for secondary automotive components, and (b) continuous carbon fiber reinforced thermosetting composites for car body applications. It is followed by future possibilities of carbon fiber reinforced thermoplastic composites for e.g. (i) crash elements, (ii) racing car seats, and (iii) production and recycling of automotive fenders.

  9. MODULATING EXCITATION THROUGH PLASTICITY AT INHIBITORY SYNAPSES

    Directory of Open Access Journals (Sweden)

    Vivien eChevaleyre

    2014-03-01

    Full Text Available Learning is believed to depend on lasting changes in synaptic efficacy such as long-term potentiation and long-term depression. As a result, a profusion of studies has tried to elucidate the mechanisms underlying these forms of plasticity. Traditionally, experience-dependent changes at excitatory synapses were assumed to underlie learning and memory formation. However, with the relatively more recent investigation of inhibitory transmission, it had become evident that inhibitory synapses are not only plastic, but also provide an additional way to modulate excitatory transmission and the induction of plasticity at excitatory synapses.Thanks to recent technological advances, progress has been made in understanding synaptic transmission and plasticity from particular interneuron subtypes. In this review article, we will describe various forms of synaptic plasticity that have been ascribed to two fairly well characterized populations of interneurons in the hippocampus, those expressing cholecystokinin (CCK and parvalbumin (PV. We will discuss the resulting changes in the strength and plasticity of excitatory transmission that occur in the local circuit as a result of the modulation of inhibitory transmission. We will focus on the hippocampus because this region has a relatively well-understood circuitry, numerous forms of activity-dependent plasticity and a multitude of identified interneuron subclasses.

  10. Challenges in plastics recycling

    DEFF Research Database (Denmark)

    Pivnenko, Kostyantyn; Jakobsen, L. G.; Eriksen, Marie Kampmann

    2015-01-01

    Recycling of waste plastics still remains a challenging area in the waste management sector. The current and potential goals proposed on EU or regional levels are difficult to achieve, and even to partially fullfil them the improvements in collection and sorting should be considerable. A study...... was undertaken to investigate the factors affecting quality in plastics recycling. The preliminary results showed factors primarily influencing quality of plastics recycling to be polymer cross contamination, presence of additives, non-polymer impurities, and polymer degradation. Deprivation of plastics quality......, with respect to recycling, has been shown to happen throughout the plastics value chain, but steps where improvements may happen have been preliminary identified. Example of Cr in plastic samples analysed showed potential spreading and accumulation of chemicals ending up in the waste plastics. In order...

  11. Glassy metallic plastics

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper reports a class of bulk metallic glass including Ce-, LaCe-, CaLi-, Yb-, and Sr-based metallic glasses, which are regarded as glassy metallic plastics because they combine some unique properties of both plastics and metallic alloys. These glassy metallic plastics have very low glass transition temperature (Tg~25oC to 150oC) and low Young’s modulus (~20 GPa to 35 GPa). Similar to glassy plastics, these metallic plastics show excellent plastic-like deformability on macro-, micro- and even nano-scale in their supercooled liquid range and can be processed, such as elongated, compressed, bent, and imprinted at low temperatures, in hot water for instance. Under ambient conditions, they display such metallic properties as high thermal and electric conductivities and excellent mechanical properties and other unique properties. The metallic plastics have potential applications and are also a model system for studying issues in glass physics.

  12. Modelling reinforcement corrosion in concrete

    DEFF Research Database (Denmark)

    Michel, Alexander; Geiker, Mette Rica; Stang, Henrik

    2012-01-01

    A physio-chemical model for the simulation of reinforcement corrosion in concrete struc-tures was developed. The model allows for simulation of initiation and subsequent propaga-tion of reinforcement corrosion. Corrosion is assumed to be initiated once a defined critical chloride threshold...... is reached causing the formation of anodic and cathodic regions along the reinforcement. Critical chloride thresholds, randomly distributed along the reinforcement sur-face, link the initiation and propagation phase of reinforcement corrosion. To demonstrate the potential use of the developed model......, a numerical example is pre-sented, that illustrates the formation of corrosion cells as well as propagation of corrosion in a reinforced concrete structure....

  13. Collapse mechanisms and strength prediction of reinforced concrete pile caps

    DEFF Research Database (Denmark)

    Jensen, Uffe G.; Hoang, Linh Cao

    2012-01-01

    This paper describes an upper bound plasticity approach for strength prediction of reinforced concrete pile caps. A number of collapse mechanisms are identified and analysed. The procedure leads to an estimate of the load-carrying capacity and an identification of the critical collapse mechanism....... It is argued that the upper bound approach may be a useful complement to the widely used lower bound strut-and-tie method. Especially when dealing with strength assessment of existing structures....

