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Sample records for composite material vessels

  1. Flexible Composite-Material Pressure Vessel

    Brown, Glen; Haggard, Roy; Harris, Paul A.

    2003-01-01

    A proposed lightweight pressure vessel would be made of a composite of high-tenacity continuous fibers and a flexible matrix material. The flexibility of this pressure vessel would render it (1) compactly stowable for transport and (2) more able to withstand impacts, relative to lightweight pressure vessels made of rigid composite materials. The vessel would be designed as a structural shell wherein the fibers would be predominantly bias-oriented, the orientations being optimized to make the fibers bear the tensile loads in the structure. Such efficient use of tension-bearing fibers would minimize or eliminate the need for stitching and fill (weft) fibers for strength. The vessel could be fabricated by techniques adapted from filament winding of prior composite-material vessels, perhaps in conjunction with the use of dry film adhesives. In addition to the high-bias main-body substructure described above, the vessel would include a low-bias end substructure to complete coverage and react peak loads. Axial elements would be overlaid to contain damage and to control fiber orientation around side openings. Fiber ring structures would be used as interfaces for connection to ancillary hardware.

  2. Fabrication techniques of metal liner used for pressure vessels made by composite material

    Takahashi, W.K.; Al-Qureshi, H.A.

    1982-01-01

    Different viable techniques for the manufacturing of metal liner used for pressure vessels are presented. The aim of these metal liner is to avoid the fluid leakage from the pressurized vessel and to serve as a mandreal to be wound by composite material. The studied techniques are described and the practical results are illustrated. Finally a comparative study of the manufacturing techniques is made in order to define the process that furnishes the metal liner with the best characteristics. The advantages offered by these type of pressure vessels when compared with the conventional metallic vessels, are also presented. (Author) [pt

  3. Optimization of Composite Material System and Lay-up to Achieve Minimum Weight Pressure Vessel

    Mian, Haris Hameed; Wang, Gang; Dar, Uzair Ahmed; Zhang, Weihong

    2013-10-01

    The use of composite pressure vessels particularly in the aerospace industry is escalating rapidly because of their superiority in directional strength and colossal weight advantage. The present work elucidates the procedure to optimize the lay-up for composite pressure vessel using finite element analysis and calculate the relative weight saving compared with the reference metallic pressure vessel. The determination of proper fiber orientation and laminate thickness is very important to decrease manufacturing difficulties and increase structural efficiency. In the present work different lay-up sequences for laminates including, cross-ply [ 0 m /90 n ] s , angle-ply [ ±θ] ns , [ 90/±θ] ns and [ 0/±θ] ns , are analyzed. The lay-up sequence, orientation and laminate thickness (number of layers) are optimized for three candidate composite materials S-glass/epoxy, Kevlar/epoxy and Carbon/epoxy. Finite element analysis of composite pressure vessel is performed by using commercial finite element code ANSYS and utilizing the capabilities of ANSYS Parametric Design Language and Design Optimization module to automate the process of optimization. For verification, a code is developed in MATLAB based on classical lamination theory; incorporating Tsai-Wu failure criterion for first-ply failure (FPF). The results of the MATLAB code shows its effectiveness in theoretical prediction of first-ply failure strengths of laminated composite pressure vessels and close agreement with the FEA results. The optimization results shows that for all the composite material systems considered, the angle-ply [ ±θ] ns is the optimum lay-up. For given fixed ply thickness the total thickness of laminate is obtained resulting in factor of safety slightly higher than two. Both Carbon/epoxy and Kevlar/Epoxy resulted in approximately same laminate thickness and considerable percentage of weight saving, but S-glass/epoxy resulted in weight increment.

  4. The Cyogenic Evaluation of Irradiated Composite Materials for Use in Composite Pressure Vessels, Phase I

    National Aeronautics and Space Administration — The intent of this proposal is to develop key building block technology for lightweight composite structures suitable for cryogenic fuel depot storage as well as...

  5. Molten material-containing vessel

    Akagawa, Katsuhiko

    1998-01-01

    The molten material-containing vessel of the present invention comprises a vessel main body having an entrance opened at the upper end, a lid for closing the entrance, an outer tube having an upper end disposed at the lower surface of the lid, extended downwardly and having an closed lower end and an inner tube disposed coaxially with the outer tube. When a molten material is charged from the entrance to the inside of the vessel main body of the molten material-containing vessel and the entrance is closed by the lid, the outer tube and the inner tube are buried in the molten material in the vessel main body, accordingly, a fluid having its temperature elevated by absorption of the heat of the molten material rises along the inner circumferential surface of the outer tube, abuts against the lower surface of the lid and cooled by exchanging heat with the lid and forms a circulating flow. Since the heat in the molten material is continuously absorbed by the fluid, transferred to the lid and released from the lid to the atmospheric air, heat releasing efficiency can be improved compared with conventional cases. (N.H.)

  6. Composite Materials

    Nielsen, Lauge Fuglsang

    This book deals with the mechanical and physical behavior of composites as influenced by composite geometry. "Composite Materials" provides a comprehensive introduction for researchers and students to modern composite materials research with a special emphasis on the significance of phase geometry......, viscoelastic behavior, and internal stress states. Other physical properties considered are thermal and electrical conductivities, diffusion coefficients, dielectric constants and magnetic permeability. Special attention is given to the effect of pore shape on the mechanical and physical behavior of porous....... The book enables the reader to a better understanding of the behavior of natural composites, improvement of such materials, and design of new materials with prescribed properties. A number of examples are presented: Special composite properties considered are stiffness, shrinkage, hygro-thermal behavior...

  7. Composite material

    Hutchens, Stacy A [Knoxville, TN; Woodward, Jonathan [Solihull, GB; Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN

    2012-02-07

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  8. Eddy current testing of composite pressure vessels

    Casperson, R.; Pohl, R.; Munzke, D.; Becker, B.; Pelkner, M.

    2018-04-01

    The use of composite pressure vessels instead of conventional vessels made of steel or aluminum grew strongly over the last decade. The reason for this trend is the tremendous weight saving in the case of composite vessels. However, the long-time behavior is not fully understood for filling and discharging cycles and creep strength and their influence on the CFRP coating (carbon fiber reinforced plastics) and the internal liner (steel, aluminum, or plastics). The CFRP ensures the pressure resistance while the inner liner is used as a container for liquid or gas. To overcome the missing knowledge of aging, BAM started an internal project to investigate degradation of these material systems. Therefore, applicable testing methods like eddy current testing are needed. Normally, high-frequency eddy current testing (HF-ET, f > 10 MHz) is deployed for CFRP due to its low conductivity of the fiber, which is in the order of 0.01 MS/s, and the capacitive coupling between the fibers. Nevertheless, in some cases conventional ET can be applied. We show a concise summary of studies on the application of conventional ET of composite pressure vessels.

  9. Composite materials

    Sambrook, D.J.

    1976-01-01

    A superconductor composite is described comprising at least one longitudinally extending superconductor filament or bundle of sub-filaments, each filament or bundle of sub-filaments being surrounded by and in good electrical contact with a matrix material, the matrix material comprising a plurality of longitudinally extending cells of a metal of high electrical conductivity surrounded by a material of lower electrical conductivity. The high electrical conductivity material surrounding the superconducting filament or bundle of sub-filaments is interrupted by a radially extending wall of the material of the lower electrical conductivity, the arrangement being such that at least two superconductor filaments or sub-filaments are circumferentially circumscribed by a single annulus of the material of high electrical conductivity. The annulus is electrically interrupted by a radially extending wall of the material of low electrical conductivity

  10. The Cryogenic Impact Resistant Evaluation of Composite Materials for Use in Composite Pressure Vessels with an Additional Cryogenic Bonding Scope, Phase II

    National Aeronautics and Space Administration — The intent of the proposed effort is to investigate the detailed composite material performance characteristics after being subjected to cryogenic temperatures and...

  11. Computerized reactor pressure vessel materials information system

    Strosnider, J.; Monserrate, C.; Kenworthy, L.D.; Tether, C.D.

    1980-10-01

    A computerized information system for storage and retrieval of reactor pressure vessel materials data was established, as part of Task Action Plan A-11, Reactor Vessel Materials Toughness. Data stored in the system are necessary for evaluating the resistance of reactor pressure vessels to flaw-induced fracture. This report includes (1) a description of the information system; (2) guidance on accessing the system; and (3) a user's manual for the system

  12. Metallic composite materials

    Frommeyer, G.

    1987-01-01

    The structure and properties of metallic composite materials and composite materials with metallic matrix are considered. In agreement with the morphology of constituent phases the following types of composite materials are described: dispersion-strengthened composite materials; particle-reinforced composite materials; fibrous composite materials; laminar composite materials. Data on strength and electric properties of the above-mentioned materials, as well as effect of the amount, location and geometric shape of the second phase on them, are presented

  13. Fabrication of toroidal composite pressure vessels. Final report

    Dodge, W.G.; Escalona, A.

    1996-01-01

    A method for fabricating composite pressure vessels having toroidal geometry was evaluated. Eight units were fabricated using fibrous graphite material wrapped over a thin-walled aluminum liner. The material was wrapped using a machine designed for wrapping, the graphite material was impregnated with an epoxy resin that was subsequently thermally cured. The units were fabricated using various winding patterns. They were hydrostatically tested to determine their performance. The method of fabrication was demonstrated. However, the improvement in performance to weight ratio over that obtainable by an all metal vessel probably does not justify the extra cost of fabrication

  14. 33 CFR 90.3 - Pushing vessel and vessel being pushed: Composite unit.

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pushing vessel and vessel being... HOMELAND SECURITY INLAND NAVIGATION RULES INLAND RULES: INTERPRETATIVE RULES § 90.3 Pushing vessel and vessel being pushed: Composite unit. Rule 24(b) of the Inland Rules states that when a pushing vessel and...

  15. 33 CFR 82.3 - Pushing vessel and vessel being pushed: Composite unit.

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pushing vessel and vessel being... HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES 72 COLREGS: INTERPRETATIVE RULES § 82.3 Pushing vessel and vessel being pushed: Composite unit. Rule 24(b) of the 72 COLREGS states that when a pushing vessel and a...

  16. Aerogel / Polymer Composite Materials

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Roberson, Luke B. (Inventor); Clayton, LaNetra M. (Inventor)

    2017-01-01

    The invention provides new composite materials containing aerogels blended with thermoplastic polymer materials at a weight ratio of aerogel to thermoplastic polymer of less than 20:100. The composite materials have improved thermal insulation ability. The composite materials also have better flexibility and less brittleness at low temperatures than the parent thermoplastic polymer materials.

  17. Pressure vessel steels: influence of chemical composition on irradiation sensitivity

    Ghoniem, M.M.; Hammad, F.H.

    1998-01-01

    Neutron irradiation of the steels used in the construction of the nuclear reactor pressure vessels can lead to the embrittlement of these materials, increasing the ductile-to-brittle transition temperature and decreasing the fracture energy, which can limit the plant life. The knowledge of irradiation embrittlement and the means for minimizing such degradation is therefore important in the field of assuring the safety of the nuclear power plants. Irradiation embrittlement is quite a complex process. It involves many variables. The most important of these are irradiation temperature, neutron fluence (neutron dose), neutron flux (neutron dose rate), and chemical composition of the irradiated material. This paper is concerned with the effect of chemical composition, the role of residual and alloying elements in the irradiation embrittlement of nuclear reactor pressure vessel steels in light water reactors. It presents a critical review for the published work in this field through the last 25 years

  18. Composite material dosimeters

    Miller, Steven D.

    1996-01-01

    The present invention is a composite material containing a mix of dosimeter material powder and a polymer powder wherein the polymer is transparent to the photon emission of the dosimeter material powder. By mixing dosimeter material powder with polymer powder, less dosimeter material is needed compared to a monolithic dosimeter material chip. Interrogation is done with excitation by visible light.

  19. Corrosion resistant composite materials

    Ul'yanin, E.A.

    1986-01-01

    Foundations for corrosion-resistant composite materials design are considered with account of components compatibility. Fibrous and lamellar composites with metal matrix, dispersion-hardened steels and alloys, refractory metal carbides-, borides-, nitrides-, silicides-based composites are described. Cermet compositions and fields of their application, such as protective coatings for operation in agressive media at high temperatures, are presented

  20. Materials for high temperature reactor vessels

    Buenaventura Pouyfaucon, A.

    2004-01-01

    Within the 5th Euraton Framework Programme, a big effort is being made to promote and consolidate the development of the High Temperature Reactor (HTR). Empresarios Agrupados is participating in this project and among others, also forms part of the HTR-M project Materials for HTRs. This paper summarises the work carried out by Empresarios Agrupados regarding the material selection of the HTR Reactor Pressure Vessel (RPV). The possible candidate materials and the most promising ones are discussed. Design aspects such as the RPV sensitive zones and material damage mechanisms are considered. Finally, the applicability of the existing design Codes and Standards for the design of the HTR RPV is also discussed. (Author)

  1. Nano-composite materials

    Lee, Se-Hee; Tracy, C. Edwin; Pitts, J. Roland

    2010-05-25

    Nano-composite materials are disclosed. An exemplary method of producing a nano-composite material may comprise co-sputtering a transition metal and a refractory metal in a reactive atmosphere. The method may also comprise co-depositing a transition metal and a refractory metal composite structure on a substrate. The method may further comprise thermally annealing the deposited transition metal and refractory metal composite structure in a reactive atmosphere.

  2. Multifunctional materials and composites

    Seo, Dong-Kyun; Jeon, Ki-Wan

    2017-08-22

    Forming multifunctional materials and composites thereof includes contacting a first material having a plurality of oxygen-containing functional groups with a chalcogenide compound, and initiating a chemical reaction between the first material and the chalcogenide compound, thereby replacing oxygen in some of the oxygen-containing functional groups with chalcogen from the chalcogen-containing compound to yield a second material having chalcogen-containing functional groups and oxygen-containing functional groups. The first material is a carbonaceous material or a macromolecular material. A product including the second material is collected and may be processed further to yield a modified product or a composite.

  3. ITER vacuum vessel, in vessel components and plasma facing materials

    Ioki, Kimihiro; Enoeda, M.; Federici, G.

    2007-01-01

    Design of the NB ports including duct liners under heat loads of the neutral beams has been developed. Design of the in-wall shielding has been developed in more details considering the supporting structure and the assembly method. The ferromagnetic inserts have previously not been installed in the outboard midplane region due to irregularity caused by the tangential ports for NB injection. Due to this configuration, the maximum ripple is relatively large (∝1 %) in a limited region of the plasma and the toroidal field flux lines fluctuate ∝10 mm in the FW region. To avoid these problems, additional ferromagnetic inserts are to be installed in the equatorial port region. Detailed studies were carried out on the ITER vacuum vessel to define appropriate codes and standards in the context of the ITER licensing in France. A set of draft documents regarding the ITER vacuum vessel structural code were prepared including an RCC-MR Addendum for the ITER VV with justified exceptions or modifications. The main deviation from the base Code is the extensive use of UT in lieu of radiography for the volumetric examination of all one-side access welds of the outer shell and field joint. The procurement allocation of blanket modules among 6 parties was fixed and the blanket module design has progressed in cooperation with parties. Fabrication of mock-ups for prequalification testing is under way and the tests will be performed in 2007-2008. Development of new beryllium materials is progressing in China and Russia. The ITER limiters will be installed in equatorial ports at two toroidal locations. The limiter plasma-facing surface protrudes ∝8 cm from the FW during the start-up and shutdown phase. In the new limiter concept, the limiters are retracted by ∝8 cm during the plasma flat top phase. This concept gives important advantages; (i) mitigation of the particle and heat loads due to disruptions, ELMs and blobs, (ii) improvement of the power coupling with the ICRH antenna

  4. Friction Material Composites Materials Perspective

    Sundarkrishnaa, K L

    2012-01-01

    Friction Material Composites is the first of the five volumes which strongly educates and updates engineers and other professionals in braking industries, research and test labs. It explains besides the formulation of design processes and its complete manufacturing input. This book gives an idea of mechanisms of friction and how to control them by designing .The book is  useful for designers  of automotive, rail and aero industries for designing the brake systems effectively with the integration of friction material composite design which is critical. It clearly  emphasizes the driving  safety and how serious designers should  select the design input. The significance of friction material component like brake pad or a liner as an integral part of the brake system of vehicles is explained. AFM pictures at nanolevel illustrate broadly the explanations given.

  5. Electrically conductive composite material

    Clough, Roger L.; Sylwester, Alan P.

    1989-01-01

    An electrically conductive composite material is disclosed which comprises a conductive open-celled, low density, microcellular carbon foam filled with a non-conductive polymer or resin. The composite material is prepared in a two-step process consisting of first preparing the microcellular carbon foam from a carbonizable polymer or copolymer using a phase separation process, then filling the carbon foam with the desired non-conductive polymer or resin. The electrically conductive composites of the present invention has a uniform and consistant pattern of filler distribution, and as a result is superior over prior art materials when used in battery components, electrodes, and the like.

  6. Storage vessel for containing radiation contaminated material

    Ogawa, Kazuya.

    1995-01-01

    A container pipe and an outer pipe are coaxially assembled integrally in a state where securing spacers are disposed between the container pipe and the outer pipe, and an annular flow channel is formed around the container pipe. Radiation contaminated material-containing body (glass solidified package) is contained in the container pipe. The container pipe and the outer pipe in an integrated state are suspended from a ceiling plug of a cell chamber of a storage vessel, and supporting devices are assembled between the pipes and a support structure. A shear/lug mechanism is used for the supporting devices. The combination of the shear/lug allows radial and vertical movement but restrict horizontal movement of the outer tube. The supporting devices are assembled while visually recognizing the state of the shear/lug mechanism between the outer pipe and the support mechanism. Accordingly, operationability upon assembling the container pipe and the outer pipe is improved. (I.N.)

  7. Composite Material Switches

    Javadi, Hamid (Inventor)

    2002-01-01

    A device to protect electronic circuitry from high voltage transients is constructed from a relatively thin piece of conductive composite sandwiched between two conductors so that conduction is through the thickness of the composite piece. The device is based on the discovery that conduction through conductive composite materials in this configuration switches to a high resistance mode when exposed to voltages above a threshold voltage.

  8. Manufacturing method for radioactive material containing vessel

    Kamino, Yoshikazu; Nishioka, Eiji; Toyota, Michinori.

    1997-01-01

    A containing vessel for radioactive materials (for example, spent fuels) comprises an inner cylinder made of stainless steel having a space for containing radioactive materials at the inside and an outer cylinder made of stainless steel disposed at the outer side of the inner cylinder. Lead homogenization is applied to a space between the inner and the outer cylinders to deposit a lead layer. Then, molten lead heated to a predetermined temperature is cast into the space between the inner and the outer cylinders. A valve is opened to discharge the molten lead in the space from a molten lead discharge pipe, and heated molten lead is injected from a molten lead supply pipe. Then, the discharge of the molten lead and the injection of the molten lead are stopped, and the lead in the space is coagulated. With such procedures, gaps are not formed between the lead of the homogenized portion and the lead of cast portion even when the thickness of the inner and the outer cylinders is great. (I.N.)

  9. Vessel calibration for accurate material accountancy at RRP

    Yanagisawa, Yuu; Ono, Sawako; Iwamoto, Tomonori

    2004-01-01

    RRP has a 800t·Upr capacity a year to re-process, where would be handled a large amount of nuclear materials as solution. A large scale plant like RRP will require accurate materials accountancy system, so that the vessel calibration with high-precision is very important as initial vessel calibration before operation. In order to obtain the calibration curve, it is needed well-known each the increment volume related with liquid height. Then we performed at least 2 or 3 times run with water for vessel calibration and careful evaluation for the calibration data should be needed. We performed vessel calibration overall 210 vessels, and the calibration of 81 vessels including IAT and OAT were held under presence of JSGO and IAEA inspectors taking into account importance on the material accountancy. This paper describes outline of the initial vessel calibration and calibration results based on back pressure measurement with dip tubes. (author)

  10. Superconducting composites materials

    Kerjouan, P.; Boterel, F.; Lostec, J.; Bertot, J.P.; Haussonne, J.M.

    1991-01-01

    The new superconductor materials with a high critical current own a large importance as well in the electronic components or in the electrotechnical devices fields. The deposit of such materials with the thick films technology is to be more and more developed in the years to come. Therefore, we tried to realize such thick films screen printed on alumina, and composed mainly of the YBa 2 Cu 3 O 7-δ material. We first realized a composite material glass/YBa 2 Cu 3 O 7-δ , by analogy with the classical screen-printed inks where the glass ensures the bonding with the substrate. We thus realized different materials by using some different classes of glass. These materials owned a superconducting transition close to the one of the pure YBa 2 Cu 3 O 7-δ material. We made a slurry with the most significant composite materials and binders, and screen-printed them on an alumina substrate preliminary or not coated with a diffusion barrier layer. After firing, we studied the thick films adhesion, the alumina/glass/composite material interfaces, and their superconducting properties. 8 refs.; 14 figs.; 9 tabs [fr

  11. Titanium Matrix Composite Pressure Vessel, Phase II

    National Aeronautics and Space Administration — For over 15 years, FMW Composite Systems has developed Metal Matrix Composite manufacturing methodologies for fabricating silicon-carbide-fiber-reinforced titanium...

  12. Nanostructured composite reinforced material

    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.

  13. Manufacturing method for radioactive material containing vessel

    Nishioka, Hideharu; Matsushita, Kazuo; Toyota, Michinori.

    1997-01-01

    Lead homogenization is applied on the inner surface of a space formed between an inner cylinder and an outer cylinder, and a molten lead heated to about 400 to 500degC is cast into a space formed between the inner cylinder and the outer cylinder in a state where the inner and the outer cylinders are heated to from 200 to 300degC. The space formed between the inner cylinder and the outer cylinder is heated to and kept at 330degC or higher for at least 2minutes after the casting of the molten lead, and then it is cooled. Thus, lowering of density of the molten lead due to excess elevation of temperature or dropping of the lead at the homogenization portion by heating the inner and the outer cylinders to an excessively high temperature are not caused. In addition, formation of gaps in the boundary between the inner cylinder and the outer cylinder or between the lead of the homogenized portion and that of the cast portion due to the melting of the lead of the homogenized portion in the space is prevented reliably thereby capable of forming a satisfactory shielding member. Then, even when the thickness of the inner cylinder and the outer cylinder is large, radioactive material containing vessel excellent in heat releasing property and radiation shielding property can be manufactured. (N.H.)

  14. High-performance fiber/epoxy composite pressure vessels

    Chiao, T. T.; Hamstad, M. A.; Jessop, E. S.; Toland, R. H.

    1978-01-01

    Activities described include: (1) determining the applicability of an ultrahigh-strength graphite fiber to composite pressure vessels; (2) defining the fatigue performance of thin-titanium-lined, high-strength graphite/epoxy pressure vessel; (3) selecting epoxy resin systems suitable for filament winding; (4) studying the fatigue life potential of Kevlar 49/epoxy pressure vessels; and (5) developing polymer liners for composite pressure vessels. Kevlar 49/epoxy and graphite fiber/epoxy pressure vessels, 10.2 cm in diameter, some with aluminum liners and some with alternation layers of rubber and polymer were fabricated. To determine liner performance, vessels were subjected to gas permeation tests, fatigue cycling, and burst tests, measuring composite performance, fatigue life, and leak rates. Both the metal and the rubber/polymer liner performed well. Proportionately larger pressure vessels (20.3 and 38 cm in diameter) were made and subjected to the same tests. In these larger vessels, line leakage problems with both liners developed the causes of the leaks were identified and some solutions to such liner problems are recommended.

  15. Micromechanics of Composite Materials

    Dvorak, George

    2013-01-01

    This book presents a broad exposition of analytical and numerical methods for modeling composite materials, laminates, polycrystals and other heterogeneous solids, with emphasis on connections between material properties and responses on several length scales, ranging from the nano and microscales to the macroscale. Many new results and methods developed by the author are incorporated into a rich fabric of the subject, which has been explored by several researchers over the last 40 years.   The first  part of the book reviews anisotropic elasticity theory, and then it describes the frequently used procedures and theorems for bounding and estimating overall properties, local fields and energy changes in elastic inhomogeneities, heterogeneous media, fiber composites and functionally graded materials.  Those are caused by mechanical loads and by phase eigenstrains, such as thermal, transformation and inelastic strains, and also by cavities and cracks.    Worked examples show that the eigendeformations may...

  16. Processing and analysis techniques involving in-vessel material generation

    Schabron, John F [Laramie, WY; Rovani, Jr., Joseph F.

    2012-09-25

    In at least one embodiment, the inventive technology relates to in-vessel generation of a material from a solution of interest as part of a processing and/or analysis operation. Preferred embodiments of the in-vessel material generation (e.g., in-vessel solid material generation) include precipitation; in certain embodiments, analysis and/or processing of the solution of interest may include dissolution of the material, perhaps as part of a successive dissolution protocol using solvents of increasing ability to dissolve. Applications include, but are by no means limited to estimation of a coking onset and solution (e.g., oil) fractionating.

  17. New sacrificial material for ex-vessel core catcher

    Komlev, Andrei A., E-mail: komlev@kth.se [Kungliga Tekniska Högskolan (KTH), AlbaNova University Centre, Nuclear Power Safety Division, Roslagstullsbacken 21, SE-106 91, Stockholm (Sweden); Almjashev, Vyacheslav I., E-mail: vac@mail.ru [A.P. Aleksandrov Research Institute of Technology, NITI, DSAR, Sosnovy Bor, 188540 (Russian Federation); Bechta, Sevostian V., E-mail: bechta@safety.sci.kth.se [Kungliga Tekniska Högskolan (KTH), AlbaNova University Centre, Roslagstullsbacken 21, SE-106 91, Stockholm (Sweden); Khabensky, Vladimir B., E-mail: vladimirkhabensky@gmail.com [A.P. Aleksandrov Research Institute of Technology, NITI, DSAR, Sosnovy Bor, 188540 (Russian Federation); Granovsky, Vladimir S., E-mail: gran@niti.ru [A.P. Aleksandrov Research Institute of Technology, NITI, DSAR, Sosnovy Bor, 188540 (Russian Federation); Gusarov, Victor V., E-mail: victor.v.gusarov@gmail.com [Ioffe Institute, 26 Polytekhnicheskaya Str., St. Petersburg, 194021 (Russian Federation)

    2015-12-15

    A new functional (sacrificial) material has been developed in the Fe{sub 2}O{sub 3}–SrO–Al{sub 2}O{sub 3}–CaO system based on strontium hexaferrite ceramic in concrete matrix. The method of producing SM has been advanced technologically; this technological effectiveness allows the SM to be used in ex-vessel core catchers with corium spreading as well as in crucible-type core catchers. Critical properties regarding the efficiency of SM in ex-vessel core catchers, such as porosity, pycnometric density, apparent density, solidus and liquidus temperatures, and water content have been measured. Suitable fractions of SrFe{sub 12}O{sub 19} and high alumina cement (HAC) were found in the SM based on thermodynamic analysis of the SM/corium interaction. The use of sacrificial steel as an additional heat adsorption component in the core catcher allowed us to increase the mass fraction range of SrFe{sub 12}O{sub 19} in the SM from 0.3−0.5 to 0.3–0.85. The activation temperature of the SM/corium interaction has been shown to correspond to the liquidus temperature of the local composition at the SM/corium interface. The calculated value of this temperature was 1716 °C. Analysis of phase transformations in the SrO–Fe{sub 2}O{sub 3} system revealed advantages of the SrFe{sub 12}O{sub 19}–based sacrificial material compared with the Fe{sub 2}O{sub 3}-contained material owing to the time proximity of SrFe{sub 12}O{sub 19} decomposition and corium interaction activation. - Highlights: • A sacrificial material (SM) was developed for ex-vessel core catcher. • Suitable proportions in the SrFe{sub 12}O{sub 19}–Al{sub 2}O{sub 3}·CaO–Fe system were determined. • Hydrogen release limitation was shown for ex-vessel corium retention with the SM. • Calculated temperature of the active initiation of corium/SM interaction is 1716 °C. • Functional properties of the SM were measured.

  18. Comparative study for the design of optimal composite pressure vessels

    Butt, A.M.; Haq, S.W.U.

    2009-01-01

    Composite pressure vessels require special design attention to the dome region because of the varying wind angles generated using the filament winding process. Geometric variations in the dome region cause the fiber to change angels and thickness and hence offer difficulty to acquire a constant stress profile (isotensoid). Therefore a dome contour which allows an isotensoid behavior is the required structure. Two design methods to generate dome profiles for similar dome openings were investigated namely Netting Analysis and Optimal Design method. Both methods assume that loads are carried by the fiber alone (monotropic) ignoring the complete composite behavior. Former method produced a lower dome internal volume and a higher fiber thickness as compared to the later optimal design method when studied against different normalized dome opening radiuses. The optimal dome contour was studied in ANSYS with a trial design. The dome was considered to have transversely isotropic property with a dome contour based on monotropic model. While investigating the dome with non linear large displacement finite element analysis, the dome still exhibited isotensoid behavior with transverse isotropic material assignment. Elliptic integrals were used to generate the optimal dome contours and hence elliptic dome contours were formed which were isotensoid in nature with complete composite representation. (author)

  19. Reactor Structural Materials: Reactor Pressure Vessel Steels

    Chaouadi, R.

    2000-01-01

    The objectives of SCK-CEN's R and D programme on Rector Pressure Vessel (RPV) Steels are:(1) to complete the fracture toughness data bank of various reactor pressure vessel steels by using precracked Charpy specimens that were tested statically as well as dynamically; (2) to implement the enhanced surveillance approach in a user-friendly software; (3) to improve the existing reconstitution technology by reducing the input energy (short cycle welding) and modifying the stud geometry. Progress and achievements in 1999 are reported

  20. Using the adaptive SMA composite cylinder concept to reduce radial dilation in composite pressure vessels

    Paine, Jeffrey S.; Rogers, Craig A.

    1995-05-01

    Composite materials are widely used in the design of pressurized gas and fluid vessels for applications ranging from underground gasoline storage tanks to rocket motors for the space shuttle. In the design of a high pressure composite vessel (Pi > 12 Ksi), thick-wall (R/h short term dilation and long term creep are not problematic for applications requiring only the containment of the pressurized fluid. In applications where metallic liners are required, however, substantial dilation and creep causes plastic yielding which leads to reduced fatigue life. To applications such as a hydraulic accumulator, where a piston is employed to fit and seal the fluid in the composite cylinder, the dilation and creep may allow leakage and pressure loss around the piston. A concept called the adaptive composite cylinder is experimentally presented. Shape memory alloy wire in epoxy resin is wrapped around or within polymer matrix composite cylinders to reduce radial dilation of the cylinder. Experimental results are presented that demonstrate the ability of the SMA wire layers to reduce radial dilation. Results from experimental testing of the recovery stress fatigue response of nitinol shape memory alloy wires is also presented.

  1. Coating material composition

    Kimura, Tadashi; Ozeki, Takao; Kobayashi, Juichi; Nakamoto, Hideo; Maeda, Yutaka.

    1969-01-01

    A coating material composition is provided which can easily be cross-linked by irradiation with active energy, particularly electron beams and ultraviolet light, using a mixture of a prepolymer (a) with an addition reaction product (b). Such compositions have coating properties as good as thermosetting acrylic or amino alkyd resins. The prepolymer (a) is produced by primarily reacting at least 0.1 mol of saturated cyclocarboxylic acid anhydrides and/or alpha-, beta-ethylene unsaturated carboxylic acid anhydrides by addition reaction with one mol of hydroxyl radicals of a basic polymer having a molecular weight of 1,000 to 100,000, the basic polymer being obtained from 1%-40% of a hydroxyl radical containing vinyl monomer and at least 30% of (meth)acrylate monomer. One mol of the sum of hydroxyl radicals and carboxyl radicals of the primary reaction product undergoes a secondary addition reaction with at least 0.1 mol of an epoxy radical-containing vinyl monomer to form the prepolymer(a). The addition reaction product(b) is produced by reacting an epoxy radical-containing vinyl monomer with alpha-, beta-ethylene unsaturated carboxylic acids or their anhydrides. The coating material composition contains a majority of a mixture consisting of 10%-90% of (a) and 90%-10% of (b) above by weight. Four examples of the production of basic polymers, seven examples of the production of prepolymers, seven examples of the production of oligomers, and five examples of applications are given. (Iwakiri, K.)

  2. Composite materials processing, applications, characterizations

    2017-01-01

    Composite materials are used as substitutions of metals/traditional materials in aerospace, automotive, civil, mechanical and other industries. The present book collects the current knowledge and recent developments in the characterization and application of composite materials. To this purpose the volume describes the outstanding properties of this class of advanced material which recommend it for various industrial applications.

  3. Crack growth rates in vessel head penetration materials

    Gomez Briceno, D.; Lapena, J.; Blazquez, F.

    1994-01-01

    The cracks detected in reactor vessel head penetrations in certain European plants have been attributed to Primary Water Stress Corrosion Cracking (PWSCC). The penetrations in question are made from Inconel 600. The susceptibility of this alloy to PWSCC has been widely studied in relation to use of this material for steam generator tubes. When the first reactor vessel head penetration cracks were detected, most of the available data on crack propagation rates were from test specimens made from steam generator tubes and tested under conditions that questioned the validity of these data for assessment of the evolution of cracks in penetrations. For this reason, the scope of the Spanish Research Project on the Inspection and Repair of PWR reactor vessel head penetrations included the acquisition of data on crack propagation rates in Inconel 600, representative of the materials used for vessel head penetrations. (authors). 1 fig., 2 tabs., 6 refs

  4. Multilayer Pressure Vessel Materials Testing and Analysis Phase 2

    Popelar, Carl F.; Cardinal, Joseph W.

    2014-01-01

    To provide NASA with a suite of materials strength, fracture toughness and crack growth rate test results for use in remaining life calculations for the vessels described above, Southwest Research Institute® (SwRI®) was contracted in two phases to obtain relevant material property data from a representative vessel. An initial characterization of the strength, fracture and fatigue crack growth properties was performed in Phase 1. Based on the results and recommendations of Phase 1, a more extensive material property characterization effort was developed in this Phase 2 effort. This Phase 2 characterization included additional strength, fracture and fatigue crack growth of the multilayer vessel and head materials. In addition, some more limited characterization of the welds and heat affected zones (HAZs) were performed. This report

  5. Materials surveillance program for C-E NSSS reactor vessels

    Koziol, J.J.

    1977-01-01

    Irradiation surveillance programs for light water NSSS reactor vessels provide the means by which the utility can assess the extent of neutron-induced changes in the reactor vessel materials. These programs are conducted to verify, by direct measurement, the conservatism in the predicted radiation-induced changes and hence the operational parameters (i.e., heat-up, cooldown, and pressurization rates). In addition, such programs provide assurance that the scheduled adjustments in the operational parameters are made with ample margin for safe operation of the plant. During the past 3 years, several documents have been promulgated establishing the criteria for determining both the initial properties of the reactor vessel materials as well as measurement of changes in these initial properties as a result of irradiation. These documents, ASTM E-185-73, ''Recommended Practice for Surveillance Tests for Nuclear Reactor Vessels,'' and Appendix H to 10 CFR 50, ''Reactor Vessel Material Surveillance Program Requirements,'' are complementary to each other. They are the result of a change in the basic philosophy regarding the design and analysis of reactor vessels. In effect, the empirical ''transition temperature approach,'' which was used for design, was replaced by the ''analytical fracture mechanics approach.'' The implementation of this technique was described in Welding Research Council Bulletin 1975 and Appendix G to ASME Code Section III. Further definition of requirements appears in Appendix G to 10 CFR 50 published in July 1973. It is the intent of this paper to describe (1) a typical materials surveillance program for the reactor vessel of a Combustion Engineering NSSS, and (2) how the results of such programs, as well as experimental programs provide feed-back for improvement of materials to enhance their radiation resistance and thereby further improve the safety and reliability of future plants. (author)

  6. Basic requirements of mechanical properties for nuclear pressure vessel materials in ASME-BPV code

    Ning Dong; Yao Weida

    2011-01-01

    The four basic aspects of strengths, ductility, toughness and fatigue strengths can be summarized for overall mechanical properties requirements of materials for nuclear pressure-retaining vessels in ASME-BPV code. These mechanical property indexes involve in the factors of melting, manufacture, delivery conditions, check or recheck for mechanical properties and chemical compositions, etc. and relate to degradation and damage accumulation during the use of materials. This paper specifically accounts for the basic requirements and theoretic basis of mechanical properties for nuclear pressure vessel materials in ASME-BPV code and states the internal mutual relationships among the four aspects of mechanical properties. This paper focuses on putting forward at several problems on mechanical properties of materials that shall be concerned about during design and manufacture for nuclear pressure vessels according to ASME-BPV code. (author)

  7. Magnetic losses in composite materials

    Ramprecht, J; Sjoeberg, D

    2008-01-01

    We discuss some of the problems involved in homogenization of a composite material built from ferromagnetic inclusions in a nonmagnetic background material. The small signal permeability for a ferromagnetic spherical particle is combined with a homogenization formula to give an effective permeability for the composite material. The composite material inherits the gyrotropic structure and resonant behaviour of the single particle. The resonance frequency of the composite material is found to be independent of the volume fraction, unlike dielectric composite materials. The magnetic losses are described by a magnetic conductivity which can be made independent of frequency and proportional to the volume fraction by choosing a certain bias. Finally, some concerns regarding particles of small size, i.e. nanoparticles, are treated and the possibility of exciting exchange modes are discussed. These exchange modes may be an interesting way to increase losses in composite materials

  8. Multilayer Pressure Vessel Materials Testing and Analysis. Phase 1

    Cardinal, Joseph W.; Popelar, Carl F.; Page, Richard A.

    2014-01-01

    To provide NASA a comprehensive suite of materials strength, fracture toughness and crack growth rate test results for use in remaining life calculations for aging multilayer pressure vessels, Southwest Research Institute (R) (SwRI) was contracted in two phases to obtain relevant material property data from a representative vessel. This report describes Phase 1 of this effort which includes a preliminary material property assessment as well as a fractographic, fracture mechanics and fatigue crack growth analyses of an induced flaw in the outer shell of a representative multilayer vessel that was subjected to cyclic pressure test. SwRI performed this Phase 1 effort under contract to the Digital Wave Corporation in support of their contract to Jacobs ATOM for the NASA Ames Research Center.

  9. Carbon/carbon composite materials

    Thebault, J.; Orly, P.

    2006-01-01

    Carbon/carbon composites are singular materials from their components, their manufacturing process as well as their characteristics. This paper gives a global overview of these particularities and applications which make them now daily used composites. (authors)

  10. Composite materials design and applications

    Gay, Daniel; Tsai, Stephen W

    2002-01-01

    PART ONE. PRINCIPLES OF CONSTRUCTIONCOMPOSITE MATERIALS, INTEREST AND PROPERTIESWhat is Composite Material Fibers and MatrixWhat can be Made Using Composite Materials?Typical Examples of Interest on the Use of Composite MaterialsExamples on Replacing Conventional Solutions with CompositesPrincipal Physical PropertiesFABRICATION PROCESSESMolding ProcessesOther Forming ProcessesPractical Hints in the Manufacturing ProcessesPLY PROPERTIESIsotropy and AnisotropyCharacteristics of the Reinforcement-Matrix MixtureUnidirectional PlyWoven FabricsMats and Reinforced MatricesMultidimensional FabricsMetal Matrix CompositesTestsSANDWICH STRUCTURES:What is a Sandwich Structure?Simplified FlexureA Few Special AspectsFabrication and Design ProblemsNondestructive Quality ControlCONCEPTION AND DESIGNDesign of a Composite PieceThe LaminateFailure of LaminatesSizing of LaminatesJOINING AND ASSEMBLYRiveting and BoltingBondingInsertsCOMPOSITE MATERIALS AND AEROSPACE CONSTRUCTIONAircraftHelicoptersPropeller Blades for AirplanesTur...

  11. Materials requirements for the ITER vacuum vessel and in-vessel components - approaching the construction phase

    Barabash, V.; Ioki, K.; Pick, M.; Girard, J.P.; Merola, M.

    2007-01-01

    Full text of publication follows: The ITER activities are fully devoted toward its construction. In accordance with the ITER integrated project schedule, the procurement specifications for the manufacturing of the Vacuum Vessel should be prepared by March 2008 and the procurement specifications for the in-vessel components (first wall/blanket, divertor) by 2009. To update the design, considering design and technology evolution, the ITER Design Review has been launched. Among the various topics being discussed are the important issues related to selection of materials, material procurement, and assessment of performance during operation. The main requirements related to materials for the vacuum vessel and the in-vessel components are summarized in the paper. The specific licensing requirements are to be followed for structural materials of pressure and nuclear pressure equipment components for construction of ITER. In addition, the procurements in ITER will be done mostly 'in-kind' and it is assumed that materials for these components will be produced by different Parties. However, in accordance with the regulatory requirements and quality requirements for operation, common specifications and the general rules to fulfill these requirements are to be adopted. For some ITER components (e.g. first wall, divertor high heat flux components), the ultimate qualification of the joining technologies (Be/Cu, SS/Cu, CFC/Cu, W/Cu) is under final evaluation. Successful accomplishment of the qualification program will allow to proceed with procurements of the components for ITER. The criteria for acceptance of these components and materials after manufacturing are described and the main results will be reported. Additional materials issues, which come from the on-going manufacturing R and D program, will be also described. Finally, further materials activity during the construction phase, needs for final qualification and acceptance of materials are discussed. (authors)

  12. Compositional attribution of non-provenienced Maya polychrome vessels

    Bishop, R.L.; Harbottle, G.; Reents, D.J.; Sayre, E.V.; van Zelst, L.

    1983-01-01

    Procedures and a few of the results of the Maya ceramic project are discussed from the perspective of non-provenienced vessel attribution ranging from site specific through a more inferential level to the rather hypothetical. The examples presented serve to illustrate the manner in which compositional and stylistic covariation are viewed in an investigation of Maya Ceramic art. The large data base from neutron activation analysis including archaeologically recovered pottery as well as the stylistically and iconographically elaborate vessels requires continued refinement in our methods of statistical analysis along with gaining a greater understanding of the sources of ceramic compositional variation in the Maya area. The mutually beneficial collaboration between science, art, and archaeology are emphasized

  13. Compositional attribution of non-provenienced Maya polychrome vessels

    Bishop, R.L.; Harbottle, G.; Reents, D.J.; Sayre, E.V.; van Zelst, L.

    1983-01-01

    Procedures and a few of the results of the Maya ceramic project are discussed from the perspective of non-provenienced vessel attribution ranging from site specific through a more inferential level to the rather hypothetical. The examples presented serve to illustrate the manner in which compositional and stylistic covariation are viewed in an investigation of Maya Ceramic art. The large data base from neutron activation analysis including archaeologically recovered pottery as well as the stylistically and iconographically elaborate vessels requires continued refinement in our methods of statistical analysis along with gaining a greater understanding of the sources of ceramic compositional variation in the Maya area. The mutually beneficial collaboration between science, art, and archaeology are emphasized.

  14. Evaluation of WWER-1000 vessel materials fracture toughness

    Grinik, Eh.U.; Revka, V.N.; Chirko, L.I.; Chajkovskij, Yu.V.

    2007-01-01

    The lifetime of WWER-1000-type reactor vessels is finally conditioned by the fracture toughness (crack growth resistance) of RPV materials. Up to now in line with the regulations the fracture toughness is characterized by the critical temperature of brittleness determined by the results of the Charpy specimen impact testing. Such approach is typical for all countries operating the water pressure reactors. However, regulatory approach is known from the western specialists not always to characterize adequately the crack growth resistance of the vessel materials and in some cases to underestimate their characteristics in the reference state that leads to unreasonably high conservatism. Excessive conservatism may lead to the invalid restrictions in the operating modes and the service life of the reactor vessel. Therefore there appeared the necessity to apply another approaches based on the state-of-the-art experimental methods of the fracture mechanics and allowing evaluating the fracture toughness parameters sufficiently. The paper presents the results of the comparison of the regulatory approach and the Master curve approach from the point of view of the adequate determination of the vessel material crack growth resistance parameters. Analysis of the experimental data of the surveillance specimens illustrated the potential possibility of applying the new statistical method for the WWER-1000- type reactor vessel lifetime extension

  15. Multifunctional Composite Materials, Phase I

    National Aeronautics and Space Administration — Polymeric composite materials that are currently utilized in aircraft structures are susceptible to significant damage from lightning strikes. Enhanced electrical...

  16. Erosion-resistant composite material

    Finch, C.B.; Tennery, V.J.; Curlee, R.M.

    A highly erosion-resistant composite material is formed of chemical vapor-deposited titanium diboride on a sintered titanium diboride-nickel substrate. This material may be suitable for use in cutting tools, coal liquefaction systems, etc.

  17. Composite materials for aircraft structures

    Baker, A. A; Dutton, Stuart; Kelly, Donald

    2004-01-01

    ... materials for aircraft structures / Alan Baker, Stuart Dutton, and Donald Kelly- 2nd ed. p. cm. - (Education series) Rev. ed. of: Composite materials for aircraft structures / edited by B. C. Hos...