  14. Thermomechanical behavior of SBR reinforced with nanotubes functionalized with polyvinylpyridine

    Energy Technology Data Exchange (ETDEWEB)

    De Falco, A. [Universidad de Buenos Aires, FCEyN, Depto. de Fisica, LPyMC, Pabellon I, Buenos Aires 1428 (Argentina); Lamanna, M. [Universidad de Buenos Aires, FCEyN, Depto. de Quimica Organica, Centro de Investigaciones en Hidratos de Carbono (CIHIDECAR) (Argentina); Goyanes, S. [Universidad de Buenos Aires, FCEyN, Depto. de Fisica, LPyMC, Pabellon I, Buenos Aires 1428 (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); D' Accorso, N.B. [Universidad de Buenos Aires, FCEyN, Depto. de Quimica Organica, Centro de Investigaciones en Hidratos de Carbono (CIHIDECAR) (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Fascio, M.L., E-mail: mfascio@qo.fcen.uba.ar [Universidad de Buenos Aires, FCEyN, Depto. de Quimica Organica, Centro de Investigaciones en Hidratos de Carbono (CIHIDECAR) (Argentina)

    2012-08-15

    The mechanical and thermal behavior of composites consisting on a styrene-butadiene rubber (SBR) matrix with a sulphur/accelerator system and multiwalled carbon nanotubes functionalized with poly-4-vinylpyridine (MWCNT-PVP) as reinforcement, were studied. The materials were tested with stress-strain tensile tests, DMTA and DSC for thermal properties. A strong increase in the plastic behavior with slight decrease of its elastic Modulus and Tg led to unexpected results.

  15. Reinforcement Magnitude: An Evaluation of Preference and Reinforcer Efficacy

    OpenAIRE

    Trosclair-Lasserre, Nicole M.; Lerman, Dorothea C; Call, Nathan A; Addison, Laura R; Kodak, Tiffany

    2008-01-01

    Consideration of reinforcer magnitude may be important for maximizing the efficacy of treatment for problem behavior. Nonetheless, relatively little is known about children's preferences for different magnitudes of social reinforcement or the extent to which preference is related to differences in reinforcer efficacy. The purpose of the current study was to evaluate the relations among reinforcer magnitude, preference, and efficacy by drawing on the procedures and results of basic experimenta...

  16. Flexural strengthening of Reinforced Concrete (RC) Beams Retrofitted with Corrugated Glass Fiber Reinforced Polymer (GFRP) Laminates

    Science.gov (United States)

    Aravind, N.; Samanta, Amiya K.; Roy, Dilip Kr. Singha; Thanikal, Joseph V.

    2015-01-01

    Strengthening the structural members of old buildings using advanced materials is a contemporary research in the field of repairs and rehabilitation. Many researchers used plain Glass Fiber Reinforced Polymer (GFRP) sheets for strengthening Reinforced Concrete (RC) beams. In this research work, rectangular corrugated GFRP laminates were used for strengthening RC beams to achieve higher flexural strength and load carrying capacity. Type and dimensions of corrugated profile were selected based on preliminary study using ANSYS software. A total of twenty one beams were tested to study the load carrying capacity of control specimens and beams strengthened with plain sheets and corrugated laminates using epoxy resin. This paper presents the experimental and theoretical study on flexural strengthening of Reinforced Concrete (RC) beams using corrugated GFRP laminates and the results are compared. Mathematical models were developed based on the experimental data and then the models were validated.

  17. Reinforcement Magnitude: An Evaluation of Preference and Reinforcer Efficacy

    Science.gov (United States)

    Trosclair-Lasserre, Nicole M.; Lerman, Dorothea C.; Call, Nathan A.; Addison, Laura R.; Kodak, Tiffany

    2008-01-01

    Consideration of reinforcer magnitude may be important for maximizing the efficacy of treatment for problem behavior. Nonetheless, relatively little is known about children's preferences for different magnitudes of social reinforcement or the extent to which preference is related to differences in reinforcer efficacy. The purpose of the current…

  18. Plastic Brains and the Dialectics of Dialectics

    Science.gov (United States)

    Loxley, Andrew; Murphy, Colette; Seery, Aidan

    2014-01-01

    This article advances the thinking of Lima, Ostermann and Rezende's "Marxism in Vygotskian approaches to cultural studies of science education" and Mark Zuss' response to their paper. Firstly, it introduces Catherine Malabou's concept of plasticity, from which Hegel's dialectic can be re-read as historical materialist…

  19. Plastic Brains and the Dialectics of Dialectics

    Science.gov (United States)

    Loxley, Andrew; Murphy, Colette; Seery, Aidan

    2014-01-01

    This article advances the thinking of Lima, Ostermann and Rezende's "Marxism in Vygotskian approaches to cultural studies of science education" and Mark Zuss' response to their paper. Firstly, it introduces Catherine Malabou's concept of plasticity, from which Hegel's dialectic can be re-read as historical materialist…

  20. Reinforcement and learning

    NARCIS (Netherlands)

    Servedio, M.R.; Sæther, S.A.; Sætre, G.-P.

    2009-01-01

    Evidence has been accumulating to support the process of reinforcement as a potential mechanism in speciation. In many species, mate choice decisions are influenced by cultural factors, including learned mating preferences (sexual imprinting) or learned mate attraction signals (e.g., bird song). It

  1. Motivated Reinforcement Learning

    CERN Document Server

    Maher, Mary Lou

    2009-01-01

    Motivated learning is a research field in artificial intelligence and cognitive modelling. This book describes how motivated reinforcement learning agents can be used in computer games for the design of non-player characters that can adapt their behaviour in response to unexpected changes in their environment

  2. Glass Fibre Reinforced Polymers

    NARCIS (Netherlands)

    Nikolaou, N.; Karagianni, L.; Sarakiniatti, M.V.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0533 Innovation & Sustainability. Fibre reinforced polymers (FRPs) have been used in many applications over the years, from new construction to retrofitting. They are lightweight, no-corrosive, exhibit high specific strength and specific

  3. Oscillations following periodic reinforcement.

    Science.gov (United States)