  18. NDE and Stress Monitoring on Composite Overwrapped Pressure Vessels, Phase I

    National Aeronautics and Space Administration — Damage caused by composite overwrapped pressure vessels (COPVs) failure can be catastrophic. Thus, monitoring condition and stress in the composite overwrap,...

  19. Stress Rupture Life Reliability Measures for Composite Overwrapped Pressure Vessels

    Murthy, Pappu L. N.; Thesken, John C.; Phoenix, S. Leigh; Grimes-Ledesma, Lorie

    2007-01-01

    Composite Overwrapped Pressure Vessels (COPVs) are often used for storing pressurant gases onboard spacecraft. Kevlar (DuPont), glass, carbon and other more recent fibers have all been used as overwraps. Due to the fact that overwraps are subjected to sustained loads for an extended period during a mission, stress rupture failure is a major concern. It is therefore important to ascertain the reliability of these vessels by analysis, since the testing of each flight design cannot be completed on a practical time scale. The present paper examines specifically a Weibull statistics based stress rupture model and considers the various uncertainties associated with the model parameters. The paper also examines several reliability estimate measures that would be of use for the purpose of recertification and for qualifying flight worthiness of these vessels. Specifically, deterministic values for a point estimate, mean estimate and 90/95 percent confidence estimates of the reliability are all examined for a typical flight quality vessel under constant stress. The mean and the 90/95 percent confidence estimates are computed using Monte-Carlo simulation techniques by assuming distribution statistics of model parameters based also on simulation and on the available data, especially the sample sizes represented in the data. The data for the stress rupture model are obtained from the Lawrence Livermore National Laboratories (LLNL) stress rupture testing program, carried out for the past 35 years. Deterministic as well as probabilistic sensitivities are examined.

  20. Composite Materials in Overhead Lines

    Sørensen, Thomas Kjærsgaard; Holbøll, Joachim

    2009-01-01

    towers and recently conductors based on composite materials are available at transmission levels. In this paper it is investigated which composite based solutions are available in connection with complete overhead line systems including insulators, towers and conductors. The components are reviewed......The use of composite materials, e.g. fibreglass materials, in overhead transmission line systems is nothing new. Composite based insulators have been applied to transmission lines for over 30 years, mainly as suspension and post insulators and often as an option for special applications. Also...... with respect to solved and persisting known failures/problems of both mechanical and electrical nature. Major challenges related to extensive use of composite materials in an overhead line system are identified, as are possible benefits - both when using standard as well as customised composite components, e...

  1. Superconducting composites materials. Materiaux composites supraconducteurs

    Kerjouan, P; Boterel, F; Lostec, J; Bertot, J P; Haussonne, J M [Centre National d' Etudes des Telecommunications (CNET), 22 - Lannion (FR)

    1991-11-01

    The new superconductor materials with a high critical current own a large importance as well in the electronic components or in the electrotechnical devices fields. The deposit of such materials with the thick films technology is to be more and more developed in the years to come. Therefore, we tried to realize such thick films screen printed on alumina, and composed mainly of the YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} material. We first realized a composite material glass/YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}, by analogy with the classical screen-printed inks where the glass ensures the bonding with the substrate. We thus realized different materials by using some different classes of glass. These materials owned a superconducting transition close to the one of the pure YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} material. We made a slurry with the most significant composite materials and binders, and screen-printed them on an alumina substrate preliminary or not coated with a diffusion barrier layer. After firing, we studied the thick films adhesion, the alumina/glass/composite material interfaces, and their superconducting properties. 8 refs.; 14 figs.; 9 tabs.

  2. Strain-Detecting Composite Materials

    Wallace, Terryl A. (Inventor); Smith, Stephen W. (Inventor); Piascik, Robert S. (Inventor); Horne, Michael R. (Inventor); Messick, Peter L. (Inventor); Alexa, Joel A. (Inventor); Glaessgen, Edward H. (Inventor); Hailer, Benjamin T. (Inventor)

    2016-01-01

    A composite material includes a structural material and a shape-memory alloy embedded in the structural material. The shape-memory alloy changes crystallographic phase from austenite to martensite in response to a predefined critical macroscopic average strain of the composite material. In a second embodiment, the composite material includes a plurality of particles of a ferromagnetic shape-memory alloy embedded in the structural material. The ferromagnetic shape-memory alloy changes crystallographic phase from austenite to martensite and changes magnetic phase in response to the predefined critical macroscopic average strain of the composite material. A method of forming a composite material for sensing the predefined critical macroscopic average strain includes providing the shape-memory alloy having an austenite crystallographic phase, changing a size and shape of the shape-memory alloy to thereby form a plurality of particles, and combining the structural material and the particles at a temperature of from about 100-700.degree. C. to form the composite material.

  3. Mechanics in Composite Materials and Process

    Lee, Dae Gil

    1993-03-01

    This book includes introduction of composite materials, stress, in-plane stiffness of laminates strain rate, ply stress, failure criterion and bending, composite materials micromechanics, composite plates and micromechanics of composite materials. It also deals with process of composite materials such as autoclave vacuum bag degassing process, connection of composite materials, filament winding process, resin transfer molding, sheet molding compound and compression molding.

  4. Aging results for PRD 49 III/epoxy and Kevlar 49/epoxy composite pressure vessels

    Hamstad, M. A.

    1983-01-01

    Kevlar 49/epoxy composite is growing in use as a structural material because of its high strength-to-weight ratio. Currently, it is used for the Trident rocket motor case and for various pressure vessels on the Space Shuttle. In 1979, the initial results for aging of filament-wound cylindrical pressure vessels which were manufactured with preproduction Kevlar 49 (Hamstad, 1979) were published. This preproduction fiber was called PRD 49 III. This report updates the continuing study to 10-year data and also presents 7.5-year data for spherical pressure vessels wound with production Kevlar 49. For completeness, this report will again describe the specimens of the original study with PRD 49 as well as specimens for the new study with Kevlar 49.

  5. Prediction of Composite Pressure Vessel Failure Location using Fiber Bragg Grating Sensors

    Kreger, Steven T.; Taylor, F. Tad; Ortyl, Nicholas E.; Grant, Joseph

    2006-01-01

    Ten composite pressure vessels were instrumented with fiber Bragg grating sensors in order to assess the strain levels of the vessel under various loading conditions. This paper and presentation will discuss the testing methodology, the test results, compare the testing results to the analytical model, and present a possible methodology for predicting the failure location and strain level of composite pressure vessels.

  6. Biotechnology and Composite Materials

    1993-04-01

    means. Silk made from the caterpillar, Bombyx mori , has outstanding mechanical and good thermal properties. The Bombyx mori synthesises the components of...Silk Proteins for Composite Fibers 185 In natural systems, the two c=nm=n sources of silks are the dch!sticated silkworm, mori , and the orb weaving...unit cell remain parallel to their original orientation during deformation. This prevents the formation of any voids or gaps in the model. Using the

  7. Composite Overwrap Pressure Vessels: Mechanics and Stress Rupture Lifting Philosophy

    Thesken, John C.; Murthy, Pappu L. N.; Phoenix, S. L.

    2009-01-01

    The NASA Engineering and Safety Center (NESC) has been conducting an independent technical assessment to address safety concerns related to the known stress rupture failure mode of filament wound pressure vessels in use on Shuttle and the International Space Station. The Shuttle s Kevlar-49 (DuPont) fiber overwrapped tanks are of particular concern due to their long usage and the poorly understood stress rupture process in Kevlar-49 filaments. Existing long term data show that the rupture process is a function of stress, temperature and time. However due to the presence of load sharing liners and the complex manufacturing procedures, the state of actual fiber stress in flight hardware and test articles is not clearly known. Indeed nonconservative life predictions have been made where stress rupture data and lifing procedures have ignored the contribution of the liner in favor of applied pressure as the controlling load parameter. With the aid of analytical and finite element results, this paper examines the fundamental mechanical response of composite overwrapped pressure vessels including the influence of elastic plastic liners and degraded/creeping overwrap properties. Graphical methods are presented describing the non-linear relationship of applied pressure to Kevlar-49 fiber stress/strain during manufacturing, operations and burst loadings. These are applied to experimental measurements made on a variety of vessel systems to demonstrate the correct calibration of fiber stress as a function of pressure. Applying this analysis to the actual qualification burst data for Shuttle flight hardware revealed that the nominal fiber stress at burst was in some cases 23 percent lower than what had previously been used to predict stress rupture life. These results motivate a detailed discussion of the appropriate stress rupture lifing philosophy for COPVs including the correct transference of stress rupture life data between dissimilar vessels and test articles.

  8. Composite Overwrap Pressure Vessels: Mechanics and Stress Rupture Lifing Philosophy

    Thesken, John C.; Murthy, Pappu L. N.; Phoenix, Leigh

    2007-01-01

    The NASA Engineering and Safety Center (NESC) has been conducting an independent technical assessment to address safety concerns related to the known stress rupture failure mode of filament wound pressure vessels in use on Shuttle and the International Space Station. The Shuttle's Kevlar-49 fiber overwrapped tanks are of particular concern due to their long usage and the poorly understood stress rupture process in Kevlar-49 filaments. Existing long term data show that the rupture process is a function of stress, temperature and time. However due to the presence of load sharing liners and the complex manufacturing procedures, the state of actual fiber stress in flight hardware and test articles is not clearly known. Indeed non-conservative life predictions have been made where stress rupture data and lifing procedures have ignored the contribution of the liner in favor of applied pressure as the controlling load parameter. With the aid of analytical and finite element results, this paper examines the fundamental mechanical response of composite overwrapped pressure vessels including the influence of elastic-plastic liners and degraded/creeping overwrap properties. Graphical methods are presented describing the non-linear relationship of applied pressure to Kevlar-49 fiber stress/strain during manufacturing, operations and burst loadings. These are applied to experimental measurements made on a variety of vessel systems to demonstrate the correct calibration of fiber stress as a function of pressure. Applying this analysis to the actual qualification burst data for Shuttle flight hardware revealed that the nominal fiber stress at burst was in some cases 23% lower than what had previously been used to predict stress rupture life. These results motivate a detailed discussion of the appropriate stress rupture lifing philosophy for COPVs including the correct transference of stress rupture life data between dissimilar vessels and test articles.

  9. 49 CFR 176.194 - Stowage of Class 1 (explosive) materials on magazine vessels.

    2010-10-01

    ... magazine vessels. 176.194 Section 176.194 Transportation Other Regulations Relating to Transportation... REGULATIONS CARRIAGE BY VESSEL Detailed Requirements for Class 1 (Explosive) Materials Magazine Vessels § 176.194 Stowage of Class 1 (explosive) materials on magazine vessels. (a) General. The requirements of...

  10. Composite materials for cryogenic structures

    Kasen, M.B.

    1978-01-01

    The paper is concerned with the composition, mechanical properties and capabilities of various types of composite materials for cryogenic structures. Attention is given to high-pressure plastic laminates, low-pressure plastic laminates, metal-matrix laminates, and aggregates (low-temperature concretes). The ability of these materials to match the strength and modulus of stainless steels suggests that their usage will substantially increase as alloying elements become scarce and more expensive

  11. Carbon nanotube composite materials

    O'Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2015-03-24

    A material consisting essentially of a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes dissolved in a solvent. Un-functionalized carbon nanotube concentrations up to 30 wt % and hydroxylated carbon nanotube concentrations up to 40 wt % can be used with even small concentrations of each (less than 2 wt %) useful in producing enhanced conductivity properties of formed thin films.

  12. Accelerated irradiation test of gundremmingen reactor vessel trepan material

    Hawthorne, J.R.

    1992-08-01

    Initial mechanical properties tests of beltline trepanned from the decommissioned KRB-A pressure vessel and archive material irradiated in the UBR test reactor revealed a major anomaly in relative radiation embrittlement sensitivity. Poor correspondence of material behavior in test vs. power reactor environments was observed for the weak test orientation (ASTL C-L) whereas correspondence was good for the strong orientation (ASTM C-L). To resolve the anomaly directly, Charpy-V specimens from a low (essentially-nil) fluence region of the vessel were irradiated together with archive material at 279 degrees C in the UBR test reactor. Properties tests before UBR irradiation revealed a significant difference in 41-J transition temperature and upper shelf energy level between the materials. However, the materials exhibited essentially the same radiation embrittlement sensitivity (both orientations), proving that the anomaly is not due to a basic difference in material irradiation resistances. Possible causes of the original anomaly and the significance to NRC Regulatory Guide 1.99 are discussed

  13. Accelerated irradiation test of Gundremmingen reactor vessel trepan material

    Hawthorne, J.R. [Materials Engineering Associates, Inc., Lanham, MD (United States)

    1992-08-01

    Initial mechanical properties tests of beltline trepanned from the decommissioned KRB-A pressure vessel and archive material irradiated in the UBR test reactor revealed a major anomaly in relative radiation embrittlement sensitivity. Poor correspondence of material behavior in test vs. power reactor environments was observed for the weak test orientation (ASTL C-L) whereas correspondence was good for the strong orientation (ASTM C-L). To resolve the anomaly directly, Charpy-V specimens from a low (essentially-nil) fluence region of the vessel were irradiated together with archive material at 279{degrees}C in the UBR test reactor. Properties tests before UBR irradiation revealed a significant difference in 41-J transition temperature and upper shelf energy level between the materials. However, the materials exhibited essentially the same radiation embrittlement sensitivity (both orientations), proving that the anomaly is not due to a basic difference in material irradiation resistances. Possible causes of the original anomaly and the significance to NRC Regulatory Guide 1.99 are discussed.

  14. An Overview of Corroded Pipe Repair Techniques Using Composite Materials

    K. S. Lim; S. N. A. Azraai; N. M. Noor; N. Yahaya

    2015-01-01

    Polymeric composites are being increasingly used as repair material for repairing critical infrastructures such as building, bridge, pressure vessel, piping and pipeline. Technique in repairing damaged pipes is one of the major concerns of pipeline owners. Considerable researches have been carried out on the repair of corroded pipes using composite materials. This article attempts a short review of the subject matter to provide insight into various techniques used in repa...

  15. Multilayer Electroactive Polymer Composite Material

    Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Park, Cheol (Inventor); Draughon, Gregory K. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

  16. Glass-Graphite Composite Materials

    Mayzan, M.Z.H.; Lloyd, J.W.; Heath, P.G.; Stennett, M.C.; Hyatt, N.C.; Hand, R.J.

    2016-01-01

    A summary is presented of investigations into the potential of producing glass-composite materials for the immobilisation of graphite or other carbonaceous materials arising from nuclear power generation. The methods are primarily based on the production of base glasses which are subsequently sintered with powdered graphite or simulant TRISO particles. Consideration is also given to the direct preparation of glass-graphite composite materials using microwave technology. Production of dense composite wasteforms with TRISO particles was more successful than with powdered graphite, as wasteforms containing larger amounts of graphite were resistant to densification and the glasses tried did not penetrate the pores under the pressureless conditions used. Based on the results obtained it is concluded that the production of dense glassgraphite composite wasteforms will require the application of pressure. (author)

  17. Damage by radiation in structural materials of BWR reactor vessels

    Robles, E.; Balcazar, M.; Alpizar, A.M.; Calderon, B.E.

    2002-01-01

    The structural materials which are manufactured the pressure vessels of the BWR reactors undergo degradation in their mechanical properties mainly due to the damage produced by the fast neutrons (E> 1 MeV) coming from the reactor core. The mechanisms of neutron damage in this type of materials are experimentally studied, through the irradiation of vessel steel in experimental reactors for a quickly ageing. Alternately the neutron damage through steel irradiation with heavy ions is simulated. In this work the first results of the damage induced by irradiation of a similar steel to the vessel of a BWR reactor are shown. The irradiation was performed with fast neutrons (E> 1 MeV, fluence of 1.45 x 10 18 n/cm 2 ) in the TRIGA Mark III Salazar reactor and separately with Ni +3 ions in a Tandetrom accelerator (E= 4.8 MeV and an ion flux rank of 0.1 to 53 ions/A 2 ). (Author)

  18. Elasto-Plastic Stress Analysis in Rotating Disks and Pressure Vessels Made of Functionally Graded Materials

    Amir T. Kalali

    Full Text Available Abstract A new elastio-plastic stress solution in axisymmetric problems (rotating disk, cylindrical and spherical vessel is presented. The rotating disk (cylindrical and spherical vessel was made of a ceramic/metal functionally graded material, i.e. a particle-reinforced composite. It was assumed that the material's plastic deformation follows an isotropic strain-hardening rule based on the von-Mises yield criterion. The mechanical properties of the graded material were modeled by the modified rule of mixtures. By assuming small strains, Hencky's stress-strain relation was used to obtain the governing differential equations for the plastic region. A numerical method for solving those differential equations was then proposed that enabled the prediction of stress state within the structure. Selected finite element results were also presented to establish supporting evidence for the validation of the proposed approach.

  19. Application of material databases for improved reliability of reactor pressure vessels

    Griesbach, T.J.; Server, W.L.; Beaudoin, B.F.; Burgos, B.N.

    1994-01-01

    A vital part of reactor vessel Life Cycle Management program must begin with an accurate characterization of the vessel material properties. Uncertainties in vessel material properties or use of bounding values may result in unnecessary conservatisms in vessel integrity calculations. These conservatisms may be eliminated through a better understanding of the material properties in reactor vessels, both in the unirradiated and irradiated conditions. Reactor vessel material databases are available for quantifying the chemistry and Charpy shift behavior of individual heats of reactor vessel materials. Application of the databases for vessels with embrittlement concerns has proven to be an effective embrittlement management tool. This paper presents details of database development and applications which demonstrate the value of using material databases for improving material chemistry and for maximizing the data from integrated material surveillance programs

  20. Material Modelling - Composite Approach

    Nielsen, Lauge Fuglsang

    1997-01-01

    is successfully justified comparing predicted results with experimental data obtained in the HETEK-project on creep, relaxation, and shrinkage of very young concretes cured at a temperature of T = 20^o C and a relative humidity of RH = 100%. The model is also justified comparing predicted creep, shrinkage......, and internal stresses caused by drying shrinkage with experimental results reported in the literature on the mechanical behavior of mature concretes. It is then concluded that the model presented applied in general with respect to age at loading.From a stress analysis point of view the most important finding...... in this report is that cement paste and concrete behave practically as linear-viscoelastic materials from an age of approximately 10 hours. This is a significant age extension relative to earlier studies in the literature where linear-viscoelastic behavior is only demonstrated from ages of a few days. Thus...

  1. Hybrid and hierarchical composite materials

    Kim, Chang-Soo; Sano, Tomoko

    2015-01-01

    This book addresses a broad spectrum of areas in both hybrid materials and hierarchical composites, including recent development of processing technologies, structural designs, modern computer simulation techniques, and the relationships between the processing-structure-property-performance. Each topic is introduced at length with numerous  and detailed examples and over 150 illustrations.   In addition, the authors present a method of categorizing these materials, so that representative examples of all material classes are discussed.

  2. Clearance potential of ITER vacuum vessel activated materials

    Cepraga, D.G.; Cambi, G.; Frisoni, M.

    2002-01-01

    To demonstrate fusion's environmental attractiveness over the entire life cycle, a waste analysis is mandatory. The clearance is recommended by IAEA for releasing activated solid materials from regulatory control and for waste management policy. The paper focuses on the approach used to support waste analyses for ITER Generic Site Safety Report. The Material Unconditional Clearance Index of all the materials/zones on the equatorial mid-plane of ITER machine have been evaluated, based on IAEA-TECDOC-855. The Bonami-Nitawl-XSDNRPM sequence of the Scale-4.4a code system (using Vitenea-J library) has been firstly used for radiation transport analyses. Then the Anita-2000 code package is used for the activation calculation. The paper presents also, as an example, an application of the clearance indexes estimation for the ITER vacuum vessel materials. The results of the Anita-2000 have been compared with those obtained using the Fispact-99 activation code. (author)

  3. Computer system for International Reactor Pressure Vessel Materials Database support

    Arutyunjan, R.; Kabalevsky, S.; Kiselev, V.; Serov, A.

    1997-01-01

    This report presents description of the computer tools for support of International Reactor Pressure Vessel Materials Database developed at IAEA. Work was focused on raw, qualified, processed materials data, search, retrieval, analysis, presentation and export possibilities of data. Developed software has the following main functions: provides software tools for querying and search of any type of data in the database; provides the capability to update the existing information in the database; provides the capability to present and print selected data; provides the possibility of export on yearly basis the run-time IRPVMDB with raw, qualified and processed materials data to Database members; provides the capability to export any selected sets of raw, qualified, processed materials data

  4. Burst pressure investigation of filament wound type IV composite pressure vessel

    Farhood, Naseer H.; Karuppanan, Saravanan; Ya, H. H.; Baharom, Mohamad Ariff

    2017-12-01

    Currently, composite pressure vessels (PVs) are employed in many industries such as aerospace, transportations, medical etc. Basically, the use of PVs in automotive application as a compressed natural gas (CNG) storage cylinder has been growing rapidly. Burst failure due to the laminate failure is the most critical failure mechanism for composite pressure vessels. It is predominantly caused by excessive internal pressure due to an overfilling or an overheating. In order to reduce fabrication difficulties and increase the structural efficiency, researches and studies are conducted continuously towards the proper selection of vessel design parameters. Hence, this paper is focused on the prediction of first ply failure pressure for such vessels utilizing finite element simulation based on Tsai-Wu and maximum stress failure criterions. The effects of laminate stacking sequence and orientation angle on the burst pressure were investigated in this work for a constant layered thickness PV. Two types of winding design, A [90°2/∓θ16/90°2] and B [90°2/∓θ]ns with different orientations of helical winding reinforcement were analyzed for carbon/epoxy composite material. It was found that laminate A sustained a maximum burst pressure of 55 MPa for a sequence of [90°2/∓15°16/90°2] while the laminate B returned a maximum burst pressure of 45 MPa corresponding to a stacking sequence of [90°2/±15°/90°2/±15°/90°2/±15° ....] up to 20 layers for a constant vessel thickness. For verification, a comparison was done with the literature under similar conditions of analysis and good agreement was achieved with a maximum difference of 4% and 10% for symmetrical and unsymmetrical layout, respectively.

  5. Online Monitoring of Composite Overwrapped Pressure Vessels (COPV)

    Pereira, Gilmar Ferreira; Figueiredo, Joana; Faria, Hugo

    2015-01-01

    product development, design and optimization, as well as to minimize the risks and improve the public acceptance. Within the scope of developing different COPV models for a wide range of operating pressures and applications, optical fiber Bragg grating (FBG) sensors were embedded in the liner......Composite overwrapped pressure vessels (COPV) have been increasingly pointed to as the most effective solution for high pressure storage of liquid and gaseous fluids. Reasonably high stiffness-to-weight ratios make them suitable for both static and mobile applications. However, higher operating...... pressures are sought continuously, to get higher energy densities in such storage systems, and safety aspects become critical. Thus, reliable design and test procedures are required to reduce the risks of undesired and unpredicted failures. An in-service health monitoring system may contribute to a better...

  6. Genetic Homogenization of Composite Materials

    P. Tobola

    2009-04-01

    Full Text Available The paper is focused on numerical studies of electromagnetic properties of composite materials used for the construction of small airplanes. Discussions concentrate on the genetic homogenization of composite layers and composite layers with a slot. The homogenization is aimed to reduce CPU-time demands of EMC computational models of electrically large airplanes. First, a methodology of creating a 3-dimensional numerical model of a composite material in CST Microwave Studio is proposed focusing on a sufficient accuracy of the model. Second, a proper implementation of a genetic optimization in Matlab is discussed. Third, an association of the optimization script and a simplified 2-dimensional model of the homogeneous equivalent model in Comsol Multiphysics is proposed considering EMC issues. Results of computations are experimentally verified.

  7. Modeling Non-Linear Material Properties in Composite Materials

    2016-06-28

    Technical Report ARWSB-TR-16013 MODELING NON-LINEAR MATERIAL PROPERTIES IN COMPOSITE MATERIALS Michael F. Macri Andrew G...REPORT TYPE Technical 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE MODELING NON-LINEAR MATERIAL PROPERTIES IN COMPOSITE MATERIALS ...systems are increasingly incorporating composite materials into their design. Many of these systems subject the composites to environmental conditions

  8. The technology development for surveillance test of reactor vessel materials

    Chang, Kee Ok; Kim, Byoung Chul; Lee, Sam Lai; Choi, Sun Phil; Park, Day Young; Choi, Kwen Jai

    1997-12-01

    Benchmark test was performed in accordance with the requirement of US NRC Reg. Guide DG-1053 for Kori unit-1 in order to determine best-estimated fast neutron fluence irradiated into reactor vessel. Since the uncertainty of radiation analysis comes from the calculation error due to neutron cross-section data, reactor core geometrical dimension, core source, mesh density, angular expansion and convergence criteria, evaluation of calculational uncertainty due to analytical method was performed in accordance with the regulatory guide and the proof was performed for entire analysis by comparing the measurement value obtained by neutron dosimetry located in surveillance capsule. Best-estimated neutron fluence in reactor vessel was calculated by bias factor, neutron flux measurement value/calculational value, from reanalysis result from previous 1st through 4th surveillance testing and finally fluence prediction was performed for the end of reactor life and the entire period of plant life extension. Pressurized thermal shock analysis was performed in accordance with 10 CFR 50.61 using the result of neutron fluence analysis in order to predict the life of reactor vessel material and the criteria of safe operation for Kori unit 1 was reestablished. (author). 55 refs., 55 figs.

  9. Assessment and selection of materials for ITER in-vessel components

    Kalinin, G.; Barabash, V.; Cardella, A.; Dietz, J.; Ioki, K.; Matera, R.; Santoro, R. T.; Tivey, R.; ITER Home Teams

    2000-12-01

    During the international thermonuclear experimental reactor (ITER) engineering design activities (EDA) significant progress has been made in the selection of materials for the in-vessel components of the reactor. This progress is a result of the worldwide collaboration of material scientists and industries which focused their effort on the optimisation of material and component manufacturing and on the investigation of the most critical material properties. Austenitic stainless steels 316L(N)-IG and 316L, nickel-based alloys Inconel 718 and Inconel 625, Ti-6Al-4V alloy and two copper alloys, CuCrZr-IG and CuAl25-IG, have been proposed as reference structural materials, and ferritic steel 430, and austenitic steel 304B7 with the addition of boron have been selected for some specific parts of the ITER in-vessel components. Beryllium, tungsten and carbon fibre composites are considered as plasma facing armour materials. The data base on the properties of all these materials is critically assessed and briefly reviewed in this paper together with the justification of the material selection (e.g., effect of neutron irradiation on the mechanical properties of materials, effect of manufacturing cycle, etc.).

  10. Composite Materials: An Educational Need.

    Saliba, Tony E.; Snide, James A.

    1990-01-01

    Described is the need to incorporate the concepts and applications of advanced composite materials into existing chemical engineering programs. Discussed are the justification for, and implementation of topics including transport phenomena, kinetics and reactor design, unit operations, and product and process design. (CW)

  11. Mechanical Properties of Composite Materials

    Mitsuhiro Okayasu

    2014-10-01

    Full Text Available An examination has been made of the mechanical and failure properties of several composite materials, such as a short and a long carbon fiber reinforced plastic (short- and long-CFRP and metal based composite material. The short CFRP materials were used for a recycled CFRP which fabricated by the following process: the CFRP, consisting of epoxy resin with carbon fiber, is injected to a rectangular plate cavity after mixing with acrylonitrile butadiene styrene resin with different weight fractions of CFRP. The fatigue and ultimate tensile strength (UTS increased with increasing CFRP content. These correlations, however, break down, especially for tensile strength, as the CFPR content becomes more than 70%. Influence of sample temperature on the bending strength of the long-CFRP was investigated, and it appears that the strength slightly degreases with increasing the temperature, due to the weakness in the matrix. Broken fiber and pull-out or debonding between the fiber and matrix were related to the main failure of the short- and long-CFRP samples. Mechanical properties of metal based composite materials have been also investigated, where fiber-like high hardness CuAl2 structure is formed in aluminum matrix. Excellent mechanical properties were obtained in this alloy, e.g., the higher strength and the higher ductility, compared tothe same alloy without the fiber-like structure. There are strong anisotropic effects on the mechanical properties due to the fiber-like metal composite in a soft Al based matrix.

  12. Durability of aircraft composite materials

    Dextern, H. B.

    1982-01-01

    Confidence in the long term durability of advanced composites is developed through a series of flight service programs. Service experience is obtained by installing secondary and primary composite components on commercial and military transport aircraft and helicopters. Included are spoilers, rudders, elevators, ailerons, fairings and wing boxes on transport aircraft and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on helicopters. Materials included in the evaluation are boron/epoxy, Kevlar/epoxy, graphite/epoxy and boron/aluminum. Inspection, maintenance, and repair results for the components in service are reported. The effects of long term exposure to laboratory, flight, and outdoor environmental conditions are reported for various composite materials. Included are effects of moisture absorption, ultraviolet radiation, and aircraft fuels and fluids.

  13. Creep of fibrous composite materials

    Lilholt, Hans

    1985-01-01

    Models are presented for the creep behaviour of fibrous composite materials with aligned fibres. The models comprise both cases where the fibres remain rigid in a creeping matrix and cases where the fibres are creeping in a creeping matrix. The treatment allows for several contributions...... to the creep strength of composites. The advantage of combined analyses of several data sets is emphasized and illustrated for some experimental data. The analyses show that it is possible to derive creep equations for the (in situ) properties of the fibres. The experiments treated include model systems...... such as Ni + W-fibres, high temperature materials such as Ni + Ni3Al + Cr3C2-fibres, and medium temperature materials such as Al + SiC-fibres. For the first two systems reasonable consistency is found for the models and the experiments, while for the third system too many unquantified parameters exist...

  14. Testing of Full Scale Flight Qualified Kevlar Composite Overwrapped Pressure Vessels

    Greene, Nathanael; Saulsberry, Regor; Yoder, Tommy; Forsyth, Brad; Thesken, John; Phoenix, Leigh

    2007-01-01

    Many decades ago NASA identified a need for low-mass pressure vessels for carrying various fluids aboard rockets, spacecraft, and satellites. A pressure vessel design known as the composite overwrapped pressure vessel (COPV) was identified to provide a weight savings over traditional single-material pressure vessels typically made of metal and this technology has been in use for space flight applications since the 1970's. A typical vessel design consisted of a thin liner material, typically a metal, overwrapped with a continuous fiber yarn impregnated with epoxy. Most designs were such that the overwrapped fiber would carry a majority of load at normal operating pressures. The weight advantage for a COPV versus a traditional singlematerial pressure vessel contributed to widespread use of COPVs by NASA, the military, and industry. This technology is currently used for personal breathing supply storage, fuel storage for auto and mass transport vehicles and for various space flight and aircraft applications. The NASA Engineering and Safety Center (NESC) was recently asked to review the operation of Kevlar 2 and carbon COPVs to ensure they are safely operated on NASA space flight vehicles. A request was made to evaluate the life remaining on the Kevlar COPVs used on the Space Shuttle for helium and nitrogen storage. This paper provides a review of Kevlar COPV testing relevant to the NESC assessment. Also discussed are some key findings, observations, and recommendations that may be applicable to the COPV user community. Questions raised during the investigations have revealed the need for testing to better understand the stress rupture life and age life of COPVs. The focus of this paper is to describe burst testing of Kevlar COPVs that has been completed as a part of an the effort to evaluate the effects of ageing and shelf life on full scale COPVs. The test articles evaluated in this discussion had a diameter of 22 inches for S/N 014 and 40 inches for S/N 011. The

  15. Structural materials for ITER in-vessel component design

    Kalinin, G. [Max-Planck-Inst. fur Plasmaphys., Garching (Germany). ITER Garching JWS; Gauster, W. [Max-Planck-Inst. fur Plasmaphys., Garching (Germany). ITER Garching JWS; Matera, R. [Max-Planck-Inst. fur Plasmaphys., Garching (Germany). ITER Garching JWS; Tavassoli, A.-A.F. [CEA Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France); Rowcliffe, A. [Oak Ridge National Lab., TN (United States); Fabritsiev, S. [Research Inst. of Electrophysical Apparatus, St. Petersburg (Russian Federation); Kawamura, H. [JAERI, IMTR Project, Ibaraki (Japan). Blanket Irradiation Lab.

    1996-10-01

    The materials proposed for ITER in-vessel components have to exhibit adequate performance for the operating lifetime of the reactor or for specified replacement intervals. Estimates show that maximum irradiation dose to be up to 5-7 dpa (for 1 MWa/m{sup 2} in the basic performance phase (BPP)) within a temperature range from 20 to 300 C. Austenitic SS 316LN-ITER Grade was defined as a reference option for the vacuum vessel, blanket, primary wall, pipe lines and divertor body. Conventional technologies and mill products are proposed for blanket, back plate and manifold manufacturing. HIPing is proposed as a reference manufacturing method for the primary wall and blanket and as an option for the divertor body. The existing data show that mechanical properties of HIPed SS are no worse than those of forged 316LN SS. Irradiation will result in property changes. Minimum ductility has been observed after irradiation in an approximate temperature range between 250 and 350 C, for doses of 5-10 dpa. In spite of radiation-induced changes in tensile deformation behavior, the fracture remains ductile. Irradiation assisted corrosion cracking is a concern for high doses of irradiation and at high temperatures. Re-welding is one of the critical issues because of the need to replace failed components. It is also being considered for the replacement of shielding blanket modules by breeding modules after the BPP. (orig.).

  16. Asymmetric Dielectric Elastomer Composite Material

    Stewart, Brian K. (Inventor)

    2014-01-01

    Embodiments of the invention provide a dielectric elastomer composite material comprising a plurality of elastomer-coated electrodes arranged in an assembly. Embodiments of the invention provide improved force output over prior DEs by producing thinner spacing between electrode surfaces. This is accomplished by coating electrodes directly with uncured elastomer in liquid form and then assembling a finished component (which may be termed an actuator) from coated electrode components.

  17. Different approaches to estimation of reactor pressure vessel material embrittlement

    V. M. Revka

    2013-03-01

    Full Text Available The surveillance test data for the nuclear power plant which is under operation in Ukraine have been used to estimate WWER-1000 reactor pressure vessel (RPV material embrittlement. The beltline materials (base and weld metal were characterized using Charpy impact and fracture toughness test methods. The fracture toughness test data were analyzed according to the standard ASTM 1921-05. The pre-cracked Charpy specimens were tested to estimate a shift of reference temperature T0 due to neutron irradiation. The maximum shift of reference temperature T0 is 84 °C. A radiation embrittlement rate AF for the RPV material was estimated using fracture toughness test data. In addition the AF factor based on the Charpy curve shift (ΔTF has been evaluated. A comparison of the AF values estimated according to different approaches has shown there is a good agreement between the radiation shift of Charpy impact and fracture toughness curves for weld metal with high nickel content (1,88 % wt. Therefore Charpy impact test data can be successfully applied to estimate the fracture toughness curve shift and therefore embrittlement rate. Furthermore it was revealed that radiation embrittlement rate for weld metal is higher than predicted by a design relationship. The enhanced embrittlement is most probably related to simultaneously high nickel and high manganese content in weld metal.

  18. Study on Material Selection of Reactor Pressure Vessel of SCWR

    Ma, Shuli; Luo, Ying; Yin, Qinwei; Li, Changxiang; Xie, Guofu

    This paper first analyzes the feasibility of SA-508 Grade 3 Class 1 Steel as an alternative material for Supercritical Water-Cooled Reactor (SCWR) Reactor Pressure Vessel (RPV). This kind of steel is limited to be applied in SCWR RPV due to its quenching property, though large forging could be accomplished by domestic manufacturers in forging aspect. Therefore, steels with higher strength and better quenching property are needed for SWCR RPV. The chemical component of SA-508 Gr.3 Cl.2 steel is similar to that of SA-508 Gr.3 Cl.1 steel, and more appropriate matching of strength and toughness could be achieved by the adjusting the elements contents, as well as proper control of tempering temperature and time. In light of the fact that Cl.2 steel has been successfully applied to steam generator, it could be an alternative material for SWCR RPV. SA-508 Gr.4N steel with high strength and good toughness is another alternative material for SCWR RPV. But large amount of research work before application is still needed for the lack of data on welding and irradiation etc.

  19. composite materials under static loading

    Hamrat Mostefa

    2018-01-01

    Full Text Available This work constitutes a contribution to the analysis of the behavior of beams repaired by composite materials. To analyze the overall behavior and failure modes of the beams, an experimental study of nine reinforced concrete beams, pre-cracked and then repaired by composite materials was conducted. Six beams were pre-cracked and repaired in the tensioned part (bending repair and in the other two beams on the tensioned and lateral parts with strips in the shape of U (shear repair. A comparative study was made between the ultimate moments measured experimentally and those calculated by the theoretical models. Compared to the control beam, the resistance gain for the beams repaired in bending is 50% to 90%, while that of beams repaired in shear is from 120% to177 %. The beams repaired in shear exhibit a ductile rupture in bending. However, the beams repaired in bending were failed by the lift-off of composite or by failure of concrete cover layer (except for beams repaired by fiber glass. BAEL99, EC2-04 and ACI318-08 models give the best prediction of the ultimate moments with a mean value of 1.16 for the ratio of MExp./Mtheor. and a mean standard deviation of 0.33.

  20. 49 CFR 176.166 - Transport of Class 1 (explosive) materials on passenger vessels.

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Transport of Class 1 (explosive) materials on....166 Transport of Class 1 (explosive) materials on passenger vessels. (a) Only the following Class 1 (explosive) materials may be transported as cargo on passenger vessels: (1) Division 1.4 (explosive...

  1. Structural considerations in design of lightweight glass-fiber composite pressure vessels

    Faddoul, J. R.

    1973-01-01

    The design concepts used for metal-lined glass-fiber composite pressure vessels are described, comparing the structural characteristics of the composite designs with each other and with homogeneous metal pressure vessels. Specific design techniques and available design data are identified. The discussion centers around two distinctly different design concepts, which provide the basis for defining metal lined composite vessels as either (1) thin-metal lined, or (2) glass fiber reinforced (GFR). Both concepts are described and associated development problems are identified and discussed. Relevant fabrication and testing experience from a series of NASA-Lewis Research Center development efforts is presented.

  2. Modern filaments for composite materials

    Krivelli-Viskonti, I.

    1982-01-01

    Analysis of modern state and ways to improve properties of different filaments for the forecast of the filament application in composite materials has been conducted. In the near future as before the greatest attention will be paid to fibre glass, as this material is widely used in the reinforcing of organic matrices. Carbon and kevlar filaments are the most prospective ones. For the service at medium, high or superhigh temperatures selection of matrix material is more significant than selection of filament. Organic matrices can not be used at temperatures > 250 deg C: this is already the range of metal matrix application. Though at temperatures above room one many filaments can be used, boron filaments and metal wire are the only reinforcing materials, inspite of the fact that carbon filaments are successfully used for metal matrix reinforcing. At very high temperatures only carbon filaments or silicon carbide ones can be used, but their cost is very high and besides economical problems there are many difficulties of technical character

  3. Design and Optimization of Filament Wound Composite Pressure Vessels

    Zu, L.

    2012-01-01

    One of the most important issues for the design of filament-wound pressure vessels reflects on the determination of the most efficient meridian profiles and related fiber architectures, leading to optimal structural performance. To better understand the design and optimization of filament-wound

  4. Development of Improved Composite Pressure Vessels for Hydrogen Storage

    Newhouse, Norman L. [Hexagon Lincoln, Lincoln, NE (United States)

    2016-04-29

    Hexagon Lincoln started this DOE project as part of the Hydrogen Storage Engineering Center of Excellence (HSECoE) contract on 1 February 2009. The purpose of the HSECoE was the research and development of viable material based hydrogen storage systems for on-board vehicular applications to meet DOE performance and cost targets. A baseline design was established in Phase 1. Studies were then conducted to evaluate potential improvements, such as alternate fiber, resin, and boss materials. The most promising concepts were selected such that potential improvements, compared with the baseline Hexagon Lincoln tank, resulted in a projected weight reduction of 11 percent, volume increase of 4 percent, and cost reduction of 10 percent. The baseline design was updated in Phase 2 to reflect design improvements and changes in operating conditions specified by HSECoE Partners. Evaluation of potential improvements continued during Phase 2. Subscale prototype cylinders were designed and fabricated for HSECoE Partners’ use in demonstrating their components and systems. Risk mitigation studies were conducted in Phase 3 that focused on damage tolerance of the composite reinforcement. Updated subscale prototype cylinders were designed and manufactured to better address the HSECoE Partners’ requirements for system demonstration. Subscale Type 1, Type 3, and Type 4 tanks were designed, fabricated and tested. Laboratory tests were conducted to evaluate vacuum insulated systems for cooling the tanks during fill, and maintaining low temperatures during service. Full scale designs were prepared based on results from the studies of this program. The operating conditions that developed during the program addressed adsorbent systems operating at cold temperatures. A Type 4 tank would provide the lowest cost and lightest weight, particularly at higher pressures, as long as issues with liner compatibility and damage tolerance could be resolved. A Type 1 tank might be the choice if the

  5. Composites materials: the technology of future

    Ahmed, M.N.; Memon, I.R.; Ahmad, F.; Zafar, N.

    2001-01-01

    Composite materials have a long history of usage. Their precise beginnings are not known; however all recorded history contains references to some form of composite material. e.g. straw was used by man to strengthen mud bricks thousands of years ago. This article presents the use of advanced composites materials in aircraft and space industry. Its brief history, use in military and civil aviation, use in space program, future usage, advantages in terms of cost, weight and strength. Use of composites in unmanned aerial vehicles and problems associated with usage of composites materials are also discussed. (author)

  6. International conference on composite materials and energy: Proceedings. Enercomp 95

    Anon.

    1995-01-01

    World demand for composite materials is continuously increasing. High strength and rigidity, associated with light weight, are the key factors for composites' success. These materials find numerous applications in all sectors of industry. Presently, a sector of particular interest in terms of demand for composite materials is the energy industry. More and more applications are found in the field of the forms of energy: electrical, petroleum, gas, nuclear, solar and wind. The topics addressed in various sessions of the conference cover potential applications of the entire range of polymer, metal and ceramic composites in all sectors of energy. Papers are divided into sessions covering the following topics: properties; design and analysis; fracture; fatigue and long-term performance; new materials; innovative processing; liquid molding; joining and repairs; radiation curing; recycling; development in ceramic materials; innovations in metallic materials; metal-matrix composites; nondestructive evaluation; energy savings in transportation; pressure vessels and piping; wind energy applications; electrical components; concrete applications; power plant applications; and new materials in the energy field. Most of the papers have been processed separately for inclusion on the data base

  7. Composite material and method of making

    Fryxell, Glen E.; Samuels, William D.; Simmons, Kevin L.

    2004-04-20

    The composite material and methods of making the present invention rely upon a fully dense monolayer of molecules attached to an oxygenated surface at one end, and an organic terminal group at the other end, which is in turn bonded to a polymer. Thus, the composite material is a second material chemically bonded to a polymer with fully dense monolayer there between.

  8. Morphology and microstructure of composite materials

    Tiwari, S. N.; Srinivansan, K.

    1991-01-01

    Lightweight continuous carbon fiber based polymeric composites are currently enjoying increasing acceptance as structural materials capable of replacing metals and alloys in load bearing applications. As with most new materials, these composites are undergoing trials with several competing processing techniques aimed at cost effectively producing void free consolidations with good mechanical properties. As metallic materials have been in use for several centuries, a considerable database exists on their morphology - microstructure; and the interrelationships between structure and properties have been well documented. Numerous studies on composites have established the crucial relationship between microstructure - morphology and properties. The various microstructural and morphological features of composite materials, particularly those accompanying different processing routes, are documented.

  9. A composite material based on recycled tires

    Malers, L.; Plesuma, R.; Locmele, L.

    2009-01-01

    The present study is devoted to the elaboration and investigation of a composite material based on mechanically grinded recycled tires and a polymer binder. The correlation between the content of the binder, some technological parameters, and material properties of the composite was clarified. The apparent density, the compressive stress at a 10% strain, the compressive elastic modulus in static and cyclic loadings, and the insulating properties (acoustic and thermal) were the parameters of special interest of the present investigation. It is found that a purposeful variation of material composition and some technological parameters leads to multifunctional composite materials with different and predictable mechanical and insulation properties.

  10. Composite materials formed with anchored nanostructures

    Seals, Roland D; Menchhofer, Paul A; Howe, Jane Y; Wang, Wei

    2015-03-10

    A method of forming nano-structure composite materials that have a binder material and a nanostructure fiber material is described. A precursor material may be formed using a mixture of at least one metal powder and anchored nanostructure materials. The metal powder mixture may be (a) Ni powder and (b) NiAl powder. The anchored nanostructure materials may comprise (i) NiAl powder as a support material and (ii) carbon nanotubes attached to nanoparticles adjacent to a surface of the support material. The process of forming nano-structure composite materials typically involves sintering the mixture under vacuum in a die. When Ni and NiAl are used in the metal powder mixture Ni.sub.3Al may form as the binder material after sintering. The mixture is sintered until it consolidates to form the nano-structure composite material.