    Monteiro, Tiago; Machado, Armando

    2009-06-01

    Three experiments examined behavior in extinction following periodic reinforcement. During the first phase of Experiment 1, four groups of pigeons were exposed to fixed interval (FI 16s or FI 48s) or variable interval (VI 16s or VI 48s) reinforcement schedules. Next, during the second phase, each session started with reinforcement trials and ended with an extinction segment. Experiment 2 was similar except that the extinction segment was considerably longer. Experiment 3 replaced the FI schedules with a peak procedure, with FI trials interspersed with non-food peak interval (PI) trials that were four times longer. One group of pigeons was exposed to FI 20s PI 80s trials, and another to FI 40s PI 160s trials. Results showed that, during the extinction segment, most pigeons trained with FI schedules, but not with VI schedules, displayed pause-peck oscillations with a period close to, but slightly greater than the FI parameter. These oscillations did not start immediately after the onset of extinction. Comparing the oscillations from Experiments 1 and 2 suggested that the alternation of reconditioning and re-extinction increases the reliability and earlier onset of the oscillations. In Experiment 3 the pigeons exhibited well-defined pause-peck cycles since the onset of extinction. These cycles had periods close to twice the value of the FI and lasted for long intervals of time. We discuss some hypotheses concerning the processes underlying behavioral oscillations following periodic reinforcement.

  4. Fibre reinforced polymer nanocomposites

    NARCIS (Netherlands)

    Vlasveld, D.P.N.

    2005-01-01

    In this thesis the results are described of the research on a combination of two types of composites: thermoplastic nanocomposites and continuous fibre composites. In this three-phase composite the main reinforcing phase are continuous glass or carbon fibres, and the matrix consists of a polyamide 6

  5. Turbomachine blade reinforcement

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Crespo, Andres Jose

    2016-09-06

    Embodiments of the present disclosure include a system having a turbomachine blade segment including a blade and a mounting segment coupled to the blade, wherein the mounting segment has a plurality of reinforcement pins laterally extending at least partially through a neck of the mounting segment.

  6. Glass Fibre Reinforced Polymers

    NARCIS (Netherlands)

    Nikolaou, N.; Karagianni, L.; Sarakiniatti, M.V.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0533 Innovation & Sustainability. Fibre reinforced polymers (FRPs) have been used in many applications over the years, from new construction to retrofitting. They are lightweight, no-corrosive, exhibit high specific strength and specific sti

  7. Reinforcement and learning

    NARCIS (Netherlands)

    Servedio, M.R.; Sæther, S.A.; Sætre, G.-P.

    2009-01-01

    Evidence has been accumulating to support the process of reinforcement as a potential mechanism in speciation. In many species, mate choice decisions are influenced by cultural factors, including learned mating preferences (sexual imprinting) or learned mate attraction signals (e.g., bird song). It

  8. Reinforced aerodynamic profile

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to the prevention of deformations in an aerodynamic profile caused by lack of resistance to the bending moment forces that are created when such a profile is loaded in operation. More specifically, the invention relates to a reinforcing element inside an aerodynamic...

  9. Behavior and Performance of GFRP Reinforced Concrete Columns with Various Types of Stirrups

    Directory of Open Access Journals (Sweden)

    Woraphot Prachasaree

    2015-01-01

    Full Text Available Fiber reinforced polymer (FRP composites are gaining acceptance in concrete structural applications due to their high ratio of strength/stiffness to self-weight and corrosion resistance. This study focused on the structural behavior and the performance of concrete columns internally reinforced with glass fiber reinforced plastic (GFRP rebars. Twelve series of concrete columns with varied longitudinal reinforcement, cross section, concrete cover, and type of lateral reinforcement were tested under compression loading. The results show that the amount of GFRP longitudinal and lateral reinforcement slightly affects the column strength. The lateral reinforcement affects the confining pressure and inelastic deformation, and its contribution to the confined compressive strength increases with the GFRP reinforcement ratio. In addition, the confining pressure increases both concrete strength and deformability in the inelastic range. The confinement effectiveness coefficient varied from 3.0 to 7.0 with longitudinal reinforcement. The average deformability factors were 4.2 and 2.8 with spirals and ties, respectively. Lateral reinforcement had a more pronounced effect on deformability than on column strength.

  10. Numerical Investigation Into The Behavior of Circular Pad Shallow Foundations Supported By Geogrid Reinforced Sand

    Directory of Open Access Journals (Sweden)

    S. M. Marandi

    2008-01-01

    Full Text Available This study seeks to widen the pool of knowledge on the use and characteristics of geosynthetics, specifically in the area of circular foundations supported by geosynthetic reinforced sand. The main objective of the work was to increase the awareness of circular foundation systems and thus increase the accuracy of current laboratory methods. Also, compare the results with that of previous papers on the subject and to provide new model curves to estimate the bearing capacity of circular foundations. In this respect, the foundation and the soil underneath was modeled using four nots isoparameters finite element aid, while, for geogrid reinforcement, the four nots one-dimentional finite element model was used. The sand behavior was based on demolition elasto-plastic drucker-prager criteria and for the reinforcement the linear criteria was used. The paper investigates the effects of the reinforcement placing properties, soil properties, reinforcement properties, and the geometric properties of circular foundations. The results showed that; the bearing capacity ratio at a settlement level for geogrid reinforced sand is effected considerably by parameters such as: reinforcement placement, reinforcement layers, reinforcement strength, geometric properties of circular foundations, and effects of using granular soils. Based on the results achieved, a number of design curves have been developed to assist with the estimation (design of field bearing capacity of shallow foundations supported by geogrid reinforced soil. Keeping in mind the settlement limitations in real space, the curves have been developed for normal settlement levels up to a settlement ratio of 2.5%.