  11. Vulnerability analysis of a pressurized aluminum composite vessel against hypervelocity impacts

    Hereil Pierre-Louis

    2015-01-01

    Full Text Available Vulnerability of high pressure vessels subjected to high velocity impact of space debris is analyzed with the response of pressurized vessels to hypervelocity impact of aluminum sphere. Investigated tanks are CFRP (carbon fiber reinforced plastics overwrapped Al vessels. Explored internal pressure of nitrogen ranges from 1 bar to 300 bar and impact velocity are around 4400 m/s. Data obtained from Xrays radiographies and particle velocity measurements show the evolution of debris cloud and shock wave propagation in pressurized nitrogen. Observation of recovered vessels leads to the damage pattern and to its evolution as a function of the internal pressure. It is shown that the rupture mode is not a bursting mode but rather a catastrophic damage of the external carbon composite part of the vessel.

  12. Compressed natural gas transportation by utilizing FRP composite pressure vessels

    Campbell, S.C. [Trans Ocean Gas Inc., St. John' s, NF (Canada)

    2004-07-01

    This paper discussed the Trans Ocean Gas (TOG) method for transporting compressed natural gas (CNG). As demand for natural gas increases and with half of the world's reserves considered stranded, a method to transport natural gas by ship is needed. CNG transportation is widely viewed as a viable method. Transported as CNG, stranded gas reserves can be delivered to existing markets or can create new natural gas markets not applicable to liquefied natural gas (LNG). In contrast to LNG, compressed gas requires no processing to offload. TOG proposes that CNG be transported using fiber reinforced plastic (FRP) pressure vessels which overcome all the deficiencies of proposed steel-based systems. FRP pressure vessels have been proven safe and reliable through critical applications in the national defense, aerospace, and natural gas vehicle industries. They are light-weight, highly reliable, have very safe failure modes, are corrosion resistant, and have excellent low temperature characteristics. Under TOG's scheme, natural gas can be stored at two thirds the density of LNG without costly processing. TOG's proposed design and testing of a CNG system was reviewed in detail. 1 fig.

  13. Mechanical Behavior of A Metal Composite Vessels Under Pressure At Cryogenic Temperatures

    Tsaplin, A. I.; Bochkarev, S. V.

    2016-01-01

    Results of an experimental investigation into the deformation and destruction of a metal composite vessel with a cryogenic gas are presented. Its structure is based on basalt, carbon, and organic fibers. The vessel proved to be serviceable at cryogenic temperatures up to a burst pressure of 45 MPa, and its destruction was without fragmentation. A mathematical model adequately describing the rise of pressure in the cryogenic vessel due to the formation of a gaseous phase upon boiling of the liquefied natural gas during its storage without drainage at the initial stage is proposed.

  14. Investigation of the design of a metal-lined fully wrapped composite vessel under high internal pressure

    Kalaycıoğlu, Barış; Husnu Dirikolu, M.

    2010-09-01

    In this study, a Type III composite pressure vessel (ISO 11439:2000) loaded with high internal pressure is investigated in terms of the effect of the orientation of the element coordinate system while simulating the continuous variation of the fibre angle, the effect of symmetric and non-symmetric composite wall stacking sequences, and lastly, a stacking sequence evaluation for reducing the cylindrical section-end cap transition region stress concentration. The research was performed using an Ansys® model with 2.9 l volume, 6061 T6 aluminium liner/Kevlar® 49-Epoxy vessel material, and a service internal pressure loading of 22 MPa. The results show that symmetric stacking sequences give higher burst pressures by up to 15%. Stacking sequence evaluations provided a further 7% pressure-carrying capacity as well as reduced stress concentration in the transition region. Finally, the Type III vessel under consideration provides a 45% lighter construction as compared with an all metal (Type I) vessel.

  15. Considerations for acoustic emission monitoring of spherical Kevlar/epoxy composite pressure vessels

    Hamstad, M. A.; Patterson, R. G.

    1977-01-01

    We are continuing to research the applications of acoustic emission testing for predicting burst pressure of filament-wound Kevlar 49/epoxy pressure vessels. This study has focused on three specific areas. The first area involves development of an experimental technique and the proper instrumentation to measure the energy given off by the acoustic emission transducer per acoustic emission burst. The second area concerns the design of a test fixture in which to mount the composite vessel so that the acoustic emission transducers are held against the outer surface of the composite. Included in this study area is the calibration of the entire test setup including couplant, transducer, electronics, and the instrument measuring the energy per burst. In the third and final area of this study, we consider the number, location, and sensitivity of the acoustic emission transducers used for proof testing composite pressure vessels.

  16. Microhardness of bulk-fill composite materials

    Kelić, Katarina; Matić, Sanja; Marović, Danijela; Klarić, Eva; Tarle, Zrinka

    2016-01-01

    The aim of the study was to determine microhardness of high- and low-viscosity bulk-fill composite resins and compare it with conventional composite materials. Four materials of high-viscosity were tested, including three bulk-fills: QuiXfi l (QF), x-tra fil (XTF) and Tetric EvoCeram Bulk Fill (TEBCF), while nanohybrid composite GrandioSO (GSO) served as control. The other four were low-viscosity composites, three bulk-fill materials: Smart Dentin Replacement (SDR), Venus Bulk Fill (VBF) and ...

  17. A review of formulas for predicting irradiation embrittlement of reactors vessel materials

    Petrequin, P.

    1995-01-01

    Formulas developed in different countries for predicting irradiation embrittlement of reactors vessel materials are presented. Results of predictions were compared with different data sets, from surveillance programmes or studies in test reactors, with different residual elements contents. Figs

  18. Wood-based composite materials : panel products, glued-laminated timber, structural composite lumber, and wood-nonwood composite materials

    Nicole M. Stark; Zhiyong Cai; Charles Carll

    2010-01-01

    This chapter gives an overview of the general types and composition of wood-based composite products and the materials and processes used to manufacture them. It describes conventional wood-based composite panels and structural composite materials intended for general construction, interior use, or both. This chapter also describes wood–nonwood composites. Mechanical...

  19. Composites and blends from biobased materials

    Kelley, S.S. [National Renewable Energy Laboratory, Golden, CO (United States)

    1995-05-01

    The program is focused on the development of composites and blends from biobased materials to use as membranes, high value plastics, and lightweight composites. Biobased materials include: cellulose derivative microporous materials, cellulose derivative copolymers, and cellulose derivative blends. This year`s research focused on developing an improved understanding of the molecular features that cellulose based materials with improved properties for gas separation applications. Novel cellulose ester membrane composites have been developed and are being evaluated under a collaborative research agreement with Dow Chemicals Company.

  20. Friction material composites copper-metal-free material design perspective

    Sundarkrishnaa, K L

    2015-01-01

    This book examines material composites used in connection with brake friction, their design and safety. To aid in understanding, the essentials of friction are explained. This second edition was extended to include friction material composites without copper, as they offer an environmentally friendlier option. The second edition is intended to support beginners by offering insights into the essentials of friction material composites, helping them to develop a broader understanding of brake friction materials. Friction materials find wide-ranging applications in household and industrial appliances, brake pads for automotive applications, rail brake friction pads and composition brake blocks. This second edition is an introductory volume to a set of related books, and is based on the author’s experience and expertise with various material manufacturers, brake manufacturers, vehicle manufacturers, researchers and testing labs around the world with which the author has been associated for the past 28 years.

  1. Application of the ASME code in designing containment vessels for packages used to transport radioactive materials

    Raske, D.T.; Wang, Z.

    1992-01-01

    The primary concern governing the design of shipping packages containing radioactive materials is public safety during transport. When these shipments are within the regulatory jurisdiction of the US Department of Energy, the recommended design criterion for the primary containment vessel is either Section III or Section VIII, Division 1, of the ASME Boiler and Pressure Vessel Code, depending on the activity of the contents. The objective of this paper is to discuss the design of a prototypic containment vessel representative of a packaging for the transport of high-level radioactive material

  2. Role of Outgassing of ITER Vacuum Vessel In-Wall Shielding Materials in Leak Detection of ITER Vacuum Vessel

    Maheshwari, A.; Pathak, H. A.; Mehta, B. K.; Phull, G. S.; Laad, R.; Shaikh, M. S.; George, S.; Joshi, K.; Khan, Z.

    2017-04-01

    ITER Vacuum Vessel is a torus-shaped, double wall structure. The space between the double walls of the VV is filled with In-Wall Shielding Blocks (IWS) and Water. The main purpose of IWS is to provide neutron shielding during ITER plasma operation and to reduce ripple of Toroidal Magnetic Field (TF). Although In-Wall Shield Blocks (IWS) will be submerged in water in between the walls of the ITER Vacuum Vessel (VV), Outgassing Rate (OGR) of IWS materials plays a significant role in leak detection of Vacuum Vessel of ITER. Thermal Outgassing Rate of a material critically depends on the Surface Roughness of material. During leak detection process using RGA equipped Leak detector and tracer gas Helium, there will be a spill over of mass 3 and mass 2 to mass 4 which creates a background reading. Helium background will have contribution of Hydrogen too. So it is necessary to ensure the low OGR of Hydrogen. To achieve an effective leak test it is required to obtain a background below 1 × 10-8 mbar 1 s-1 and hence the maximum Outgassing rate of IWS Materials should comply with the maximum Outgassing rate required for hydrogen i.e. 1 x 10-10 mbar 1 s-1 cm-2 at room temperature. As IWS Materials are special materials developed for ITER project, it is necessary to ensure the compliance of Outgassing rate with the requirement. There is a possibility of diffusing the gasses in material at the time of production. So, to validate the production process of materials as well as manufacturing of final product from this material, three coupons of each IWS material have been manufactured with the same technique which is being used in manufacturing of IWS blocks. Manufacturing records of these coupons have been approved by ITER-IO (International Organization). Outgassing rates of these coupons have been measured at room temperature and found in acceptable limit to obtain the required Helium Background. On the basis of these measurements, test reports have been generated and got

  3. Composite Materials for Low-Temperature Applications

    2008-01-01

    Composite materials with improved thermal conductivity and good mechanical strength properties should allow for the design and construction of more thermally efficient components (such as pipes and valves) for use in fluid-processing systems. These materials should have wide application in any number of systems, including ground support equipment (GSE), lunar systems, and flight hardware that need reduced heat transfer. Researchers from the Polymer Science and Technology Laboratory and the Cryogenics Laboratory at Kennedy Space Center were able to develop a new series of composite materials that can meet NASA's needs for lightweight materials/composites for use in fluid systems and also expand the plastic-additive markets. With respect to thermal conductivity and physical properties, these materials are excellent alternatives to prior composite materials and can be used in the aerospace, automotive, military, electronics, food-packaging, and textile markets. One specific application of the polymeric composition is for use in tanks, pipes, valves, structural supports, and components for hot or cold fluid-processing systems where heat flow through materials is a problem to be avoided. These materials can also substitute for metals in cryogenic and other low-temperature applications. These organic/inorganic polymeric composite materials were invented with significant reduction in heat transfer properties. Decreases of 20 to 50 percent in thermal conductivity versus that of the unmodified polymer matrix were measured. These novel composite materials also maintain mechanical properties of the unmodified polymer matrix. These composite materials consist of an inorganic additive combined with a thermoplastic polymer material. The intrinsic, low thermal conductivity of the additive is imparted into the thermoplastic, resulting in a significant reduction in heat transfer over that of the base polymer itself, yet maintaining most of the polymer's original properties. Normal

  4. Material problems in accident analysis of prestressed concrete reactor vessels

    Bazant, Z.P.

    1977-01-01

    Due to their very high energy absorption capability, as well as their inherent safety advantages, prestressed concrete reactor vessels are presently being keenly studied as the basic barrier to contain hypothetical core disruptive accidents in a fast breeder reactor. One problem investigated is the nonlinear constitutive behavior and failure criteria for concrete. Previously, a comprehensive theory, called endochronic theory, has been shown to satisfy all basic currently known features of test data. Nevertheless uncertainty still exists with regard to non-proportional loading paths, for which good test data are lacking at present. An extension of the endochronic theory which correlates best with general experimental evidence and includes fracturing terms is given, and a comparison with vertex-type hardening in plasticity is made. A second problem which must be analysed in accident situations is the high temperature shock on the concrete walls (due to liquid sodium, up to 850 0 C). Refining a previous crude formulation, a rational model for calculating moisture and heat transfer and pore pressures in concrete subjected to thermal shock is presented. In conclusion, a new design concept, in which the concrete vessel is completely dehydrated and kept hot throughout its service life in order to substantially improve its response to thermal shock as well as liquid sodium contact, is described. (Auth.)

  5. Composites as structural materials in fusion reactors

    Megusar, J.

    1989-01-01

    In fusion reactors, materials are used under extreme conditions of temperature, stress, irradiation, and chemical environment. The absence of adequate materials will seriously impede the development of fusion reactors and might ultimately be one of the major difficulties. Some of the current materials problems can be solved by proper design features. For others, the solution will have to rely on materials development. A parallel and balanced effort between the research in plasma physics and fusion-related technology and in materials research is, therefore, the best strategy to ultimately achieve economic, safe, and environmentally acceptable fusion. The essential steps in developing composites for structural components of fusion reactors include optimization of mechanical properties followed by testing under fusion-reactor-relevant conditions. In optimizing the mechanical behavior of composite materials, a wealth of experience can be drawn from the research on ceramic matrix and metal matrix composite materials sponsored by the Department of Defense. The particular aspects of this research relevant to fusion materials development are methodology of the composite materials design and studies of new processing routes to develop composite materials with specific properties. Most notable examples are the synthesis of fibers, coatings, and ceramic materials in their final shapes form polymeric precursors and the infiltration of fibrous preforms by molten metals

  6. Nanocellulose based polymer composite for acoustical materials

    Farid, Mohammad; Purniawan, Agung; Susanti, Diah; Priyono, Slamet; Ardhyananta, Hosta; Rahmasita, Mutia E.

    2018-04-01

    Natural fibers are biodegradable materials that are innovatively and widely used for composite reinforcement in automotive components. Nanocellulose derived from natural fibers oil palm empty bunches have properties that are remarkable for use as a composite reinforcement. However, there have not been many investigations related to the use of nanocellulose-based composites for wideband sound absorption materials. The specimens of nanocellulose-based polyester composite were prepared using a spray method. An impedance tube method was used to measure the sound absorption coefficient of this composite material. To reveal the characteristics of the nanocellulose-based polyester composite material, SEM (scanning electron microscope), TEM (Transmission Electron Microscope), FTIR (Fourier Transform Infra Red), TGA (Thermogravimetric Analysis), and density tests were performed. Sound absorption test results showed the average value of sound absorption coefficient of 0.36 to 0,46 for frequency between 500 and 4000 Hz indicating that this nanocellulose-based polyester composite materials had a tendency to wideband sound absorption materials and potentially used as automotive interior materials.

  7. Ceramic composites: Enabling aerospace materials

    Levine, S. R.

    1992-01-01

    Ceramics and ceramic matrix composites (CMC) have the potential for significant impact on the performance of aerospace propulsion and power systems. In this paper, the potential benefits are discussed in broad qualitative terms and are illustrated by some specific application case studies. The key issues in need of resolution for the potential of ceramics to be realized are discussed.

  8. Biomedical composites materials, manufacturing and engineering

    Davim, J Paulo

    2013-01-01

    Composite materials are engineered materials, made from two or more constituents with significantly different physical or chemical properties which remain separate on a macroscopic level within the finished structure. Due to their special mechanical and physical properties they have the potential to replace conventional materials in various fields such as the biomedical industry.

  9. Chemical composition of lunar material.

    Maxwell, J A; Abbey, S; Champ, W H

    1970-01-30

    Chemical and emission spectrographic analyses of three Apollo 11 samples, 10017-29, 10020-30, and 10084-132, are given. Major and minor constituents were determined both by conventional rock analysis methods and by a new composite scheme utilizing a lithium fluoborate method for dissolution of the samples and atomic absorption spectroscopy and colorimetry. Trace constituents were determined by optical emission spectroscopy involving a d-c arc, air-jet controlled.

  10. Fibrous and textile materials for composite applications

    Fangueiro, Raul

    2016-01-01

    This book focuses on the fibers and textiles used in composite materials. It presents both existing technologies currently used in commercial applications and the latest advanced research and developments. It also discusses the different fiber forms and architectures, such as short fibers, unidirectional tows, directionally oriented structures or advanced 2D- and 3D-textile structures that are used in composite materials. In addition, it examines various synthetic, natural and metallic fibers that are used to reinforce polymeric, cementitious and metallic matrices, as well as fiber properties, special functionalities, manufacturing processes, and composite processing and properties. Two entire chapters are dedicated to advanced nanofiber and nanotube reinforced composite materials. The book goes on to highlight different surface treatments and finishes that are applied to improve fiber/matrix interfaces and other essential composite properties. Although a great deal of information about fibers and textile str...

  11. German boiler and pressure vessel codes and standards: materials, manufacture, testing, equipment, erection and operation

    Steffen, H.P.

    1987-01-01

    The methods by which the safety objectives on the operation of steam boilers and pressure vessels in Germany can be reached are set out in Technical Rules which are compiled and established in technical committees. Typical applications are described in the Technical Rules. A chart shows how the laws, provisions and Technical Rules for the sections 'steam boiler plant' and 'pressure vessels' are interlinked. This chapter concentrates on legal aspects, materials, manufacture, testing, erection and operation of boilers and pressure vessels in Germany. (U.K.)

  12. Mechanics of composite materials: Unified micromechanical approach

    Aboundi, J.

    1991-01-01

    Although many books have been written on the mechanics of composite materials, only a vew few have been devoted almost exclusively to the micromechanics aspects. The present monograph is devoted primarily to the micromechanics of fiber and particle reinforced composites with some additional treatment of laminates as well. Thus, this book would probably be more suitable as a reference book than a textbook

  13. Weld repair of helium degraded reactor vessel material

    Kanne, W.R. Jr.; Lohmeier, D.A.; Louthan, M.R. Jr.; Rankin, D.T.; Franco-Ferreira, E.A.; Bruck, G.J.; Madeyski, A.; Shogan, R.P.; Lessmann, G.G.

    1990-01-01

    Welding methods for modification or repair of irradiated nuclear reactor vessels are being evaluated at the Savannah River Site. A low-penetration weld overlay technique has been developed to minimize the adverse effects of irradiation induced helium on the weldability of metals and alloys. This technique was successfully applied to Type 304 stainless steel test plates that contained 3 to 220 appm helium from tritium decay. Conventional welding practices caused significant cracking and degradation in the test plates. Optical microscopy of weld surfaces and cross sections showed that large surface toe cracks formed around conventional welds in the test plates but did not form around overlay welds. Scattered incipient underbead cracks (grain boundary separations) were associated with both conventional and overlay test welds. Tensile and bend tests were used to assess the effect of base metal helium content on the mechanical integrity of the low-penetration overlay welds. The axis of tensile specimens was perpendicular to the weld-base metal interface. Tensile specimens were machined after studs were resistance welded to overlay surfaces

  14. Cast iron as structural material for hot-working reactor vessels (PCIV)

    Ostendorf, H.; Schmidt, G.; Pittack, W.

    1977-01-01

    Cast iron with lamellar graphite is best suited for prestressed structures, because its compressive strength is nearly 4 times its tensile strength. In comparison to room temperature, cast iron with lamellar graphite shows essentially no loss of strength up to temperatures of 400 0 C. Under the particular aspect to use cast iron for hot-working prestressed reactor pressure vessels (PCIV) (Prestressed cast iron vessel=PCIV) a materials testing program is carried out, which meets the strict certification requirements for materials in the construction of reactor pressure vessels and which completes the presently available knowledge of cast iron. Especially in the following fields an extension and supplement of the present level of knowledge is necessary: mechanical properties under compressive stresses; material properties at elevated temperatures; influence of irradiation on mechanical and physical properties; production standards and quality control. The state of the research and the available data of the material testing program are reported

  15. Cast iron as structural material for hot-working reactor vessels (PCIV)

    Ostendorf, H.; Schmidt, G.; Pittack, W.

    1977-01-01

    Cast iron with lamellar graphite is best suited for prestressed structures, because its compressive strength is nearly 4 times its tensile strength. In comparison to room temperature, cast iron with lamellar graphite shows essentially no loss of strength up to temperatures of 400 0 C. Under the particular aspect to use cast iron for hot-working prestressed reactor pressure vessels (PCIV) (Prestressed cast iron vessel=PCIV) a materials testing program is carried out, which meets the strict certification requirements for materials in the construction of reactor pressure vessels and which completes the presently available knowledge of cast iron. Especially in the following fields an extension and supplement of the present level of knowledge is necessary. - Mechanical properties under compressive stresses. - Material properties at elevated temperatures. - Influence of irradiation on mechanical and physical properties. - Production standards and quality control. The state of the research and the available data of the material testing program are reported. (Auth.)

  16. Technical meeting on materials for in-vessel components of ITER

    Kalinin, G.; Barabash, V.

    2000-01-01

    The Technical meeting on materials for in-vessel components of ITER was held at the ITER Joint Work Site in Garching from 31 January to 4 February. The main objectives of the meetings were: 1. to summarize the requirements, 2. to review new data, 3. to discuss in detail the R and D program and to discuss the material assessment report

  17. Development of a Numerical Model of Hypervelocity Impact into a Pressurized Composite Overwrapped Pressure Vessel

    Garcia, M. A.; Davis, B. A.; Miller, J. E.

    2017-01-01

    As the outlook for space exploration becomes more ambitious and spacecraft travel deeper into space than ever before, it is increasingly important that propulsion systems perform reliably within the space environment. The increased reliability compels designers to increase design margin at the expense of system mass, which contrasts with the need to limit vehicle mass to maximize payload. Such are the factors that motivate the integration of high specific strength composite materials in the construction of pressure vessels commonly referred to as composite overwrapped pressure vessels (COPV). The COPV consists of a metallic liner for the inner shell of the COPV that is stiff, negates fluid permeation and serves as the anchor for composite laminates or filaments, but the liner itself cannot contain the stresses from the pressurant it contains. The compo-site-fiber reinforced polymer (CFRP) is wound around the liner using a combination of hoop (circumferential) and helical orientations. Careful consideration of wrap orientation allows the composite to evenly bear structural loading and creates the COPV's characteristic high strength to weight ratio. As the CFRP overwrap carries most of the stresses induced by pressurization, damage to the overwrap can affect mission duration, mission success and potentially cause loss-of-vehicle/loss-of-crew. For this reason, it is critical to establish a fundamental understanding of the mechanisms involved in the failure of a stressed composite such as that of the COPV. One of the greatest external threats to the integrity of a spacecraft's COPV is an impact from the meteoroid and orbital debris environments (MMOD). These impacts, even from submillimeter particles, generate extremely high stress states in the CFRP that can damage numerous fibers. As a result of this possibility, initial assumptions in survivability analysis for some human-rated NASA space-craft have assumed that any alteration of the vessel due to impact is

  18. Composite materials for wind power turbine blades

    Brøndsted, P.; Lilholt, H.; Lystrup, Aa.

    2005-01-01

    , and industrial potential. The important technologies of today are prepreg (pre-impregnated) technology and resin infusion technology. The mechanical properties of fiber composite materials are discussed, with a focus on fatigue performance. Damage and materials degradation during fatigue are described. Testing...

  19. Progress in understanding the mechanical behavior of pressure-vessel materials at elevated temperatures

    Swindeman, R.W.; Brinkman, C.R.

    1981-01-01

    Progress during the 1970's on the production of high-temperature mechanical properties data for pressure vessel materials was reviewed. The direction of the research was toward satisfying new data requirements to implement advances in high-temperature inelastic design methods. To meet these needs, servo-controlled testing machines and high-resolution extensometry were developed to gain more information on the essential behavioral features of high-temperature alloys. The similarities and differences in the mechanical response of various pressure vessel materials were identified. High-temperature pressure vessel materials that have received the most attention included Type 304 stainless steel, Type 316 stainless steel, 2 1/4 Cr-1 Mo steel, alloy 800H, and Hastelloy X

  20. Damping in aerospace composite materials

    Agneni, A.; Balis Crema, L.; Castellani, A.

    Experimental results are presented on specimens of carbon and Kevlar fibers in epoxy resin, materials used in many aerospace structures (control surfaces and wings in aircraft, large antennas in spacecraft, etc.). Some experimental methods of estimating damping ratios are first reviewed, either in the time domain or in the frequency domain. Some damping factor estimates from experimental tests are then shown; in order to evaluate the effects of the aerospace environment, damping factors have been obtained in a typical range of temperature, namely between +120 C and -120 C, and in the pressure range from room pressure to 10 exp -6 torr. Finally, a theoretical approach for predicting the bounds of the damping coefficients is shown, and prediction data are compared with experimental results.

  1. General and crevice corrosion study of the in-wall shielding materials for ITER vacuum vessel

    Joshi, K. S.; Pathak, H. A.; Dayal, R. K.; Bafna, V. K.; Kimihiro, Ioki; Barabash, V.

    2012-11-01

    Vacuum vessel In-Wall Shield (IWS) will be inserted between the inner and outer shells of the ITER vacuum vessel. The behaviour of IWS in the vacuum vessel especially concerning the susceptibility to crevice of shielding block assemblies could cause rapid and extensive corrosion attacks. Even galvanic corrosion may be due to different metals in same electrolyte. IWS blocks are not accessible until life of the machine after closing of vacuum vessel. Hence, it is necessary to study the susceptibility of IWS materials to general corrosion and crevice corrosion under operations of ITER vacuum vessel. Corrosion properties of IWS materials were studied by using (i) Immersion technique and (ii) Electro-chemical Polarization techniques. All the sample materials were subjected to a series of examinations before and after immersion test, like Loss/Gain weight measurement, SEM analysis, and Optical stereo microscopy, measurement of surface profile and hardness of materials. After immersion test, SS 304B4 and SS 304B7 showed slight weight gain which indicate oxide layer formation on the surface of coupons. The SS 430 material showed negligible weight loss which indicates mild general corrosion effect. On visual observation with SEM and Metallography, all material showed pitting corrosion attack. All sample materials were subjected to series of measurements like Open Circuit potential, Cyclic polarization, Pitting potential, protection potential, Critical anodic current and SEM examination. All materials show pitting loop in OC2 operating condition. However, its absence in OC1 operating condition clearly indicates the activity of chloride ion to penetrate oxide layer on the sample surface, at higher temperature. The critical pitting temperature of all samples remains between 100° and 200°C.

  2. Processes for fabricating composite reinforced material

    Seals, Roland D.; Ripley, Edward B.; Ludtka, Gerard M.

    2015-11-24

    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.

  3. Microwave Measurements of Ferrite Polymer Composite Materials

    Rastislav Dosoudil

    2004-01-01

    Full Text Available The article focuses on the microwave measurements performed on the nickel-zinc sintered ferrite with the chemical formula Ni0.3Zn0.7Fe2O4 produced by the ceramic technique and composite materials based on this ferrite and a non-magnetic polymer (polyvinyl chloride matrix. The prepared composite samples had the same particle size distribution 0-250um but different ferrite particle concentrations between 23 vol% and 80 vol%. The apparatus for measurement of the signal proportional to the absolute value of scattering parameter S11 (reflexion coefficient is described and the dependence of measured reflected signal on a bias magnetic field has been studied. By means of experiments, the resonances to be connected with the geometry of microwave experimental set-up were distinguished from ferromagnetic resonance arising in ferrite particles of composite structure. The role of local interaction fields of ferrite particles in composite material has been discussed.

  4. Health monitoring method for composite materials

    Watkins, Jr., Kenneth S.; Morris, Shelby J [Hampton, VA

    2011-04-12

    An in-situ method for monitoring the health of a composite component utilizes a condition sensor made of electrically conductive particles dispersed in a polymeric matrix. The sensor is bonded or otherwise formed on the matrix surface of the composite material. Age-related shrinkage of the sensor matrix results in a decrease in the resistivity of the condition sensor. Correlation of measured sensor resistivity with data from aged specimens allows indirect determination of mechanical damage and remaining age of the composite component.

  5. Machining of Fibre Reinforced Plastic Composite Materials

    2018-01-01

    Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented. PMID:29562635

  6. Machining of Fibre Reinforced Plastic Composite Materials

    Alessandra Caggiano

    2018-03-01

    Full Text Available Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented.

  7. Embrittlement of the nuclear icebreaker Lenin reactor pressure vessel materials reconstruction

    Krasikov, E.A.; Nikolaenko, V.A.

    2008-01-01

    Paper deals with the results of the efforts to examine the radiation damage of the Lenin nuclear-powered ice-breaker decommissioned reactor pressure vessel on the basis of which one has determined the peculiar features of the metal radiation embrittlement. Under 10 10 -10 11 s -1 cm -2 low density neutron flux irradiation one notes the most intensive embrittlement of the metal. Then, as the noxious element content in the metal matrix grows smaller the embrittlement reduces up to the change of sign as to the normal curve plotted at the neutron flux density exceeding 10 13 s -1 cm -2 . One assumes that as a result of the low density neutron flux irradiation the reactor pressure vessel edge spaces at some operation stages may be damaged more severely in contrast to these near the reactor core. The neutron irradiation density is the factor affecting the reactor vessel material embrittlement, that is why, it is important to study the damage mechanism of the materials of the power reactor vessels under design characterized by the low radiation load. The mentioned is important, as well, to evaluate the efficiency of the efforts undertaken to mitigate the effect of the neutron radiation on the reactor vessel [ru

  8. Homogenization in thermoelasticity: application to composite materials

    Peyroux, R [Lab. de Mecanique et Genie Civil, Univ. Montpellier 2, 34 Montpellier (France); Licht, C [Lab. de Mecanique et Genie Civil, Univ. Montpellier 2, 34 Montpellier (France)

    1993-11-01

    One of the obstacles to the industrial use of metal matrix composite materials is the damage they rapidly undergo when they are subjected to cyclic thermal loadings; local thermal stresses of high level can develop, sometimes nearby or over the elastic limit, due to the mismatch of elastic and thermal coefficients between the fibers and the matrix. For the same reasons, early cracks can appear in composites like ceramic-ceramic. Therefore, we investigate the linear thermoelastic behaviour of heterogeneous materials, taking account of the isentropic coupling term in the heat conduction equation. In the case of periodic materials, recent results, using the homogenization theory, allowed us to describe macroscopic and microscopic behaviours of such materials. This paper is concerned with the numerical simulation of this problem by a finite element method, using a multiscale approach. (orig.).

  9. Design and material selection for ITER first wall/blanket, divertor and vacuum vessel

    Ioki, K.; Barabash, V.; Cardella, A.; Elio, F.; Gohar, Y.; Janeschitz, G.; Johnson, G.; Kalinin, G.; Lousteau, D.; Onozuka, M.; Parker, R.; Sannazzaro, G.; Tivey, R. [ITER JCT, Garching (Germany)

    1998-10-01

    Design and R and D have progressed on the ITER vacuum vessel, shielding and breeding blankets, and the divertor. The principal materials have been selected and the fabrication methods selected for most of the components based on design and R and D results. The resulting design changes are discussed for each system. (orig.) 11 refs.

  10. Design and material selection for ITER first wall/blanket, divertor and vacuum vessel

    Ioki, K.; Barabash, V.; Cardella, A.; Elio, F.; Gohar, Y.; Janeschitz, G.; Johnson, G.; Kalinin, G.; Lousteau, D.; Onozuka, M.; Parker, R.; Sannazzaro, G.; Tivey, R.

    1998-10-01

    Design and R&D have progressed on the ITER vacuum vessel, shielding and breeding blankets, and the divertor. The principal materials have been selected and the fabrication methods selected for most of the components based on design and R&D results. The resulting design changes are discussed for each system.

  11. Structured Piezoelectric Composites: Materials and Applications

    Van den Ende, D.A.

    2012-01-01

    The piezoelectric effect, which causes a material to generate a voltage when it deforms, is very suitable for making integrated sensors, and (micro-) generators. However, conventional piezoelectric materials are either brittle ceramics or certain polymers with a low thermal stability, which limits their practical application to certain specific fields. Piezoelectric composites, which contain an active piezoelectric (ceramic) phase in a robust polymer matrix, can potentially have better proper...

  12. Preliminary Validation of Composite Material Constitutive Characterization

    John G. Michopoulos; Athanasios lliopoulos; John C. Hermanson; Adrian C. Orifici; Rodney S. Thomson

    2012-01-01

    This paper is describing the preliminary results of an effort to validate a methodology developed for composite material constitutive characterization. This methodology involves using massive amounts of data produced from multiaxially tested coupons via a 6-DoF robotic system called NRL66.3 developed at the Naval Research Laboratory. The testing is followed by...

  13. Composite materials. From gammas to weight measurement

    Anon.

    1998-01-01

    A gamma photons backscattering gauge called 'Filbor 2' has been designed by the CEA/DAMRI (Saclay, France) and allows to measure the resin content of fiber wicks (boron, carbon, kevlar, glass..) devoted to the manufacturing of elements made of composite materials. (J.S.)

  14. Ceramic nanostructure materials, membranes and composite layers

    Burggraaf, A.J.; Keizer, Klaas; van Hassel, B.A.

    1989-01-01

    Synthesis methods to obtain nanoscale materials will be briefly discussed with a focus on sol-gel methods. Three types of nanoscale composites (powders, membranes and ion implanted layers) will be discussed and exemplified with recent original research results. Ceramic membranes with a thickness of

  15. Use of Master Curve technology for assessing shallow flaws in a reactor pressure vessel material

    Bass, Bennett Richard; Taylor, Nigel

    2006-01-01

    In the NESC-IV project an experimental/analytical program was performed to develop validated analysis methods for transferring fracture toughness data to shallow flaws in reactor pressure vessels subject to biaxial loading in the lower-transition temperature region. Within this scope an extensive range of fracture tests was performed on material removed from a production-quality reactor pressure vessel. The Master Curve analysis of this data is reported and its application to the assessment of the project feature tests on large beam test pieces.

  16. Materials interaction tests to identify base and coating materials for an enhanced in-vessel core catcher design

    Rempe, J.L.; Knudson, D.L.; Condie, K.G.; Swank, W.D. [Idaho National Engineering and Environmental Laboratory, Idaho Falls ID (United States); Cheung, F.B. [Pennsylvania State University, Department of Mechanical and Nuclear Engineering, University Park PA (United States); Suh, K.Y. [Seoul National University, Department of Nuclear Engineering, Seoul (Korea, Republic of); Kim, S.B. [Korea Atomic Energy Research Institute, Severe Accident Research Project, Taejon (Korea, Republic of)

    2004-07-01

    An enhanced in-vessel core catcher is being designed and evaluated, it must ensure In-Vessel Retention of core materials that may relocate under severe accident conditions in advanced reactors. To reduce cost and simplify manufacture and installation, this new core catcher design consists of several interlocking sections that are machined to fit together when inserted into the lower head. If needed, the core catcher can be manufactured with holes to accommodate lower head penetrations. Each section of the core catcher consists of two material layers with an option to add a third layer (if deemed necessary): a base material, which has the capability to support and contain the mass of core materials that may relocate during a severe accident; an insulating oxide coating material on top of the base material, which resists interactions with high-temperature core materials; and an optional coating on the bottom side of the base material to prevent any potential oxidation of the base material during the lifetime of the reactor. Initial evaluations suggest that a thermally-sprayed oxide material is the most promising candidate insulator coating for a core catcher. Tests suggest that 2 coatings can provide adequate protection to a stainless steel core catcher: -) a 500 {mu}m thick zirconium dioxide coating over a 100-200 {mu}m Inconel 718 bond coating, and -) a 500 {mu}m thick magnesium zirconate coating.

  17. Accelerated Aging of Polymer Composite Bridge Materials

    Carlson, Nancy Margaret; Blackwood, Larry Gene; Torres, Lucinda Laine; Rodriguez, Julio Gallardo; Yoder, Timothy Scott

    1999-03-01

    Accelerated aging research on samples of composite material and candidate ultraviolet (UV) protective coatings is determining the effects of six environmental factors on material durability. Candidate fastener materials are being evaluated to determine corrosion rates and crevice corrosion effects at load-bearing joints. This work supports field testing of a 30-ft long, 18-ft wide polymer matrix composite (PMC) bridge at the Idaho National Engineering and Environmental Laboratory (INEEL). Durability results and sensor data from tests with live loads provide information required for determining the cost/benefit measures to use in life-cycle planning, determining a maintenance strategy, establishing applicable inspection techniques, and establishing guidelines, standards, and acceptance criteria for PMC bridges for use in the transportation infrastructure.

  18. Reactor vessel dismantling at the high flux materials testing reactor Petten

    Tas, A.; Teunissen, G.

    1986-01-01

    The project of replacing the reactor vessel of the high flux materials testing reactor (HFR) originated in 1974 when results of several research programs confirmed severe neutron embrittlement of aluminium alloys suggesting a limited life of the existing facility. This report describes the dismantling philosophy and organisation, the design of special underwater equipment, the dismantling of the reactor vessel and thermal column, and the conditioning and shielding activities resulting in a working area for the installation of the new vessel with no access limitations due to radiation. Finally an overview of the segmentation, waste disposal and radiation exposure is given. The total dismantling, segmentation and conditioning activities resulted in a total collective radiation dose of 300 mSv. (orig.) [de

  19. In-Vessel Coil Material Failure Rate Estimates for ITER Design Use

    L. C. Cadwallader

    2013-01-01

    The ITER international project design teams are working to produce an engineering design for construction of this large tokamak fusion experiment. One of the design issues is ensuring proper control of the fusion plasma. In-vessel magnet coils may be needed for plasma control, especially the control of edge localized modes (ELMs) and plasma vertical stabilization (VS). These coils will be lifetime components that reside inside the ITER vacuum vessel behind the blanket modules. As such, their reliability is an important design issue since access will be time consuming if any type of repair were necessary. The following chapters give the research results and estimates of failure rates for the coil conductor and jacket materials to be used for the in-vessel coils. Copper and CuCrZr conductors, and stainless steel and Inconel jackets are examined.

  20. Thick SS316 materials TIG welding development activities towards advanced fusion reactor vacuum vessel applications

    Kumar, B. Ramesh; Gangradey, R.

    2012-11-01

    Advanced fusion reactors like ITER and up coming Indian DEMO devices are having challenges in terms of their materials design and fabrication procedures. The operation of these devices is having various loads like structural, thermo-mechanical and neutron irradiation effects on major systems like vacuum vessel, divertor, magnets and blanket modules. The concept of double wall vacuum vessel (VV) is proposed in view of protecting of major reactor subsystems like super conducting magnets, diagnostic systems and other critical components from high energy 14 MeV neutrons generated from fusion plasma produced by D-T reactions. The double walled vacuum vessel is used in combination with pressurized water circulation and some special grade borated steel blocks to shield these high energy neutrons effectively. The fabrication of sub components in VV are mainly used with high thickness SS materials in range of 20 mm- 60 mm of various grades based on the required protocols. The structural components of double wall vacuum vessel uses various parts like shields, ribs, shells and diagnostic vacuum ports. These components are to be developed with various welding techniques like TIG welding, Narrow gap TIG welding, Laser welding, Hybrid TIG laser welding, Electron beam welding based on requirement. In the present paper the samples of 20 mm and 40 mm thick SS 316 materials are developed with TIG welding process and their mechanical properties characterization with Tensile, Bend tests and Impact tests are carried out. In addition Vickers hardness tests and microstructural properties of Base metal, Heat Affected Zone (HAZ) and Weld Zone are done. TIG welding application with high thick SS materials in connection with vacuum vessel requirements and involved criticalities towards welding process are highlighted.

  1. Thick SS316 materials TIG welding development activities towards advanced fusion reactor vacuum vessel applications

    Kumar, B Ramesh; Gangradey, R

    2012-01-01

    Advanced fusion reactors like ITER and up coming Indian DEMO devices are having challenges in terms of their materials design and fabrication procedures. The operation of these devices is having various loads like structural, thermo-mechanical and neutron irradiation effects on major systems like vacuum vessel, divertor, magnets and blanket modules. The concept of double wall vacuum vessel (VV) is proposed in view of protecting of major reactor subsystems like super conducting magnets, diagnostic systems and other critical components from high energy 14 MeV neutrons generated from fusion plasma produced by D-T reactions. The double walled vacuum vessel is used in combination with pressurized water circulation and some special grade borated steel blocks to shield these high energy neutrons effectively. The fabrication of sub components in VV are mainly used with high thickness SS materials in range of 20 mm- 60 mm of various grades based on the required protocols. The structural components of double wall vacuum vessel uses various parts like shields, ribs, shells and diagnostic vacuum ports. These components are to be developed with various welding techniques like TIG welding, Narrow gap TIG welding, Laser welding, Hybrid TIG laser welding, Electron beam welding based on requirement. In the present paper the samples of 20 mm and 40 mm thick SS 316 materials are developed with TIG welding process and their mechanical properties characterization with Tensile, Bend tests and Impact tests are carried out. In addition Vickers hardness tests and microstructural properties of Base metal, Heat Affected Zone (HAZ) and Weld Zone are done. TIG welding application with high thick SS materials in connection with vacuum vessel requirements and involved criticalities towards welding process are highlighted.

  2. Condition Assessment of Kevlar Composite Materials Using Raman Spectroscopy

    Washer, Glenn; Brooks, Thomas; Saulsberry, Regor

    2007-01-01

    This viewgraph presentation includes the following main concepts. Goal: To evaluate Raman spectroscopy as a potential NDE tool for the detection of stress rupture in Kevlar. Objective: Test a series of strand samples that have been aged under various conditions and evaluate differences and trends in the Raman response. Hypothesis: Reduction in strength associated with stress rupture may manifest from changes in the polymer at a molecular level. If so, than these changes may effect the vibrational characteristics of the material, and consequently the Raman spectra produced from the material. Problem Statement: Kevlar composite over-wrapped pressure vessels (COPVs) on the space shuttles are greater than 25 years old. Stress rupture phenomena is not well understood for COPVs. Other COPVs are planned for hydrogen-fueled vehicles using Carbon composite material. Raman spectroscopy is being explored as an non-destructive evaluation (NDE) technique to predict the onset of stress rupture in Kevlar composite materials. Test aged Kevlar strands to discover trends in the Raman response. Strength reduction in Kevlar polymer will manifest itself on the Raman spectra. Conclusions: Raman spectroscopy has shown relative changes in the intensity and FWHM of the 1613 cm(exp -1) peak. Reduction in relative intensity for creep, fleet leader, and SIM specimens compared to the virgin strands. Increase in FWHM has been observed for the creep and fleet leader specimens compared to the virgin strands. Changes in the Raman spectra may result from redistributing loads within the material due to the disruption of hydrogen bonding between crystallites or defects in the crystallites from aging the Kevlar strands. Peak shifting has not been observed to date. Analysis is ongoing. Stress measurements may provide a tool in the short term.

  3. Influence of INCONEL 625 composition on the activation characteristics of the vacuum vessel of experimental fusion tokamaks

    Cambi, G.; Cepraga, D.G.; Boeriu, S.; Maganzani, I.

    1995-01-01

    The radioactive inventory, the decay heat and the contact dose rate of permanent components such as the vacuum vessel of two experimental fusion tokamaks, the compact IGNITOR-ULT and the ITER-EDA fusion machines, are evaluated by using the ENEA-Bologna integrated methodology. The vacuum vessel material considered is the INCONEL 625. The neutron flux is calculated using the VITAMIN-C 171-group library, based on EFF-2 data and the 1-D transport code XSDRNPM in the S 8 -P 3 approximation. The ANITA-2 code, using updated cross sections and decay data libraries based on EAF-3 and IRDF90 evaluation files is used for activation calculations. The fusion neutron source has been normalised to a neutron first wall load of 2 MW/m 2 and 1 MW/m 2 for IGNITOR-ULT and ITER, respectively. The material irradiation have been described by multistep time histories, resulting in the designed total fluence. Variations in the composition of INCONEL 625 have been assessed and their impact on the activation characteristics are discussed, also from the point of view of waste disposal. (orig.)

  4. Design prediction for long term stress rupture service of composite pressure vessels

    Robinson, Ernest Y.

    1992-01-01

    Extensive stress rupture studies on glass composites and Kevlar composites were conducted by the Lawrence Radiation Laboratory beginning in the late 1960's and extending to about 8 years in some cases. Some of the data from these studies published over the years were incomplete or were tainted by spurious failures, such as grip slippage. Updated data sets were defined for both fiberglass and Kevlar composite stand test specimens. These updated data are analyzed in this report by a convenient form of the bivariate Weibull distribution, to establish a consistent set of design prediction charts that may be used as a conservative basis for predicting the stress rupture life of composite pressure vessels. The updated glass composite data exhibit an invariant Weibull modulus with lifetime. The data are analyzed in terms of homologous service load (referenced to the observed median strength). The equations relating life, homologous load, and probability are given, and corresponding design prediction charts are presented. A similar approach is taken for Kevlar composites, where the updated stand data do show a turndown tendency at long life accompanied by a corresponding change (increase) of the Weibull modulus. The turndown characteristic is not present in stress rupture test data of Kevlar pressure vessels. A modification of the stress rupture equations is presented to incorporate a latent, but limited, strength drop, and design prediction charts are presented that incorporate such behavior. The methods presented utilize Cartesian plots of the probability distributions (which are a more natural display for the design engineer), based on median normalized data that are independent of statistical parameters and are readily defined for any set of test data.

  5. Reinforced concrete treatment as composite material

    Oller, S.; Onate, E.; Miguel, J.