  11. [Behavioral therapy of ticks with negative reinforcement in children].

    Science.gov (United States)

    Nabieva, T N; Mukhin, E I

    2003-01-01

    Thirty-two children suffering from motor and vocal ticks exhibited weakness and distonia of ticks-prone muscles were examined. Based on the results obtained earlier, a complex of physical exercises has been worked out and conducted for 20 days. The patients were divided into 3 groups: 1st (n = 10) group did the exercises daily for training the ticks-prone muscles; the 2nd one (n = 10) exercised only after tick's appearance--negative reinforcement; 3rd group (n = 12) did exercises after tick's appearance as well but on irregular basis--probable negative reinforcement. In the 1st group, the exercising resulted in muscle strengthening and decrease of tick's number. The patients of the 2nd group got rid of ticks for 20 days. The probable tick's reinforcement in children of the 3rd group did not change pathological muscle activity. The central mechanisms of cortical plasticity in behavioral therapy of ticks are discussed.

  12. Fracture and fatigue of discontinuously reinforced copper/tungsten composites

    Science.gov (United States)

    Harris, B.; Ramani, S. V.

    1975-01-01

    The strength, toughness and resistance to cyclic crack propagation of composites consisting of copper reinforced with short tungsten wires of various lengths have been studied and the results compared with the behavior of continuously reinforced composites manufactured by the same method, i.e., by vacuum hot-pressing. It has been found that whereas the resistance to fatigue crack growth of continuously reinforced composites is very similar to that of continuous Al/stainless steel composites reported elsewhere, the addition of short fibers completely changes the mode of fracture, and no direct comparisons are possible. In effect, short fibers inhibit single crack growth by causing plastic flow to be distributed rather than localized, and although these composites are much less strong than continuous fiber composites, they nevertheless have much greater fatigue resistance.

  13. Aligned Carbon Nanotube Reinforcement of Aerospace Carbon Fiber Composites: Substructural Strength Evaluation for Aerostructure Applications

    OpenAIRE

    Guzman de Villoria, Roberto; Ydrefors, L.; Hallander, P.; Ishiguro, Kyoko; Nordin, P.; Wardle, Brian L.

    2012-01-01

    Vertically aligned carbon nanotubes (VACNTs) are placed between all plies in an aerospace carbon fiber reinforced plastic laminate (unidirectional plies, [(0/90/±45)2]s) to reinforce the interlaminar region in the z-direction. Significant improvement in Mode I and II interlaminar toughness have been observed previously. In this work, several substructural in-plane strength tests relevant to aerostructures were undertaken: bolt/tension-bearing, open hole compression, and L-shape laminate be...

  14. Multiwall carbon nanotubes reinforced epoxy nanocomposites

    Science.gov (United States)

    Chen, Wei

    The emergence of carbon nanotubes (CNTs) has led to myriad possibilities for structural polymer composites with superior specific modulus, strength, and toughness. While the research activities in carbon nanotube reinforced polymer composites (NRPs) have made enormous progress towards fabricating next-generation advanced structural materials with added thermal, optical, and electrical advantages, questions concerning the filler dispersion, interface, and CNT alignment in these composites remain partially addressed. In this dissertation, the key technical challenges related to the synthesis, processing, and reinforcing mechanics governing the effective mechanical properties of NRPs were introduced and reviewed in the first two chapters. Subsequently, issues on the dispersion, interface control, hierarchical structure, and multi-functionality of NRPs were addressed based on functionalized multi-walled carbon nanotube reinforced DGEBA epoxy systems (NREs). In chapter 3, NREs with enhanced flexural properties were discussed in the context of improved dispersion and in-situ formation of covalent bonds at the interface. In chapter 4, NREs with controlled interface and tailored thermomechanical properties were demonstrated through the judicious choice of surface functionality and resin chemistry. In chapter 5, processing-condition-induced CNT organization in hierarchical epoxy nanocomposites was analyzed. In Chapter 6, possibilities were explored for multi-functional NREs for underwater acoustic structural applications. Finally, the findings of this dissertation were concluded and future research was proposed for ordered carbon nanotube array reinforced nanocomposites in the last chapter. Four journal publications resulted from this work are listed in Appendix.

  15. Token reinforcement: a review and analysis.

    Science.gov (United States)

    Hackenberg, Timothy D

    2009-03-01

    Token reinforcement procedures and concepts are reviewed and discussed in relation to general principles of behavior. The paper is divided into four main parts. Part I reviews and discusses previous research on token systems in relation to common behavioral functions--reinforcement, temporal organization, antecedent stimulus functions, and aversive control--emphasizing both the continuities with other contingencies and the distinctive features of token systems. Part II describes the role of token procedures in the symmetrical law of effect, the view that reinforcers (gains) and punishers (losses) can be measured in conceptually analogous terms. Part III considers the utility of token reinforcement procedures in cross-species analysis of behavior more generally, showing how token procedures can be used to bridge the methodological gulf separating research with humans from that with other animals. Part IV discusses the relevance of token systems to the field of behavioral economics. Token systems have the potential to significantly advance research and theory in behavioral economics, permitting both a more refined analysis of the costs and benefits underlying standard economic models, and a common currency more akin to human monetary systems. Some implications for applied research and for broader theoretical integration across disciplines will also be considered.