    1995-01-01

    This paper presents the general mixing theory applied to the numerical simulation of multiphase composite material behaviour as reinforced concrete materials. This theory is based on the mixture of that composite basic substances and allows to evaluate the inter-dependence behaviour between the different compounding constitutive models. If it would be necessary to consider the initial anisotropy of each compound it could be done by mean of the mapped isotropic plastic formulation. The approach is a generalization of the classic isotropic plasticity theory to be applied to either ortho tropic or anisotropic materials such as reinforced concrete. The existence of a stress and strain real anisotropic spaces, and the respective fictitious isotropic spaces are assumed, where a mapped fictitious problem is solved. Those spaces are relating by means of two fourth order transformation tensors. Both formulation are joined establishing a powerful work tool for the treatment of bulk-fiber composite materials. The induced anisotropy behaviour is take into account by each compounding constitutive formulation. (author). 24 refs., 3 figs

  6. Additive Manufacturing of Composites and Complex Materials

    Spowart, Jonathan E.; Gupta, Nikhil; Lehmhus, Dirk

    2018-03-01

    Advanced composite materials form an important class of high-performance industrial materials used in weight-sensitive applications such as aerospace structures, automotive structures and sports equipment. In many of these applications, parts are made in small production runs, are highly customized and involve long process development times. Developments in additive manufacturing (AM) methods have helped in overcoming many of these limitations. The special topic of Additive Manufacturing of Composites and Complex Materials captures the state of the art in this area by collecting nine papers that present much novel advancement in this field. The studies under this topic show advancement in the area of AM of carbon fiber and graphene-reinforced composites with high thermal and electrical conductivities, development of new hollow glass particle-filled syntactic foam filaments for printing lightweight structures and integration of sensors or actuators during AM of metallic parts. Some of the studies are focused on process optimization or modification to increase the manufacturing speed or tuning manufacturing techniques to enable AM of new materials.

  7. Thermal and mechanical cyclic loading of thick spherical vessels made of transversely isotropic materials

    Komijani, M.; Mahbadi, H.; Eslami, M.R.

    2013-01-01

    The aim of this paper is to obtain the dependency of the ratcheting, reversed plasticity, or shakedown behavior of spherical vessels made of some anisotropic materials to the stress category of imposed cyclic loading. The Hill anisotropic yield criterion with the kinematic hardening theories of plasticity based on the Prager and Armstrong–Frederick models are used to predict the yield of the vessel and obtain the plastic strains. An iterative numerical method is used to simulate the cyclic loading behavior of the structure. The effect of mean and amplitude of the mechanical and thermal loads on cyclic behavior and ratcheting rate of the vessel is investigated respectively. The ratcheting rate for the vessels made of transversely isotropic material is evaluated for the various ratios of anisotropy. -- Highlights: ► Cyclic loading analysis of anisotropic spheres is assessed. ► Using the Prager model results in ratcheting. ► Armstrong-Frederick model predicts ratcheting for load controlled cyclic loadings. ► The A-F model predicts ratcheting to a stabilized cycle for thermal loadings

  8. Voluntary Consensus Organization Standards for Nondestructive Evaluation of Thin-Walled Metallic Liners and Composite Overwraps in Composite Overwrapped Pressure Vessels

    Waller, Jess; Saulsberry, Regor

    2012-01-01

    NASA fracture control requirements outlined in NASA-STD-5009 and NASA-STD-5014 are predicated on the availability and use of sensitive nondestructive evaluation (NDE) methods that can detect and monitor defects, thereby providing data that can be used to predict failure or reduce the risk of failure in fracture critical components. However, in the case of composite materials and components, including composite overwrapped pressure vessels (COPVs), the effect of defects is poorly understood, the NDE methods used to evaluate locate and size defects are typically at lower technical readiness level than analogous NDE methods used for metals, and demonstration studies to verify the probability of detection (POD) are generally lacking or unavailable. These factors together make failure prediction of fracture critical composite materials and components based on size, quantity, or orientation of defects nearly impossible. Also, when inspecting metal liners in as-manufactured COPVs, sensitivity is lost and only the inner surface of the liner is accessible. Also, NDE of COPVs as applied during manufacturing varies significantly from manufacturer to manufacturer and has not yet been standardized. Although requirements exist to perform NDE immediately after manufacturing to establish initial integrity of the parts, procedural detail for NDE of composites is still nonexistent or under development. For example, in practice, only a visual inspection of COPVs is performed during manufacturing and service, leaving in question whether defects of concern, for example, bridging, overwrap winding anomalies, impact damage below visible threshold, out-of-family strain growth, and liner buckling have been adequately detected and monitored. To address these shortcomings, in 2005 the NASA Nondestructive Evaluation Working Group (NNWG) began funding work to develop and adopt standards for nondestructive evaluation of aerospace composites in collaboration with the American Society for Testing

  9. Evaluation and prediction of neutron embrittlement in reactor pressure vessel materials. Final report

    Hawthorne, J.R.; Menke, B.H.; Loss, F.J.; Watson, H.E.; Hiser, A.L.; Gray, R.A.

    1982-12-01

    This study evaluates the effects of fast neutron irradiation on the mechanical properties of eight nuclear reactor vessel materials. The materials include submerged arc weldments, three plates, and one forging. The materials are in the unirradiated and irradiated conditions with regard to tensile, Charpy impact, and static and dynamic fracture toughness properties. Correlations between impact and fracture toughness parameters are developed from the experimental results. The observed shifts in transition temperature and the drop in upper-shelf energy are compared with predictions developed from the Regulatory Guide 1.99.1 trend curves

  10. Reactor pressure vessel embrittlement management through EPRI-Developed material property databases

    Rosinski, S.T.; Server, W.L.; Griesbach, T.J.

    1997-01-01

    Uncertainties and variability in U.S. reactor pressure vessel (RPV) material properties have caused the U.S. Nuclear Regulatory Commission (NRC) to request information from all nuclear utilities in order to assess the impact of these data scatter and uncertainties on compliance with existing regulatory criteria. Resolving the vessel material uncertainty issues requires compiling all available data into a single integrated database to develop a better understanding of irradiated material property behavior. EPRI has developed two comprehensive databases for utility implementation to compile and evaluate available material property and surveillance data. RPVDATA is a comprehensive reactor vessel materials database and data management program that combines data from many different sources into one common database. Searches of the data can be easily performed to identify plants with similar materials, sort through measured test results, compare the ''best-estimates'' for reported chemistries with licensing basis values, quantify variability in measured weld qualification and test data, identify relevant surveillance results for characterizing embrittlement trends, and resolve uncertainties in vessel material properties. PREP4 has been developed to assist utilities in evaluating existing unirradiated and irradiated data for plant surveillance materials; PREP4 evaluations can be used to assess the accuracy of new trend curve predictions. In addition, searches of the data can be easily performed to identify available Charpy shift and upper shelf data, review surveillance material chemistry and fabrication information, review general capsule irradiation information, and identify applicable source reference information. In support of utility evaluations to consider thermal annealing as a viable embrittlement management option, EPRI is also developing a database to evaluate material response to thermal annealing. Efforts are underway to develop an irradiation

  11. Investigation and analysis on ITER in-vessel coils’ raw-materials

    Jin, Huan; Wu, Yu; Long, Feng; Yu, Min; Han, Qiyang; Liu, Huajun

    2013-01-01

    Highlights: • The R and D works for the ITER in-vessel coils (IVC) are now being conducted in Institute of Plasma Physics, and the analysis work are being done by Princeton Plasma Physics Laboratory. • There is little published paper about the raw materials for ITER IVC coils. • This manuscript points out the progress of the selected materials for ITER IVC coils. -- Abstract: The ITER in-vessel coils (IVCs) consist of 27 coils edge localized modes (ELM) and 2 coils vertical stabilization (VS) which are all mounted on the vacuum vessel wall behind the shield modules. The IVCs design and manufacturing work is being conducted in between Institute of Plasma Physics Chinese Academy of Sciences (ASIPP) and Princeton Plasma Physics Laboratory (PPPL). Because the position of ELM and VS coils is close and face to the plasma, the IVCs must undergo a severe environment, such as the high dose of radiation and high operation temperature, thus the conventional electrical insulation materials cannot be used. And the technology of “Stainless Steel Jacketed Mineral Insulated Conductor” (SSMIC) is deemed as the best choice to provide the necessary radiation resistance and compatibility strength in ITER's vacuum vessel. While mineral insulated conductor technology is not new, and is similar to the mineral insulated cable used in industrial. Some difficulties still need to be solved, such as searching for the proper raw-materials to make sure that the conductor have the properties of high current carrying capability, the necessary radiation resistance, the proper strength, at the same time, it must be come true in manufacture technology. This paper described the analysis of the materials for VS and ELM coil conductor

  12. Raw material variability as archaeological tools: Preliminary results from a geochemical study of the basalt vessel workshop at Iron Age Tel Hazor, Israel

    Tatjana Gluhak

    2016-10-01

    Full Text Available The discovery of a basalt vessel workshop at Tel Hazor, one of the most important Iron Age sites in the Near East, marks a turning point in our understanding of stone artifact production and distribution during the1st millennium BCE. It offers a rare opportunity to characterize ancient raw material sources, production sites, and study production, trade and distribution systems. The basalt vessel workshop, the only one of its kind in the Levant, produced large quantities of bowl preforms and production waste. To better understand the production and distribution systems behind this specialized production center, in 2011 we initiated a focused geochemical project that concentrated on the products of this unique workshop.  We measured the major and trace element composition of 44 unfinished basalt vessels from the workshop and other contexts at Hazor, and can demonstrate that the majority of these objects were derived from one specific, geochemically well-constrained, basaltic rock source. Only a few bowls clearly deviate from this geochemical composition and were produced using raw material from other sources. Thus, we believe that one major quarry existed that supplied the Hazor workshop with the majority of the basaltic raw material. The products from this specific extraction site provide us with a “Hazor reference group” that can be used to test whether or not finished vessels from Hazor and contemporary sites were produced in the Hazor workshop.

  13. Stratospheric experiments on curing of composite materials

    Chudinov, Viacheslav; Kondyurin, Alexey; Svistkov, Alexander L.; Efremov, Denis; Demin, Anton; Terpugov, Viktor; Rusakov, Sergey

    2016-07-01

    Future space exploration requires a large light-weight structure for habitats, greenhouses, space bases, space factories and other constructions. A new approach enabling large-size constructions in space relies on the use of the technology of polymerization of fiber-filled composites with a curable polymer matrix applied in the free space environment on Erath orbit. In orbit, the material is exposed to high vacuum, dramatic temperature changes, plasma of free space due to cosmic rays, sun irradiation and atomic oxygen (in low Earth orbit), micrometeorite fluence, electric charging and microgravitation. The development of appropriate polymer matrix composites requires an understanding of the chemical processes of polymer matrix curing under the specific free space conditions to be encountered. The goal of the stratospheric flight experiment is an investigation of the effect of the stratospheric conditions on the uncured polymer matrix of the composite material. The unique combination of low residual pressure, high intensity UV radiation including short-wave UV component, cosmic rays and other aspects associated with solar irradiation strongly influences the chemical processes in polymeric materials. We have done the stratospheric flight experiments with uncured composites (prepreg). A balloon with payload equipped with heater, temperature/pressure/irradiation sensors, microprocessor, carrying the samples of uncured prepreg has been launched to stratosphere of 25-30 km altitude. After the flight, the samples have been tested with FTIR, gel-fraction, tensile test and DMA. The effect of cosmic radiation has been observed. The composite was successfully cured during the stratospheric flight. The study was supported by RFBR grants 12-08-00970 and 14-08-96011.

  14. Using Composite Materials in a Cryogenic Pump

    Batton, William D.; Dillard, James E.; Rottmund, Matthew E.; Tupper, Michael L.; Mallick, Kaushik; Francis, William H.

    2008-01-01

    Several modifications have been made to the design and operation of an extended-shaft cryogenic pump to increase the efficiency of pumping. In general, the efficiency of pumping a cryogenic fluid is limited by thermal losses which is itself caused by pump inefficiency and leakage of heat through the pump structure. A typical cryogenic pump includes a drive shaft and two main concentric static components (an outer pressure containment tube and an intermediate static support tube) made from stainless steel. The modifications made include replacement of the stainless-steel drive shaft and the concentric static stainless-steel components with components made of a glass/epoxy composite. The leakage of heat is thus reduced because the thermal conductivity of the composite is an order of magnitude below that of stainless steel. Taking advantage of the margin afforded by the decrease in thermal conductivity, the drive shaft could be shortened to increase its effective stiffness, thereby increasing the rotordynamic critical speeds, thereby further making it possible to operate the pump at a higher speed to increase pumping efficiency. During the modification effort, an analysis revealed that substitution of the shorter glass/epoxy shaft for the longer stainless-steel shaft was not, by itself, sufficient to satisfy the rotordynamic requirements at the desired increased speed. Hence, it became necessary to increase the stiffness of the composite shaft. This stiffening was accomplished by means of a carbon-fiber-composite overwrap along most of the length of the shaft. Concomitantly with the modifications described thus far, it was necessary to provide for joining the composite-material components with metallic components required by different aspects of the pump design. An adhesive material formulated specially to bond the composite and metal components was chosen as a means to satisfy these requirements.

  15. The elastic response of composite materials

    Laws, N.

    1980-01-01

    The theory of linear elasticity is used to study the elastic response of composite materials. The main concern is the prediction of overall moduli. Some attention is paid to the problem of deciding upon when the idea of an overall modulus is meaningful. In addition it is shown how to calculate some rigorous bounds on the overall moduli, and some predictions of the self-consistent method are discussed. The paper mainly concentrates on isotropic dispersions of spheres, unidirectional fibre-reinforced materials and laminates. (author)

  16. A new approach for modeling composite materials

    Alcaraz de la Osa, R.; Moreno, F.; Saiz, J. M.

    2013-03-01

    The increasing use of composite materials is due to their ability to tailor materials for special purposes, with applications evolving day by day. This is why predicting the properties of these systems from their constituents, or phases, has become so important. However, assigning macroscopical optical properties for these materials from the bulk properties of their constituents is not a straightforward task. In this research, we present a spectral analysis of three-dimensional random composite typical nanostructures using an Extension of the Discrete Dipole Approximation (E-DDA code), comparing different approaches and emphasizing the influences of optical properties of constituents and their concentration. In particular, we hypothesize a new approach that preserves the individual nature of the constituents introducing at the same time a variation in the optical properties of each discrete element that is driven by the surrounding medium. The results obtained with this new approach compare more favorably with the experiment than previous ones. We have also applied it to a non-conventional material composed of a metamaterial embedded in a dielectric matrix. Our version of the Discrete Dipole Approximation code, the EDDA code, has been formulated specifically to tackle this kind of problem, including materials with either magnetic and tensor properties.

  17. Advanced Technology Composite Fuselage - Materials and Processes

    Scholz, D. B.; Dost, E. F.; Flynn, B. W.; Ilcewicz, L. B.; Nelson, K. M.; Sawicki, A. J.; Walker, T. H.; Lakes, R. S.

    1997-01-01

    The goal of Boeing's Advanced Technology Composite Aircraft Structures (ATCAS) program was to develop the technology required for cost and weight efficient use of composite materials in transport fuselage structure. This contractor report describes results of material and process selection, development, and characterization activities. Carbon fiber reinforced epoxy was chosen for fuselage skins and stiffening elements and for passenger and cargo floor structures. The automated fiber placement (AFP) process was selected for fabrication of monolithic and sandwich skin panels. Circumferential frames and window frames were braided and resin transfer molded (RTM'd). Pultrusion was selected for fabrication of floor beams and constant section stiffening elements. Drape forming was chosen for stringers and other stiffening elements. Significant development efforts were expended on the AFP, braiding, and RTM processes. Sandwich core materials and core edge close-out design concepts were evaluated. Autoclave cure processes were developed for stiffened skin and sandwich structures. The stiffness, strength, notch sensitivity, and bearing/bypass properties of fiber-placed skin materials and braided/RTM'd circumferential frame materials were characterized. The strength and durability of cocured and cobonded joints were evaluated. Impact damage resistance of stiffened skin and sandwich structures typical of fuselage panels was investigated. Fluid penetration and migration mechanisms for sandwich panels were studied.

  18. Three-Dimensional Digital Image Correlation of a Composite Overwrapped Pressure Vessel During Hydrostatic Pressure Tests

    Revilock, Duane M., Jr.; Thesken, John C.; Schmidt, Timothy E.

    2007-01-01

    Ambient temperature hydrostatic pressurization tests were conducted on a composite overwrapped pressure vessel (COPV) to understand the fiber stresses in COPV components. Two three-dimensional digital image correlation systems with high speed cameras were used in the evaluation to provide full field displacement and strain data for each pressurization test. A few of the key findings will be discussed including how the principal strains provided better insight into system behavior than traditional gauges, a high localized strain that was measured where gages were not present and the challenges of measuring curved surfaces with the use of a 1.25 in. thick layered polycarbonate panel that protected the cameras.

  19. Nuclear reactor pressure vessel surveillance capsule examinations. Application of American Society for Testing and Materials Standards

    Perrin, J.S.

    1978-01-01

    A series of pressure vessel surveillance capsules is installed in each commercial nuclear power plant in the United States. A capsule typically contains neutron dose meters, thermal monitors, tensile specimens, and Charpy V-notch impact specimens. In order to determine property changes of the pressure vessel resulting from irradiation, surveillance capsules are periodically removed during the life of a reactor and examined. There are numerous standards, regulations, and codes governing US pressure vessel surveillance capsule programmes. These are put out by the US Nuclear Regulatory Commission, the Boiler and Pressure Vessel Committee of the American Society of Mechanical Engineers, and the American Society for Testing and Materials (ASTM). A majority of the pertinent ASTM standards are under the jurisdiction of ASTM Committee E-10 on Nuclear Applications and Measurements of Radiation Effects. The standards, regulations, and codes pertaining to pressure vessel surveillance play an important role in ensuring reliability of the nuclear pressure vessels. ASTM E 185-73 is the Standard Recommended Practice for Surveillance Tests for Nuclear Reactors. This standard recommends procedures for both the irradiation and subsequent testing of surveillance capsules. ASTM E 185-73 references many additional specialized ASTM standards to be followed in specific areas of a surveillance capsule examination. A key element of surveillance capsule programmes is the Charpy V-notch impact test, used to define curves of fracture behaviour over a range of temperatures. The data from these tests are used to define the adjusted reference temperature used in determining pressure-temperature operating curves for a nuclear power plant. (author)

  20. Improved Materials for Composite and Adhesive Joints.

    1984-07-01

    Analysis of Thick Composites," 28th National Society for Advancement of Material and Process Engineering Symposium, Disneyland Hotel, Anaheim... Grant , "Deconvolution as an Aid to Quantification in Electron Spectroscopy Studies of Surfaces and Thin Films," IX International Vacuum Congress, V...International Conference on Solid Surfaces, Madrid, Spain, Sept. 26-Oct. 1, 1983. 8. M. F. Koenig and J. T. Grant , "Direct Comparison of Deconvoluted

  1. Alkali metal protective garment and composite material

    Ballif, III, John L.; Yuan, Wei W.

    1980-01-01

    A protective garment and composite material providing satisfactory heat resistance and physical protection for articles and personnel exposed to hot molten alkali metals, such as sodium. Physical protection is provided by a continuous layer of nickel foil. Heat resistance is provided by an underlying backing layer of thermal insulation. Overlying outer layers of fireproof woven ceramic fibers are used to protect the foil during storage and handling.

  2. Thermally Conductive Structural 2D Composite Materials

    2012-08-14

    Dimensional Pitch Polyimide Composite Micrographs ........ 27 Figure 23. 4-Ply Silver Polyimide Laminate ...through-thickness thermal conductivity of up to 20 W/m.K. This novel structural prepreg material will be developed through engineering of an optimal fiber...with an EPON 862/Epikure W epoxy resin system to form unidirectional prepreg tapes. Each prepreg was then cut to 6 inch by 6 inch plies and

  3. Nanocellulose Composite Materials Synthesizes with Ultrasonic Agitation

    Kidd, Timothy; Folken, Andrew; Fritch, Byron; Bradley, Derek

    We have extended current techniques in forming nanocellulose composite solids, suspensions and aerogels to enhance the breakdown of cellulose into its molecular components. Using only mechanical processing which includes ball milling, using a simple mortar and pestle, and ultrasonic agitation, we are able to create very low concentration uniform nanocellulose suspensions in water, as well as incorporate other materials such as graphite, carbon nanotubes, and magnetic materials. Of interest is that no chemical processing is necessary, nor is the use of nanoparticles, necessary for composite formation. Using both graphite and carbon nanotubes, we are able to achieve conducting nanocellulose solids and aerogels. Standard magnetic powder can also be incorporated to create magnetic solids. The technique also allows for the creation of an extremely fine nanocellulose suspension in water. Using extremely low concentrations, less than 1% cellulose by mass, along with careful control over processing parameters, we are able to achieve highly dilute, yet homogenous nanocellulose suspensions. When air dried, these suspensions have similar hardness and strength properties to those created with more typical starting cellulose concentrations (2-10%). However, when freeze-dried, these dilute suspensions form aerogels with a new morphology with much higher surface area than those with higher starting concentrations. We are currently examining the effect of this higher surface area on the properties of nanocellulose aerogel composites and how it influences the impact of incorporating nanocellulose into other polymer materials.

  4. Safety Evaluation Report: Development of Improved Composite Pressure Vessels for Hydrogen Storage, Lincoln Composites, Lincoln, NE, May 25, 2010

    Fort, III, William C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kallman, Richard A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Maes, Miguel [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Skolnik, Edward G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weiner, Steven C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2010-12-22

    Lincoln Composites operates a facility for designing, testing, and manufacturing composite pressure vessels. Lincoln Composites also has a U.S. Department of Energy (DOE)-funded project to develop composite tanks for high-pressure hydrogen storage. The initial stage of this project involves testing the permeation of high-pressure hydrogen through polymer liners. The company recently moved and is constructing a dedicated research/testing laboratory at their new location. In the meantime, permeation tests are being performed in a corner of a large manufacturing facility. The safety review team visited the Lincoln Composites site on May 25, 2010. The project team presented an overview of the company and project and took the safety review team on a tour of the facility. The safety review team saw the entire process of winding a carbon fiber/resin tank on a liner, installing the boss and valves, and curing and painting the tank. The review team also saw the new laboratory that is being built for the DOE project and the temporary arrangement for the hydrogen permeation tests.

  5. Elution of Monomers from Provisional Composite Materials

    Simon Daniel Schulz

    2015-01-01

    Full Text Available The aim of this study was to evaluate the elution of substances from different materials used for the manufacturing of temporary indirect restorations, after storage in saliva and ethanol 75%. 10 samples of three chemically cured materials (Protemp 3 Garant, Systemp.c&b, and Trim and one light-cured material (Clip F were stored in saliva and ethanol 75% for 24 h, 7, and days 28 days. From the storage media at each time period, samples were prepared and analysed by LC-MS/MS, in order to access the elution of monomers. The results differed among the materials (P ≤ 0.05. No monomers were detected in the samples of Protemp 3 Garant and Clip F. Substances were detected only in ethanol samples of Systemp.c&b and Trim. The amount of BisGMA, TEGDMA, and UDMA 2 released from Systemp.c&b was higher compared to Trim. Storage time affected the release of substances (P ≤ 0.05. The highest release was observed within the first 24 h. It can be concluded that provisional resin composite materials do not show high release of monomers and this release is material dependent. However, the detection of additional peaks during the analysis, suggesting the formation of by-products of the eluted substances, may not be in favour of these materials with respect to their toxicity.

  6. Development of active and sensitive material systems based on composites

    Asanuma, Hiroshi

    2002-07-01

    This paper describes new concepts proposed by the author to realize active and sensitive structural material systems. Two examples of multifunctional composites were fabricated and evaluated in this study as follows: (1) An active laminate of aluminum plate (works as muscle), epoxy film (as insulator), unidirectional CFRP prepreg (as bone and blood vessel) and copper foil electrode (to apply voltage on CFRP) was made with an embedded optical fiber multiply fractured in the CFRP layer (works as nerve), of which curvature change could be effectively monitored with the fractured optical fiber. (2) A stainless steel fiber/aluminum active composite with embedded Ti oxide/Ti composite fiber was fabricated. The Ti oxide/Ti fiber could work as a sensor for temperature by removing a part of the oxide before embedment to make a metallic contact between the embedded titanium fiber and aluminum matrix to be able to generate thermal electromotive force, and also could work as a sensor for strain and as a heater for actuation. In the both cases, the outputs from their embedded sensors can be used to control their actuations.

  7. Experimental Validation of Ex-Vessel Neutron Spectrum by Means of Dosimeter Materials Activation Method

    S.A. Santa

    2017-06-01

    Full Text Available Neutron spectrum information in reactor core and around of ex-vessel reactor needs to be known with a certain degree of accuracy to support the development of fuels, materials, and other components. The most common method to determine neutron spectra is by utilizing the radioactivation of dosimeter materials. This report presents the evaluation of neutron flux incident on M3dosimeter sets which were irradiated outside the reactor vessel,as well as the validation of  neutron spectrum calculation. Al capsules containing both dosimeter set covered withCd and dosimeter set without Cd cover have been irradiated during the 35th operational cycle in the M3 ex-vessel irradiation hole position207 cmfrom core centerline at the space between the reactor vessel and the safety vessel. The capsules were positioned at Z=0.0 cm of core midplane. Each dosimeter set consists of Co-Al, Sc, Fe, Np, Nb, Ni, B, and Ta. The gamma-ray spectra of irradiated dosimeter materials were measured by 63 cc HPGe solid-state detector and photo-peak spectra were analyzed using BOB75 code. The reaction rates of each dosimeter materials and its uncertainty were analyzed based on 59Co (n,g 60Co, 237Np (n,f 95Zr-103Ru,  45Sc (n,g 46Sc, 58Fe (n,g 59Fe, 181Ta (n,g 182Ta, and 58Ni (n,p58Co reactions. The measured Cd ratios indicate that neutron spectrum at the irradiated dosimeter sets was dominated by low energy neutron. The experimental result shows that the calculated neutron spectra by DORT code at the ex-vessel positions need correction, especially in the fast neutron energy region, so as to obtain reasonable unfolding result consistent with the reaction rate measurement without any exception. Using biased DORT initial spectrum, the neutron spectrum and its integral quantity were unfolded by NEUPAC code. The result shows that total neutron flux, flux above 1.0 MeV, flux above 0.1 MeV, and the displacement rate of the dosimeter set not covered with Cd were 1.75× 1012 n cm2 s-1, 1

  8. Evaluation of fatigue damage of pressure vessel materials by observation of microstructures

    Yoshida, Kazuo

    1994-01-01

    As the important factor as the secular change mode of pressure vessel materials, there is fatigue damage. In USA, there is the move to use LWRs by extending their life, and it becomes necessary to show the soundness of the structures of machinery and equipment for long period. For exactly evaluating the soundness of the structures of machinery and equipment, it is important to clarify the degree of secular deterioration of the materials. In this report, by limiting to the fatigue damage of LWR pressure vessel steel, the method of grasping the change of microstructure and the method of estimating the degree of fatigue damage from the change of microstructure are shown. The change of microstructure arising in materials due to fatigue advances in the following steps, namely, the multiplication of dislocations, the tangling of dislocations, the formation of cell structure, the turning of cells, the formation of microcracks, the growth of cracks and fracture. In the case of pressure vessel steel, due to the quenching and tempering, the cell structure is formed from the beginning, and the advance of fatigue is recognized as the increase of the turning angle of cell structures. The detection of fatigue damage by microstructure is reported. (K.I.)

  9. Synthesizing Smart Polymeric and Composite Materials

    Gong, Chaokun

    Smart materials have been widely investigated to explore new functionalities unavailable to traditional materials or to mimic the multifunctionality of biological systems. Synthetic polymers are particularly attractive as they already possess some of the attributes required for smart materials, and there are vast room to further enhance the existing properties or impart new properties by polymer synthesis or composite formulation. In this work, three types of smart polymer and composites have been investigated with important new applications: (1) healable polymer composites for structural application and healable composite conductor for electronic device application; (2) conducting polymer polypyrrole actuator for implantable medical device application; and (3) ferroelectric polymer and ceramic nanoparticles composites for electrocaloric effect based solid state refrigeration application. These application entail highly challenging materials innovation, and my work has led to significant progress in all three areas. For the healable polymer composites, well known intrinsically healable polymer 2MEP4F (a Diels-Alder crosslinked polymer formed from a monomer with four furan groups and another monomer with two maleimide groups) was first chosen as the matrix reinforced with fiber. Glass fibers were successfully functionalized with maleimide functional groups on their surface. Composites from functionalized glass fibers and 2MEP4F healable polymer were made to compare with composites made from commercial carbon fibers and 2MEP4F polymer. Dramatically improved short beam shear strength was obtained from composite of functionalized glass fibers and 2MEP4F polymer. The high cost of 2MEP4F polymer can potentially limit the large-scale application of the developed healable composite, we further developed a new healable polymer with much lower cost. This new polymer was formed through the Diels-Alder crosslinking of poly(furfuryl alcohol) (PFA) and 1,1'-(Methylenedi-4

  10. Contribution of materials investigations and operating experience of reactor vessel internals to PWRs' safety, performance and reliability

    Lemaire, E.; Monteil, N.; Jardin, N.; Doll, M.

    2015-01-01

    The Reactor Pressure Vessel Internals (RVI) include all the components inside the pressure vessel, except the nuclear fuel, the rod cluster assemblies and the instrumentation. The RVI consist of bolted and welded structures that are divided into two sub-assemblies: the upper internals which are removed at every refueling outage and the lower internals which are systematically removed for inspection at every 10-year outage. The main functions of the RVI are to position the core, to support it, and to provide a coolant flow by channeling the fluid. Moreover, the lower internals contribute to a neutron protection of the reactor pressure vessel by absorbing most of the neutron flux from the core. Depending on their location and material composition, the RVI components can face different ageing phenomena, that are actual or potential (such as wear, fatigue, stress corrosion cracking, irradiation assisted stress corrosion cracking, hardening and loss of ductility due to neutron irradiation, irradiation creep and irradiation swelling). EDF has developed a strategy for managing ageing and demonstrating the capacity of the RVI to perform their design functions over 40 years of operation. This overall approach is periodically revisited to take into account the most recent knowledge obtained from the following main topics: Safety Analyses, Research-Development programs, In-Service Inspection (ISI) results, Maintenance programs and Metallurgical Examinations. Based on continuous improvements in those fields, the goal of this paper is to present the way that materials investigations and operating experience obtained on RVI are managed by EDF to improve RVI safety, performance and reliability. It is shown that a perspective of 60 years of operation of RVI components is supported by large Research-Development efforts combined with field experience. (authors)

  11. Gamma irradiation technology for composite materials

    Romero, Guillermo R; Gonzalez, Maria E.

    2003-01-01

    A composite of sugar cane bagasse and low-density polyethylene was prepared. Gamma -radiation of Cobalt-60 (Co 60 ) and reactive additives were used, to make compatible the lignocellulosic fibers with the polymeric matrix. Gamma-radiation was applied in different stages with different purposes: a) Irradiation of cellulosic fibers treated or not with reactive additive, in presence of air, to produce macro radicals increasing their reactivity during extrusion with polyethylene. A homogeneous and fusible material resulted that can be used as raw material in thermoforming processes with cost in between that of its constitutive elements; b) Irradiation of final products, to produce the cross-linking of polymeric chains. The fibers remain trapped in the cross-linked matrix. A homogeneous and infusible material with high mechanical properties was obtained. (author)

  12. Properties of nanoclay PVA composites materials

    Mohamed H. M. Ali

    2012-03-01

    Full Text Available Polyvinyl alcohol (PVA/ Na-rich Montmorillonite (MMT nanocomposites were prepared using solution method to create polymer-clay nanocomposite (PCN material. The PCN material was studied using X-ray diffraction (XRD, demonstrating polymer-clay intercalation that has a high d-spacing (lower diffraction angles in the PCN XRD pattern, compared to the pure MMT clay XRD pattern, which has a low d-spacing (high diffraction angles. The nano-scanning electron microscope (NSEM was used to study the morphological image of the PVA, MMT and PCN materials. The results showed that intercalation that took place between the PVA and MMT produced the PCN material. The mechanical properties of the pure PVA and the intercalated polymer material were studied. It was found that the small amount of MMT clay made the tensile modulus and percentage of the total elongation of the nano-composite significantly higher than the pure PVA polymer value, due to polymer-clay intercalation. The thermal stability of the intercalated polymer has been studied using thermal analytical techniques such as thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. The results showed that the PCN material is more thermally stable than the pure PVA polymer.

  13. Research on the preparation, biocompatibility and bioactivity of magnesium matrix hydroxyapatite composite material.

    Linsheng, Li; Guoxiang, Lin; Lihui, Li

    2016-08-12

    In this paper, magnesium matrix hydroxyapatite composite material was prepared by electrophoretic deposition method. The optimal process parameters of electrophoretic deposition were HA suspension concentration of 0.02 kg/L, aging time of 10 days and voltage of 60 V. Animal experiment and SBF immersion experiment were used to test the biocompatibility and bioactivity of this material respectively. The SD rats were divided into control group and implant group. The implant surrounding tissue was taken to do tissue biopsy, HE dyed and organizational analysis after a certain amount of time in the SD rat body. The biological composite material was soaked in SBF solution under homeothermic condition. After 40 days, the bioactivity of the biological composite material was evaluated by testing the growth ability of apatite on composite material. The experiment results showed that magnesium matrix hydroxyapatite biological composite material was successfully prepared by electrophoretic deposition method. Tissue hyperplasia, connective tissue and new blood vessels appeared in the implant surrounding soft tissue. No infiltration of inflammatory cells of lymphocytes and megakaryocytes around the implant was found. After soaked in SBF solution, a layer bone-like apatite was found on the surface of magnesium matrix hydroxyapatite biological composite material. The magnesium matrix hydroxyapatite biological composite material could promot calcium deposition and induce bone-like apatite formation with no cytotoxicity and good biocompatibility and bioactivity.

  14. Ultimate load analysis of prestressed concrete reactor pressure vessels considering a general material law

    Schimmelpfennig, K.

    1975-01-01

    A method of analysis is presented, by which progressive fracture processes in axisymmetric prestressed concrete pressure vessels during increasing internal pressure can be evaulated by means of a continuum calculation considering a general material law. Formulations used in the analysis concerning material behaviour are derived on one hand from appropriate results of testing small concrete specimens, and are on the other hand gained by parametric studies in order to solve questions still existing by recalulating fracture tests on concrete bodies with more complex states of stress. Due attention is focussed on investigating the behaviour of construction members subjected to high shear forces (end slabs.). (Auth.)

  15. Industry to Education Technical Transfer Program & Composite Materials. Composite Materials Course. Fabrication I Course. Fabrication II Course. Composite Materials Testing Course. Final Report.

    Massuda, Rachel

    These four reports provide details of projects to design and implement courses to be offered as requirements for the associate degree program in composites and reinforced plastics technology. The reports describe project activities that led to development of curricula for four courses: composite materials, composite materials fabrication I,…

  16. Foam/Aerogel Composite Materials for Thermal and Acoustic Insulation and Cryogen Storage

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Weiser, Erik S. (Inventor); Sass, Jared P. (Inventor)

    2011-01-01

    The invention involves composite materials containing a polymer foam and an aerogel. The composite materials have improved thermal insulation ability, good acoustic insulation, and excellent physical mechanical properties. The composite materials can be used, for instance, for heat and acoustic insulation on aircraft, spacecraft, and maritime ships in place of currently used foam panels and other foam products. The materials of the invention can also be used in building construction with their combination of light weight, strength, elasticity, ability to be formed into desired shapes, and superior thermal and acoustic insulation power. The materials have also been found to have utility for storage of cryogens. A cryogenic liquid or gas, such as N.sub.2 or H.sub.2, adsorbs to the surfaces in aerogel particles. Thus, another embodiment of the invention provides a storage vessel for a cryogen.

  17. Micromechanical models for graded composite materials

    Reiter, T; Dvorak, G.J.; Tvergaard, Viggo

    1997-01-01

    of piecewise homogeneous layers with equivalent elastic properties estimated by Mori-Tanaka and self-consistent methods are also analysed under similar boundary conditions. Comparisons of the overall and local fields predicted by the discrete and homogenized models are made using a C/SiC composite system...... fields are predicted by Mori-Tanaka estimates. On the other hand, the response of graded materials with a skeletal microstructure in a wide transition zone between clearly defined matrix phases is better approximated by the self-consistent estimates. Certain exceptions are noted for loading by overall...... transverse shear stress; The results suggest that the averaging methods originally developed for statistically homogeneous aggregates may be selectively applied, with a reasonable degree of confidence, to aggregates dth composition gradients, subjected to both uniform and nonuniform overall loads. (C) 1997...

  18. Glasses, ceramics, and composites from lunar materials

    Beall, George H.

    1992-01-01

    A variety of useful silicate materials can be synthesized from lunar rocks and soils. The simplest to manufacture are glasses and glass-ceramics. Glass fibers can be drawn from a variety of basaltic glasses. Glass articles formed from titania-rich basalts are capable of fine-grained internal crystallization, with resulting strength and abrasion resistance allowing their wide application in construction. Specialty glass-ceramics and fiber-reinforced composites would rely on chemical separation of magnesium silicates and aluminosilicates as well as oxides titania and alumina. Polycrystalline enstatite with induced lamellar twinning has high fracture toughness, while cordierite glass-ceramics combine excellent thermal shock resistance with high flexural strengths. If sapphire or rutile whiskers can be made, composites of even better mechanical properties are envisioned.

  19. Radioactive material-containing vessel and method of manufacturing the same

    Kanazawa, Hiroshi; Wada, Katsuyoshi; Ota, Shigeo; Nishioka, Eiji; Okuno, Michinori.

    1995-01-01

    In a vessel for containing radioactive materials having an outer wall with a structure of interposing a lead layer, as a shielding material between inner and outer cylinders made of steel plates, the inner cylinder and the lead layer are in close contact by way of a thin layer of a lead/tin type soldering material and to such an extent that the boundary layer is not detected by supersonic inspection. In addition, flux is coated to the steel plate, which forms the inner cylinder, on the surface being in contact with the lead layer, then a thin layer of the soldering material such as lead or tin is formed, to cast the lead between the inner and the outer cylinders. Then, since the inner cylinder and the lead layer are thermally joined tightly, heat generated at the inside can effectively be released to the outside, so that it is effective as a high-performance cask for transporting a large amount of radioactive materials such as spent nuclear fuels having high temperature afterheat. In addition, a containing vessel with good contact between the inner cylinder and the lead can be manufactured at a low cost only applying a simple primer treatment on the surface of the inner cylinder in addition to an existent lead casting method. (N.H.)

  20. Irradiation experiments on materials for core internals, pressure vessel and fuel cladding

    Tsukada, Takashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Materials degradation due to the aging phenomena is one of the key issues for the life assessment and extension of the light water reactors (LWRs). This presentation introduces JAERI`s activities in the field of LWR material researches which utilize the research and testing reactors for irradiation experiments. The activities are including the material studies for the core internals, pressure vessel and fuel cladding. These materials are exposed to the neutron/gamma radiation and high temperature water environments so that it is worth reviewing their degradation phenomena as the continuum. Three topics are presented; For the core internal materials, the irradiation assisted stress corrosion cracking (IASCC) of austenitic stainless steels is the present major concern. At JAERI the effects of alloying elements on IASCC have been investigated through the post-irradiation stress corrosion cracking tests in high-temperature water. The radiation embrittlement of pressure vessel steels is still a significant issue for LWR safety, and at JAERI some factors affecting the embrittlement behavior such as a dose rate have been investigated. Waterside corrosion of Zircaloy fuel cladding is one of the limiting factors in fuel rod performance and an in-situ measurement of the corrosion rate in high-temperature water was performed in JMTR. To improve the reliability of experiments and to extent the applicability of experimental techniques, a mutual utilization of the technical achievements in those irradiation experiments is desired. (author)

  1. Characterization of material composite marble-polyester

    Corpas, F. A.

    2002-12-01

    Full Text Available In this work we characterize a new material composite, formed with a polyester and crushed white marble mixture. The final purpose is double: to obtain a material for applications sufficiently competitive after an economic viability study, increasing the yield of the main commodity, using waste marble and improving the jobs in the quarries area. From the results obtained, we deduce then that this material could be used to inside and outside adornment.

    En este trabajo, caracterizamos un nuevo material compuesto, formado con una mezcla de poliéster y de mármol blanco triturado. El propósito final es doble: por un lado obtener un material para aplicaciones lo suficientemente competitivas como para que se pueda iniciar un estudio económico de viabilidad, aumentando el rendimiento de la materia prima y mejorando las salidas laborales de las comarcas extractoras. Para la caracterización del material se ha determinado el porcentaje adecuado de poliéster. Así como las propiedades mecánicas (flexión, compresión y dureza, químicas, fatiga térmica y su influencia a la exposición solar In order to characterized of material, we have determined the suitable porcentage of polyester Also we have carried out a study of the mechanical (stretching, resistance to traction, hardeness and thermal fatigue chemicals properties and solar radiation influence. De los resultados obtenidos, este material podría ser utilizado para ornamentación tanto de interior como de exterior.

  2. Heavy section steel technology program technical report No. 38. Fracture toughness characterization of HSST intermediate pressure vessel material

    Mager, T.R.; Yanichko, S.E.; Singer, L.R.

    1974-12-01

    The primary objective of the Heavy Section Steel Technology (HSST) Program is to develop pertinent fracture technology to demonstrate the structural reliability of present and contemplated water-cooled nuclear reactor pressure vessels. In order to demonstrate the ability to predict failure of large, heavy-walled pressure vessels under service type loading conditions, the fracture toughness properties of the vessel's materials must be characterized. The sampling procedure and test results are presented for vessel material supplied by the Oak Ridge National Laboratory that were used to characterize the fracture toughness of the HSST Intermediate Test Vessels. The metallurgical condition and heat treatment of the test material was representative of the vessel simulated service test condition. Test specimen locations and orientations were selected by the Oak Ridge National Laboratory and are representative of flaw orientations incorporated in the test vessels. The fracture toughness is documented for the materials from each of the eight HSST Intermediate Pressure Vessels tested to date. 7 references. (U.S.)

  3. In-Situ Nondestructive Evaluation of Kevlar(Registered Trademark)and Carbon Fiber Reinforced Composite Micromechanics for Improved Composite Overwrapped Pressure Vessel Health Monitoring

    Waller, Jess; Saulsberry, Regor

    2012-01-01

    NASA has been faced with recertification and life extension issues for epoxy-impregnated Kevlar 49 (K/Ep) and carbon (C/Ep) composite overwrapped pressure vessels (COPVs) used in various systems on the Space Shuttle and International Space Station, respectively. Each COPV has varying criticality, damage and repair histories, time at pressure, and pressure cycles. COPVs are of particular concern due to the insidious and catastrophic burst-before-leak failure mode caused by stress rupture (SR) of the composite overwrap. SR life has been defined [1] as the minimum time during which the composite maintains structural integrity considering the combined effects of stress level(s), time at stress level(s), and associated environment. SR has none of the features of predictability associated with metal pressure vessels, such as crack geometry, growth rate and size, or other features that lend themselves to nondestructive evaluation (NDE). In essence, the variability or surprise factor associated with SR cannot be eliminated. C/Ep COPVs are also susceptible to impact damage that can lead to reduced burst pressure even when the amount of damage to the COPV is below the visual detection threshold [2], thus necessitating implementation of a mechanical damage control plan [1]. Last, COPVs can also fail prematurely due to material or design noncompliance. In each case (SR, impact or noncompliance), out-of-family behavior is expected leading to a higher probability of failure at a given stress, hence, greater uncertainty in performance. For these reasons, NASA has been actively engaged in research to develop NDE methods that can be used during post-manufacture qualification, in-service inspection, and in-situ structural health monitoring. Acoustic emission (AE) is one of the more promising NDE techniques for detecting and monitoring, in real-time, the strain energy release and corresponding stress-wave propagation produced by actively growing flaws and defects in composite

  4. Composite materials for thermal energy storage

    Benson, D. K.; Burrows, R. W.; Shinton, Y. D.

    1985-01-01

    A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations are discussed. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

  5. Composite materials for thermal energy storage

    Benson, D.K.; Burrows, R.W.; Shinton, Y.D.

    1985-01-04

    A composite material for thermal energy storage based upon polyhydric alcohols, such as pentaerythritol, trimethylol ethane (also known as pentaglycerine), neopentyl glycol and related compounds including trimethylol propane, monoaminopentaerythritol, diamino-pentaerythritol and tris(hydroxymethyl)acetic acid, separately or in combinations, which provide reversible heat storage through crystalline phase transformations. These PCM's do not become liquid during use and are in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, porous rock, and mixtures thereof. Particulate additions such as aluminum or graphite powders, as well as metal and carbon fibers can also be incorporated therein. Particulate and/or fibrous additions can be introduced into molten phase change materials which can then be cast into various shapes. After the phase change materials have solidified, the additions will remain dispersed throughout the matrix of the cast solid. The polyol is in contact with at least one material selected from the group consisting of metals, carbon, siliceous, plastic, cellulosic, natural fiber, artificial fiber, concrete, gypsum, and mixtures thereof.