  16. Response deprivation, reinforcement, and economics

    OpenAIRE

    Allison, James

    1993-01-01

    Reinforcement of an instrumental response results not from a special kind of response consequence known as a reinforcer, but from a special kind of schedule known as a response-deprivation schedule. Under the requirements of a response-deprivation schedule, the baseline rate of the instrumental response permits less than the baseline rate of the contingent response. Because reinforcement occurs only if the schedule deprives the organism of the contingent response, reinforcement cannot result ...

  17. Cellular fiber–reinforced concrete

    OpenAIRE

    Isachenko S.; Kodzoev M.

    2016-01-01

    Methods disperse reinforcement of concrete matrix using polypropylene, glass, basalt and metal fibers allows to make the construction of complex configuration, solve the problem of frost products. Dispersed reinforcement reduces the overall weight of the structures. The fiber replaces the secondary reinforcement, reducing the volume of use of structural steel reinforcement. Cellular Fiber concretes are characterized by high-performance properties, especially increased bending strength and...

  18. Reinforcing aspects of androgens.

    Science.gov (United States)

    Wood, Ruth I

    2004-11-15

    Are androgens reinforcing? Androgenic-anabolic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, often with negative long-term health consequences. As a result, in 1991, testosterone was declared a controlled substance. Recently, Brower [K.J. Brower, Anabolic steroid abuse and dependence. Curr. Psychiatry Rep. 4 (2002) 377-387.] proposed a two-stage model of AAS dependence. Users initiate steroid use for their anabolic effects on muscle growth. With continued exposure, dependence on the psychoactive effects of AAS develops. However, it is difficult in humans to separate direct psychoactive effects of AAS from the user's psychological dependence on the anabolic effects of AAS. Thus, studies in laboratory animals are useful to explore androgen reinforcement. Testosterone induces a conditioned place preference in rats and mice, and is voluntarily consumed through oral, intravenous, and intracerebroventricular self-administration in hamsters. Active, gonad-intact male and female hamsters will deliver 1 microg/microl testosterone into the lateral ventricles. Indeed, some individuals self-administer testosterone intracerebroventricularly to the point of death. Male rats develop a conditioned place preference to testosterone injections into the nucleus accumbens, an effect blocked by dopamine receptor antagonists. These data suggest that androgen reinforcement is mediated by the brain. Moreover, testosterone appears to act through the mesolimbic dopamine system, a common substrate for drugs of abuse. Nonetheless, androgen reinforcement is not comparable to that of cocaine or heroin. Instead, testosterone resembles other mild reinforcers, such as caffeine, nicotine, or benzodiazepines. The potential for androgen addiction remains to be determined.

  19. Clinical Use of GalaFLEX in Facial and Breast Cosmetic Plastic Surgery.

    Science.gov (United States)

    Adams, William P; Toriumi, Dean M; Van Natta, Bruce W

    2016-11-01

    Resolution of ptosis is a key step to the success of many plastic surgery procedures. Ptosis is a manifestation of tissue stretch. Tissue stretch can occur as a result of the natural aging process or health of the patient, or tissue may stretch under added weight or volume, such as when implants are placed. Surgical rejuvenation of ptotic tissues is very effective and results in marked changes in the patient profile yet the tissue that resulted in the need for the procedure first place has not improved and ptosis can recur. Recent developments in long-term resorbable porous materials have provided surgeons with the opportunity to experiment with tissue reinforcement in plastic surgery procedures. These new materials have a low profile, rapid tissue integration, and a long-term strength retention profile. Long-term resorbable scaffolds such as poly-4-hydroxybutyrate (P4HB) natural scaffold (GalaFLEX scaffold, Galatea Surgical, Inc., Lexington, MA) have shown promise for a host of plastic surgery indications. This article presents clinical experience with GalaFLEX for soft tissue reinforcement in three different clinical applications; including the reinforcement of the superficial muscular aponeurotic system (SMAS) in minimally invasive facelift, reinforcement of the skin envelope in mastopexy, and reinforcement of the breast capsule (pocket) in revisional breast surgery. Soft tissue reinforcement has been shown to provide increased mechanical strength as well as improved maintenance of postoperative results. 5 Therapeutic. © 2016 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  20. PREPARATION AND CHARACTERIZATION OF MODIFIED STARCH-BASED BIODEGRADABLE MATERIALS REINFORCED WITH PULP FIBER

    Institute of Scientific and Technical Information of China (English)

    LingfangJi; ShucaiLi

    2004-01-01

    Native corn starch and hydroxypropyl starch (HPS) based plastic films were prepared using the short pulp fiber as reinforcement and the glycerol as the plasticizer. The results of tensile test showed that the tensile strength and the elongation at break increased with the pulp contents. With the glycerol contents, the elongation at break increased considerably, but the tensile strength decreased. The water uptake of the films decreased with the pulp contents and hydroxypropylation, but increased with the glycerol contents. So it is concluded that the films was reinforced by pulp fiber and hydroxypropylation.

  1. Stud Reinforcement in Beam-Column Joints under Seismic Loads

    Science.gov (United States)

    Ibrahim, Hatem Hassan Ali

    reinforcing exterior beam-column joints. A three dimensional finite element model was developed. The concrete material model used combines constitutive models for cracking and plasticity. The model was verified against the experimental results. Good agreement was found between the experimental and numerical hysteretic behaviour. The strengths and weaknesses of the model were identified. The model was used to study the effect of various parameters on the joint behaviour including: concrete strength, column load and out-of-plane confinement.