  6. Carbon Fiber Composite Materials for Automotive Applications

    Norris, Jr., Robert E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mainka, Hendrik [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-06-01

    Volkswagen (VW) is internationally recognized for quantity and quality of world-wide vehicle production and the Oak Ridge National Laboratory (ORNL) is internationally recognized in materials research and development. With automotive production ramping up in the recently constructed VW Group of America facility in Chattanooga, Tennessee, ORNL and VW initiated discussions in 2012 concerning opportunities for collaboration around ORNL’s carbon fiber and composites programs. ORNL is conducting an internationally recognized program to develop and implement lower cost carbon fibers and composites for automotive and other “energy missions” for the US Department of Energy. Significant effort is ongoing in selecting, developing, and evaluating alternative precursors, developing and demonstrating advanced conversion techniques, and developing and tailoring surface treatment, sizings, and formatting fiber for specific composite matrices and end-use applications. ORNL already had North America’s most comprehensive suite of tools for carbon fiber research and development and established a semiproduction demonstration line referred to as the Carbon Fiber Technology Facility (CFTF) to facilitate implementation of low cost carbon fiber (LCCF) approaches in early 2013. ORNL and VW agreed to collaborate in a formal Cooperative Research and Development Agreement (NFE-12-03992) specifically focused on evaluating applicability of low cost carbon fiber products for potential vehicle components. The goal of the work outlined in this report was to develop and qualify uses for carbon fiber-reinforced structures in connection with civilian ground transportation. Significant progress was achieved in evaluating and understanding lignin-based precursor materials; however, availability of carbon fiber converted from lignin precursor combined with logistical issues associated with the Visa limitations for the VW participant resulted in significantly shortening of the collaboration

  7. Ceramic Matrix Composite (CMC) Materials Characterization

    Calomino, Anthony

    2001-01-01

    Under the former NASA EPM Program, much initial progress was made in identifying constituent materials and processes for SiC/SiC ceramic composite hot-section components. This presentation discusses the performance benefits of these approaches and elaborates on further constituent and property improvements made under NASA UEET. These include specific treatments at NASA that significantly improve the creep and environmental resistance of the Sylramic(TM) SiC fiber as well as the thermal conductivity and creep resistance of the CVI Sic matrix. Also discussed are recent findings concerning the beneficial effects of certain 2D-fabric architectures and carbon between the BN interphase coating and Sic matrix.

  8. Ceramic Matrix Composite (CMC) Materials Development

    DiCarlo, James

    2001-01-01

    Under the former NASA EPM Program, much initial progress was made in identifying constituent materials and processes for SiC/SiC ceramic composite hot-section components. This presentation discusses the performance benefits of these approaches and elaborates on further constituent and property improvements made under NASA UEET. These include specific treatments at NASA that significantly improve the creep and environmental resistance of the Sylramic(TM) Sic fiber as well as the thermal conductivity and creep resistance of the CVI Sic matrix. Also discussed are recent findings concerning the beneficial effects of certain 2D-fabric architectures and carbon between the BN interphase coating and Sic matrix.

  9. Intelligent Image Segment for Material Composition Detection

    Liang Xiaodan

    2017-01-01

    Full Text Available In the process of material composition detection, the image analysis is an inevitable problem. Multilevel thresholding based OTSU method is one of the most popular image segmentation techniques. How, with the increase of the number of thresholds, the computing time increases exponentially. To overcome this problem, this paper proposed an artificial bee colony algorithm with a two-level topology. This improved artificial bee colony algorithm can quickly find out the suitable thresholds and nearly no trap into local optimal. The test results confirm it good performance.

  10. Numerical investigations on pressurized AL-composite vessel response to hypervelocity impacts: Comparison between experimental works and a numerical code

    Mespoulet Jérôme

    2015-01-01

    Full Text Available Response of pressurized composite-Al vessels to hypervelocity impact of aluminum spheres have been numerically investigated to evaluate the influence of initial pressure on the vulnerability of these vessels. Investigated tanks are carbon-fiber overwrapped prestressed Al vessels. Explored internal air pressure ranges from 1 bar to 300 bar and impact velocity are around 4400 m/s. Data obtained from experiments (Xray radiographies, particle velocity measurement and post-mortem vessels have been compared to numerical results given from LS-DYNA ALE-Lagrange-SPH full coupling models. Simulations exhibit an under estimation in term of debris cloud evolution and shock wave propagation in pressurized air but main modes of damage/rupture on the vessels given by simulations are coherent with post-mortem recovered vessels from experiments. First results of this numerical work are promising and further simulation investigations with additional experimental data will be done to increase the reliability of the simulation model. The final aim of this crossed work is to numerically explore a wide range of impact conditions (impact angle, projectile weight, impact velocity, initial pressure that cannot be explore experimentally. Those whole results will define a rule of thumbs for the definition of a vulnerability analytical model for a given pressurized vessel.

  11. New generation of full composite vessels for 70 MPa gaseous hydrogen storage : results and achievements of the French HyBou project

    Nony, F. [CEA Materials, Monts (France); Weber, M. [Air Liquide, Paris (France); Tcharkhtchi, A. [Ecole Nationale Superieure d' Arts et Metiers, Paris (France); Lafarie-Frenot, M.C. [Ecole Nationale Superique De Mecanique et d' Aerotechnique, Poitiers (France); Perrier, O. [Raigi, Arbouville (France)

    2009-07-01

    The French collaborative Project known as HyBou explores hydrogen storage as a key enabling technology for the extensive use of hydrogen as an energy carrier. HyBou aims to develop robust, safe and efficient compressed gaseous hydrogen (CGH2) storage systems and validate innovative materials and processes suitable for storage vessel manufacturing with improved performance at low cost. The development of a new generation of type-4 70 MPa vessel was described along with a newly developed liner based on polyurethane materials. The new liner presents increased thermal stability, hydrogen barrier properties and cost effectiveness. The project also aims to evaluate the potential of new high resistance fibers and develop an improved thermosetting resin for composite winding with enhanced mechanical resistance and durability. A specific apparatus was therefore designed to characterize and evaluate coupled thermal and mechanical fatigue resistance in representative conditions.

  12. Shock resistance of composite material pipes

    Pays, M.F.

    1995-01-01

    Composite materials have found a wide range of applications for EDF nuclear plants. Applications include fire pipework, demineralized water, service water, and emergency-supplied service water piping. Some of those pipework is classified nuclear safety, their integrity (resistance to water aging and earthquakes or accidental excess pressure (water hammer)) must be safeguarded. As composite materials generally suffer damage for low energy impacts (under 10 J), the pipes planned for the Civaux power plant have been studied for their resistance to a low speed shock (0 to 50 m/s) and of a 0 to 110 J energy level. For three representative diameters (20, 150, 600 mm), the minimum impact energy that leads to a leak has been determined to be respectively 18, 20 and 48 J. Then the leak rate versus impact energy was plotted; until roughly 90 J, the leak rate remains stable at less than 25 cm 3 /h and raises to higher values (300 cm 3 /h) afterwards. The level of leakage in the range of impact energy tested always stays within the limits set by the Safety Authorities for metallic pipes. These results have been linked to destructive examinations, to clarify the damage mechanisms. Other tests are still ongoing to follow the evolution of the damage and of the leak rate while the pipe is maintained under service pressure during one year

  13. New ASTM Standards for Nondestructive Testing of Aerospace Composites

    Waller, Jess M.; Saulsberry, Regor L.

    2010-01-01

    Problem: Lack of consensus standards containing procedural detail for NDE of polymer matrix composite materials: I. Flat panel composites. II. Composite components with more complex geometries a) Pressure vessels: 1) composite overwrapped pressure vessels (COPVs). 2) composite pressure vessels (CPVs). III. Sandwich core constructions. Metal and brittle matrix composites are a possible subject of future effort.

  14. Correlation between Composition and Properties of Composite Material Based on Scrap Tires

    Mālers, L; Plēsuma, R; Ločmele, L; Kalniņš, M

    2010-01-01

    Purpose of present work is to investigate mechanical and insulation properties of the composite material based on scrap tires and polyurethane-type binder in correlation with composition of composite material. The studies of material’s hardness must be considered as an express-method for estimation of the selected mechanical properties (E and ccompressive stress) of the composite material without direct experimental testing of given parameters. It was shown that composite material must be r...

  15. A composite chitosan-gelatin bi-layered, biomimetic macroporous scaffold for blood vessel tissue engineering.

    Badhe, Ravindra V; Bijukumar, Divya; Chejara, Dharmesh R; Mabrouk, Mostafa; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Kondiah, Pierre P D; Pillay, Viness

    2017-02-10

    A composite chitosan-gelatin macroporous hydrogel-based scaffold with bi-layered tubular architecture was engineered by solvent casting-co-particulate leaching. The scaffold constituted an inner macroporous layer concealed by a non-porous outer layer mimicking the 3D matrix of blood vessels with cellular adhesion and proliferation. The scaffold was evaluated for its morphological, physicochemical, physicomechanical and biodurability properties employing SEM, FTIR, DSC, XRD, porositometry, rheology and texture analysis. The fluid uptake and biodegradation in the presence of lysozymes was also investigated. Cellular attachment and proliferation was analysed using human dermal fibroblasts (HDF-a) seeded onto the scaffold and evaluated by MTT assay, SEM, and confocal microscopy. Results demonstrated that the scaffold had a desirable tensile strength=95.81±11kPa, elongation at break 112.5±13%, porosity 82% and pores between 100 and 230μm, 50% in vitro biodegradation at day 16 and proliferated fibroblasts over 20 days. These results demonstrate that scaffold may be an excellent tubular archetype for blood vessel tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. The 5th surveillance testing for Kori unit 1 reactor vessel materials

    Chang, Kee Ok; Kim, Byoung Chul; Lee, Sam Lai; Choi, Kwun Jae; Gong, Un Sik; Chang, Jong Hwa; Joo, Yong Sun; Ahn, Sang Bok; Hong, Joon Hwa [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-08-01

    Surveillance testing for reactor vessel materials is performed in order to evaluate the irradiation embrittlement due to neutrons during operation and set the condition of safe operation of nuclear reactor. The 5th surveillance testing was performed primarily by Korea Atomic Energy Research Institute and Westinhouse corporation partially involved in testing and calculation data evaluation in order to obtain reliable test result. Fast neutron fluences for capsule V, T, S, R and P were 5.087E+18, 1.115E+19, 1.228E+19, 2.988E+19, and 3.938E+19n/cm2, respectively. The bias factor, the ratio of calculation/measurement, was 0.940 for the 1st through 5th testing and the calculational uncertainty, 7% satisfied the requirement of USNRC Reg.Guide DG-1053, 20%. The best estimated neutron fluence for reactor vessel inside surface was 1.9846E+19n/cm{sup 2} based on the end of 17th fuel cycle and it was predicted that the fluences of vessel inside surface at 24, 32, 40 and 48EFPY would reach 3.0593E+19, 4.0695E+19, 5.0797E+19 and 6.0900E+19n/cm{sup 2} based on the current calculation. PTS analysis for Kori unit 1 showed that 27.93EFPY was the threshold value for 300 deg F requirement. 71 refs., 33 figs., 52 tabs. (Author)

  17. Application of micromechanical models of ductile fracture initiation to reactor pressure vessel materials

    Chaouadi, R.; Walle, E. van; Fabry, A.; Velde, J. van de; Meester, P. de

    1996-01-01

    The aim of the current study is the application of local micromechanical models to predict crack initiation in ductile materials. Two reactor pressure vessel materials have been selected for this study: JRQ IAEA monitor base metal (A533B Cl.1) and Doel-IV weld material. Charpy impact tests have been performed in both un-irradiated and irradiated conditions. In addition to standard tensile tests, notched tensile specimens have been tested. The upper shelf energy of the weld material remains almost un-affected by irradiation, whereas a decrease of 20% is detected for the base metal. Accordingly, the tensile properties of the weld material do not reveal a clear irradiation effect on the yield and ultimate stresses, this in contrast to the base material flow properties. The tensile tests have been analyzed in terms of micromechanical models. A good correlation is found between the standard tests and the micromechanical models, that are able to predict the ductile damage evolution in these materials. Additional information on the ductility behavior of these materials is revealed by this micromechanical analysis

  18. Material properties of Bohunice 1 and 2 reactor pressure vessel materials before and after annealing

    Brumovsky, M.; Novosad, P.; Vacek, M.

    1994-01-01

    Six types of experimental RPV materials were studied before and after irradiation in host nuclear power and research reactors. Recovery of RPV materials from radiation hardening and embrittlement after annealing was evaluated including a rate of radiation damage after reirradiation used. (author). 3 refs, 4 figs, 2 tabs

  19. Manufacturing and material properties of forgings for reactor pressure vessel of high temperature engineering test reactor

    Sato, I.; Suzuki, K.

    1994-01-01

    For the reactor pressure vessel (RPV) of high temperature engineering test reactor (HTTR) which has been developed by Japan Atomic Energy Research Institute (JAERI), 2 1/4Cr-1Mo steel is used first in the world. Material confirmation test has been carried out to demonstrate good applicability of forged low Si 2 1/4Cr-1Mo steel to the RPV of HTTR. Recently, JSW has succeeded in the manufacturing of large size ring forgings and large size forged cover dome integrated with nozzles for stand pipe for the RPV. This paper describes the results of the material confirmation test as well as the manufacturing and material properties of the large forged cover dome integrated with nozzles for stand pipe. (orig.)

  20. The 4th surveillance testing for Kori unit 3 reactor vessel materials

    Chang, Kee Ok; Kim, Byoung Chul; Lee, Sam Lai; Choi, Kwun Jae; Gong, Un Sik; Chang, Jong Hwa; Joo, Yong Sun; Ahn, Sang Bok; Hong, Joon Hwa [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-10-01

    Surveillance testing for reactor vessel materials is performed in order to evaluate the irradiation embrittlement due to neutrons during operation and set the condition of safe operation of nuclear reactor. The 4th surveillance testing was performed completely by Korea Atomic Energy Research Institute at Taejeon after the capsule was transported from Kori site including its removal from reactor. Fast neutron fluences for capsules were calculated and various testing including mechanical and chemistry analysis were performed in order to evaluate the integrity of Kori unit 3 reactor vessel during the operation until life time. The evaluation results are as follows; Fast neutron fluences for capsules U, V, X and W are 4.983E+18, 1.641E+19, 3.158E+19, and 4.469E+19n/cm{sup 2}, respectively. The bias factor, the ratio of calculation/measurement, was 0.840 for the 1st through 4th testing and the calculational uncertainty, 12% satisfied the requirement of USNRC Reg.Guide DG-1053, 20%. The best estimated neutron fluence for reactor vessel inside surface was 1.362E+19n/cm{sup 2} based on the end of 12th fuel cycle and it was predicted that the fluences of vessel inside surface at 32, 40, 48 and 56EFPY would reach 3.481E+19, 4.209E+19, 5.144E+19 and 5.974E+19n/cm{sup 2} based on the current calculation. The result through this analysis for Kori unit 3 showed that there would be no problem for the pressurized thermal shock(PTS) during the operation until design life. 48 refs., 35 figs., 41 tabs. (Author)

  1. The 5th surveillance testing for Kori unit 2 reactor vessel materials

    Chang, Kee Ok; Kim, Byoung Chul; Lee, Sam Lai; Choi, Kwon Jae; Gong, Un Sik; Chang, Jong Hwa; Joo, Yong Sun; Ahn, Sang Bok; Hong, Joon Hwa [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-03-01

    Surveillance testing for reactor vessel materials is performed in order to evaluate the irradiation embrittlement due to neutrons during operation and set the condition of safe operation of nuclear reactor. The 5th surveillance testing was performed completely by Korea Atomic Energy Research Institute at Taejeon after the capsule was transported from Kori site including its removal from reactor. Fast neutron fluences for capsules were calculated and various testing including mechanical and chemistry analysis were performed in order to evaluate the integrity of Kori unit 2 reactor vessel during the operation until life time. The evaluation results are as follows; Fast neutron fluences for capsules V, R, P, T and N are 2.837E+18, 1.105E+19, 2.110E+19, 3.705E+19 and 4.831E+19n/cm{sup 2}, respectively. The bias factor, the ratio of measurement/calculation, was 0.918 for the 1st through 5th testing and the calculational uncertainty, 11.6% satisfied the requirement of USNRC Reg.Guide DG-1053, 20%. The best estimated neutron fluence for reactor vessel inside surface was 1.898E+19n/cm{sup 2} based on the end of 15th fuel cycle and it was predicted that the fluences of vessel inside surface at 32, 40, 48 and 56EFPY would reach 4.203E+19, 5.232E+19, 6.262E+19 and 7.291E+19n/cm{sup 2} based on the current calculation. The result through this analysis for Kori unit 2 showed that there would be no problem for the pressurized thermal shock(PTS) during the operation until design life. 49 refs., 35 figs., 48 tabs. (Author)

  2. Mechanical properties and examination of cracking in TMI-2 pressure vessel lower head material

    Diercks, D.R.; Neimark, L.A.

    1993-09-01

    Mechanical tests have been conducted on material from 15 samples removed from the lower head of the Three Mile Island unit 2 nuclear reactor pressure vessel. Measured properties include tensile properties and hardness profiles at room temperature, tensile and creep properties at temperatures of 600 to 1200 degrees C, and Charpy V-notch impact properties at -20 to +300 degrees C. These data, which were used in the subsequent analyses of the margin-to-failure of the lower head during the accident, are presented here. In addition, the results of metallographic and scanning electron microscope examinations of cladding cracking in three of the lower head samples are discussed

  3. Users manual data base MATSURV. Reactor pressure vessel material surveillance data management system

    Kenworthy, L.D.; Tether, C.D.

    1980-02-01

    This Users Guide to the data management system MATSURV has been prepared to assist the user in all facets of the task of processing data related to reactor pressure vessel materials surveillance; preparation of raw data for input, input of data, modification of existing data, retrieval and display of data, and the creation of data reports. MATSURV is structured upon the System 2000 data base management system which is maintained on the IBM 370/168 computer at National Institutes of Health. An overview of System 2000 is provided

  4. Composition of estuarine colloidal material: organic components

    Sigleo, A.C.; Hoering, T.C.; Helz, G.R.

    1982-01-01

    Colloidal material in the size range 1.2 nm to 0.4 ??m was isolated by ultrafiltration from Chesapeake Bay and Patuxent River waters (U.S.A.). Temperature controlled, stepwise pyrolysis of the freeze-dried material, followed by gas chromatographic-mass spectrometric analyses of the volatile products indicates that the primary organic components of this polymer are carbohydrates and peptides. The major pyrolysis products at the 450??C step are acetic acid, furaldehydes, furoic acid, furanmethanol, diones and lactones characteristic of carbohydrate thermal decomposition. Pyrroles, pyridines, amides and indole (protein derivatives) become more prevalent and dominate the product yield at the 600??C pyrolysis step. Olefins and saturated hydrocarbons, originating from fatty acids, are present only in minor amounts. These results are consistent with the composition of Chesapeake phytoplankton (approximately 50% protein, 30% carbohydrate, 10% lipid and 10% nucleotides by dry weight). The pyrolysis of a cultured phytoplankton and natural particulate samples produced similar oxygen and nitrogencontaining compounds, although the proportions of some components differ relative to the colloidal fraction. There were no lignin derivatives indicative of terrestrial plant detritus in any of these samples. The data suggest that aquatic microorganisms, rather than terrestrial plants, are the dominant source of colloidal organic material in these river and estuarine surface waters. ?? 1982.

  5. Composite materials from new textile technologies

    Jiménez, M. A.

    1997-12-01

    Full Text Available The present paper describes in a general way the most important of the advanced textile technologies which are oriented to the manufacturing of organic matrix composite materials, the paper presents their applications and the possibilities of future development. The use of these advanced weaving techniques allows the production of near-net-shaped preforms, which results in important savings in processing costs; moreover, these textile processes offer the possibility of introducing out-of plane reinforcing fibres, so there is an important increment of the impact strength and the damage tolerance of the final material.

    En el presente artículo se describen, de forma genérica, las más importantes de las tejedurías avanzadas destinadas a la fabricación de materiales compuestos de matriz orgánica, presentándose sus aplicaciones y futuras posibilidades de desarrollo. La utilización de estos procesos de tejeduría avanzados permite la elaboración de preformas cercanas a la forma final de la pieza, lo que se traduce en importantes reducciones en los costes de fabricación; además, estos procesos textiles ofrecen la posibilidad de introducir fibras de refuerzo fuera del plano, aumentando de forma considerable la resistencia a impacto y la tolerancia al daño del material final.

  6. Characterization of Decommissioned PWR Vessel Internals Materials Samples: Material Certification, Fluence, and Temperature (Nonproprietary Version)

    Krug, M.; Shogan, R.; Fero, A.; Snyder, M.

    2004-01-01

    Pressurized water reactor (PWR) cores, operate under extreme environmental conditions due to coolant chemistry, operating temperature, and neutron exposure. Extending the life of PWRs require detailed knowledge of the changes in mechanical and corrosion properties of the structural austenitic stainless steel components adjacent to the fuel. This report contains basic material characterization information of the as-installed samples of reactor internals material which were harvested from a decommissioned PWR

  7. Supercapacitors Based on Nickel Oxide/Carbon Materials Composites

    Lota, Katarzyna; Sierczynska, Agnieszka; Lota, Grzegorz

    2011-01-01

    In the thesis, the properties of nickel oxide/active carbon composites as the electrode materials for supercapacitors are discussed. Composites with a different proportion of nickel oxide/carbon materials were prepared. A nickel oxide/carbon composite was prepared by chemically precipitating nickel hydroxide on an active carbon and heating the hydroxide at 300 ∘C in the air. Phase compositions of the products were characterized using X-ray diffractometry (XRD). The morphology of the composite...

  8. The significance of cladding material on the integrity of nuclear pressure vessels with cracks

    Sattari-Far, Iradj.

    1989-05-01

    The significance of the austenitic cladding layer is reviewed in this literature study. The cladding induced stresses are generally not considered when evaluating the severity of flaws in reactor pressure vessels. It has been shown that this emission may be misleading. The necessity to consider the cladding induced stresses is also emphasized in the latest edition of ASME XI. Contrary to what is commonly assumed, the austenitic cladding displays a charpy V transition region with a low ductility. The interface material (HAZ) is the most influenced region by irradiation, and a transition shift of over 100 degree C may be expected. Because of the significant difference in the thermal expansion coefficients of the cladding and the base metal, cladding induced stresses can be set up. Even after PWHT, residual stresses of yield magnitude remain in the cladding and the HAZ at ambient temperature. The cladding induced stresses are temperature dependent and decrease as the temperature increases. The cladding induced stresses have a significant influence on small defects near the inside surface of a pressure vessel. For semielliptical surface cracks, the maximum CTOD-value along the crack front is not found at the deepest point, but in the cladding/base metal interface, having a magnitude three times higher than the value in the deepest point. It implies that this type of crack would propagate along the clad/base material interface. At some point in time, the crack will reach a geometry which may cause such a severe condition at the deepest point that it will start to grow in the depth direction as well. The initiation and growth behaviour of such cracks need to be investigated to be able to assess the significance of cladding on the integrity of nuclear pressure vessels. (author) (50 figs., 33 refs.)

  9. Results and analysis of reactor-material experiments on ex-vessel corium quench and dispersal

    Spencer, B.W.; McUmber, L.M.; Sienicki, J.J.; Squarer, D.

    1984-01-01

    Results of reactor-material experiments and related analysis are described in which molten corium is injected into a mock-up of the reactor cavity region of a PWR. The experiments address ex-vessel interactions such as steam generation (for those cases in which water is present), water and corium dispersal from the cavity, hydrogen generation, direct atmosphere heating by dispersed corium, and debris characterization. Test results indicate efficiencies of steam generation by corium quench ranging up to 65%. Corium sweepout of up to 62% of the injected material was found for those conditions in which steam generation flowrate was augmented by vessel blowdown. The dispersed corium caused very little direct heating of the atmosphere for the configuration employing a trap at the exit of the cavity-to-containment pathway. Corium sweepout phenomena were modeled for high-pressure blowdown conditions, and the results applied to the full-size reactor system predict essentially complete sweepout of corium from the reactor cavity

  10. On the relationship between the Bulgar ceramic vessels production technology and their functional purposes: molding compositions characteristics (after the 2011-2012 studies on the Bulgar settlement site

    Bakhmatova Vera N.

    2014-06-01

    Full Text Available Results of research in the mode of preparing molding compositions as one of technological stages in Bulgar pottery production are presented in the article. The subject of study was the common Bulgar ceramics from the Bulgar settlement site of the Golden Horde period (2011-2012 excavations. Four basic functional groups of ceramics were selected: kitchen, transportation, tableware, technical items. The study was conducted with the aim of identifying the dependence of pottery technology on the pottery functional purpose. While analyzing the materials, a complex methodology has been applied: a synthesis of traditional archaeological and natural science methods (A.A. Bobrinsky’s technical and technological method, petrography, X-ray phase analysis. The studies have shown that different functional forms of pottery had generated a variety of approaches to their manufacture. In most cases, special recipes were absent, but a certain differentiation could be traced in the choice of raw materials for the manufacture of vessels for different functional purposes. A further detailed study of the stages associated with raw materials selection and extraction, as well as that of the vessel hollow body design, and the methods of vessel strengthening (drying and firing are in prospect.

  11. Fracture toughness requirements of reactor vessel material in evaluation of the safety analysis report of nuclear power plants

    Widia Lastana Istanto

    2011-01-01

    Fracture toughness requirements of reactor vessel material that must be met by applicants for nuclear power plants construction permit has been investigated in this paper. The fracture toughness should be described in the Safety Analysis Reports (SARs) document that will be evaluated by the Nuclear Energy Regulatory Agency (BAPETEN). Because BAPETEN does not have a regulations or standards/codes regarding the material used for the reactor vessel, especially in the fracture toughness requirements, then the acceptance criteria that applied to evaluate the fracture toughness of reactor vessel material refers to the regulations/provisions from the countries that have been experienced in the operation of nuclear power plants, such as from the United States, Japan and Korea. Regulations and standards used are 10 CFR Part 50, ASME and ASTM. Fracture toughness of reactor vessel materials are evaluated to ensure compliance of the requirements and provisions of the Regulatory Body and the applicable standards, such as ASME or ASTM, in order to assure a reliability and integrity of the reactor vessels as well as providing an adequate safety margin during the operation, testing, maintenance, and postulated accident conditions over the reactor vessel lifetime. (author)

  12. Demineralized dentin matrix composite collagen material for bone tissue regeneration.

    Li, Jianan; Yang, Juan; Zhong, Xiaozhong; He, Fengrong; Wu, Xiongwen; Shen, Guanxin

    2013-01-01

    Demineralized dentin matrix (DDM) had been successfully used in clinics as bone repair biomaterial for many years. However, particle morphology of DDM limited it further applications. In this study, DDM and collagen were prepared to DDM composite collagen material. The surface morphology of the material was studied by scanning electron microscope (SEM). MC3T3-E1 cells responses in vitro and tissue responses in vivo by implantation of DDM composite collagen material in bone defect of rabbits were also investigated. SEM analysis showed that DDM composite collagen material evenly distributed and formed a porous scaffold. Cell culture and animal models results indicated that DDM composite collagen material was biocompatible and could support cell proliferation and differentiation. Histological evaluation showed that DDM composite collagen material exhibited good biocompatibility, biodegradability and osteoconductivity with host bone in vivo. The results suggested that DDM composite collagen material might have a significant clinical advantage and potential to be applied in bone and orthopedic surgery.

  13. A Theoretical Investigation of Composite Overwrapped Pressure Vessel (COPV) Mechanics Applied to NASA Full Scale Tests

    Thesken, John C.; Murthy, Pappu L. N.; Phoenix, S. L.; Greene, N.; Palko, Joseph L.; Eldridge, Jeffrey; Sutter, James; Saulsberry, R.; Beeson, H.

    2009-01-01

    A theoretical investigation of the factors controlling the stress rupture life of the National Aeronautics and Space Administration's (NASA) composite overwrapped pressure vessels (COPVs) continues. Kevlar (DuPont) fiber overwrapped tanks are of particular concern due to their long usage and the poorly understood stress rupture process in Kevlar filaments. Existing long term data show that the rupture process is a function of stress, temperature and time. However due to the presence of a load sharing liner, the manufacturing induced residual stresses and the complex mechanical response, the state of actual fiber stress in flight hardware and test articles is not clearly known. This paper is a companion to a previously reported experimental investigation and develops a theoretical framework necessary to design full-scale pathfinder experiments and accurately interpret the experimentally observed deformation and failure mechanisms leading up to static burst in COPVs. The fundamental mechanical response of COPVs is described using linear elasticity and thin shell theory and discussed in comparison to existing experimental observations. These comparisons reveal discrepancies between physical data and the current analytical results and suggest that the vessel s residual stress state and the spatial stress distribution as a function of pressure may be completely different from predictions based upon existing linear elastic analyses. The 3D elasticity of transversely isotropic spherical shells demonstrates that an overly compliant transverse stiffness relative to membrane stiffness can account for some of this by shifting a thin shell problem well into the realm of thick shell response. The use of calibration procedures are demonstrated as calibrated thin shell model results and finite element results are shown to be in good agreement with the experimental results. The successes reported here have lead to continuing work with full scale testing of larger NASA COPV

  14. Design and preliminary analysis of in-vessel core catcher made of high-temperature ceramics material in PWR

    Xu Hong; Ma Li; Wang Junrong; Zhou Zhiwei

    2011-01-01

    In order to protect the interior wall of pressure vessel from melting, as an additional way to external reactor vessel cooling (ERVC), a kind of in-vessel core catcher (IVCC) made of high-temperature ceramics material was designed. Through the high-temperature and thermal-resistance characteristic of IVCC, the distributing of heat flux was optimized. The results show that the downward average heat flux from melt in ceramic layer reduces obviously and the interior wall of pressure vessel doesn't melt, keeping its integrity perfectly. Increasing of upward heat flux from metallic layer makes the upper plenum structure's temperature ascend, but the temperature doesn't exceed its melting point. In conclusion, the results indicate the potential feasibility of IVCC made of high-temperature ceramics material. (authors)

  15. Composite Materials in Aircraft Mishaps Involving Fire: A Literature Review

    Wright, Mark

    2003-01-01

    .... The Naval Air Systems Command (NAVAIR), which provides technical guidance for aircraft fire safety, was concerned that hazards presented by new composite materials and greater quantities of composites may not be adequately addressed...

  16. Developing Raman spectroscopy for the nondestructive testing of composite materials.

    2009-08-01

    The proposed research will develop the application of Raman Spectroscopy as a nondestructive evaluation tool for the condition assessment of carbon fiber composites. Composite materials are increasingly being used in engineered structures and compone...

  17. Developing polymer composite materials: carbon nanotubes or graphene?

    Sun, Xuemei; Sun, Hao; Li, Houpu; Peng, Huisheng

    2013-10-04

    The formation of composite materials represents an efficient route to improve the performances of polymers and expand their application scopes. Due to the unique structure and remarkable mechanical, electrical, thermal, optical and catalytic properties, carbon nanotube and graphene have been mostly studied as a second phase to produce high performance polymer composites. Although carbon nanotube and graphene share some advantages in both structure and property, they are also different in many aspects including synthesis of composite material, control in composite structure and interaction with polymer molecule. The resulting composite materials are distinguished in property to meet different applications. This review article mainly describes the preparation, structure, property and application of the two families of composite materials with an emphasis on the difference between them. Some general and effective strategies are summarized for the development of polymer composite materials based on carbon nanotube and graphene. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Numerical simulation of mechanical behavior of composite materials

    Oller, Sergio

    2014-01-01

    An original mechanical formulation to treat nonlinear orthotropic behavior of composite materials is presented in this book. It also examines different formulations that allow us to evaluate the behavior of composite materials through the composition of its components, obtaining a new composite material. Also two multiple scale homogenization methods are given, one based on the analytical study of the cells (Ad-hoc homogenization), and other one, more general based on the finite element procedure applied on the macro scale (upper-scale) and in the micro scale (sub-scale). A very general formulation to simulate the mechanical behavior for traditional composite structures (plywood, reinforced concrete, masonry, etc.), as well as the new composite materials reinforced with long and short fibers, nanotubes, etc., are also shown in this work. Typical phenomena occurring in composite materials are also described in this work, including fiber-matrix debounding, local buckling of fibers and its coupling with the over...

  19. Closed vessel miniaturized microwave assisted chelating extraction for determination of trace metals in plant materials

    Czarnecki, Sezin; Duering, Rolf-Alexander

    2013-04-01

    In recent years, the use of closed vessel microwave assisted extraction (MAE) for plant samples has shown increasing research interest which will probably substitute conventional procedures in the future due to their general disadvantages including consumption of time and solvents. The objective of this study was to demonstrate an innovative miniaturized closed vessel microwave assisted extraction (µMAE) method under the use of EDTA (µMAE-EDTA) to determine metal contents (Cd, Co, Cu, Mn, Ni, Pb, Zn) in plant samples (Lolio-Cynosuretum) by inductively coupled plasma-optical emission spectrometry (ICP-OES). Validation of the method was done by comparison of the results with another miniaturized closed vessel microwave HNO3 method (µMAE-H) and with two other macro scale MAE procedures (MAE-H and MAE-EDTA) which were applied by using a mixture of nitric acid (HNO3) and hydrogen peroxide (H2O2) (MAE-H) and EDTA (MAE-EDTA), respectively. The already established MAE-H method is taken into consideration as a reference validation MAE method for plant material. A conventional plant extraction (CE) method, based on dry ashing and dissolving of the plant material in HNO3, was used as a confidence comparative method. Certified plant reference materials (CRMs) were used for comparison of recovery rates from different extraction protocols. This allowed the validation of the applicability of the µMAE-EDTA procedure. For 36 real plant samples with triplicates each, µMAE-EDTA showed the same extraction yields as the MAE-H in the determination of Cd, Co, Cu, Mn, Ni, Pb, and Zn contents in plant samples. Analytical parameters in µMAE-EDTA should be further investigated and adapted for other metals of interest. By the reduction and elimination of the use of hazardous chemicals in environmental analysis and thus allowing a better understanding of metal distribution and accumulation process in plants and also the metal transfer from soil to plants and into the food chain, µ

  20. Assessment of Radiation Embrittlement in Nuclear Reactor Pressure Vessel Surrogate Materials

    Balzar, Davor

    2010-10-01

    The radiation-enhanced formation of small (1-2 nm) copper-rich precipitates (CRPs) is critical for the occurrence of embrittlement in nuclear-reactor pressure vessels. Small CRPs are coherent with the bcc matrix, which causes local matrix strain and interaction with the dislocation strain fields, thus impeding dislocation mobility. As CRPs grow, there is a critical size at which a phase transformation occurs, whereby the CRPs are no longer coherent with the matrix, and the strain is relieved. Diffraction-line-broadening analysis (DLBA) and small-angle neutron scattering (SANS) were used to characterize the precipitate formation in surrogate ferritic reactor-pressure vessel steels. The materials were aged for different times at elevated temperature to produce a series of specimens with different degrees of copper precipitation. SANS measurements showed that the precipitate size distribution broadens and shifts toward larger sizes as a function of ageing time. Mechanical hardness showed an increase with ageing time, followed by a decrease, which can be associated with the reduction in the number density as well as the loss of coherency at larger sizes. Inhomogeneous strain correlated with mechanical hardness.

  1. Composite Material Hazard Assessment at Crash Sites

    2015-01-01

    polymer matrix composites, ceramic matrix composites, and metal matrix composites. Advanced composites use various resin systems including polyester...intensity, and its growth rate. Broadly classified polycyclic aromatic hydrocarbons (naphthalene), nitrogen-containing aromatics (aniline), and phenol...detect. aNIOSH Method 7400 reported Total Dusts and Inhalable results using a 0.8-um mixed cellulose ester filter . bNIOSH Method 600 reported Respirable

  2. Performance ratio hardness characteristics polystyrene-metal composite materials

    Klepikov, V.F.; Prokhorenko, E.M.; Lytvynenko, V.V.; Zakharchenko, A.A.; Hazhmuradov, M.A.

    2015-01-01

    The methods of measuring the hardness of layered polystyrene-metallic composite materials. It is proposed to use powder-like tungsten and powder-like steel as radiation-protective layer. A measurement of the hardness of composites of different composition, and given its dependence on the particle size and their form. The possibility of increasing the hardness of the composites reinforced with metallic additives. Radiation-protective characteristics were calculated for the studied species of composite materials. Influence of the quantitative composition of the metal components is studied on the change of the absorbed dose of gamma radiation

  3. Multi-material Preforming of Structural Composites

    Norris, Robert E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Eberle, Cliff C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pastore, Christopher M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sudbury, Thomas Z. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Xiong, Fue [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hartman, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-05-01

    Fiber-reinforced composites offer significant weight reduction potential, with glass fiber composites already widely adopted. Carbon fiber composites deliver the greatest performance benefits, but their high cost has inhibited widespread adoption. This project demonstrates that hybrid carbon-glass solutions can realize most of the benefits of carbon fiber composites at much lower cost. ORNL and Owens Corning Reinforcements along with program participants at the ORISE collaborated to demonstrate methods for produce hybrid composites along with techniques to predict performance and economic tradeoffs. These predictions were then verified in testing coupons and more complex demonstration articles.

  4. Non-Catalytic Self Healing Composite Material Solution, Phase I

    National Aeronautics and Space Administration — Fiber reinforce polymer (FRP) composite materials are seeing increasing use in the construction of a wide variety of aerospace structures. However, uncertainties...

  5. Assessment of aluminum structural materials for service within the ANS reflector vessel

    Farrell, K.

    1995-08-01

    Most of the components in the Advanced Neutron Source (ANS) reactor, including the reflector vessel, will be built from the aluminum alloy 6061 (lMg,0.6Si) in its precipitation-hardened T6 and T651 conditions. The microstructural and mechanical characteristics of the alloy are described, and its operating boundaries of stress, temperature, and time in its unirradiated state are defined. The material's responses to neutron radiation exposure in aqueous environments are reviewed in detail. The particular service conditions of stress, temperature, and radiation exposure expected for individual components in the ANS are listed, and the suitability of each component to meet the demands is assessed. Areas of uncertainties are outlined, and various suggestions and recommendations are made to give improved confidence in the predictions

  6. Contribution of the different erosion processes to material release from the vessel walls of fusion devices during plasma operation

    Behrisch, R.

    2002-01-01

    In high temperature plasma experiments several processes contribute to erosion and loss of material from the vessel walls. This material may enter the plasma edge and the central plasma where it acts as impurities. It will finally be re-deposited at other wall areas. These erosion processes are: evaporation due to heating of wall areas. At very high power deposition evaporation may become very large, which has been named ''blooming''. Large evaporation and melting at some areas of the vessel wall surface may occur during heat pulses, as observed in plasma devices during plasma disruptions. At tips on the vessel walls and/or hot spots on the plasma exposed solid surfaces electrical arcs between the plasma and the vessel wall may ignite. They cause the release of ions, atoms and small metal droplets, or of carbon dust particles. Finally, atoms from the vessel walls are removed by physical and chemical sputtering caused by the bombardment of the vessel walls with ions as well as energetic neutral hydrogen atoms from the boundary plasma. All these processes have been, and are, observed in today's plasma experiments. Evaporation can in principle be controlled by very effective cooling of the wall tiles, arcing is reduced by very stable plasma operation, and sputtering by ions can be reduced by operating with a cold plasma in front of the vessel walls. However, sputtering by energetic neutrals, which impinge on all areas of the vessel walls, is likely to be the most critical process because ions lost from the plasma recycle as neutrals or have to be refuelled by neutrals leading to the charge exchange processes in the plasma. In order to quantify the wall erosion, ''materials factors'' (MF) have been introduced in the following for the different erosion processes. (orig.)

  7. Supervisory control of drilling of composite materials

    Ozaki, Motoyoshi

    Composite materials have attractive features, such as high ratios of strength-to-weight and stiffness-to-weight. However, they are easily damaged when they are machined. A typical damage is delamination, which can occur when fiber reinforced composite laminates are drilled. The objective of this research is to study the drilling processes of carbon fiber reinforced laminates, and to develop and test a supervisory control strategy for their delamination-free drilling. Characterization of thrust force and torque is achieved through constant feedrate drilling experiments. The average values of thrust force and torque during the full engagement of the drill are utilized to obtain the Shaw's equations' parameters. The thrust force profile just before exit is given special attention. The Hocheng-Dharan equations, which give conservative values of delamination at the entrance and at the exit, are modified to express the influence of one lamina thickness explicitly. They are utilized not only for the characterization of thrust force but also for the determination of the thrust force reference for force control. In the design of the controllers of thrust force and torque, both thrust force and torque are assumed to be proportional to FPHR (Feed Per Half Revolution). A discrete-time dynamic model is established for the case when the time interval for a half revolution of the drill is divided by the sampling time, and the model is extended to the case of general spindle speeds. PI controllers are designed for the dynamic models of thrust force and torque. Root-locus techniques are used in the analysis. The phases of the drilling process are introduced and the control strategy at each phase is explained. The supervisory controller chooses not only the best control strategy for each phase, but also the reference value and the controller gain that are suitable at each drill position. Drilling experiments are conducted to show the usefulness of the concepts introduced in this

  8. Design and Fabrication of Aerospace-Grade Digital Composite Materials

    National Aeronautics and Space Administration — This project aims to advance design rules and fabrication approaches to create aerospace-grade structures from digital composite materials. Digital materials are...

  9. Characteristics analysis on a superconductor resonance coil WPT system according to cooling vessel materials in different distances

    Jeong, In-Sung; Lee, Yu-Kyeong; Choi, Hyo-Sang

    2016-01-01

    Highlights: • WPT using the superconductor coil was needed research for cooling vessel. FRP, bakelite, polystyrene, aluminum, and iron were applied as the cooling vessel material to analyze the WPT distance efficiency. • When the distance between the transmitter and receiver coils was 2000 mm, FRP being used for the cooling vessel made the transmission efficiency higher than any other materials. The efficiency and distance of sending power can be improved in the superconductor coil if the cooling vessel is made with FRP. - Abstract: The interest in wireless power transfer (WPT) that can send power without using wires has been increasing recently. Especially, there is a great interest in the wireless power devices for portable IT devices. The WPT devices that have been developed so far use the magnetic induction method, and they are not active due to their distance problem. A magnetic resonance WPT method was developed and has been actively researched to resolve this problem. A superconductor coil was applied in this study to increase the efficiency of the magnetic resonance WPT. FRP, bakelite, polystyrene, aluminum, and iron were applied as the cooling vessel material to analyze the WPT distance. The distance between the transmitter and receiver coils started from 800 mm and was increased by 200 mm. The reflection coefficient was measured at each distance. As a result, FRP, bakelite, plastic PVC, polystyrene of the reflection coefficient was similar. From among these FRP being used for the cooling vessel made the transmission characteristics higher than any other materials when the distance between the transmitter and receiver coils was 2,000 mm. On the other hand, the reflection coefficient dropped when iron was used. It is estimated based on the experimental results that the wireless power transmission characteristics and distance of sending power can be improved in the superconductor coil if the cooling vessel is made with FRP.

  10. Characteristics analysis on a superconductor resonance coil WPT system according to cooling vessel materials in different distances

    Jeong, In-Sung, E-mail: no21park@hanmail.net; Lee, Yu-Kyeong; Choi, Hyo-Sang, E-mail: hyosang@chosun.ac.kr

    2016-11-15

    Highlights: • WPT using the superconductor coil was needed research for cooling vessel. FRP, bakelite, polystyrene, aluminum, and iron were applied as the cooling vessel material to analyze the WPT distance efficiency. • When the distance between the transmitter and receiver coils was 2000 mm, FRP being used for the cooling vessel made the transmission efficiency higher than any other materials. The efficiency and distance of sending power can be improved in the superconductor coil if the cooling vessel is made with FRP. - Abstract: The interest in wireless power transfer (WPT) that can send power without using wires has been increasing recently. Especially, there is a great interest in the wireless power devices for portable IT devices. The WPT devices that have been developed so far use the magnetic induction method, and they are not active due to their distance problem. A magnetic resonance WPT method was developed and has been actively researched to resolve this problem. A superconductor coil was applied in this study to increase the efficiency of the magnetic resonance WPT. FRP, bakelite, polystyrene, aluminum, and iron were applied as the cooling vessel material to analyze the WPT distance. The distance between the transmitter and receiver coils started from 800 mm and was increased by 200 mm. The reflection coefficient was measured at each distance. As a result, FRP, bakelite, plastic PVC, polystyrene of the reflection coefficient was similar. From among these FRP being used for the cooling vessel made the transmission characteristics higher than any other materials when the distance between the transmitter and receiver coils was 2,000 mm. On the other hand, the reflection coefficient dropped when iron was used. It is estimated based on the experimental results that the wireless power transmission characteristics and distance of sending power can be improved in the superconductor coil if the cooling vessel is made with FRP.

  11. Some functional properties of composite material based on scrap tires

    Plesuma, Renate; Malers, Laimonis

    2013-09-01

    The utilization of scrap tires still obtains a remarkable importance from the aspect of unloading the environment from non-degradable waste [1]. One of the most prospective ways for scrap tires reuse is a production of composite materials [2] This research must be considered as a continuation of previous investigations [3, 4]. It is devoted to the clarification of some functional properties, which are considered important for the view of practical applications, of the composite material. Some functional properties of the material were investigated, for instance, the compressive stress at different extent of deformation of sample (till 67% of initial thickness) (LVS EN 826) [5] and the resistance to UV radiation (modified method based on LVS EN 14836) [6]. Experiments were realized on the purposefully selected samples. The results were evaluated in the correlation with potential changes of Shore C hardness (Shore scale, ISO 7619-1, ISO 868) [7, 8]. The results showed noticeable resistance of the composite material against the mechanical influence and ultraviolet (UV) radiation. The correlation with the composition of the material, activity of binder, definite technological parameters, and the conditions supported during the production, were determined. It was estimated that selected properties and characteristics of the material are strongly dependent from the composition and technological parameters used in production of the composite material, and from the size of rubber crumb. Obtained results show possibility to attain desirable changes in the composite material properties by changing both the composition and technological parameters of examined material.

  12. Influence of prolonged service of steam turbines on the properties of materials of rotor and vessel components

    Anfimov, V.M.; Artamonov, V.V.; Chizhik, T.A.

    1984-01-01

    The structure and mechanical properties of steam turbine elements of 25Kh1MF, 25Kh1M1FA (rotors), 15Kh1M1FL (vessel components) steels have been investigated both in initial state and after 200 000 h operation. The structure stability and phase composition of rotor steels providing conservation of heat resistance at a required level was established. Examination of vessel components showed a decrease in the yield strength by 15-20% and durability - by 10% as compared to initial ones. The conclusion on a possible prolongation of the steam turbine service life to 200 000 h is drawn. The nominal service life equals 100 000 h

  13. Microhardness of resin composite materials light-cured through fiber reinforced composite.

    Fennis, W.M.M.; Ray, N.J.; Creugers, N.H.J.; Kreulen, C.M.

    2009-01-01

    OBJECTIVES: To compare polymerization efficiency of resin composite basing materials when light-cured through resin composite and fiber reinforced composite (FRC) by testing microhardness. METHODS: Simulated indirect restorations were prepared by application of resin composite (Clearfil AP-X) or FRC

  14. Composite materials application on FORMOSAT-5 remote sensing instrument structure

    Jen-Chueh Kuo

    2017-01-01

    Full Text Available Composite material has been widely applied in space vehicle structures due to its light weight and designed stiffness modulus. Some special mechanical properties that cannot be changed in general metal materials, such as low CTE (coefficient of thermal expansion and directional material stiffness can be artificially adjusted in composite materials to meet the user’s requirements. Space-qualified Carbon Fiber Reinforced Plastic (CFRP composite materials are applied In the FORMOSAT-5 Remote Sensing (RSI structure because of its light weight and low CTE characteristics. The RSI structural elements include the primary mirror supporting plate, secondary mirror supporting ring, and supporting frame. These elements are designed, manufactured, and verified using composite materials to meet specifications. The structure manufacturing process, detailed material properties, and CFRP structural element validation methods are introduced in this paper.

  15. Process for fabricating composite material having high thermal conductivity

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    2001-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  16. Evaluation of Composite Materials for Use on Launch Complexes

    Finchum, A.; Welch, Peter J.

    1989-01-01

    Commercially available composite structural shapes were evaluated for use. These composites, fiberglass-reinforced polyester and vinylester resin materials are being used extensively in the fabrication and construction of low maintenance, corrosion resistant structures. The evaluation found that in many applications these composite materials can be successfully used at the space center. These composite materials should not be used where they will be exposed to the hot exhaust plume/cloud of the launch vehicle during the liftoff, and caution should be taken in their use in areas where electrostatic discharge and hypergolic propellant compatibility are primary concerns.

  17. Characterization of terahertz waves on foreign materials of composite materials

    Im, Kwang-Hee; Kim, Sun-Kyu; Chiou, Chien-Ping; Jung, Jong-An

    2018-04-01

    Carbon-fiber reinforced plastics (CFRP) are widely utilized due to their comparatively high performance in engineering structures. It is well understood that a nondestructive technique would be very beneficial. A new terahertz radiation has been recognized for its importance in technological applications. Recently, T-ray (terahertz ray) advances in technology and instrumentation have provided a probing field on the electromagnetic spectrum. In carbon composites, the penetration characterization of T-ray waves was fundamentally investigated in order to measure the painting thickness. Also, another study dealt with THz scan images of honeycomb sandwich composite panels using a refractive index (n), an absorption coefficient (α), the electrical conductivity of glass fiber embedded epoxy matrix composites, and carbon fiber reinforced plastics (CFRP) skin. For experiments, a method of detecting FRP composites with impact damage is presented, which utilizes aluminum wires intertwined with woven carbon fibers as they are inserted into the surface of the CFRP honeycomb sandwich panels. Intensive characterization of T-ray for the nondestructive evaluation (NDE) of carbon composite reinforced plastics (CFRP) composites is discussed in relation to the E-field influence with CFRP composite laminates.

  18. Report on material and fabrication tests of the KUHFR core vessel

    Yoshida, H.; Kozuka, T.; Achiwa, N.; Mitani, S.; Kawano, S.; Araki, Y.; Shibata, T.

    1983-01-01

    For the material of the cylindrical reactor core vessel of the Kyoto University High Flux Reactor (KUHFR), A6061 alloy is selected because the aged state of the alloy is known to show the highest resistance against void swelling due to high-dose irradiation. The fabrication possibility of the large-scale tubes is also tested because the sizes (40 cmdiameter and 43 cmdiameter x 960 cm with a thickness of 10 mm for the inner- and outer-tubes, respectively) are just over the largest limit of the conventional factory fabrication. The results are summarized as follows. (1) From an ingot of A6061 alloy a raw inner-tube is hot-extruded by the 3,000 ton press machine. The shape of the extruded tubes is effectively corrected by stretch forming and other special methods. (2) The real scale tubes are heat-treated under the various conditions (T1, T4 and T6) and their size changes are measured just after the every heat-treatment. (3) The hydropressure for a pipe prepared by welding from an aged-tube shows a fairly uniform strain distribution and the breaking initiation at the reasonable pressure in the welded part. (4) Each of the welded specimens prepared using three kinds of welding rods shows sufficient strength in both of bending and tensile test for the JIS standard. Their microstructures correspond to the result of the mechanical tests for each welded specimen. The confidence for the fabrication possibility of the real core vessel has been given through the present tests. (author)

  19. Mechanical properties of wood-based composite materials

    Zhiyong Cai; Robert J. Ross

    2010-01-01

    The term composite is used to describe any wood material bonded together with adhesives. The current product mix ranges from fiberboard to laminated beams and components. In this chapter, wood-based composite materials are classified into the following categories: panel products (plywood, oriented strandboard (OSB), particleboard, fiberboard, medium-density fiberboard...

  20. Advanced organic composite materials for aircraft structures: Future program

    1987-01-01

    Revolutionary advances in structural materials have been responsible for revolutionary changes in all fields of engineering. These advances have had and are still having a significant impact on aircraft design and performance. Composites are engineered materials. Their properties are tailored through the use of a mix or blend of different constituents to maximize selected properties of strength and/or stiffness at reduced weights. More than 20 years have passed since the potentials of filamentary composite materials were identified. During the 1970s much lower cost carbon filaments became a reality and gradually designers turned from boron to carbon composites. Despite progress in this field, filamentary composites still have significant unfulfilled potential for increasing aircraft productivity; the rendering of advanced organic composite materials into production aircraft structures was disappointingly slow. Why this is and research and technology development actions that will assist in accelerating the application of advanced organic composites to production aircraft is discussed.

  1. Evaluation of Stability Parameters in In-Vessel Compositing of Municipal Solid Waste

    M. M. Amin

    2011-10-01

    Full Text Available Composting is a reliable technology for production of stabilized organic matter that is suitable for agriculture, but this process should be carefully monitored with appropriate indices. Quality of compost is important from maturity and stability viewpoint, but in most compost factories proper attention is not paid to it. This study was designed to evaluate the stability indices in municipal solid waste composting, for selecting the best index in quality monitoring of the wastes. Processed and shredded municipal solid waste from Isfahan compost plant was used as raw material in an in-vessel composting process. A cylindrical reactor with 1 m height and 50 cm diameter made of Pyrex glass was designed. Air was supplied at a specifically flow rate 0.2 L/min.kg to maintain aerobic condition. NH4+/ NO3 ratio, dehydrogenase enzyme activity (DA, pH, oxidation reduction potential (ORP or Eh and specific oxygen uptake rate (SOUR were used as stability indices. These parameters were measured during 40 days of composting process. Changes in these parameters during this period were surveyed and analyzed. Statistical analysis was carried out to choose best of them. Results showed that among the indices, SOUR can show the different stages of microbial decomposition and a numerical value for compost stability also SOUR value less than 2 mg O2/gVS.h can show the full stability of compost.

  2. Endurance test report of rubber sealing materials for the containment vessel

    Yamamoto, R.; Watanabe, K.; Hanashima, K.

    2015-01-01

    In the event of a nuclear power plant accident such as a core meltdown and a cooling system failure, the containment contains radioactive materials released from the reactor pressure vessel to reduce the activity of the radioactive materials and the effects of radiation in the vicinity of the plant. Since high sealing performance and high pressure resistance are required of the containment, a silicone or EPDM rubber gasket with high heat and radiation resistance is used for the sealing of the sealing boundary of the containment. In recent years, it has been shown that a large amount of steam is released into the containment in the case of a severe accident. Consequently, radiation resistance at high temperature as well as steam resistance is required of the rubber gasket placed at the sealing boundary. However, the steam resistance of silicone rubber is not necessarily as good as that of EPDM rubber. Therefore, it is necessary to evaluate the sealing characteristics of rubber gaskets in such a degrading environment in a severe accident. O. Kato et al. [1] conducted a study on the degradation status of rubber gaskets and their application limits at high temperature. However, few studies have evaluated rubber gaskets in high-temperature radiation and steam environments. In this study, we degraded silicone rubber and EPDM rubber used for the containment in the high-temperature radiation and steam environments expected to occur in a severe accident and evaluated the useful life of the rubber as a sealing material by estimating the change in its performance as a sealing material from the change in permanent compressive strain in the rubber. (author)

  3. Structural mechanisms of the flux effect for VVER-1000 reactor pressure vessel materials

    Gurovich, B.; Kuleshova, E.; Fedotova, S.; Maltsev, D.; Zabusov, O.; Frolov, A.; Erak, D.; Zhurko, D.

    2015-01-01

    To justify the lifetime extension of VVER-1000 reactor pressure vessels (RPV) up to 60 years and more it is necessary to expand the existing surveillance samples database to beyond design fluence by means of accelerated irradiation in a research reactor. Herewith since the changes in mechanical properties of materials under irradiation are due to occurring structural changes, correct analysis of the data obtained at accelerated irradiation of VVER-1000 RPV materials requires a clear understanding of the structural mechanisms that are responsible for the flux effect in VVER-1000 RPV steels. Two mechanisms are responsible for radiation embrittlement of VVER-1000 RPV steels: the hardening one (radiation hardening due to formation of radiation-induced Ni-based precipitates and radiation defects) and non-hardening one (due to formation of impurities segregations at grain boundaries - reversible temper brittleness). In this context for an adequate interpretation of the mechanical tests results when justifying the lifetime extension of existing units a complex of comparative structural studies (TEM, SEM and AES) of VVER-1000 RPV materials irradiated in different conditions (in research reactor IR-8 and within surveillance samples) was performed. It is shown that the flux effect is observed for materials with high nickel content (weld metals with Ni content > 1.35%) and it is mostly due to the contribution of non-hardening mechanism of radiation embrittlement (the difference in the accumulation kinetics of grain boundary phosphorus segregation) and somewhat contribution of the hardening mechanism (the difference in density of radiation-induced precipitates). Therefore when analyzing the results obtained from the accelerated irradiation of VVER-1000 WM the correction for the flux effect should be made. (authors)

  4. Structural materials requirements for in-vessel components of fusion power plants

    Schaaf, B. van der

    2000-01-01

    The economic production of fusion energy is determined by principal choices such as using magnetic plasma confinement or generating inertial fusion energy. The first generation power plants will use deuterium and tritium mixtures as fuel, producing large amounts of highly energetic neutrons resulting in radiation damage in materials. In the far future the advanced fuels, 3 He or 11 B, determine power plant designs with less radiation damage than in the first generation. The first generation power plants design must anticipate radiation damage. Solid sacrificing armour or liquid layers could limit component replacements costs to economic levels. There is more than radiation damage resistance to determine the successful application of structural materials. High endurance against cyclic loading is a prominent requirement, both for magnetic and inertial fusion energy power plants. For high efficiency and compactness of the plant, elevated temperature behaviour should be attractive. Safety and environmental requirements demand that materials have low activation potential and little toxic effects under both normal and accident conditions. The long-term contenders for fusion power plant components near the plasma are materials in the range from innovative steels, such as reduced activation ferritic martensitic steels, to highly advanced ceramic composites based on silicon carbide, and chromium alloys. The steels follow an evolutionary path to basic plant efficiencies. The competition on the energy market in the middle of the next century might necessitate the riskier but more rewarding development of SiCSiC composites or chromium alloys

  5. Results and analysis of reactor-material experiments on ex-vessel corium quench and dispersal

    Spencer, B.W.; McUmber, L.M.; Sienicki, J.J.; Squarer, D.

    1984-01-01

    The results of reactor material experiments and related analysis are described in which molten corium is injected into a mock-up of the reactor cavity region of a PWR. The experiments address exvessel interactions such as steam generation (for those cases in which water is present), water and corium dispersal from the cavity, hydrogen generation, direct atmosphere heating by dispersed corium, and debrids characterization. Test results indicate efficiencies of steam generation by corium quench ranging up to 65%. Corium sweepout of up to 62% of the injected material was found for those conditions in which steam generation flowrate was augmented by vessel blowdown. The dispersed corium caused very little direct heating of the atmosphere for the configuration employing a trap at the exit of the cavity-to-containment pathway. Corium sweepout phenomena were modeled for high-pressure blowdown conditions, and the results applied to the full-size reactor system predict essentially complete sweepout of corium from the reactor cavity. (orig.)

  6. Advanced composite structures. [metal matrix composites - structural design criteria for spacecraft construction materials

    1974-01-01

    A monograph is presented which establishes structural design criteria and recommends practices to ensure the design of sound composite structures, including composite-reinforced metal structures. (It does not discuss design criteria for fiber-glass composites and such advanced composite materials as beryllium wire or sapphire whiskers in a matrix material.) Although the criteria were developed for aircraft applications, they are general enough to be applicable to space vehicles and missiles as well. The monograph covers four broad areas: (1) materials, (2) design, (3) fracture control, and (4) design verification. The materials portion deals with such subjects as material system design, material design levels, and material characterization. The design portion includes panel, shell, and joint design, applied loads, internal loads, design factors, reliability, and maintainability. Fracture control includes such items as stress concentrations, service-life philosophy, and the management plan for control of fracture-related aspects of structural design using composite materials. Design verification discusses ways to prove flightworthiness.

  7. Fiber-reinforced composites materials, manufacturing, and design

    Mallick, P K

    2007-01-01

    The newly expanded and revised edition of Fiber-Reinforced Composites: Materials, Manufacturing, and Design presents the most up-to-date resource available on state-of-the-art composite materials. This book is unique in that it not only offers a current analysis of mechanics and properties, but also examines the latest advances in test methods, applications, manufacturing processes, and design aspects involving composites. This third edition presents thorough coverage of newly developed materials including nanocomposites. It also adds more emphasis on underlying theories, practical methods, and problem-solving skills employed in real-world applications of composite materials. Each chapter contains new examples drawn from diverse applications and additional problems to reinforce the practical relevance of key concepts. New in The Third Edition: Contains new sections on material substitution, cost analysis, nano- and natural fibers, fiber architecture, and carbon-carbon composites Provides a new chapter on poly...

  8. Thermo-stimulated current and dielectric loss in composite materials

    Nishijima, S.; Hagihara, T.; Okada, T.

    1986-01-01

    Thermo-stimulated current and dielectric loss measurements have been performed on five kinds of commercially available composite materials in order to study the electric properties of composite materials at low temperatures. Thermo-stimulated current measurements have been made on the composite materials in which the matrix quality was changed intentionally. The changes in the matrices were introduced by gamma irradiation or different curing conditions. Thermo-stimulated current and dielectric loss measurements revealed the number and the molecular weight of dipolar molecules. The different features of thermo-stimulated current and dielectric losses were determined for different composite materials. The gamma irradiation and the curing conditions especially affect the thermo-stimulated current features. The changes in macroscopic mechanical properties reflect those of thermo-stimulated current. It was found that the change in quality and/or degradation of the composite materials could be detected by means of thermo-stimulated current and/or dielectric loss measurements

  9. Strain Measurement during Stress Rupture of Composite Over-Wrapped Pressure Vessel with Fiber Bragg Gratings Sensors

    Banks, Curtis E.; Grant, Joseph; Russell, Sam; Arnett, Shawn

    2008-01-01

    Fiber optic Bragg gratings were used to measure strain fields during Stress Rupture (SSM) test of Kevlar Composite Over-Wrapped Pressure Vessels (COPV). The sensors were embedded under the over-wrapped attached to the liner released from the Kevlar and attached to the Kevlar released from the liner. Additional sensors (foil gages and fiber bragg gratings) were surface mounted on the COPY liner.

  10. ECODESIGN CRITERIA FOR COMPOSITE MATERIALS AND ...

    into mechanical characterization tests, in advanced composite formulations and ... of aerospace & automobile, marine construction, renewable energy, modern ... These eco-coefficients are to be inserted into the classical lamination theory.

  11. Radiation Processing of Advanced Composite Materials

    Kang, Phil Hyun; Jeun, Joonpyo; Nho, Young Chang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-04-15

    Advanced composites, such as carbon-fiber-reinforced plastics, are being used widely for many applications. Carbon fiber/epoxies composites have attracted special attention from the aircraft, aerospace, marine engineering, sporting goods and transportation industries, because they have useful mechanical properties including high strength-to-weight and stiffness-to-weight ratios, a corrosion resistant, impact and damage tolerance characteristics and wear properties. Thermal curing has been the dominant industrial process for advanced composites until now, however, a radiation curing process using UV, microwave x-ray, electron-beam(E-beam) and {gamma}-ray has emerged as a better alternative in recent years. These processes are compatible with the manufacturing of composites using traditional fabrication methods including a filament/tape winding, pultrusion, resin transfer moulding and hand lay-up. In this study, E-beam curable carbon fiber/epoxy composites were manufactured, and their mechanical properties were investigated. Two epoxy resins (bisphenol-A, bisphenol-F) containing photo-initiators (tri aryl sulfonium hexafluorophosphate, tri aryl sulfonium hexafluoroantimonate) were used as a matrix and a 4H-satin carbon woven fabric was used as a reinforcement. And then an electron beam irradiated the composites up to 200 kGy in a vacuum and an inert atmosphere. The cure cycle was optimized and the properties of composites were evaluated and analyzed via a differential scanning calorimetry, scanning electron microscopy, sol-gel extractions, FT-NIR, universal test machine, and an impact tester. The gel content, glass transition temperature and mechanical strength of the irradiated composites were increased with an increasing radiation dose.

  12. Band Structure Characteristics of Nacreous Composite Materials with Various Defects

    Yin, J.; Zhang, S.; Zhang, H. W.; Chen, B. S.

    2016-06-01

    Nacreous composite materials have excellent mechanical properties, such as high strength, high toughness, and wide phononic band gap. In order to research band structure characteristics of nacreous composite materials with various defects, supercell models with the Brick-and-Mortar microstructure are considered. An efficient multi-level substructure algorithm is employed to discuss the band structure. Furthermore, two common systems with point and line defects and varied material parameters are discussed. In addition, band structures concerning straight and deflected crack defects are calculated by changing the shear modulus of the mortar. Finally, the sensitivity of band structures to the random material distribution is presented by considering different volume ratios of the brick. The results reveal that the first band gap of a nacreous composite material is insensitive to defects under certain conditions. It will be of great value to the design and synthesis of new nacreous composite materials for better dynamic properties.

  13. Multilayer composite material and method for evaporative cooling

    Buckley, Theresa M. (Inventor)

    2002-01-01

    A multilayer composite material and method for evaporative cooling of a person employs an evaporative cooling liquid that changes phase from a liquid to a gaseous state to absorb thermal energy. The evaporative cooling liquid is absorbed into a superabsorbent material enclosed within the multilayer composite material. The multilayer composite material has a high percentage of the evaporative cooling liquid in the matrix. The cooling effect can be sustained for an extended period of time because of the high percentage of phase change liquid that can be absorbed into the superabsorbent. Such a composite can be used for cooling febrile patients by evaporative cooling as the evaporative cooling liquid in the matrix changes from a liquid to a gaseous state to absorb thermal energy. The composite can be made with a perforated barrier material around the outside to regulate the evaporation rate of the phase change liquid. Alternatively, the composite can be made with an imperveous barrier material or semipermeable membrane on one side to prevent the liquid from contacting the person's skin. The evaporative cooling liquid in the matrix can be recharged by soaking the material in the liquid. The multilayer composite material can be fashioned into blankets, garments and other articles.

  14. Composite materials with ionic conductivity: from inorganic composites to hybrid membranes

    Yaroslavtsev, Andrei B [N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

    2009-11-30

    Information on composite materials with ionic conductivity including inorganic composites and hybrid polymeric ion exchange membranes containing inorganic or polymeric nanoparticles is generalized. The nature of the effect of increase in the ionic conductivity in this type of materials and the key approaches used for theoretical estimation of the conductivity are considered. Data on the ionic conductivity and some other important properties of composites and membrane materials are presented. Prospects for utilization of composite materials and hybrid membranes in hydrogen power engineering are briefly outlined.

  15. Standard Guide for Testing Polymer Matrix Composite Materials

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This guide summarizes the application of ASTM standard test methods (and other supporting standards) to continuous-fiber reinforced polymer matrix composite materials. The most commonly used or most applicable ASTM standards are included, emphasizing use of standards of Committee D30 on Composite Materials. 1.2 This guide does not cover all possible standards that could apply to polymer matrix composites and restricts discussion to the documented scope. Commonly used but non-standard industry extensions of test method scopes, such as application of static test methods to fatigue testing, are not discussed. A more complete summary of general composite testing standards, including non-ASTM test methods, is included in the Composite Materials Handbook (MIL-HDBK-17). Additional specific recommendations for testing textile (fabric, braided) composites are contained in Guide D6856. 1.3 This guide does not specify a system of measurement; the systems specified within each of the referenced standards shall appl...

  16. Discussion on the Standardization of Shielding Materials — Sensitivity Analysis of Material Compositions

    Ogata Tomohiro

    2017-01-01

    Full Text Available The overview of standardization activities for shielding materials is described. We propose a basic approach for standardizing material composition used in radiation shielding design for nuclear and accelerator facilities. We have collected concrete composition data from actual concrete samples to organize a representative composition and its variance data. Then the sensitivity analysis of the composition variance has been performed through a simple 1-D dose calculation. Recent findings from the analysis are summarized.

  17. Interlaminar fracture toughness for composite materials

    Lee, Kang Yong; Kwon, Soon Man

    1991-01-01

    The new equation of energy release rate for a double cantilever beam specimen is proposed within the framework of the higher order shear deformable plate theory. The interlaminar fracture toughnesses by present theory, ASTM round robin test method and acoustic emission method are compared for thermoset Graphite/Epoxy and thermoplastic AS4/PEEK composites. As a result, the interlaminar fracture toughness values by present theory show good agreement within 5% when compared with ones by ASTM method and it is shown that ones by acoustic emission method yield the lower values than ones by ASTM method. It is observed that the interlaminar fracture toughness of thermoplastic AS4/PEEK composite is about ten times larger than one of thermoset Graphite/Epoxy composite. (Author)

  18. Effect of matrix cracking and material uncertainty on composite plates

    Gayathri, P.; Umesh, K.; Ganguli, R.

    2010-01-01

    A laminated composite plate model based on first order shear deformation theory is implemented using the finite element method. Matrix cracks are introduced into the finite element model by considering changes in the A, B and D matrices of composites. The effects of different boundary conditions, laminate types and ply angles on the behavior of composite plates with matrix cracks are studied. Finally, the effect of material property uncertainty, which is important for composite material on the composite plate, is investigated using Monte Carlo simulations. Probabilistic estimates of damage detection reliability in composite plates are made for static and dynamic measurements. It is found that the effect of uncertainty must be considered for accurate damage detection in composite structures. The estimates of variance obtained for observable system properties due to uncertainty can be used for developing more robust damage detection algorithms.

  19. Mechanics of composite material subjected to eigenstress

    Fuglsang Nielsen, L.

    In this SBI Bulletin a theory is presented dealing with the mechanical behavior of composites subjected to hygro-thermal actions such as shrinkage caused by moisture variations and expansion caused by temperature variations of freezing of water in pore systems. Special attention is given to the t......In this SBI Bulletin a theory is presented dealing with the mechanical behavior of composites subjected to hygro-thermal actions such as shrinkage caused by moisture variations and expansion caused by temperature variations of freezing of water in pore systems. Special attention is given...

  20. Flexible composite material with phase change thermal storage

    Buckley, Theresa M. (Inventor)

    2001-01-01

    A highly flexible composite material having a flexible matrix containing a phase change thermal storage material. The composite material can be made to heat or cool the body or to act as a thermal buffer to protect the wearer from changing environmental conditions. The composite may also include an external thermal insulation layer and/or an internal thermal control layer to regulate the rate of heat exchange between the composite and the skin of the wearer. Other embodiments of the PCM composite also provide 1) a path for evaporation or direct absorption of perspiration from the skin of the wearer for improved comfort and thermal control, 2) heat conductive pathways within the material for thermal equalization, 3) surface treatments for improved absorption or rejection of heat by the material, and 4) means for quickly regenerating the thermal storage capacity for reuse of the material. Applications of the composite materials are also described which take advantage of the composite's thermal characteristics. The examples described include a diver's wet suit, ski boot liners, thermal socks, ,gloves and a face mask for cold weather activities, and a metabolic heating or cooling blanket useful for treating hypothermia or fever patients in a medical setting and therapeutic heating or cooling orthopedic joint supports.

  1. Optimization of sensor introduction into laminated composite materials

    Schaaf, Kristin; Nemat-Nasser, Sia

    2008-03-01

    This work seeks to extend the functionality of the composite material beyond that of simply load-bearing and to enable in situ sensing, without compromising the structural integrity of the host composite material. Essential to the application of smart composites is the issue of the mechanical coupling of the sensor to the host material. Here we present various methods of embedding sensors within the host composite material. In this study, quasi-static three-point bending (short beam) and fatigue three-point bending (short beam) tests are conducted in order to characterize the effects of introducing the sensors into the host composite material. The sensors that are examined include three types of polyvinylidene fluoride (PVDF) thin film sensors: silver ink with a protective coating of urethane, silver ink without a protective coating, and nickel-copper alloy without a protective coating. The methods of sensor integration include placement at the midplane between the layers of prepreg material as well as a sandwich configuration in which a PVDF thin film sensor is placed between the first and second and nineteenth and twentieth layers of prepreg. Each PVDF sensor is continuous and occupies the entire layer, lying in the plane normal to the thickness direction in laminated composites. The work described here is part of an ongoing effort to understand the structural effects of integrating microsensor networks into a host composite material.

  2. Validity of exploration for suitable vessels for replantation in the distal fingertip amputation in early childhood: replantation or composite graft.

    Imaizumi, Atsushi; Ishida, Kunihiro; Arashiro, Ken; Nishizeki, Osamu

    2013-09-01

    Composite grafting, grafting without microvascular anastomoses, has been widely performed for distal fingertip amputation in children with variable results, whereas successful replantation of these amputations using microsurgical technique has been reported. However, most of these reports included a wide age-range and a mix of different amputation levels. This study reviewed our cases of paediatric digital amputation, in order to verify the value of distal fingertip replantation over composite grafting, especially in early childhood. Seventeen young children (aged 3 years and 8 months on average), with single-digit fingertip amputations in Tamai zone I were reviewed from 1993-2008. Each amputation was subdivided into three types: distal, middle, and proximal. There were three distal, 13 middle, and one proximal type zone I amputations. All were crush or avulsion injuries. All three distal-type cases were reattached as primary composite grafts with one success. For middle-type cases, the survival rate of primary composite graft without exploration for possible vessels for anastomosis was 57%. On exploration, suitable vessels for anastomosis were found 50% of the time, in which all replantations were succeeded. The remaining cases were reattached as secondary composite grafts, with one success using the pocket method. Consequently, the success rate after exploration was 67%. The only one proximal-type amputation was failed in replantation. For the middle-type zone I amputation in early childhood, replantation has a high success rate if suitable vessels can be found. Therefore, exploration is recommended for amputations at this level with a view to replantation, irrespective of the mechanism of injury.

  3. Structured Piezoelectric Composites : Materials and Applications

    Van den Ende, D.A.

    2012-01-01

    The piezoelectric effect, which causes a material to generate a voltage when it deforms, is very suitable for making integrated sensors, and (micro-) generators. However, conventional piezoelectric materials are either brittle ceramics or certain polymers with a low thermal stability, which limits

  4. Quantitative Evaluation of Delamination Inside of Composite Materials by ESPI

    Kim, Koung Suk; Yang, Kwang Young; Kang, Ki Soo; Ji, Chang June

    2004-01-01

    Electronic speckle pattern interferometry (ESPI) for quantitative evaluation of delaminations inside of a composite material plate is described. Delaminations caused by the impact on composite materials are difficult to detect visual inspection and ultrasonic testing due to non-homeogenous structure. This paper proposes the quantitative evaluation technique of the defects made in the composite plates by impact load. Artificial defects are introduced inside of the composite plate for the development of a reliable ESPI inspection technique. Real defects produced by impact tester are inspected and compared with the results of visual inspection which shows a good agreement within 5% error

  5. Composite metal foil and ceramic fabric materials

    Webb, Brent J.; Antoniak, Zen I.; Prater, John T.; DeSteese, John G.

    1992-01-01

    The invention comprises new materials useful in a wide variety of terrestrial and space applications. In one aspect, the invention comprises a flexible cloth-like material comprising a layer of flexible woven ceramic fabric bonded with a layer of metallic foil. In another aspect, the invention includes a flexible fluid impermeable barrier comprising a flexible woven ceramic fabric layer having metal wire woven therein. A metallic foil layer is incontinuously welded to the woven metal wire. In yet another aspect, the invention includes a material comprising a layer of flexible woven ceramic fabric bonded with a layer of an organic polymer. In still another aspect, the invention includes a rigid fabric structure comprising a flexible woven ceramic fabric and a resinous support material which has been hardened as the direct result of exposure to ultraviolet light. Inventive methods for producing such material are also disclosed.

  6. The stress analysis method for three-dimensional composite materials

    Nagai, Kanehiro; Yokoyama, Atsushi; Maekawa, Zen'ichiro; Hamada, Hiroyuki

    1994-05-01

    This study proposes a stress analysis method for three-dimensionally fiber reinforced composite materials. In this method, the rule-of mixture for composites is successfully applied to 3-D space in which material properties would change 3-dimensionally. The fundamental formulas for Young's modulus, shear modulus, and Poisson's ratio are derived. Also, we discuss a strength estimation and an optimum material design technique for 3-D composite materials. The analysis is executed for a triaxial orthogonally woven fabric, and their results are compared to the experimental data in order to verify the accuracy of this method. The present methodology can be easily understood with basic material mechanics and elementary mathematics, so it enables us to write a computer program of this theory without difficulty. Furthermore, this method can be applied to various types of 3-D composites because of its general-purpose characteristics.

  7. Damage Evaluation and Analysis of Composite Pressure Vessels Using Fiber Bragg Gratings to Determine Structural Health

    Kunzler, Marley; Udd, Eric; Kreger, Stephen; Johnson, Mont; Henrie, Vaughn

    2005-01-01

    .... Using fiber Bragg gratings embedded into the weave structure of carbon fiber epoxy composites allow the capability to monitor these composites during manufacture, cure, general aging, and damage...

  8. Microbiological destruction of composite polymeric materials in soils

    Legonkova, O. A.; Selitskaya, O. V.

    2009-01-01

    Representatives of the same species of microscopic fungi developed on composite materials with similar polymeric matrices independently from the type of soils, in which the incubation was performed. Trichoderma harzianum, Penicillium auranthiogriseum, and Clonostachys solani were isolated from the samples of polyurethane. Fusarium solani, Clonostachys rosea, and Trichoderma harzianum predominated on the surface of ultrathene samples. Ulocladium botrytis, Penicillium auranthiogriseum, and Fusarium solani predominated in the variants with polyamide. Trichoderma harzianum, Penicillium chrysogenum, Aspergillus ochraceus, and Acremonium strictum were isolated from Lentex-based composite materials. Mucor circinelloides, Trichoderma harzianum, and Penicillium auranthiogriseum were isolated from composite materials based on polyvinyl alcohol. Electron microscopy demonstrated changes in the structure of polymer surface (loosening and an increase in porosity) under the impact of fungi. The physicochemical properties of polymers, including their strength, also changed. The following substances were identified as primary products of the destruction of composite materials: stearic acid for polyurethane-based materials; imide of dithiocarbonic acid and 1-nonadecen in variants with ultrathene; and tetraaminopyrimidine and isocyanatodecan in variants with polyamide. N,N-dimethyldodecan amide, 2-methyloximundecanon and 2-nonacosane were identified for composites on the base of Lentex A4-1. Allyl methyl sulfide and imide of dithiocarbonic acid were found in variants with the samples of composites based on polyvinyl alcohol. The identified primary products of the destruction of composite materials belong to nontoxic compounds.

  9. Mathematical model predicts the elastic behavior of composite materials

    Zoroastro de Miranda Boari

    2005-03-01

    Full Text Available Several studies have found that the non-uniform distribution of reinforcing elements in a composite material can markedly influence its characteristics of elastic and plastic deformation and that a composite's overall response is influenced by the physical and geometrical properties of its reinforcing phases. The finite element method, Eshelby's method and dislocation mechanisms are usually employed in formulating a composite's constitutive response. This paper discusses a composite material containing SiC particles in an aluminum matrix. The purpose of this study was to find the correlation between a composite material's particle distribution and its resistance, and to come up with a mathematical model to predict the material's elastic behavior. The proposed formulation was applied to establish the thermal stress field in the aluminum-SiC composite resulting from its fabrication process, whereby the mixture is prepared at 600 °C and the composite material is used at room temperature. The analytical results, which are presented as stress probabilities, were obtained from the mathematical model proposed herein. These results were compared with the numerical ones obtained by the FEM method. A comparison of the results of the two methods, analytical and numerical, reveals very similar average thermal stress values. It is also shown that Maxwell-Boltzmann's distribution law can be applied to identify the correlation between the material's particle distribution and its resistance, using Eshelby's thermal stresses.

  10. Standard practice for examination of Gas-Filled filament-wound composite pressure vessels using acoustic emission

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice provides guidelines for acoustic emission (AE) examination of filament-wound composite pressure vessels, for example, the type used for fuel tanks in vehicles which use natural gas fuel. 1.2 This practice requires pressurization to a level equal to or greater than what is encountered in normal use. The tanks' pressurization history must be known in order to use this practice. Pressurization medium may be gas or liquid. 1.3 This practice is limited to vessels designed for less than 690 bar [10,000 psi] maximum allowable working pressure and water volume less than 1 m3 or 1000 L [35.4 ft3]. 1.4 AE measurements are used to detect emission sources. Other nondestructive examination (NDE) methods may be used to gain additional insight into the emission source. Procedures for other NDE methods are beyond the scope of this practice. 1.5 This practice applies to examination of new and in-service filament-wound composite pressure vessels. 1.6 This practice applies to examinations conducted at amb...

  11. Mechanical behaviour of composite materials made by resin film infusion

    Casavola C.

    2010-06-01

    Full Text Available Innovative composite materials are frequently used in designing aerospace, naval and automotive components. In the typical structure of composites, multiple layers are stacked together with a particular sequence in order to give specific mechanical properties. Layers are organized with different angles, different sequences and different technological process to obtain a new and innovative material. From the standpoint of engineering designer it is useful to consider the single layer of composite as macroscopically homogeneous material. However, composites are non homogeneous bodies. Moreover, layers are not often perfectly bonded together and delamination often occurs. Other violations of lamination theory hypotheses, such as plane stress and thin material, are not unusual and in many cases the transverse shear flexibility and the thickness-normal stiffness should be considered. Therefore the real behaviour of composite materials is quite different from the predictions coming from the traditional lamination theory. Due to the increasing structural performance required to innovative composites, the knowledge of the mechanical properties for different loading cases is a fundamental source of concern. Experimental characterization of materials and structures in different environmental conditions is extremely important to understand the mechanical behaviour of these new materials. The purpose of the present work is to characterize a composite material developed for aerospace applications and produced by means of the resin film infusion process (RFI. Different tests have been carried out: tensile, open-hole and filled-hole tensile, compressive, openhole and filled-hole compressive. The experimental campaign has the aim to define mechanical characteristics of this RFI composite material in different conditions: environmental temperature, Hot/Wet and Cold.

  12. Using Virtual Testing for Characterization of Composite Materials

    Harrington, Joseph

    Composite materials are finally providing uses hitherto reserved for metals in structural systems applications -- airframes and engine containment systems, wraps for repair and rehabilitation, and ballistic/blast mitigation systems. They have high strength-to-weight ratios, are durable and resistant to environmental effects, have high impact strength, and can be manufactured in a variety of shapes. Generalized constitutive models are being developed to accurately model composite systems so they can be used in implicit and explicit finite element analysis. These models require extensive characterization of the composite material as input. The particular constitutive model of interest for this research is a three-dimensional orthotropic elasto-plastic composite material model that requires a total of 12 experimental stress-strain curves, yield stresses, and Young's Modulus and Poisson's ratio in the material directions as input. Sometimes it is not possible to carry out reliable experimental tests needed to characterize the composite material. One solution is using virtual testing to fill the gaps in available experimental data. A Virtual Testing Software System (VTSS) has been developed to address the need for a less restrictive method to characterize a three-dimensional orthotropic composite material. The system takes in the material properties of the constituents and completes all 12 of the necessary characterization tests using finite element (FE) models. Verification and validation test cases demonstrate the capabilities of the VTSS.

  13. Evaluation of radiation-shielding properties of the composite material

    Pavlenko, V.I.; Chekashina, N.I.; Yastrebinskij, R.N.; Sokolenko, I.V.; Noskov, A.V.

    2016-01-01

    The paper presents the evaluation of radiation-shielding properties of composite materials with respect to gamma-radiation. As a binder for the synthesis of radiation-shielding composites we used lead boronsilicate glass matrix. As filler we used nanotubular chrysotile filled with lead tungstate PbWO4. It is shown that all the developed composites have good physical-mechanical characteristics, such as compressive strength, thermal stability and can be used as structural materials. On the basis of theoretical calculation we described the graphs of the gamma-quanta linear attenuation coefficient depending on the emitted energy for all investigated composites. We founded high radiation-shielding properties of all the composites on the basis of theoretical and experimental data compared to materials conventionally used in the nuclear industry - iron, concrete, etc

  14. Choosing the optimal Pareto composition of the charge material for the manufacture of composite blanks

    Zalazinsky, A. G.; Kryuchkov, D. I.; Nesterenko, A. V.; Titov, V. G.

    2017-12-01

    The results of an experimental study of the mechanical properties of pressed and sintered briquettes consisting of powders obtained from a high-strength VT-22 titanium alloy by plasma spraying with additives of PTM-1 titanium powder obtained by the hydride-calcium method and powder of PV-N70Yu30 nickel-aluminum alloy are presented. The task is set for the choice of an optimal charge material composition of a composite material providing the required mechanical characteristics and cost of semi-finished products and items. Pareto optimal values for the composition of the composite material charge have been obtained.

  15. Development of Composite Materials with High Passive Damping Properties

    Crocker, Malcolm J

    2006-01-01

    .... However their fatigue, vibration and acoustic properties are known less. This is a problem since such composite materials tend to be more brittle than metals because of the possibility of delamination and fiber breakage...

  16. Composite Materials for Thermal Energy Storage: Enhancing Performance through Microstructures

    Ge, Zhiwei; Ye, Feng; Ding, Yulong

    2014-01-01

    Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. PMID:24591286

  17. Review of probabilistic models of the strength of composite materials

    Sutherland, L.S.; Guedes Soares, C.

    1997-01-01

    The available literature concerning probabilistic models describing the strength of composite materials has been reviewed to highlight the important aspects of this behaviour which will be of interest to the modelling and analysis of a complex system. The success with which these theories have been used to predict experimental results has been discussed. Since the brittle reinforcement phase largely controls the strength of composites, the probabilistic theories used to describe the strength of brittle materials, fibres and bundles of fibres have been detailed. The use of these theories to predict the strength of composite materials has been considered, along with further developments incorporating the damage accumulation observed in the failure of such materials. Probabilistic theories of the strength of short-fibre composites have been outlined. Emphasis has been placed throughout on straightforward engineering explanations of these theories and how they may be used, rather than providing comprehensive statistical descriptions

  18. Composite materials for thermal energy storage: enhancing performance through microstructures.

    Ge, Zhiwei; Ye, Feng; Ding, Yulong

    2014-05-01

    Chemical incompatibility and low thermal conductivity issues of molten-salt-based thermal energy storage materials can be addressed by using microstructured composites. Using a eutectic mixture of lithium and sodium carbonates as molten salt, magnesium oxide as supporting material, and graphite as thermal conductivity enhancer, the microstructural development, chemical compatibility, thermal stability, thermal conductivity, and thermal energy storage performance of composite materials are investigated. The ceramic supporting material is essential for preventing salt leakage and hence provides a solution to the chemical incompatibility issue. The use of graphite gives a significant enhancement on the thermal conductivity of the composite. Analyses suggest that the experimentally observed microstructural development of the composite is associated with the wettability of the salt on the ceramic substrate and that on the thermal conduction enhancer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. How to determine composite material properties using numerical homogenization

    Andreassen, Erik; Andreasen, Casper Schousboe

    2014-01-01

    Numerical homogenization is an efficient way to determine effective macroscopic properties, such as the elasticity tensor, of a periodic composite material. In this paper an educational description of the method is provided based on a short, self-contained Matlab implementation. It is shown how...... the basic code, which computes the effective elasticity tensor of a two material composite, where one material could be void, is easily extended to include more materials. Furthermore, extensions to homogenization of conductivity, thermal expansion, and fluid permeability are described in detail. The unit...

  20. Preliminary materials selection issues for the next generation nuclear plant reactor pressure vessel.

    Natesan, K.; Majumdar, S.; Shankar, P. S.; Shah, V. N.; Nuclear Engineering Division

    2007-03-21

    In the coming decades, the United States and the entire world will need energy supplies to meet the growing demands due to population increase and increase in consumption due to global industrialization. One of the reactor system concepts, the Very High Temperature Reactor (VHTR), with helium as the coolant, has been identified as uniquely suited for producing hydrogen without consumption of fossil fuels or the emission of greenhouse gases [Generation IV 2002]. The U.S. Department of Energy (DOE) has selected this system for the Next Generation Nuclear Plant (NGNP) Project, to demonstrate emissions-free nuclear-assisted electricity and hydrogen production within the next 15 years. The NGNP reference concepts are helium-cooled, graphite-moderated, thermal neutron spectrum reactors with a design goal outlet helium temperature of {approx}1000 C [MacDonald et al. 2004]. The reactor core could be either a prismatic graphite block type core or a pebble bed core. The use of molten salt coolant, especially for the transfer of heat to hydrogen production, is also being considered. The NGNP is expected to produce both electricity and hydrogen. The process heat for hydrogen production will be transferred to the hydrogen plant through an intermediate heat exchanger (IHX). The basic technology for the NGNP has been established in the former high temperature gas reactor (HTGR) and demonstration plants (DRAGON, Peach Bottom, AVR, Fort St. Vrain, and THTR). In addition, the technologies for the NGNP are being advanced in the Gas Turbine-Modular Helium Reactor (GT-MHR) project, and the South African state utility ESKOM-sponsored project to develop the Pebble Bed Modular Reactor (PBMR). Furthermore, the Japanese HTTR and Chinese HTR-10 test reactors are demonstrating the feasibility of some of the planned components and materials. The proposed high operating temperatures in the VHTR place significant constraints on the choice of material selected for the reactor pressure vessel for

  1. Mechanical behaviour of dental composite filling materials using digital holography

    Monteiro, J.M.; Lopes, H.; Vaz, M.A.P.; Campos, J.C. Reis

    2010-01-01

    One of the most common clinical problems in dentistry is tooth decay. Among the dental filling materials used to repair tooth structure that has been destroyed by decay are dental amalgam and composite materials based on acrylics. Dental amalgam has been used by dentists for the past 150 years as a dental restorative material due to its low cost, ease of application, strength, durability, and bacteriostatic effects. However its safety as a filling material has been questioned due to th...