  2. Classroom Management and Negative Reinforcement.

    Science.gov (United States)

    Tauber, Robert T.

    Of the four simple consequences for behavior, none is more misunderstood than negative reinforcement. A Negative Reinforcement Quiz administered to 233 student teachers from two universities revealed that the vast majority of respondents mistakenly viewed negative reinforcement as a synonym for punishment, and believe that negative reinforcement…

  3. Short fiber reinforced thermoplastic blends

    NARCIS (Netherlands)

    Malchev, P.G.

    2008-01-01

    The present thesis investigates the potential of short fiber reinforced thermoplastic blends, a combination of an immiscible polymer blend and a short fiber reinforced composite, to integrate the easy processing solutions available for short fiber reinforced composites with the high mechanical perfo

  4. Short fiber reinforced thermoplastic blends

    NARCIS (Netherlands)

    Malchev, P.G.

    2008-01-01

    The present thesis investigates the potential of short fiber reinforced thermoplastic blends, a combination of an immiscible polymer blend and a short fiber reinforced composite, to integrate the easy processing solutions available for short fiber reinforced composites with the high mechanical perfo

  5. Stress-strain response of plastic waste mixed soil.

    Science.gov (United States)

    Babu, G L Sivakumar; Chouksey, Sandeep Kumar

    2011-03-01

    Recycling plastic waste from water bottles has become one of the major challenges worldwide. The present study provides an approach for the use plastic waste as reinforcement material in soil. The experimental results in the form of stress-strain-pore water pressure response are presented. Based on experimental test results, it is observed that the strength of soil is improved and compressibility reduced significantly with addition of a small percentage of plastic waste to the soil. The use of the improvement in strength and compressibility response due to inclusion of plastic waste can be advantageously used in bearing capacity improvement and settlement reduction in the design of shallow foundations. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. LARS人工韧带移植重建膝关节前交叉韧带28例%Anterior cruciate ligament reconstruction using ligament advanced reinforcement system artificial ligament in 28 cases

    Institute of Scientific and Technical Information of China (English)

    符培亮; 吴宇黎; 吴海山; 陈宣; 李晓华; 钱齐荣; 祝云利

    2008-01-01

    背景:以往的人工韧带容易出现材料疲劳而导致断裂,并且因为组织相容性的问题容易出现关节的滑膜炎.目的:随访观察LARS人工韧带在前交叉韧带损伤移植重建中的应用效果.设计、时间及地点:自身对照,随访观察,于2004-08/2007-01在上海长征医院骨科关节外科进行.参试者:前交叉韧带损伤患者28例,运动伤16例,车祸伤12例.材料:LARS人工韧带由法国LARS公司产品,材料主要成分为高韧性的聚酯纤维(聚对苯二甲酸乙二醇脂).方法:对28例前交叉韧带损伤的患者行关节镜下LAPS人工韧带重建,并进行平均20个月的随访.主要观察指标:移植前和随访时患者的前抽屉试验、Lysholm评分、关节活动度.结果:28例患膝不稳定症状消失,前抽屉试验阴性,关节功能良好,伸屈度5.71°~129.64°.根据Lysholm膝关节评分法,平均积分由移植前的(45.74±9.82)分提高到移植后的(86.5±6.44)分(P<0.001).所有病例均于移植后2个月左右恢复正常活动,无急慢性滑膜炎出现,无材料宿主反应.结论:LARS人工韧带是较安全的移植材料,特别适合运动导致的前交叉韧带损伤.中短期随访结果显示优良.%BACKGROUND: Previous artificial ligament is easy to break for material fatigue and to appear synonitis for materialbiocompatibility.OBJECTIVE: To observe the application effect of ligament advanced reinforcement system (LARS) artificial ligament inreconstruction of anterior cruciate ligament via follow-up.DESIGN, TIME AND SETTING: An own control, follow-up observation was performed between August 2004 andJanuary 2007 at the Department of Orthopedics and Joint Surgery, Shanghai Changzheng Hospital, Shanghai, China.PARTICIPANTS: Twenty-eight patients with anterior cruciate ligament injury, including 16 with sport injury and 12 withvehicle accident injury.MATERIALS: The main component of LARS artificial ligament (Laboratoire d'Applieation et de Recherche

  7. Plastic Pollution from Ships

    OpenAIRE

    Čulin, Jelena; Bielić, Toni

    2016-01-01

    The environmental impact of shipping on marine environment includes discharge of garbage. Plastic litter is of particular concern due to abundance, resistance to degradation and detrimental effect on marine biota. According to recently published studies, a further research is required to assess human health risk. Monitoring data indicate that despite banning plastic disposal at sea, shipping is still a source of plastic pollution. Some of the measures to combat the problem are discussed.