  2. Low-Cost Composite Materials and Structures for Aircraft Applications

    Deo, Ravi B.; Starnes, James H., Jr.; Holzwarth, Richard C.

    2003-01-01

    A survey of current applications of composite materials and structures in military, transport and General Aviation aircraft is presented to assess the maturity of composites technology, and the payoffs realized. The results of the survey show that performance requirements and the potential to reduce life cycle costs for military aircraft and direct operating costs for transport aircraft are the main reasons for the selection of composite materials for current aircraft applications. Initial acquisition costs of composite airframe components are affected by high material costs and complex certification tests which appear to discourage the widespread use of composite materials for aircraft applications. Material suppliers have performed very well to date in developing resin matrix and fiber systems for improved mechanical, durability and damage tolerance performance. The next challenge for material suppliers is to reduce material costs and to develop materials that are suitable for simplified and inexpensive manufacturing processes. The focus of airframe manufacturers should be on the development of structural designs that reduce assembly costs by the use of large-scale integration of airframe components with unitized structures and manufacturing processes that minimize excessive manual labor.

  3. Composite perovskite materials, methods of making, and methods of use

    Yu, Weili; Amassian, Aram

    2017-01-01

    Embodiments of the present disclosure provide materials, devices and systems including a composite of halide perovskite single crystals and nanotubes, and the like. Embodiments of the composite can be used in devices such as detectors, solar panels, transistors, sensors, and the like.

  4. Composite perovskite materials, methods of making, and methods of use

    Yu, Weili

    2017-12-14

    Embodiments of the present disclosure provide materials, devices and systems including a composite of halide perovskite single crystals and nanotubes, and the like. Embodiments of the composite can be used in devices such as detectors, solar panels, transistors, sensors, and the like.

  5. Multifunctional composite material based on carbon-filled polyurethane

    Malinovskaya, T; Melentyev, S; Pavlov, S

    2015-01-01

    The research paper deals with the performance of composite resistive material heating coatings based on the polyurethane binder, filled with colloidal-graphite preparation C- 1, which can be used in structures of electric heaters. Frequency dependences of transmission and reflection coefficients, dielectric permeability of composite materials with the various content of carbon fillers (technical carbon, graphite) in polyurethane varnish in ranges of frequencies 26-40 GHz and 110-260 GHz are experimentally investigated. (paper)

  6. Production and Mechanical Characterization of Ballistic Thermoplastic Composite Materials

    D. Korsacilar; C. Atas

    2014-01-01

    In this study, first thermoplastic composite materials /plates that have high ballistic impact resistance were produced. For this purpose, the thermoplastic prepreg and the vacuum bagging technique were used to produce a composite material. Thermoplastic prepregs (resin-impregnated fiber) that are supplied ready to be used, namely high-density polyethylene (HDPE) was chosen as matrix and unidirectional glass fiber was used as reinforcement. In order to compare the fiber c...

  7. Uncertainty on Fatigue Damage Accumulation for Composite Materials

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    2009-01-01

    In the present paper stochastic models for fatigue damage accumulation for composite materials are presented based on public available constant and variable amplitude fatigue tests. The methods used for estimating the SN-curve and accumulated fatigue damage are presented.......In the present paper stochastic models for fatigue damage accumulation for composite materials are presented based on public available constant and variable amplitude fatigue tests. The methods used for estimating the SN-curve and accumulated fatigue damage are presented....

  8. Mechanical compatibility and stress analyses in composite materials

    Schimmoeller, H.; Ruge, J.

    1976-01-01

    This paper gives a short description of the problem of mechanical interactions and mechanical compatibility in composite bodies. The formation of stress-strain states, caused by the mechanical compatibility by bonding of the interfaces, is discussed. The difference between the continuous and discontinuous type of material transition in the interface is described. Flat laminated materials are at first considered. For this type of composite bodies thermal stresses and thermal residual stresses are elastically-plastically calculated. (orig.) [de

  9. Mechanical Characterization of Cotton Fiber/Polyester Composite Material

    Altaf Hussain Rajper

    2014-04-01

    Full Text Available Development of composite from natural fiber for lower structural application is growing for long-term sustainable perspective. Cotton fiber composite material has the added advantages of high specific strength, corrosion resistance, low cost and low weight compared to glass fiber on the expense of internal components of IC engines. The primary aim of the research study is to examine the effect of the cotton fiber on mechanical properties of lower structural applications when added with the polyester resin. In this paper composite material sample has been prepared by hand Lay-Up process. A mould is locally developed in the laboratory for test sample preparation. Initially samples of polyester resin with appropriate ratio of the hardener were developed and tested. At the second stage yarns of cotton fiber were mixed with the polyester resin and sample specimens were developed and tested. Relative effect of the cotton as reinforcing agent was examined and observed that developed composite specimen possess significant improvement in mechanical properties such as tensile strength was improved as 19.78 % and modulus of elasticity was increased up to 24.81%. Through this research it was also observed that developed composite material was of ductile nature and its density decreases up to 2.6%. Results from this study were compared with relevant available advanced composite materials and found improved mechanical properties of developed composite material

  10. Ceramic matrix composites -- Advanced high-temperature structural materials

    Lowden, R.A.; Ferber, M.K.; DiPietro, S.G.

    1995-01-01

    This symposium on Ceramic Matrix Composites: Advanced High-Temperature Structural Materials was held at the 1994 MRS Fall Meeting in Boston, Massachusetts on November 28--December 2. The symposium was sponsored by the Department of Energy's Office of Industrial Technology's Continuous Fiber Ceramic Composites Program, the Air Force Office of Scientific Research, and NASA Lewis Research Center. Among the competing materials for advanced, high-temperature applications, ceramic matrix composites are leading candidates. The symposium was organized such that papers concerning constituents--fibers and matrices--were presented first, followed by composite processing, modeling of mechanical behavior, and thermomechanical testing. More stable reinforcements are necessary to enhance the performance and life of fiber-reinforced ceramic composites, and to ensure final acceptance of these materials for high-temperature applications. Encouraging results in the areas of polymer-derived SiC fibers and single crystal oxide filaments were given, suggesting composites with improved thermomechanical properties and stability will be realized in the near future. The significance of the fiber-matrix interface in the design and performance of these materials is evident. Numerous mechanical models to relate interface properties to composite behavior, and interpret test methods and data, were enthusiastically discussed. One issue of great concern for any advanced material for use in extreme environments is stability. This theme arose frequently throughout the symposium and was the topic of focus on the final day. Fifty nine papers have been processed separately for inclusion on the data base

  11. Composite Material Suitable for Use as Electrode Material in a SOC

    2010-01-01

    The present invention relates to composite material suitable for use as an electrode material in a solid oxide cell, said composite material consist of at least two non-miscible mixed ionic and electronic conductors. Further provided is a composite material suitable for use as an electrode material...... in a solid oxide cell, said composite material being based on (Gd1-xSrx)1-sFe1-yCoyO3-[delta] or (Ln1-xSrx)1-sFe1-yCioyO3-[delta](s equal to 0.05 or larger) wherein Ln is a lanthanide element, Sc or Y, said composite material comprising at least two phases which are non-miscible, said composite material...... being obtainable by the glycine nitrate combustion method. Said composite material may be used for proving an electrode material in the form of at least a two-phase system showing a very low area specific resistance of around 0.1 [Omega]cm2 at around 600 DEG C....

  12. Statistical analysis and interpolation of compositional data in materials science.

    Pesenson, Misha Z; Suram, Santosh K; Gregoire, John M

    2015-02-09

    Compositional data are ubiquitous in chemistry and materials science: analysis of elements in multicomponent systems, combinatorial problems, etc., lead to data that are non-negative and sum to a constant (for example, atomic concentrations). The constant sum constraint restricts the sampling space to a simplex instead of the usual Euclidean space. Since statistical measures such as mean and standard deviation are defined for the Euclidean space, traditional correlation studies, multivariate analysis, and hypothesis testing may lead to erroneous dependencies and incorrect inferences when applied to compositional data. Furthermore, composition measurements that are used for data analytics may not include all of the elements contained in the material; that is, the measurements may be subcompositions of a higher-dimensional parent composition. Physically meaningful statistical analysis must yield results that are invariant under the number of composition elements, requiring the application of specialized statistical tools. We present specifics and subtleties of compositional data processing through discussion of illustrative examples. We introduce basic concepts, terminology, and methods required for the analysis of compositional data and utilize them for the spatial interpolation of composition in a sputtered thin film. The results demonstrate the importance of this mathematical framework for compositional data analysis (CDA) in the fields of materials science and chemistry.

  13. Material parameter identification on metal matrix composites

    Jansen van Rensburg, GJ

    2012-07-01

    Full Text Available conditions that best replicate the experimental data. The quality of the fits is subject to the limits of the material model and boundary parameterisation. An alternative procedure that uses the time and strain history to evolve the yield stress is also...

  14. Zirconia-hydroxyapatite composite material with micro porous structure.

    Matsumoto, Takuya Junior; An, Sang-Hyun; Ishimoto, Takuya; Nakano, Takayoshi; Matsumoto, Takuya; Imazato, Satoshi

    2011-11-01

    Titanium plates and apatite blocks are commonly used for restoring large osseous defects in dental and orthopedic surgery. However, several cases of allergies against titanium have been recently reported. Also, sintered apatite block does not possess sufficient mechanical strength. In this study, we attempted to fabricate a composite material that has mechanical properties similar to biocortical bone and high bioaffinity by compounding hydroxyapatite (HAp) with the base material zirconia (ZrO(2)), which possesses high mechanical properties and low toxicity toward living organisms. After mixing the raw material powders at several different ZrO(2)/HAp mixing ratios, the material was compressed in a metal mold (8 mm in diameter) at 5 MPa. Subsequently, it was sintered for 5 h at 1500°C to obtain the ZrO(2)/HAp composite. The mechanical property and biocompatibility of materials were investigated. Furthermore, osteoconductivity of materials was investigated by animal studies. A composite material with a minute porous structure was successfully created using ZrO(2)/HAp powders, having different particle sizes, as the starting material. The material also showed high protein adsorption and a favorable cellular affinity. When the mixing ratio was ZrO(2)/HAp=70/30, the strength was equal to cortical bone. Furthermore, in vivo experiments confirmed its high osteoconductivity. The composite material had strength similar to biocortical bones with high cell and tissue affinities by compounding ZrO(2) and HAp. The ZrO(2)/HAp composite material having micro porous structure would be a promising bone restorative material. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Materials selection, qualification and manufacturing of the in-vessel divertor cryopump for JET

    Papastergiou, S.; Obert, W.; Thompson, E.

    1994-01-01

    The introduction of a cryopump into the interior of a large tokamak raises several technical problems related to the thermal stresses, eddy current forces and choice of materials. The JET divertor cryopump has been optimized in terms of stresses, flow stability and operation - the liquid nitrogen cooled chevron structure in particular having to fulfill conflicting requirements at cryogenic temperatures. These requirements include good thermal conductivity in order to minimize thermal gradients (to reduce the radiative heat load onto the liquid helium circuit), high electrical resistivity (to minimize eddy current stresses), high mechanical strength and good mechanical formability. This paper reports on the materials selection based on measurements of properties at cryogenic and elevated temperatures and the development of an optimized thermal treatment combining solution heat treatment, brazing and precipitation hardening. It also reports on the successful development of various manufacturing technologies which have been employed including (a) techniques for brazing of the chosen copper alloy onto inconel and stainless steel, (b) surface blackening of the copper alloy with plasma sprayed ceramic coatings that are vacuum compatible and able to withstand temperatures between 70 K and 1135 K and (c) plasma spray deposition of copper onto stainless steel in order to produce an anisotropic composite material with improved thermal conductivity, high strength and high electrical resistivity for use at temperatures between 70 K and 650 K

  16. Electrode material comprising graphene-composite materials in a graphite network

    Kung, Harold H.; Lee, Jung K.

    2017-08-08

    A durable electrode material suitable for use in Li ion batteries is provided. The material is comprised of a continuous network of graphite regions integrated with, and in good electrical contact with a composite comprising graphene sheets and an electrically active material, such as silicon, wherein the electrically active material is dispersed between, and supported by, the graphene sheets.

  17. Method of tissue repair using a composite material

    Hutchens, Stacy A.; Woodward, Jonathan; Evans, Barbara R.; O' Neill, Hugh M.

    2016-03-01

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  18. Method of tissue repair using a composite material

    Hutchens, Stacy A; Woodward, Jonathan; Evans, Barbara R; O'Neill, Hugh M

    2014-03-18

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  19. Carbon Cryogel Silicon Composite Anode Materials for Lithium Ion Batteries

    Woodworth James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 10 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-4,9 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  20. Lightweight Composite Materials for Heavy Duty Vehicles

    Pruez, Jacky; Shoukry, Samir; Williams, Gergis; Shoukry, Mark

    2013-08-31

    The main objective of this project is to develop, analyze and validate data, methodologies and tools that support widespread applications of automotive lightweighting technologies. Two underlying principles are guiding the research efforts towards this objective: • Seamless integration between the lightweight materials selected for certain vehicle systems, cost-effective methods for their design and manufacturing, and practical means to enhance their durability while reducing their Life-Cycle-Costs (LCC). • Smooth migration of the experience and findings accumulated so far at WVU in the areas of designing with lightweight materials, innovative joining concepts and durability predictions, from applications to the area of weight savings for heavy vehicle systems and hydrogen storage tanks, to lightweighting applications of selected systems or assemblies in light–duty vehicles.

  1. Nonmetallic and composite materials as solid superleaks

    Goldschvartz, J.M.

    1982-01-01

    This chapter discusses the devices in general solid porous materials in which the so-called diameter of the pores, gaps, inter-crystalline spaces, or small channels, etc, are equal or smaller than 100 0 A. Examines silicon carbide, wonderstone, talc-stone, rocks as superleaks, magnetic superleaks, the onset point of a superleak, determination of the onset point, and some applications of superleaks (as a filter, as an isotope separator, as a separator in the 3 He- 4 He dilution refrigerator, in a vortex refrigerator, in a servo-valve for liquid helium two (the cocatron), method of measuring the size of sub-microscopic pores, ultra cold neutrons, superconductors pressed into porous materials)

  2. Accelerated hygrothermal stabilization of composite materials

    Gale, Jeffrey Alan [Univ. of California, Davis, CA (United States)

    1994-05-01

    Experimentation validated a simple moisture conditioning scheme to prepare Gr/Ep composite parts for precision applications by measuring dimensional changes over 90 days. It was shown that an elevated temperature moisture conditioning scheme produced a dimensionally stable part from which precision structures could be built/machined without significant moisture induced dimensional changes after fabrication. Conversely, that unconditioned Gr/Ep composite panels exhibited unacceptably large dimensional changes (i.e., greater than 125 ppM). It was also shown that time required to produce stable parts was shorter, by more than an order of magnitude, employing the conditioning scheme than using no conditioning scheme (46 days versus 1000+ days). Two final use environments were chosen for the experiments: 50% RH/21C and 0% RH/21C. Fiberite 3034K was chosen for its widespread use in aerospace applications. Two typical lay-ups were chosen, one with low sensitivity to hygrothermal distortions and the other high sensitivity: [0, ± 45, 90]s, [0, ± 15, 0]s. By employing an elevated temperature, constant humidity conditioning scheme, test panels achieved an equilibrium moisture content in less time, by more than an order of magnitude, than panels exposed to the same humidity environment and ambient temperature. Dimensional changes, over 90 days, were up to 4 times lower in the conditioned panels compared to unconditioned panels. Analysis of weight change versus time of test coupons concluded that the out-of-autoclave moisture content of Fiberite 3034K varied between 0.06 and 0.1%.

  3. RF electromagnetic wave absorbing properties of ferrite polymer composite materials

    Dosoudil, Rastislav; Usakova, Marianna; Franek, Jaroslav; Slama, Jozef; Olah, Vladimir

    2006-01-01

    The frequency dispersion of complex initial (relative) permeability (μ * =μ ' -jμ ' ') and the electromagnetic wave absorbing properties of composite materials based on NiZn sintered ferrite and a polyvinylchloride (PVC) polymer matrix have been studied in frequency range from 1MHz to 1GHz. The complex permeability of the composites was found to increase as the ferrite content increased, and was characterized by frequency dispersion localized above 50MHz. The variation of return loss (RL) of single-layer RF absorbers using the prepared composite materials has been investigated as a function of frequency, ferrite content and the thickness of the absorbers

  4. Practical Considerations of Design, Fabrication and Tests for Composite Materials,

    1982-09-01

    Harris 2 School of Materials Science University of Bath Claverton Down Bath AB2 7AY UK 1. THE IDEA OF A COMPOSITE The concept is a familiar one even to...A.R. Bunsell " Comportement en torsion des fibres de Kevlar-29 " Colloque nt CNRS No. 319 Comportement plastique des solides anisotropes. 16-19 June...d’hhlicoptares en composites : conception , rdalisation et comportement en operation ". Advances in Composite Materials Vol II Ed. A.R. Bunsell, C. Bathias

  5. Enhancement of the quality of the reactor pressure vessel used in light water power plants by advanced material, fabrication and testing technologies

    Kussmaul, K.; Ewald, J.; Maier, G.; Schellhammer, W.

    1980-01-01

    Fracture safe assessment of nuclear reactor pressure vessels (RPV) is based upon an adequate stress analysis, reliable material characteristics, and acceptable defect sizes. Problems may arise concerning inhomogeneties, low toughness and crack phenomena as observed in the base material and heat affected zone (HAZ). Therefore, efforts have been made to develop a steel which would be both non-susceptible to embrittlement and/or cracking in the HAZ, and have a higher upper-shelf toughness of base and HAZ material. Tests have been made on inhomogeneties and defects and also on improvement of chemical composition, the steel-making process, welding procedures and the optimum temperature cycle and level for stress-relief heat treatment. To solve these problems, common testing methods were supplemented by tangential-cut techniques, small HAZ-tensile test procedures and HAZ-simulation techniques. Results indicate that 50 per cent of 100 investigated component-strength welds are affected by micro stress-relief cracking (SRC) on a micro-and millimetre scale. The 22 NiMoCr 37 steel with optimised chemical composition, and the 20 MnMoNi 55 steel are both resistant to stress-relief embrittlement and SRC. Specific welding techniques are found to limit SRC and proposals for optimum stress-relief temperatures are given. For the generation of new components, the fracture-safe analysis can now be based completely upon homogeneous and high upper-shelf base materials including the HAZ. (author)

  6. Multilayer Electroactive Polymer Composite Material Comprising Carbon Nanotubes

    Ounaies, Zoubeida (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Draughon, Gregory K. (Inventor)

    2009-01-01

    An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

  7. Supercapacitors Based on Nickel Oxide/Carbon Materials Composites

    Katarzyna Lota

    2011-01-01

    Full Text Available In the thesis, the properties of nickel oxide/active carbon composites as the electrode materials for supercapacitors are discussed. Composites with a different proportion of nickel oxide/carbon materials were prepared. A nickel oxide/carbon composite was prepared by chemically precipitating nickel hydroxide on an active carbon and heating the hydroxide at 300 ∘C in the air. Phase compositions of the products were characterized using X-ray diffractometry (XRD. The morphology of the composites was observed by SEM. The electrochemical performances of composite electrodes used in electrochemical capacitors were studied in addition to the properties of electrode consisting of separate active carbon and nickel oxide only. The electrochemical measurements were carried out using cyclic voltammetry, galvanostatic charge/discharge, and impedance spectroscopy. The composites were tested in 6 M KOH aqueous electrolyte using two- and three-electrode Swagelok systems. The results showed that adding only a few percent of nickel oxide to active carbon provided the highest value of capacity. It is the confirmation of the fact that such an amount of nickel oxide is optimal to take advantage of both components of the composite, which additionally can be a good solution as a negative electrode in asymmetric configuration of electrode materials in an electrochemical capacitor.

  8. Development and characterization of composite materials for production of composite risers by filament winding

    Sobrinho, L.L.; Bastian, F.L. [Federal University of Rio de Janeiro, RJ (Brazil). Dept. of Metallurgical and Materials Engineering], e-mail: ledjane@metalmat.ufrj.br; Calado, V.M.A. [Federal University of Rio de Janeiro, RJ (Brazil). Escola de Quimica

    2008-07-01

    Industry has been challenged to provide riser systems which are more cost effective and which can fill the technology gaps with respect to water depth, riser diameter and high temperatures left open by flexible, steel catenary risers (SCRs) and hybrid risers. Composite materials present advantages over conventional steel risers because composite materials are lighter, more fatigue and corrosion resistant, better thermal insulators and can be designed for improving the structural and mechanical response. Besides, composite materials present some attractive attributes for the offshore service, such as: high specific strength and stiffness. This paper focuses on the development and characterization of a polymer matrix (epoxy) and of material composite (epoxy/fiber glass), which will be used in a development for composites risers by the filament winding process (wet winding). (author)

  9. Structurally integrated fiber optic damage assessment system for composite materials.

    Measures, R M; Glossop, N D; Lymer, J; Leblanc, M; West, J; Dubois, S; Tsaw, W; Tennyson, R C

    1989-07-01

    Progress toward the development of a fiber optic damage assessment system for composite materials is reported. This system, based on the fracture of embedded optical fibers, has been characterized with respect to the orientation and location of the optical fibers in the composite. Together with a special treatment, these parameters have been tailored to yield a system capable of detecting the threshold of damage for various impacted Kevlar/epoxy panels. The technique has been extended to measure the growth of a damage region which could arise from either impact, manufacturing flaws, or static overloading. The mechanism of optical fiber fracture has also been investigated. In addition, the influence of embedded optical fibers on the tensile and compressive strength of the composite material has been studied. Image enhanced backlighting has been shown to be a powerful and convenient method of assessing internal damage to translucent composite materials.

  10. Cylindrical concave body of composite fibrous material

    1979-01-01

    The invention is concerned with a cylindrical concave body of compound fibrous material which is intended to be exposed to high rotation speeds around its own longitudinal axis. The concave body in question has at least one layer of fibrils that are interwoven and enclose an identical angle with the longitudinal axis of the concave body in both directions. The concave body in question also has at least a second layer of fibrils that run in the direction of the circumference and are fitted radially to the outside. The cylindrical concave body of the invention is particularly well suited for application as a rotor tube in a gas ultra-centrifuge

  11. How to replace a reactor pressure vessel

    Huber, R.

    1996-01-01

    A potential life extending procedure for a nuclear reactor after, say, 40 years of service life, might in some circumstances be the replacement of the reactor pressure vessel. Neutron induced degradation of the vessel might make replacement by one of a different material composition desirable, for example. Although the replacement of heavy components, such as steam generators, has been possible for many years, the pressure vessel presents a much more demanding task if only because it is highly irradiated. Some preliminary feasibility studies by Siemens are reported for the two removal strategies that might be considered. These are removal of the entire pressure vessel in one piece and dismantling it into sections. (UK)

  12. Fracture-mechanics data deduced from thermal-shock and related experiments with LWR pressure-vessel material

    Cheverton, R.D.; Canonico, D.A.; Iskander, S.K.; Bolt, S.E.; Holz, P.P.; Nanstad, R.K.; Stelzman, W.J.

    1982-01-01

    Pressurized water reactors (PWRs) are susceptible to certain types of hypothetical accidents that can subject the reactor pressure vessel to severe thermal shock, that is, a rapid cooling of the inner surface of the vessel wall. The thermal-shock loading, coupled with the radiation-induced reduction in the material fracture toughness, introduces the possibility of propagation of preexistent flaws and what at one time were regarded as somewhat unique fracture-oriented conditions. Several postulated reactor accidents have been analyzed to discover flaw behavior trends; seven intermediate-scale thermal-shock experiments with steel cylinders have been conducted; and corresponding materials characterization studies have been performed. Flaw behavior trends and related fracture-mechanics data deduced from these studies are discussed

  13. Measurement of complex permittivity of composite materials using waveguide method

    Tereshchenko, O.V.; Buesink, Frederik Johannes Karel; Leferink, Frank Bernardus Johannes

    2011-01-01

    Complex dielectric permittivity of 4 different composite materials has been measured using the transmissionline method. A waveguide fixture in L, S, C and X band was used for the measurements. Measurement accuracy is influenced by air gaps between test fixtures and the materials tested. One of the

  14. Antibacterial properties of nanocomposite materials and compositions on there bases

    Podol'skaya, V.I.; Vojtenko, O.Yu.; Grishenko, N.I.; Ul'berg, Z.P.; Yakubenko, L.N.

    2012-01-01

    The structured nanobiocomposite materials based on microbial cells and colloidal silver can serve as the new adjuvant systems. These composite materials being filled with active components, in particular the medications allow to prepare the long release preparations with synergetic effect or can just contribute to prolonged drug action

  15. Hybrid Composite Material and Solid Particle Erosion Studies

    Chellaganesh, D.; Khan, M. Adam; Ashif, A. Mohamed; Ragul Selvan, T.; Nachiappan, S.; Winowlin Jappes, J. T.

    2018-04-01

    Composite is one of the predominant material for most challenging engineering components. Most of the components are in the place of automobile structure, aircraft structures, and wind turbine blade and so on. At the same all the components are indulged to mechanical loading. Recent research on composite material are machinability, wear, tear and corrosion studies. One of the major issue on recent research was solid particle air jet erosion. In this paper hybrid composite material with and without filler. The fibre are in the combination of hemp – kevlar (60:40 wt.%) as reinforcement using epoxy as a matrix. The natural material palm and coconut shell are used as filler materials in the form of crushed powder. The process parameter involved are air jet velocity, volume of erodent and angle of impingement. Experiment performed are in eight different combinations followed from 2k (k = 3) factorial design. From the investigation surface morphology was studied using electron microscope. Mass change with respect to time are used to calculate wear rate and the influence of the process parameters. While solid particle erosion the hard particle impregnates in soft matrix material. Influence of filler material has reduced the wear and compared to plain natural composite material.

  16. Development of ductile cementitious composites incorporating microencapsulated phase change materials

    Savija, B.; Lukovic, M.; Chaves Figueiredo, S.; de Mendoca Filho, Fernando Franca; Schlangen, H.E.J.G.

    2017-01-01

    Abstract In the past two decades, much research has been devoted to overcoming the inherent brittleness of cementitious materials. To that end, several solutions have been proposed, mainly utilizing fibres. One of the most promising classes of materials is strain hardening cementitious composite

  17. Evaluation of Shielding Performance for Newly Developed Composite Materials

    Evans, Beren Richard

    This work details an investigation into the contributing factors behind the success of newly developed composite neutron shield materials. Monte Carlo simulation methods were utilized to assess the neutron shielding capabilities and secondary radiation production characteristics of aluminum boron carbide, tungsten boron carbide, bismuth borosilicate glass, and Metathene within various neutron energy spectra. Shielding performance and secondary radiation data suggested that tungsten boron carbide was the most effective composite material. An analysis of the macroscopic cross-section contributions from constituent materials and interaction mechanisms was then performed in an attempt to determine the reasons for tungsten boron carbide's success over the other investigated materials. This analysis determined that there was a positive correlation between a non-elastic interaction contribution towards a material's total cross-section and shielding performance within the thermal and epi-thermal energy regimes. This finding was assumed to be a result of the boron-10 absorption reaction. The analysis also determined that within the faster energy regions, materials featuring higher non-elastic interaction contributions were comparable to those exhibiting primarily elastic scattering via low Z elements. This allowed for the conclusion that composite shield success within higher energy neutron spectra does not necessitate the use elastic scattering via low Z elements. These findings suggest that the inclusion of materials featuring high thermal absorption properties is more critical to composite neutron shield performance than the presence of constituent materials more inclined to maximize elastic scattering energy loss.

  18. Biotransformation of an uncured composite material

    Welsh, Clement J.; Glass, Michael J.; Cheslack, Brian; Pryor, Robert; Tran, Duan K.; Bowers-Irons, Gail

    1994-01-01

    The feasibility of biologically degrading prepreg wastes was studied. The work was conducted with the intention of obtaining baseline data that would facilitate the achievement of two long-range goals. These goals are: (1) the biological remediation of the hazardous components in the prepreg wastes, and (2) providing the potential for recycling the prepreg waste fibers. The experiments examined a prepreg that employs an bismaleimide resin system. Initial results demonstrated an obvious deterioration of the prepreg material when incubated with several bacterial strains. The most active cultures were identified as a mixture of 'Bacillus cereus' and 'Pseudomonas sp'. Gas chromatography analyses revealed seven primary compounds in the resin mixture. Biotransformation studies, using the complete prepreg material, demonstrated on obvious loss of all seven organic compounds. Gas chromatography-mass spectrometry analyses resulted in structure assignments for the two primary components of the resin. Both were analogs of Bisphenol A; one being bismaleimide, and the other being Bisphenol A containing a diglycidyl moiety. The 'diglycidyl analog' was purified using thin-layer chromatography and the biotransformation of this compound (at 27 ug/ml bacterial culture) was monitored. After a seven-day incubation, approximately 40% of the organic compound was biotransformed. These results demonstrate the biotransformation of the prepreg resin and indicate that biological remediation of the prepreg wastes is feasible.

  19. Polymeric compositions incorporating polyethylene glycol as a phase change material

    Salyer, Ival O.; Griffen, Charles W.

    1989-01-01

    A polymeric composition comprising a polymeric material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the composition is useful in making molded and/or coated materials such as flooring, tiles, wall panels and the like; paints containing polyethylene glycols or end-capped polyethylene glycols are also disclosed.

  20. Recent advances and developments in composite dental restorative materials.

    Cramer, N B; Stansbury, J W; Bowman, C N

    2011-04-01

    Composite dental restorations represent a unique class of biomaterials with severe restrictions on biocompatibility, curing behavior, esthetics, and ultimate material properties. These materials are presently limited by shrinkage and polymerization-induced shrinkage stress, limited toughness, the presence of unreacted monomer that remains following the polymerization, and several other factors. Fortunately, these materials have been the focus of a great deal of research in recent years with the goal of improving restoration performance by changing the initiation system, monomers, and fillers and their coupling agents, and by developing novel polymerization strategies. Here, we review the general characteristics of the polymerization reaction and recent approaches that have been taken to improve composite restorative performance.

  1. Recent developments of discrete material optimization of laminated composite structures

    Lund, Erik; Sørensen, Rene

    2015-01-01

    This work will give a quick summary of recent developments of the Discrete Material Optimization approach for structural optimization of laminated composite structures. This approach can be seen as a multi-material topology optimization approach for selecting the best ply material and number...... of plies in a laminated composite structure. The conceptual combinatorial design problem is relaxed to a continuous problem such that well-established gradient based optimization techniques can be applied, and the optimization problem is solved on basis of interpolation schemes with penalization...

  2. Microscale Fracture of Composite Materials for Wind Turbine Blades

    Martyniuk, Karolina

    which are the most extensively used in the rotor blades, has been shown to play an important role on the overall response of the material. The properties of a fibre/matrix interface have been found to have a significant influence on the macroscopic behavior of composites. Therefore, the characterization......Due to the increase in wind turbines size it is essential that weight savings due to design changes do not compromise the reliability of the rotor blades. The reliability can be increased by improving design rules and the material models that describe the materials properties. More reliable...... materials models can be developed if the understanding of the microscale damage- the first stage of material failure- is increased. Therefore it is important to characterize materials’ microstructures and micro-cracks initiation and propagation.The microstructure of fibre reinforced composite materials...

  3. Composition of waste materials and recyclables

    Götze, Ramona

    involves several steps to prepare the samples mechanically and/or chemically for final analysis. Not all sample preparation methods are equally well suited for specific waste characterization purposes. The correctness of results and practical feasibility of sample preparation was strongly affected...... for future modelling and assessment of waste management systems. The analyzed fractions were selected based on material properties with relevance for potential recycling processes. The physico-chemical analysis revealed chemical differences between residual and source-segregated samples for several fractions....... The results for parameters associated with organic matter confirmed the idea of cross-contaminated recyclables in residual waste, whereas the results for heavy metals and trace elements were more complex. For many fractions rather high metal contents were found to be intrinsic properties of the recyclables...

  4. Fracture toughness of fibrous composite materials

    Poe, C. C., Jr.

    1984-01-01

    Laminates with various proportions of 0 deg, 45 deg, and 90 deg plies were fabricated from T300/5208 and T300/BP-907 graphite/epoxy prepreg tape material. The fracture toughness of each laminate orientation or lay-up was determined by testing center-cracked specimens, and it was also predicted with the general fracture-toughness parameter. The predictions were good except when crack-tip splitting was large, at which time the toughness and strengths tended to be underpredicted. By using predictions, a parametric study was also made of factors that influence fracture toughness. Fiber and matrix properties as well as lay-up were investigated. Without crack-tip splitting, fracture toughness increases in proportion to fiber strength and fiber volume fraction, increases linearly with E(22)/E(11), is largest when the modulus for non-0 deg fibers is greater than that of 0 deg fibers, and is smallest for 0(m)/90(p)(s) lay-ups. (The E(11) and E(22) are Young's moduli of the lamina parallel to and normal to the direction of the fibers, respectively). For a given proportion of 0 deg plies, the most notch-sensitive lay-ups are 0(m)/90(p)(s) and the least sensitive are 0(m)/45(n)(s) and alpha(s). Notch sensitivity increases with the proportion of 0 deg plies and decreases with alpha. Strong, tough matrix materials, which inhibit crack-tip splitting, generally lead to minimum fracture toughness.

  5. Left-handed materials in metallic magnetic granular composites

    Chui, S.T.; Lin, Z.F.; Hu, L.-B.

    2003-01-01

    There is recently interests in the 'left-handed' materials. In these materials the direction of the wave vector of electromagnetic radiation is opposite to the direction of the energy flow. We present simple arguments that suggests that magnetic composites can also be left-handed materials. However, the physics involved seems to be different from the original argument. In our argument, the imaginary part of the dielectric constant is much larger than the real part, opposite to the original argument

  6. Concept of a Conducting Composite Material for Lightning Strike Protection

    Katunin A.; Krukiewicz K.; Herega A.; Catalanotti G.

    2016-01-01

    The paper focuses on development of a multifunctional material which allows conducting of electrical current and simultaneously holds mechanical properties of a polymeric composite. Such material could be applied for exterior fuselage elements of an aircraft in order to minimize damage occurring during lightning strikes. The concept introduced in this paper is presented from the points of view of various scientific disciplines including materials science, chemistry, structural physics and mec...

  7. Tribology of ceramics and composites materials science perspective

    Basu, Bikramjit

    2011-01-01

    This book helps students and practicing scientists alike understand that a comprehensive knowledge about the friction and wear properties of advanced materials is essential to further design and development of new materials. With important introductory chapters on the fundamentals, processing, and applications of tribology, the book then examines in detail the nature and properties of materials, the friction and wear of structural ceramics, bioceramics, biocomposites, and nanoceramics, as well as lightweight composites and the friction and wear of ceramics in a cryogenic environment.

  8. Longevity of dental amalgam in comparison to composite materials

    Windisch, Friederike

    2008-11-01

    Full Text Available Health political background: Caries is one of the most prevalent diseases worldwide. For (direct restaurations of carious lesions, tooth-coloured composite materials are increasingly used. The compulsory health insurance pays for composite fillings in front teeth; in posterior teeth, patients have to bear the extra cost. Scientific background: Amalgam is an alloy of mercury and other metals and has been used in dentistry for more than one hundred and fifty years. Composites consist of a resin matrix and chemically bonded fillers. They have been used for about fifty years in front teeth. Amalgam has a long longevity; the further development of composites has also shown improvements regarding their longevity. Research questions: This HTA-report aims to evaluate the longevity (failure rate, median survival time (MST, median age of direct amalgam fillings in comparison to direct composite fillings in permanent teeth from a medical and economical perspective and discusses the ethical, legal and social aspects of using these filling materials. Methods: The systematic literature search yielded a total of 1,149 abstracts. After a two-step selection process based on defined criteria 25 publications remained to be assessed. Results: The medical studies report a longer longevity for amalgam fillings than for composite fillings. However, the results of these studies show a large heterogeneity. No publication on the costs or the cost-effectiveness of amalgam and composite fillings exists for Germany. The economic analyses (NL, SWE, GB report higher costs for composite fillings when longevity is assumed equal (for an observation period of five years or longer for amalgam compared to composite fillings. These higher costs are due to the higher complexity of placing composite fillings. Discussion: Due to different study designs and insufficient documentation of study details, a comparison of different studies on longevity of direct amalgam and composite

  9. Tungsten-based composite materials for fusion reactor shields

    Greenspan, E.; Karni, Y.

    1985-01-01

    Composite tungsten-based materials were recently proposed for the heavy constituent of compact fusion reactor shields. These composite materials will enable the incorporation of tungsten - the most efficient nonfissionable inelastic scattering (as well as good neutron absorbing and very good photon attenuating) material - in the shield in a relatively cheap way and without introducing voids (so as to enable minimizing the shield thickness). It is proposed that these goals be achieved by bonding tungsten powder, which is significantly cheaper than high-density tungsten, with a material having the following properties: good shielding ability and relatively low cost and ease of fabrication. The purpose of this work is to study the effectiveness of the composite materials as a function of their composition, and to estimate the economic benefit that might be gained by the use of these materials. Two materials are being considered for the binder: copper, second to tungsten in its shielding ability, and iron (or stainless steel), the common fusion reactor shield heavy constituent

  10. Analytical solution of the thermo-mechanical stresses in a multilayered composite pressure vessel considering the influence of the closed ends

    Zhang, Q.; Wang, Z.W.; Tang, C.Y.; Hu, D.P.; Liu, P.Q.; Xia, L.Z.

    2012-01-01

    Limited work has been reported on determining the thermo-mechanical stresses in a multilayered composite pressure vessel when the influence of its closed ends is considered. In this study, an analytical solution was derived for determining the stress distribution of a multilayered composite pressure vessel subjected to an internal fluid pressure and a thermal load, based on thermo-elasticity theory. In the solution, a pseudo extrusion pressure was proposed to emulate the effect of the closed ends of the pressure vessel. To validate the analytical solution, the stress distribution of the pressure vessel was also computed using finite element (FE) method. It was found that the analytical results were in good agreement with the computational ones, and the effect of thermal load on the stress distribution was discussed in detail. The proposed analytical solution provides an exact means to design multilayered composite pressure vessels. Highlights: ► The thermal-mechanical stress was derived for a multilayered pressure vessel. ► A new pseudo extrusion pressure was proposed to emulate the effect of closed ends. ► The analytical results are in good agreement with the computational ones using FEM. ► The solution provides an exact way to design the multilayered pressure vessel.

  11. Evaluation of Acoustic Emission NDE of Kevlar Composite Over Wrapped Pressure Vessels

    Horne, Michael R.; Madaras, Eric I.

    2008-01-01

    Pressurization and failure tests of small Kevlar/epoxy COPV bottles were conducted during 2006 and 2007 by Texas Research Institute Austin, Inc., at TRI facilities. This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests. Results of some of the tests indicate a possibility that AE can be used to track the stress-rupture degradation of COPV vessels.

  12. Composites Materials and Manufacturing Technologies for Space Applications

    Vickers, J. H.; Tate, L. C.; Gaddis, S. W.; Neal, R. E.

    2016-01-01

    Composite materials offer significant advantages in space applications. Weight reduction is imperative for deep space systems. However, the pathway to deployment of composites alternatives is problematic. Improvements in the materials and processes are needed, and extensive testing is required to validate the performance, qualify the materials and processes, and certify components. Addressing these challenges could lead to the confident adoption of composites in space applications and provide spin-off technical capabilities for the aerospace and other industries. To address the issues associated with composites applications in space systems, NASA sponsored a Technical Interchange Meeting (TIM) entitled, "Composites Materials and Manufacturing Technologies for Space Applications," the proceedings of which are summarized in this Conference Publication. The NASA Space Technology Mission Directorate and the Game Changing Program chartered the meeting. The meeting was hosted by the National Center for Advanced Manufacturing (NCAM)-a public/private partnership between NASA, the State of Louisiana, Louisiana State University, industry, and academia, in association with the American Composites Manufacturers Association. The Louisiana Center for Manufacturing Sciences served as the coordinator for the TIM.

  13. Towards an Ultrasonic Guided Wave Procedure for Health Monitoring of Composite Vessels: Application to Hydrogen-Powered Aircraft.

    Yaacoubi, Slah; McKeon, Peter; Ke, Weina; Declercq, Nico F; Dahmene, Fethi

    2017-09-19

    This paper presents an overview and description of the approach to be used to investigate the behavior and the defect sensitivity of various ultrasonic guided wave (UGW) modes propagating specifically in composite cylindrical vessels in the framework of the safety of hydrogen energy transportation such as hydrogen-powered aircrafts. These structures which consist of thick and multi-layer composites are envisioned for housing hydrogen gas at high pressures. Due to safety concerns associated with a weakened structure, structural health monitoring techniques are needed. A procedure for optimizing damage detection in these structural types is presented. It is shown that a finite element method can help identify useful experimental parameters including frequency range, excitation type, and receiver placement.

  14. Towards an Ultrasonic Guided Wave Procedure for Health Monitoring of Composite Vessels: Application to Hydrogen-Powered Aircraft

    Slah Yaacoubi

    2017-09-01

    Full Text Available This paper presents an overview and description of the approach to be used to investigate the behavior and the defect sensitivity of various ultrasonic guided wave (UGW modes propagating specifically in composite cylindrical vessels in the framework of the safety of hydrogen energy transportation such as hydrogen-powered aircrafts. These structures which consist of thick and multi-layer composites are envisioned for housing hydrogen gas at high pressures. Due to safety concerns associated with a weakened structure, structural health monitoring techniques are needed. A procedure for optimizing damage detection in these structural types is presented. It is shown that a finite element method can help identify useful experimental parameters including frequency range, excitation type, and receiver placement.

  15. Review on advanced composite materials boring mechanism and tools

    Shi, Runping; Wang, Chengyong

    2011-05-01

    With the rapid development of aviation and aerospace manufacturing technology, advanced composite materials represented by carbon fibre reinforced plastics (CFRP) and super hybrid composites (fibre/metal plates) are more and more widely applied. The fibres are mainly carbon fibre, boron fibre, Aramid fiber and Sic fibre. The matrixes are resin matrix, metal matrix and ceramic matrix. Advanced composite materials have higher specific strength and higher specific modulus than glass fibre reinforced resin composites of the 1st generation. They are widely used in aviation and aerospace industry due to their high specific strength, high specific modulus, excellent ductility, anticorrosion, heat-insulation, sound-insulation, shock absorption and high&low temperature resistance. They are used for radomes, inlets, airfoils(fuel tank included), flap, aileron, vertical tail, horizontal tail, air brake, skin, baseboards and tails, etc. Its hardness is up to 62~65HRC. The holes are greatly affected by the fibre laminates direction of carbon fibre reinforced composite material due to its anisotropy when drilling in unidirectional laminates. There are burrs, splits at the exit because of stress concentration. Besides there is delamination and the hole is prone to be smaller. Burrs are caused by poor sharpness of cutting edge, delamination, tearing, splitting are caused by the great stress caused by high thrust force. Poorer sharpness of cutting edge leads to lower cutting performance and higher drilling force at the same time. The present research focuses on the interrelation between rotation speed, feed, drill's geometry, drill life, cutting mode, tools material etc. and thrust force. At the same time, holes quantity and holes making difficulty of composites have also increased. It requires high performance drills which won't bring out defects and have long tool life. It has become a trend to develop super hard material tools and tools with special geometry for drilling

  16. Automated image segmentation and registration of vessel wall MRI for quantitative assessment of carotid artery vessel wall dimensions and plaque composition

    Klooster, Ronald van 't

    2014-01-01

    The main goal of this thesis was to develop methods for automated segmentation, registration and classification of the carotid artery vessel wall and plaque components using multi-sequence MR vessel wall images to assess atherosclerosis. First, a general introduction into atherosclerosis and

  17. Standard Guide for Predicting Radiation-Induced Transition Temperature Shift in Reactor Vessel Materials, E706 (IIF)

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This guide presents a method for predicting reference transition temperature adjustments for irradiated light-water cooled power reactor pressure vessel materials based on Charpy V-notch 30-ftlbf (41-J) data. Radiation damage calculative procedures have been developed from a statistical analysis of an irradiated material database that was available as of May 2000. The embrittlement correlation used in this guide was developed using the following variables: copper and nickel contents, irradiation temperature, and neutron fluence. The form of the model was based on current understanding for two mechanisms of embrittlement: stable matrix damage (SMD) and copper-rich precipitation (CRP); saturation of copper effects (for different weld materials) was included. This guide is applicable for the following specific materials, copper, nickel, and phosphorus contents, range of irradiation temperature, and neutron fluence based on the overall database: 1.1.1 MaterialsA 533 Type B Class 1 and 2, A302 Grade B, A302 G...

  18. Composite materials research and education program: The NASA-Virginia Tech composites program

    Herakovich, C. T.