  8. Research advance of near-surface mounted fiber-reinforced polymer to concrete%表层嵌贴FRP-混凝土黏结加固研究进展

    Institute of Scientific and Technical Information of China (English)

    童谷生; 蔡少杰

    2014-01-01

    Near-surface mounted(NSM)fiber-reinforced polymer(FRP)reinforcement is one of the latest and most promising strength-ening techniques for reinforced concrete(RC)structures.Research on this topic mainly focused on the bonding mechanism and the flexural strengthening.The paper presents bond mechanics of NSM FRP bars/strips to concrete including the bond test methods ,effect of test vari-ables,bond failure modes,analytical modeling,local bond shear stress-slip relationship.It provides a critical review of existing research in this area,identifies gaps of knowledge,and outlines directions for further research.%表层嵌贴FRP修复加固混凝土结构是一种富有前景的新型技术,目前该技术领域的研究主要集中在黏结机理和抗弯加固两方面。论述表层嵌贴FRP-混凝土的试验方法、主要控制参数、破坏模式、黏结机理、界面黏结滑移本构关系等。最后,对目前国内外表层嵌贴FRP-混凝土黏结性能的研究现状进行探讨,希望为表层嵌贴FRP加固技术的进一步研究发展提供方向。

  9. A Perspective on the Prowaste Concept: Efficient Utilization of Plastic Waste through Product Design and Process Innovation

    Directory of Open Access Journals (Sweden)

    Antonio Greco

    2014-07-01

    Full Text Available This work is aimed to present an innovative technology for the reinforcement of beams for urban furniture, produced by in-mold extrusion of plastics from solid urban waste. This material, which is usually referred to as “recycled plastic lumber”, is characterized by very poor mechanical properties, which results in high deflections under flexural loads, particularly under creep conditions. The Prowaste project, founded by the EACI (European Agency for Competitiveness and Innovation in the framework of the Eco-Innovation measure, was finalized to develop an innovative technology for selective reinforcement of recycled plastic lumber. Selective reinforcement was carried out by the addition of pultruded glass rods in specific positions with respect to the cross section of the beam, which allowed optimizing the reinforcing efficiency. The reinforcement of the plastic lumber beams with pultruded rods was tested at industrial scale plant, at Solteco SL (Alfaro, Spain. The beams obtained, characterized by low cost and weight, were commercialized by the Spanish company. The present paper presents the most relevant results of the Prowaste project. Initially, an evaluation of the different materials candidates for the reinforcement of recycled plastic lumber is presented. Plastic lumber beams produced in the industrial plant were characterized in terms of flexural properties. The results obtained are interpreted by means of beam theory, which allows for extrapolation of the characteristic features of beams produced by different reinforcing elements. Finally, a theoretical comparison with other approaches which can be used for the reinforcement of plastic lumber is presented, highlighting that, among others, the Prowaste concept maximizes the stiffening efficiency, allowing to significantly reduce the weight of the components.

  10. Handbook of Plastic Welding

    DEFF Research Database (Denmark)

    Islam, Aminul

    The purpose of this document is to summarize the information about the laser welding of plastic. Laser welding is a matured process nevertheless laser welding of micro dimensional plastic parts is still a big challenge. This report collects the latest information about the laser welding of plasti...... as a knowledge handbook for laser welding of plastic components. This document should provide the information for all aspects of plastic laser welding and help the design engineers to take all critical issues into consideration from the very beginning of the design phase....

  11. Plastics and health risks.

    Science.gov (United States)

    Halden, Rolf U

    2010-01-01

    By 2010, the worldwide annual production of plastics will surpass 300 million tons. Plastics are indispensable materials in modern society, and many products manufactured from plastics are a boon to public health (e.g., disposable syringes, intravenous bags). However, plastics also pose health risks. Of principal concern are endocrine-disrupting properties, as triggered for example by bisphenol A and di-(2-ethylhexyl) phthalate (DEHP). Opinions on the safety of plastics vary widely, and despite more than five decades of research, scientific consensus on product safety is still elusive. This literature review summarizes information from more than 120 peer-reviewed publications on health effects of plastics and plasticizers in lab animals and humans. It examines problematic exposures of susceptible populations and also briefly summarizes adverse environmental impacts from plastic pollution. Ongoing efforts to steer human society toward resource conservation and sustainable consumption are discussed, including the concept of the 5 Rs--i.e., reduce, reuse, recycle, rethink, restrain--for minimizing pre- and postnatal exposures to potentially harmful components of plastics.

  12. Synaptic Plasticity and Nociception

    Institute of Scientific and Technical Information of China (English)

    ChenJianguo

    2004-01-01

    Synaptic plasticity is one of the fields that progresses rapidly and has a lot of success in neuroscience. The two major types of synaptie plasticity: long-term potentiation ( LTP and long-term depression (LTD are thought to be the cellular mochanisms of learning and memory. Recently, accumulating evidence suggests that, besides serving as a cellular model for learning and memory, the synaptic plasticity involves in other physiological or pathophysiological processes, such as the perception of pain and the regulation of cardiovascular system. This minireview will focus on the relationship between synaptic plasticity and nociception.

  13. Local melting to design strong and plastically deformable bulk metallic glass composites

    Science.gov (United States)

    Qin, Yue-Sheng; Han, Xiao-Liang; Song, Kai-Kai; Tian, Yu-Hao; Peng, Chuan-Xiao; Wang, Li; Sun, Bao-An; Wang, Gang; Kaban, Ivan; Eckert, Jürgen

    2017-02-01

    Recently, CuZr-based bulk metallic glass (BMG) composites reinforced by the TRIP (transformation-induced plasticity) effect have been explored in attempt to accomplish an optimal of trade-off between strength and ductility. However, the design of such BMG composites with advanced mechanical properties still remains a big challenge for materials engineering. In this work, we proposed a technique of instantaneously and locally arc-melting BMG plate to artificially induce the precipitation of B2 crystals in the glassy matrix and then to tune mechanical properties. Through adjusting local melting process parameters (i.e. input powers, local melting positions, and distances between the electrode and amorphous plate), the size, volume fraction, and distribution of B2 crystals were well tailored and the corresponding formation mechanism was clearly clarified. The resultant BMG composites exhibit large compressive plasticity and high strength together with obvious work-hardening ability. This compelling approach could be of great significance for the steady development of metastable CuZr-based alloys with excellent mechanical properties.

  14. The behavioral economics of substance use disorders: reinforcement pathologies and their repair.

    Science.gov (United States)

    Bickel, Warren K; Johnson, Matthew W; Koffarnus, Mikhail N; MacKillop, James; Murphy, James G

    2014-01-01

    The field of behavioral economics has made important inroads into the understanding of substance use disorders through the concept of reinforcer pathology. Reinforcer pathology refers to the joint effects of (a) the persistently high valuation of a reinforcer, broadly defined to include tangible commodities and experiences, and/or (b) the excessive preference for the immediate acquisition or consumption of a commodity despite long-term negative outcomes. From this perspective, reinforcer pathology results from the recursive interactions of endogenous person-level variables and exogenous environment-level factors. The current review describes the basic principles of behavioral economics that are central to reinforcer pathology, the processes that engender reinforcer pathology, and the approaches and procedures that can repair reinforcement pathologies. The overall goal of this review is to present a new understanding of substance use disorders as viewed by recent advances in behavioral economics.

  15. Analytical Model for Fictitious Crack Propagation in Reinforced Concrete Beams without Debonding

    DEFF Research Database (Denmark)

    Ulfkjær, J. P.; Brincker, Rune

    1994-01-01

    , the crack growth is further simplified by introducing a continuous layer of springs at the midsection mainly representing a simplified material response around the fracture zone. In the reinforcement the strain condition is assumed to be equal to the strain condition in the concrete. the important question......The non-linear fracture mechanical problem of combined crack growth and reinforcement action is modelled by adopting a simplified fictitious crack model for concrete and a linear elastic-plastic action for the reinforcement. The softening relation of the concrete is assumed to be linear, however...

  16. Analysis of the strength and stiffness of timber beams reinforced with carbon fiber and glass fiber

    Directory of Open Access Journals (Sweden)

    Juliano Fiorelli

    2003-06-01

    Full Text Available An experimental analysis of pinewood beams (Pinus caribea var hondurensis reinforced with glass and/or carbon fibers is discussed. The theoretical model employed to calculate the beam's bending strength takes into account the timber's ultimate limit states of tensile strength and failure by compression, considering a model of fragile elastic tension and plastic elastic compression. The validity of the theoretical model is confirmed by a comparison of the theoretical and experimental results, while the efficiency of the fiber reinforcement is corroborated by the increased strength and stiffness of the reinforced timber beams.

  17. Conditioned Reinforcement and Response Strength

    Science.gov (United States)

    Shahan, Timothy A

    2010-01-01

    Stimuli associated with primary reinforcers appear themselves to acquire the capacity to strengthen behavior. This paper reviews research on the strengthening effects of conditioned reinforcers within the context of contemporary quantitative choice theories and behavioral momentum theory. Based partially on the finding that variations in parameters of conditioned reinforcement appear not to affect response strength as measured by resistance to change, long-standing assertions that conditioned reinforcers do not strengthen behavior in a reinforcement-like fashion are considered. A signposts or means-to-an-end account is explored and appears to provide a plausible alternative interpretation of the effects of stimuli associated with primary reinforcers. Related suggestions that primary reinforcers also might not have their effects via a strengthening process are explored and found to be worthy of serious consideration. PMID:20885815

  18. Mechanically reinforced glass beams

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Olesen, John Forbes

    2007-01-01

    The use of glass as a load carrying material in structural elements is rarely seen even though glass is a popular material for many architects. This is owed to the unreliable and low tensile strength, which is due to surface flaws and high brittleness of the material. These properties lead...... to breakage without any warning or ductility, which can be catastrophic if no precautions are taken. One aspect of this issue is treated here by looking at the possibility of mechanically reinforcing glass beams in order to obtain ductile failure for such a structural component. A mechanically reinforced...... laminated float glass beam is constructed and tested in four-point bending. The beam consist of 4 layers of glass laminated together with a slack steel band glued onto the bottom face of the beam. The glass parts of the tested beams are \\SI{1700}{mm} long and \\SI{100}{mm} high, and the total width of one...

  19. Nanostructured composite reinforced material

    Science.gov (United States)

    Seals, Roland D [Oak Ridge, TN; Ripley, Edward B [Knoxville, TN; Ludtka, Gerard M [Oak Ridge, TN

    2012-07-31

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  20. South Oregon Coast Reinforcement.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1998-05-01

    The Bonneville Power Administration is proposing to build a transmission line to reinforce electrical service to the southern coast of Oregon. This FYI outlines the proposal, tells how one can learn more, and how one can share ideas and opinions. The project will reinforce Oregon`s south coast area and provide the necessary transmission for Nucor Corporation to build a new steel mill in the Coos Bay/North Bend area. The proposed plant, which would use mostly recycled scrap metal, would produce rolled steel products. The plant would require a large amount of electrical power to run the furnace used in its steel-making process. In addition to the potential steel mill, electrical loads in the south Oregon coast area are expected to continue to grow.