    1980-01-01

    Major areas of study include: (1) edge effects in finite width laminated composites subjected to mechanical, thermal and hygroscopic loading with temperature dependent material properties and the influence of edge effects on the initiation of failure; (2) shear and compression testing of composite materials at room and elevated temperatures; (3) optical techniques for precise measurement of coefficients of thermal expansion of composites; (4) models for the nonlinear behavior of composites including material nonlinearity and damage accumulation and verification of the models under biaxial loading; (5) compressive failure of graphite/epoxy plates with circular holes and the buckling of composite cylinders under combined compression and torsion; (6) nonlinear mechanical properties of borsic/aluminum, graphite/polyimide and boron/aluminum; (7) the strength characteristics of spliced sandwich panels; and (8) curved graphite/epoxy panels subjected to internal pressure.

  19. Chemistry and technology of radiation processed composite materials

    Czvikovszky, T.

    1985-01-01

    Composite materials of synthetics (based on monomers, oligomers and thermoplastics) and of natural polymers (wood and other fibrous cellulosics) prepared by radiation processing, offer valuable structural materials with enhanced coupling forces between the components. The applied polymer chemistry of such composites shows several common features with that of radiation grafting, e.g. the polymerization rate of oligomer-monomer mixtures in wood remains in most cases proportional to the square-root of the initiating dose-rate, just as in the simultaneous grafting, demonstrating that the chain termination kinetics remain regularly bimolecular in the corresponding dose-rate ranges. In the processing experiences of such composites, low dose requirement, easy process-control, and good technical feasibility have been found for composites of wood with oligomer-monomer mixtures, for coconut fibres with unsaturated polyesters and for pretreated wood fibre with polypropylene. (author)

  20. Integral analysis of debris material and heat transport in reactor vessel lower plenum

    Suh, K.Y.; Henry, R.E.

    1994-01-01

    An integral, fast-running, two-region model has been developed to characterize the debris material and heat transport in the reactor lower plenum under severe accident conditions. The debris bed is segregated into the oxidic pool and an overlying metallic layer. Debris crusts can develop on three surfaces: the top of the molten pool, the RPV wall, and the internal structures. To account for the decay heat generation, the crust temperature profile is assumed to be parabolic. The oxidic debris pool is homogeneously mixed and has the same material composition, and hence the same thermophysical properties, as the crusts, while the metallic constituents are assumed to rise to the top of the debris pool. Steady-state relationships are used to describe the heat transfer rates, with the assessment of solid or liquid state, and the liquid superheat in the pool being based on the average debris temperature. Natural convection heat transfer from the molten debris pool to the upper, lower and embedded crusts is calculated based on the pool Rayleigh number with the conduction heat transfer from the crusts being determined by the crust temperature profile. The downward heat flux is transferred to the lowest part of the RPV lower head through a crust-to-RPV contact resistance. The sideward heat flux is transferred to the upper regions of the RPV lower head as well as to the internal structures. The upward heat flux goes to the metal layer, water, or available heat sink structures above. Quenching due to water ingression is modeled separately from the energy transfer through the crust. The RPV wall temperature distribution and the primary system pressure are utilized to estimate challenges to the RPV integrity. ((orig.))

  1. Investigating accidents involving aircraft manufactured from polymer composite materials

    Dunn, Leigh

    2013-01-01

    This thesis looks into the examination of polymer composite wreckage from the perspective of the aircraft accident investigator. It develops an understanding of the process of wreckage examination as well as identifying the potential for visual and macroscopic interpretation of polymer composite aircraft wreckage. The in-field examination of aircraft wreckage, and subsequent interpretations of material failures, can be a significant part of an aircraft accident investigation. ...

  2. Cementitious composite materials with improved self-healing potential

    Cornelia BAERA

    2015-12-01

    Full Text Available Cement-based composites have proved, over the time, certain abilities of self-healing the damages (cracks and especially microcracs that occur within their structure. Depending on the level of damage and of the composite type in which this occurs, the self - healing process (SH can range from crack closing or crack sealing to the stage of partial or even complete recovery of material physical - mechanical properties. The aim of this paper is to present the general concept of Engineered Cementitious Composites (ECCs with their unique properties including their self-healing (SH capacity, as an innovative direction for a global sustainable infrastructure. The experimental steps initiated for the development in Romania of this unique category of materials, using materials available on the local market, are also presented.

  3. Vegetable Fibers for Composite Materials In Constructive Sector

    Giglio, Francesca; Savoja, Giulia

    2017-08-01

    The aim of the research is to study and to test bio-mixture for laminas to use in construction field components. Composite materials are becoming more common in different sectors, but their embodied energy is an environmental problem. For this, in recent years, the researchers investigate new mixtures for composites, in particular with vegetable fibers and bio-based epoxy resin. The research carried out different laboratory tests for material and mechanical characterization, starting from the analysis of vegetable fibers, and arriving to test different kind of laminas with sundry fabrics and bio-based epoxy resin. In the most general organization of the theme, the research has the overall objective to contribute to reduce composites environmental impacts, with the promotion of local production chains about innovative materials from renewable and sustainable sources.

  4. Shear bond strength of indirect composite material to monolithic zirconia.

    Sari, Fatih; Secilmis, Asli; Simsek, Irfan; Ozsevik, Semih

    2016-08-01

    This study aimed to evaluate the effect of surface treatments on bond strength of indirect composite material (Tescera Indirect Composite System) to monolithic zirconia (inCoris TZI). Partially stabilized monolithic zirconia blocks were cut into with 2.0 mm thickness. Sintered zirconia specimens were divided into different surface treatment groups: no treatment (control), sandblasting, glaze layer & hydrofluoric acid application, and sandblasting + glaze layer & hydrofluoric acid application. The indirect composite material was applied to the surface of the monolithic zirconia specimens. Shear bond strength value of each specimen was evaluated after thermocycling. The fractured surface of each specimen was examined with a stereomicroscope and a scanning electron microscope to assess the failure types. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey LSD tests (α=.05). Bond strength was significantly lower in untreated specimens than in sandblasted specimens (Pcomposite material and monolithic zirconia.

  5. Electromagnetic characterization of fine-scale particulate composite materials

    Talbot, P.; Konn, A.M.; Brosseau, C.

    2002-01-01

    We report the results of the composition and frequency-dependent complex permittivity and permeability of ZnO and γ-Fe 2 O 3 composites prepared by powder pressing. The electromagnetic properties of these materials exhibit a strong dependence on the powder size of the starting materials. In the microwave frequency range, the permittivity and permeability show nonlinear variations with volume fraction of Fe 2 O 3 . As the particle size decreases from a few micrometers to a few tens of nanometers, the data indicate that local mesostructural factors such as shape anisotropy, porosity and possible effect of the binder are likely to be intertwined in the understanding of electromagnetic properties of fine-scale particulate composite materials

  6. Compositional characteristics of some Apollo 14 clastic materials.

    Lindstrom, M. M.; Duncan, A. R.; Fruchter, J. S.; Mckay, S. M.; Stoeser, J. W.; Goles, G. G.; Lindstrom, D. J.

    1972-01-01

    Eighty-two subsamples of Apollo 14 materials have been analyzed by instrumental neutron activation analysis techniques for as many as 25 elements. In many cases, it was necessary to develop new procedures to allow analyses of small specimens. Compositional relationships among Apollo 14 materials indicate that there are small but systematic differences between regolith from the valley terrain and that from Cone Crater ejecta. Fragments from 1-2 mm size fractions of regolith samples may be divided into compositional classes, and the 'soil breccias' among them are very similar to valley soils. Multicomponent linear mixing models have been used as interpretive tools in dealing with data on regolith fractions and subsamples from breccia 14321. These mixing models show systematic compositional variations with inferred age for Apollo 14 clastic materials.

  7. Radiation processed composite materials of wood and elastic polyester resins

    Tapolcai, I.; Czvikovszky, T.

    1983-01-01

    The radiation polymerization of multifunctional unsaturated polyester-monomer mixtures in wood forms interpenetrating network system. The mechanical resistance (compression, abrasion, hardness, etc.) of these composite materials are generally well over the original wood, however the impact strength is almost the same or even reduced, in comparison to the wood itself. An attempt is made using elastic polyester resins to produced wood-polyester composite materials with improved modulus of elasticity and impact properties. For the impregnation of European beech wood two types of elastic unsaturated polyester resins were used. The exothermic effect of radiation copolymerization of these resins in wood has been measured and the dose rate effects as well as hardening dose was determined. Felxural strength and impact properties were examined. Elastic unsaturated polyester resins improved the impact strength of wood composite materials. (author)

  8. Prediction of strength of wood composite materials using ultrasonic

    Mahmoud, M.K.; Emam, A.

    2005-01-01

    Wood is a biological material integrating a very large variability of its mechanical properties (tensile and compressive), on the two directional longitudinal and transverse Ultrasonic method has been utilized to measure both wood physical and / or wood mechanical properties. The aim of this article is to show the development of ultrasonic technique for quality evaluation of trees, wood material and wood based composites. For quality assessment of these products we discuss the nondestructive evaluation of different factors such as: moisture content, temperature, biological degradation induced by bacterial attack and fungal attack. These techniques were adapted for trees, timber and wood based composites. The present study discusses the prediction of tensile and compressive strength of wood composite materials using ultrasonic testing. Empirical relationships between the tensile properties, compression strength and ultrasonic were proposed. The experimental results indicate the possibility of establishing a relationship between tensile strength and compression values. Moreover, the fractures in tensile and compressive are discussed by photographic

  9. Percolation Phenomena For New Magnetic Composites And Tim Nanocomposites Materials

    Ahmed Thabet Mohamed

    2015-01-01

    Full Text Available This paper presents a theoretical investigation in order to obtain new composite and nanocomposite magnetic industrial materials. The effective conductivity and thermal effective conductivity have been predicted by adding various types and percentages of conductive particles (Al2O3, MgO, ZnO, Graphite etc. to the main matrices of Epoxy, Iron and Silicon for formulating new composite and nanocomposite industrial materials. The characterization of effective conductivity of new polymeric composites has been investigated with various applied forces, inclusion types and their concentrations. In addition, the effect of inclusion types and their concentrations on the effective thermal conductivities of thermal interface nanocomposite industrial materials has been explained and discussed.

  10. Development of a Weibull model of cleavage fracture toughness for shallow flaws in reactor pressure vessel material

    Bass, B.R.; Williams, P.T.; McAfee, W.J.; Pugh, C.E. [Oak Ridge National Lab., Heavy-Section Steel Technology Program, Oak Ridge, TN (United States)

    2001-07-01

    A primary objective of the United States Nuclear Regulatory Commission (USNRC) -sponsored Heavy-Section Steel Technology (HSST) Program is to develop and validate technology applicable to quantitative assessments of fracture prevention margins in nuclear reactor pressure vessels (RPVs) containing flaws and subjected to service-induced material toughness degradation. This paper describes an experimental/analytical program for the development of a Weibull statistical model of cleavage fracture toughness for applications to shallow surface-breaking and embedded flaws in RPV materials subjected to multi-axial loading conditions. The experimental part includes both material characterization testing and larger fracture toughness experiments conducted using a special-purpose cruciform beam specimen developed by Oak Ridge National Laboratory for applying biaxial loads to shallow cracks. Test materials (pressure vessel steels) included plate product forms (conforming to ASTM A533 Grade B Class 1 specifications) and shell segments procured from a pressurized-water reactor vessel intended for a nuclear power plant. Results from tests performed on cruciform specimens demonstrated that biaxial loading can have a pronounced effect on shallow-flaw fracture toughness in the lower-transition temperature region. A local approach methodology based on a three-parameter Weibull model was developed to correlate these experimentally-observed biaxial effects on fracture toughness. The Weibull model, combined with a new hydrostatic stress criterion in place of the more commonly used maximum principal stress in the kernel of the Weibull stress integral definition, is shown to provide a scaling mechanism between uniaxial and biaxial loading states for 2-dimensional flaws located in the A533-B plate material. The Weibull stress density was introduced as a matrice for identifying regions along a semi-elliptical flaw front that have a higher probability of cleavage initiation. Cumulative

  11. Development of a Weibull model of cleavage fracture toughness for shallow flaws in reactor pressure vessel material

    Bass, B.R.; Williams, P.T.; McAfee, W.J.; Pugh, C.E.

    2001-01-01

    A primary objective of the United States Nuclear Regulatory Commission (USNRC) -sponsored Heavy-Section Steel Technology (HSST) Program is to develop and validate technology applicable to quantitative assessments of fracture prevention margins in nuclear reactor pressure vessels (RPVs) containing flaws and subjected to service-induced material toughness degradation. This paper describes an experimental/analytical program for the development of a Weibull statistical model of cleavage fracture toughness for applications to shallow surface-breaking and embedded flaws in RPV materials subjected to multi-axial loading conditions. The experimental part includes both material characterization testing and larger fracture toughness experiments conducted using a special-purpose cruciform beam specimen developed by Oak Ridge National Laboratory for applying biaxial loads to shallow cracks. Test materials (pressure vessel steels) included plate product forms (conforming to ASTM A533 Grade B Class 1 specifications) and shell segments procured from a pressurized-water reactor vessel intended for a nuclear power plant. Results from tests performed on cruciform specimens demonstrated that biaxial loading can have a pronounced effect on shallow-flaw fracture toughness in the lower-transition temperature region. A local approach methodology based on a three-parameter Weibull model was developed to correlate these experimentally-observed biaxial effects on fracture toughness. The Weibull model, combined with a new hydrostatic stress criterion in place of the more commonly used maximum principal stress in the kernel of the Weibull stress integral definition, is shown to provide a scaling mechanism between uniaxial and biaxial loading states for 2-dimensional flaws located in the A533-B plate material. The Weibull stress density was introduced as a matrice for identifying regions along a semi-elliptical flaw front that have a higher probability of cleavage initiation. Cumulative

  12. On the Mechanical Behavior of Advanced Composite Material Structures

    Vinson, Jack

    During the period between 1993 and 2004, the author, as well as some colleagues and graduate students, had the honor to be supported by the Office of Naval Research to conduct research in several aspects of the behavior of structures composed of composite materials. The topics involved in this research program were numerous, but all contributed to increasing the understanding of how various structures that are useful for marine applications behaved. More specifically, the research topics focused on the reaction of structures that were made of fiber reinforced polymer matrix composites when subjected to various loads and environmental conditions. This included the behavior of beam, plate/panel and shell structures. It involved studies that are applicable to fiberglass, graphite/carbon and Kevlar fibers imbedded in epoxy, polyester and other polymeric matrices. Unidirectional, cross-ply, angle ply, and woven composites were involved, both in laminated, monocoque as well as in sandwich constructions. Mid-plane symmetric as well as asymmetric laminates were studied, the latter involving bending-stretching coupling and other couplings that only can be achieved with advanced composite materials. The composite structures studied involved static loads, dynamic loading, shock loading as well as thermal and hygrothermal environments. One major consideration was determining the mechanical properties of composite materials subjected to high strain rates because the mechanical properties vary so significantly as the strain rate increases. A considerable number of references are cited for further reading and study for those interested.

  13. COMPUTER MODELING OF STRUCTURAL - CONCENTRATION CHARACTERISTICS OF BUILDING COMPOSITE MATERIALS

    I. I. Zaripova

    2015-09-01

    Full Text Available In the article the computer modeling of structural and concentration characteristics of the building composite material on the basis of the theory of the package. The main provisions of the algorithmon the basis of which it was possible to get the package with a significant number of packaged elements, making it more representative in comparison with existing analogues modeling. We describe the modeled area related areas, the presence of which determines the possibility of a percolation process, which in turn makes it possible to study and management of individual properties of the composite material of construction. As an example of the construction of a composite material is considered concrete that does not exclude the possibility of using algorithms and modeling results of similar studies for composite matrix type (matrix of the same material and distributed in a certain way by volume particles of another substance. Based on modeling results can be manufactured parts and construction elementsfor various purposes with improved technical characteristics (by controlling the concentration composition substance.

  14. Flame-Resistant Composite Materials For Structural Members

    Spears, Richard K.

    1995-01-01

    Matrix-fiber composite materials developed for structural members occasionally exposed to hot, corrosive gases. Integral ceramic fabric surface layer essential for resistance to flames and chemicals. Endures high temperature, impedes flame from penetrating to interior, inhibits diffusion of oxygen to interior where it degrades matrix resin, resists attack by chemicals, helps resist erosion, and provides additional strength. In original intended application, composite members replace steel structural members of rocket-launching structures that deteriorate under combined influences of atmosphere, spilled propellants, and rocket exhaust. Composites also attractive for other applications in which corrosion- and fire-resistant structural members needed.

  15. Interfacial stabilities of high-temperature composite materials

    Chang, Y.A.; DeKock, J.; Zhang, M.X.; Kieschke, R.

    1993-01-01

    The thermodynamic and kinetic principles necessary to control interfacial reactions between the matrix and reinforcement in composite materials are presented. The concept of interfacial control has been applied to Ti-based/Al 2 O 3 composite. Results are presented which include estimated diffusivities for the reaction in β-Ti/Al 2 O 3 composites, estimated phase relationships for the systems Ti-Al-O, Ti-Y-O, Nb-Y-O and Nb-Al-O at 1100 C, and a coating scheme for αAl 2 O 3 fibers. 71 refs

  16. Evaluation of the Structural Safety of a Vessel with Different Material(Cr-13)-Supplemented Screw Thread

    Choi, Yong Hoon; Bae, Jun Ho; Kim, Chul [Pusan National University, Busan (Korea, Republic of)

    2015-04-15

    The dome and neck part of a vessel is generally formed by a hot spinning process with a seamless tube. However, as studies on and design data from the hot spinning process are insufficient, this process has been performed based on trial and error and the experiences of field engineers. Changes in the inner diameter from the bottom to the top of the neck have occurred mainly because of the characteristics of the hot spinning process due to the high-speed rotation of the rollers. In this study, a theoretical and finite element analysis of the vessel is conducted with different material(Cr-13)-supplemented screw threads for tapping and to reduce shape errors. Based on the results, the structural safety under the operating conditions is evaluated.

  17. Resolution of the reactor vessel materials toughness safety issue; Task Action Plan A-11; Appendices C-K

    Johnson, R.E.

    1981-09-01

    The central problem in the Unresolved Safety Issue A-11, 'Reactor Vessel Materials Toughness,' was to provide guidance in performing analyses for reactor pressure vessels (RPVs) which fail to meet the toughness requirements during service life as a result of neutron radiation embrittlement. A technical team of recognized experts was organized to assist the NRC staff in addressing the problem. Using the foundation of the tearing modulus concept, which has been developed under earlier NRC sponsorship, relationships were obtained which provided approximate solutions to the RPV fracture problem with assumed beltline region flaws. Volume I of this report is a brief presentation of the problem and the results; Volume II provides the detailed technical foundations

  18. Silicon carbide composites as fusion power reactor structural materials

    Snead, L.L., E-mail: SneadLL@ORNL.gov [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Nozawa, T. [Fusion Research and Development Directorate, Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai, Ibaraki 319-1195 (Japan); Ferraris, M. [Politecnico di Torino-DISMIC c. Duca degli Abruzzi, 24I-10129 Torino (Italy); Katoh, Y. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Shinavski, R. [Hypertherm HTC, 18411 Gothard St., Units A/B/C, Huntington Beach, CA 92648 (United States); Sawan, M. [University of Wisconsin, Madison 417 Engineering Research Building, 1500 Engineering Drive Madison, WI 53706-1687 (United States)

    2011-10-01

    Silicon carbide was first proposed as a low activation fusion reactor material in the mid 1970s. However, serious development of this material did not begin until the early 1990s, driven by the emergence of composite materials that provided enhanced toughness and an implied ability to use these typically brittle materials in engineering application. In the decades that followed, SiC composite system was successfully transformed from a poorly performing curiosity into a radiation stable material of sufficient maturity to be considered for near term nuclear and non-nuclear systems. In this paper the recent progress in the understanding and of basic phenomenon related to the use of SiC and SiC composite in fusion applications will be presented. This work includes both fundamental radiation effects in SiC and engineering issues such as joining and general materials properties. Additionally, this paper will briefly discuss the technological gaps remaining for the practical application of this material system in fusion power devices such as DEMO and beyond.

  19. Composite materials for protection against electromagnetic microwave radiation

    Senyk, IV; Barsukov, VZ; Savchenko, BM; Shevchenko, KL; Plavan, VP; Shpak, Yu V; Kruykova, OA

    2016-01-01

    A fairly wide range of carbon-polymer composite materials was synthesized and studied in terms of their potential to protect people and electronic equipment from exposure to electromagnetic radiation (EMR). The materials studied included three main groups: (1) PVC polymer composites filled with various carbon-containing fillers (colloidal graphite, thermally expanded graphite, acetylene black, graphitized carbon black, carbon nanotubes, graphene) at concentrations ranging from 5 to 20%; (2) carbon cloth - commercial and modified with nanometal additives (e.g., nanoparticles of Cu, TiN, etc.); (3) highly-filled polymer-carbon composites in the form of paint. The transmission rate a of electromagnetic radiation was investigated for such materials in the frequency range of 10 GHz as well as their electrical conductivity. The results showed that the shielding ability of the materials of group (2) is significantly higher than that of the materials of group (1), which is probably due to the presence of strong internal skeleton of conductivity. Nevertheless, some highly-filled mixed polymer-carbon composites in the form of paint demonstrate even more shielding ability than carbon cloth and could be used for the defense against EMR. (paper)

  20. Numerical investigation of porous materials composites reinforced with natural fibers

    Chikhi, M.; Metidji, N.; Mokhtari, F.; Merzouk, N. k.

    2018-05-01

    The present article tends to predict the effective thermal properties of porous biocomposites materials. The composites matrix consists on porous materials namely gypsum and the reinforcement is a natural fiber as date palm fibers. The numerical study is done using Comsol software resolving the heat transfer equation. The results are fitted with theoretical model and experimental results. The results of this study indicate that the porosity has an effect on the Effective thermal conductivity biocompoites.

  1. Eddy current modeling in linear and nonlinear multifilamentary composite materials

    Menana, Hocine; Farhat, Mohamad; Hinaje, Melika; Berger, Kevin; Douine, Bruno; Lévêque, Jean

    2018-04-01

    In this work, a numerical model is developed for a rapid computation of eddy currents in composite materials, adaptable for both carbon fiber reinforced polymers (CFRPs) for NDT applications and multifilamentary high temperature superconductive (HTS) tapes for AC loss evaluation. The proposed model is based on an integro-differential formulation in terms of the electric vector potential in the frequency domain. The high anisotropy and the nonlinearity of the considered materials are easily handled in the frequency domain.

  2. Natural Kenaf Fiber Reinforced Composites as Engineered Structural Materials

    Dittenber, David B.

    The objective of this work was to provide a comprehensive evaluation of natural fiber reinforced polymer (NFRP)'s ability to act as a structural material. As a chemical treatment, aligned kenaf fibers were treated with sodium hydroxide (alkalization) in different concentrations and durations and then manufactured into kenaf fiber / vinyl ester composite plates. Single fiber tensile properties and composite flexural properties, both in dry and saturated environments, were assessed. Based on ASTM standard testing, a comparison of flexural, tensile, compressive, and shear mechanical properties was also made between an untreated kenaf fiber reinforced composite, a chemically treated kenaf fiber reinforced composite, a glass fiber reinforced composite, and oriented strand board (OSB). The mechanical properties were evaluated for dry samples, samples immersed in water for 50 hours, and samples immersed in water until saturation (~2700 hours). Since NFRPs are more vulnerable to environmental effects than synthetic fiber composites, a series of weathering and environmental tests were conducted on the kenaf fiber composites. The environmental conditions studied include real-time outdoor weathering, elevated temperatures, immersion in different pH solutions, and UV exposure. In all of these tests, degradation was found to be more pronounced in the NFRPs than in the glass FRPs; however, in nearly every case the degradation was less than 50% of the flexural strength or stiffness. Using a method of overlapping and meshing discontinuous fiber ends, large mats of fiber bundles were manufactured into composite facesheets for structural insulated panels (SIPs). The polyisocyanurate foam cores proved to be poorly matched to the strength and stiffness of the NFRP facesheets, leading to premature core shear or delamination failures in both flexure and compressive testing. The NFRPs were found to match well with the theoretical stiffness prediction methods of classical lamination

  3. High-Capacity, High-Voltage Composite Oxide Cathode Materials

    Hagh, Nader M.

    2015-01-01

    This SBIR project integrates theoretical and experimental work to enable a new generation of high-capacity, high-voltage cathode materials that will lead to high-performance, robust energy storage systems. At low operating temperatures, commercially available electrode materials for lithium-ion (Li-ion) batteries do not meet energy and power requirements for NASA's planned exploration activities. NEI Corporation, in partnership with the University of California, San Diego, has developed layered composite cathode materials that increase power and energy densities at temperatures as low as 0 degC and considerably reduce the overall volume and weight of battery packs. In Phase I of the project, through innovations in the structure and morphology of composite electrode particles, the partners successfully demonstrated an energy density exceeding 1,000 Wh/kg at 4 V at room temperature. In Phase II, the team enhanced the kinetics of Li-ion transport and electronic conductivity at 0 degC. An important feature of the composite cathode is that it has at least two components that are structurally integrated. The layered material is electrochemically inactive; however, upon structural integration with a spinel material, the layered material can be electrochemically activated and deliver a large amount of energy with stable cycling.

  4. Modeling the Mechanical Behavior of Ceramic Matrix Composite Materials

    Jordan, William

    1998-01-01

    Ceramic matrix composites are ceramic materials, such as SiC, that have been reinforced by high strength fibers, such as carbon. Designers are interested in using ceramic matrix composites because they have the capability of withstanding significant loads while at relatively high temperatures (in excess of 1,000 C). Ceramic matrix composites retain the ceramic materials ability to withstand high temperatures, but also possess a much greater ductility and toughness. Their high strength and medium toughness is what makes them of so much interest to the aerospace community. This work concentrated on two different tasks. The first task was to do an extensive literature search into the mechanical behavior of ceramic matrix composite materials. This report contains the results of this task. The second task was to use this understanding to help interpret the ceramic matrix composite mechanical test results that had already been obtained by NASA. Since the specific details of these test results are subject to the International Traffic in Arms Regulations (ITAR), they are reported in a separate document (Jordan, 1997).

  5. Compendium of Material Composition Data for Radiation Transport Modeling

    Williams, Ralph G.; Gesh, Christopher J.; Pagh, Richard T.

    2006-01-01

    Computational modeling of radiation transport problems including homeland security, radiation shielding and protection, and criticality safety all depend upon material definitions. This document has been created to serve two purposes: (1) to provide a quick reference of material compositions for analysts and (2) a standardized reference to reduce the differences between results from two independent analysts. Analysts are always encountering a variety of materials for which elemental definitions are not readily available or densities are not defined. This document provides a location where unique or hard to define materials will be located to reduce duplication in research for modeling purposes. Additionally, having a common set of material definitions helps to standardize modeling across PNNL and provide two separate researchers the ability to compare different modeling results from a common materials basis.

  6. Innovative Structural Materials and Sections with Strain Hardening Cementitious Composites

    Dey, Vikram

    The motivation of this work is based on development of new construction products with strain hardening cementitious composites (SHCC) geared towards sustainable residential applications. The proposed research has three main objectives: automation of existing manufacturing systems for SHCC laminates; multi-level characterization of mechanical properties of fiber, matrix, interface and composites phases using servo-hydraulic and digital image correlation techniques. Structural behavior of these systems were predicted using ductility based design procedures using classical laminate theory and structural mechanics. SHCC sections are made up of thin sections of matrix with Portland cement based binder and fine aggregates impregnating continuous one-dimensional fibers in individual or bundle form or two/three dimensional woven, bonded or knitted textiles. Traditional fiber reinforced concrete (FRC) use random dispersed chopped fibers in the matrix at a low volume fractions, typically 1-2% to avoid to avoid fiber agglomeration and balling. In conventional FRC, fracture localization occurs immediately after the first crack, resulting in only minor improvement in toughness and tensile strength. However in SHCC systems, distribution of cracking throughout the specimen is facilitated by the fiber bridging mechanism. Influence of material properties of yarn, composition, geometry and weave patterns of textile in the behavior of laminated SHCC skin composites were investigated. Contribution of the cementitious matrix in the early age and long-term performance of laminated composites was studied with supplementary cementitious materials such as fly ash, silica fume, and wollastonite. A closed form model with classical laminate theory and ply discount method, coupled with a damage evolution model was utilized to simulate the non-linear tensile response of these composite materials. A constitutive material model developed earlier in the group was utilized to characterize and

  7. Composite glass ceramics - a promising material for aviation

    М. В. Дмитрієв

    2000-12-01

    Full Text Available The analysis of the technical and technological characteristics of the composite ceramic as a material for electrical and structural parts in aircraft. The economic and technological advantages compared to ceramic pottery and proposed options for development of production in Ukraine

  8. A comparison of microhardness of indirect composite restorative materials

    Miranda, Carolina Baptista; Pagani, Clóvis; Bottino, Marco Cícero

    2003-01-01

    The purpose of this study was to compare the microhardness of four indirect composite resins. Forty cylindrical samples were prepared according to the manufacturer’s recommendations using a Teflon mold. Ten specimens were produced from each tested material, constituting four groups (n=10) as foll...... esthetics and adequate mechanical properties may be considered as substitutes of natural teeth....

  9. Engineered cementitious composites with low volume of cementitious materials

    Zhou, J.; Quian, S.; Van Breugel, K.

    2010-01-01

    Engineered cementitious composite (ECC) is an ultra ductile cement-based material reinforced with fibers. It is characterized by high tensile ductility and tight crack width control. Thanks to the excellent performance, ECC is emerging in broad applications to enhance the loading capacity and the

  10. Preparation of Magnetic Composite Materials: Experiments for Secondary School Students

    Baldíková, Eva; Pospíšková, K.; Maděrová, Zdeňka; Šafaříková, Miroslava; Šafařík, Ivo

    2016-01-01

    Roč. 110, č. 1 (2016), s. 64-68 ISSN 0009-2770 Keywords : dyes removal * nanoparticles * mechanochemistry * technology * adsorbent * fe3o4 * magnetic modification * magnetic composite materials * magnetic separation * microwave-assisted synthesis * mechanochemical synthesis Impact factor: 0.387, year: 2016

  11. Physical and Model Uncertainty for Fatigue Design of Composite Material

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    The main aim of the present report is to establish stochastic models for the uncertainties related to fatigue design of composite materials. The uncertainties considered are the physical uncertainty related to the static and fatigue strength and the model uncertainty related to Miners rule...

  12. Manufacturing of aluminum composite material using stir casting process

    Jokhio, M.H.; Panhwar, M.I.; Unar, M.A.

    2011-01-01

    Manufacturing of aluminum alloy based casting composite materials via stir casting is one of the prominent and economical route for development and processing of metal matrix composites materials. Properties of these materials depend upon many processing parameters and selection of matrix and reinforcements. Literature reveals that most of the researchers are using 2, 6 and 7 xxx aluminum matrix reinforced with SiC particles for high strength properties whereas, insufficient information is available on reinforcement of 'AI/sub 2/O/sub 3/' particles in 7 xxx aluminum matrix. The 7 xxx series aluminum matrix usually contains Cu-Zn-Mg; Therefore, the present research was conducted to investigate the effect of elemental metal such as Cu-Zn-Mg in aluminum matrix on mechanical properties of stir casting of aluminum composite materials reinforced with alpha 'AI/sub 2/O/sub 3/' particles using simple foundry melting alloying and casting route. The age hardening treatments were also applied to study the aging response of the aluminum matrix on strength, ductility and hardness. The experimental results indicate that aluminum matrix cast composite can be manufactured via conventional foundry method giving very good responses to the strength and ductility up to 10% 'AI/sub 2/O/sub 3/' particles reinforced in aluminum matrix. (author)

  13. Polyvinyl alcohol–cellulose composite: a taste sensing material

    Unknown

    any lipid. PVA–cellulose composite has been modified to use as the sensor material. ... sis and SEM were done to get an idea about the structure and morphology of the prepared ..... mers for evaluation and classification of coffees, in Natural.

  14. Probabilistic Fatigue Design of Composite Material for Wind Turbine Blades

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    2011-01-01

    In the present paper a probabilistic design approach to fatigue design of wind turbine blades is presented. The physical uncertainty on the fatigue strength for composite material is estimated using public available fatigue tests. Further, the model uncertainty on Miner rule for damage accumulation...

  15. NASA Composite Materials Development: Lessons Learned and Future Challenges

    Tenney, Darrel R.; Davis, John G., Jr.; Pipes, R. Byron; Johnston, Norman

    2009-01-01

    Composite materials have emerged as the materials of choice for increasing the performance and reducing the weight and cost of military, general aviation, and transport aircraft and space launch vehicles. Major advancements have been made in the ability to design, fabricate, and analyze large complex aerospace structures. The recent efforts by Boeing and Airbus to incorporate composite into primary load carrying structures of large commercial transports and to certify the airworthiness of these structures is evidence of the significant advancements made in understanding and use of these materials in real world aircraft. NASA has been engaged in research on composites since the late 1960 s and has worked to address many development issues with these materials in an effort to ensure safety, improve performance, and improve affordability of air travel for the public good. This research has ranged from synthesis of advanced resin chemistries to development of mathematical analyses tools to reliably predict the response of built-up structures under combined load conditions. The lessons learned from this research are highlighted with specific examples to illustrate the problems encountered and solutions to these problems. Examples include specific technologies related to environmental effects, processing science, fabrication technologies, nondestructive inspection, damage tolerance, micromechanics, structural mechanics, and residual life prediction. The current state of the technology is reviewed and key issues requiring additional research identified. Also, grand challenges to be solved for expanded use of composites in aero structures are identified.

  16. and O-based composite materials derived from differential ...

    Abstract. In this work, we have made an effort to determine whether the effective atomic numbers of H-, C-, N- and O-based composite materials would indeed remain a constant over the energy grid of 280–1200 keV wherein incoherent scattering dominates their interaction with photons. For this purpose, the differential ...

  17. Optimum material gradient composition for the functionally graded ...

    This study investigates the relation between the material gradient properties and the optimum sensing/actuation design of the functionally graded piezoelectric beams. Three-dimensional (3D) finite element analysis has been employed for the prediction of an optimum composition profile in these types of sensors and ...

  18. Data-driven design optimization for composite material characterization

    John G. Michopoulos; John C. Hermanson; Athanasios Iliopoulos; Samuel G. Lambrakos; Tomonari Furukawa

    2011-06-01

    The main goal of the present paper is to demonstrate the value of design optimization beyond its use for structural shape determination in the realm of the constitutive characterization of anisotropic material systems such as polymer matrix composites with or without damage. The approaches discussed are based on the availability of massive experimental data...

  19. The Deflated Preconditioned Conjugate Gradient Method Applied to Composite Materials

    Jönsthövel, T.B.

    2012-01-01

    Simulations with composite materials often involve large jumps in the coefficients of the underlying stiffness matrix. These jumps can introduce unfavorable eigenvalues in the spectrum of the stiffness matrix. We show that the rigid body modes; the translations and rotations, of the disjunct rigid

  20. Quantitative Description of the Morphology and Microdamages of Composite Materials

    Axelsen, M. S.

    The purpose of the present Ph.D project is to investigate correlation between the microstructure variability and transverse mechanical properties. The material considered here is a polymer based unidirectional composite with long cylindrical fibers, and the transverse properties can be analysed...

  1. Machining of Machine Elements Made of Polymer Composite Materials

    Baurova, N. I.; Makarov, K. A.

    2017-12-01

    The machining of the machine elements that are made of polymer composite materials (PCMs) or are repaired using them is considered. Turning, milling, and drilling are shown to be most widely used among all methods of cutting PCMs. Cutting conditions for the machining of PCMs are presented. The factors that most strongly affect the roughness parameters and the accuracy of cutting PCMs are considered.

  2. Manufacturing of Aluminum Composite Material Using Stir Casting Process

    Muhammad Hayat Jokhio

    2011-01-01

    Full Text Available Manufacturing of aluminum alloy based casting composite materials via stir casting is one of the prominent and economical route for development and processing of metal matrix composites materials. Properties of these materials depend upon many processing parameters and selection of matrix and reinforcements. Literature reveals that most of the researchers are using 2, 6 and 7xxx aluminum matrix reinforced with SiC particles for high strength properties whereas, insufficient information is available on reinforcement of \\"Al2O3\\" particles in 7xxx aluminum matrix. The 7xxx series aluminum matrix usually contains Cu-Zn-Mg. Therefore, the present research was conducted to investigate the effect of elemental metal such as Cu-Zn-Mg in aluminum matrix on mechanical properties of stir casting of aluminum composite materials reinforced with alpha \\"Al2O3\\" particles using simple foundry melting alloying and casting route. The age hardening treatments were also applied to study the aging response of the aluminum matrix on strength, ductility and hardness. The experimental results indicate that aluminum matrix cast composite can be manufactured via conventional foundry method giving very good responses to the strength and ductility up to 10% \\"Al2O3\\" particles reinforced in aluminum matrix.

  3. Mishap risk control for advanced aerospace/composite materials

    Olson, John M.

    1994-01-01

    Although advanced aerospace materials and advanced composites provide outstanding performance, they also present several unique post-mishap environmental, safety, and health concerns. The purpose of this paper is to provide information on some of the unique hazards and concerns associated with these materials when damaged by fire, explosion, or high-energy impact. Additionally, recommended procedures and precautions are addressed as they pertain to all phases of a composite aircraft mishap response, including fire-fighting, investigation, recovery, clean-up, and guidelines are general in nature and not application-specific. The goal of this project is to provide factual and realistic information which can be used to develop consistent and effective procedures and policies to minimize the potential environmental, safety, and health impacts of a composite aircraft mishap response effort.

  4. State-of-the-art of biodegradable composite materials

    Baley, Ch.; Grohens, Y.; Pillin, I.

    2004-01-01

    Nowadays, the market demand for environment friendly materials is in strong growth. The biodegradable composites (biodegradable fibres and polymers) mainly extracted from renewable resources will be a major contributor to the production of new industrial high performance products partially solving the problem of waste management. At the end of the lifetime, a structural bio-composite could be be crushed and recycled through a controlled industrial composting process. This the state-of-the-art report focuses on the biopolymers the vegetable fibres properties, the mechanisms of biodegradation and the examples of biodegradable composites. Eco-design of new products requires these new materials for which a life cycle analysis is nevertheless necessary to validate their environmental benefits. (authors)

  5. Resolution of the Task A-11 reactor-vessel materials-toughness safety issue. Appendices C-K

    1982-10-01

    The central problem in the unresolved safety issue A-11, Reactor Vessel Materials Toughness, was to provide guidance in performing analyses required by 10 CFR Part 50, Appendix G, Section V.C. for reactor pressure vessels (RPVs) which fail to meet the toughness requirement during service life as a result of neutron radiation embrittlement. Although the methods of linear-elastic fracture mechanics (LEFM) were adequate for low-temperature RPV problems, they were inapplicable under operating conditions because vessel steels, even those which exhibit less than 50 ft-lb of C/sub v/ energy, were relatively tough at temperatures where the impact energy reached its upper shelf values. A technical team of recognized experts was organized to assist the NRC staff in addressing the problem. Using the foundation of the tearing modulus concept, which had been developed under earlier NRC sponsorship, relationships were obtained which provided approximate solutions to the problem of RPV fracture with assumed beltline region flaws. The first paper of this report is a summary of the problem, the solutions, and the results of verification analyses. The details are provided in a series of appendices in Volumes I and II

  6. Investigating accidents involving aircraft manufactured from polymer composite materials

    Dunn, Leigh

    This study looks into the examination of polymer composite wreckage from the perspective of the aircraft accident investigator. It develops an understanding of the process of wreckage examination as well as identifying the potential for visual and macroscopic interpretation of polymer composite aircraft wreckage. The in-field examination of aircraft wreckage, and subsequent interpretations of material failures, can be a significant part of an aircraft accident investigation. As the use of composite materials in aircraft construction increases, the understanding of how macroscopic failure characteristics of composite materials may aid the field investigator is becoming of increasing importance.. The first phase of this research project was to explore how investigation practitioners conduct wreckage examinations. Four accident investigation case studies were examined. The analysis of the case studies provided a framework of the wreckage examination process. Subsequently, a literature survey was conducted to establish the current level of knowledge on the visual and macroscopic interpretation of polymer composite failures. Relevant literature was identified and a compendium of visual and macroscopic characteristics was created. Two full-scale polymer composite wing structures were loaded statically, in an upward bending direction, until each wing structure fractured and separated. The wing structures were subsequently examined for the existence of failure characteristics. The examination revealed that whilst characteristics were present, the fragmentation of the structure destroyed valuable evidence. A hypothetical accident scenario utilising the fractured wing structures was developed, which UK government accident investigators subsequently investigated. This provided refinement to the investigative framework and suggested further guidance on the interpretation of polymer composite failures by accident investigators..

  7. Carbon fibre as a composites materials precursor-A review

    Ismail, A.F.; Yusof, N.; Mustafa, A.

    2010-01-01

    Carbon fibers are widely used as reinforcement in composite materials such as carbon fiber reinforced plastics, carbon fiber reinforced ceramics, carbon-carbon composites and carbon fiber reinforced metals, due to their high specific strength and modulus. Carbon fiber composites are ideally suited to applications where strength, stiffness, lower weight and outstanding fatigue characteristics are critical requirements. Generally, there are two main sectors of carbon fiber applications. Application of carbon fiber in high technology sectors includes aerospace and nuclear engineering whereby the use of carbon fiber is driven by maximum performance and not significantly influenced by cost factors. Meanwhile, the application in general engineering and transportations sector is dominated by cost constraints. Carbon fibers used in composites are often coated or surface treated to improve interaction between the fiber surface and the matrix. PAN/ CNT composite fibers are good candidates for the development of next generation carbon fibers with improved tensile strength and modulus while retaining its compressive strength. This paper aims at reviewing and critically discussing the fabrication aspects of carbon fiber for composites which can be divided into several sections: precursor selection, spinning process, pretreatment of the precursor, pyrolysis process, and also surface treatment of the carbon fiber. The future direction of carbon fiber for composite is also briefly identified to further extend the boundary of science and technology in order to fully exploit its potential. (author)

  8. Enhanced laminated composite phase change material for energy storage

    Darkwa, J.; Zhou, T. [Centre for Sustainable Energy Technologies (CSET), The University of Nottingham Ningbo, 199 Taikang East Road, Ningbo 315100 (China)

    2011-02-15

    This paper summarises studies undertaken towards the development of a laminated composite aluminium/hexadecane phase change material (PCM) drywall based on previous analytical work. The study also covered the selection and testing of various types of adhesive materials and identified Polyvinyl acetate (PVA) material as a suitable bonding material. For the purpose of comparison pure hexadecane and composite aluminium/hexadecane samples were developed and tested. The test results revealed faster thermal response by the aluminium/hexadecane sample regarding the rate of heat flux and also achieved about 10% and 15% heat transfer enhancements during the charging and discharging periods respectively. Its measured effective thermal conductivity also increased remarkably to 1.25 W/mK as compared with 0.15 W/mK for pure hexadecane. However there was about 5% less total cumulative thermal energy discharged at the end of the test which indicates that its effective thermal capacity was reduced by the presence of the aluminium particles. The study has shown that some of the scientific and technical barriers associated with the development of laminated composite PCM drywall systems can be overcome but further investigations of effects of adhesive materials are needed. (author)

  9. New methods of analysis of materials strength data for the ASME Boiler and Pressure Vessel Code

    Booker, M.K.; Booker, B.L.P.

    1980-01-01

    Tensile and creep data of the type used to establish allowable stress levels for the ASME Boiler and Pressure Vessel Code have been examined for type 321H stainless steel. Both inhomogeneous, unbalanced data sets and well-planned homogeneous data sets have been examined. Data have been analyzed by implementing standard manual techniques on a modern digital computer. In addition, more sophisticated techniques, practical only through the use of the computer, have been applied. The result clearly demonstrates the efficacy of computerized techniques for these types of analyses

  10. International workshop on WWER-440 reactor pressure vessel embrittlement and annealing. Working material

    1994-01-01

    The purpose of the Workshop was essentially to discuss the WWER 440 model 230 reactor pressure vessel integrity in terms of the measures already taken, current activities and future plans. The meeting was arranged in two parts, namely, the Scientific programme followed by the consideration, review and revision of the IAEA Consultancy report on RPV Embrittlement and Annealing. This particular report covers the first part of the meeting i.e., the Scientific Programme, in the form of proceedings of the meeting, while the re-drafted Consultancy report will be issued later. The meeting was attended by sixty-six representatives from thirteen countries. Refs, figs and tabs

  11. Package of programs for calculating accidents involving melting of the materials in a fast-reactor vessel

    Vlasichev, G.N.

    1994-01-01

    Methods for calculating one-dimensional nonstationary temperature distribution in a system of physically coupled materials are described. Six computer programs developed for calculating accident processes for fast reactor core melt are described in the article. The methods and computer programs take into account melting, solidification, and, in some cases, vaporization of materials. The programs perform calculations for heterogeneous systems consisting of materials with arbitrary but constant composition and heat transfer conditions at material boundaries. Additional modules provide calculations of specific conditions of heat transfer between materials, the change in these conditions and configuration of the materials as a result of coolant boiling, melting and movement of the fuel and structural materials, temperature dependences of thermophysical properties of the materials, and heat release in the fuel. 11 refs., 3 figs

  12. Preparation of the Jaws Damaged Parts from Composite Biopolymers Materials

    Riyam A. Al-husseini

    2017-10-01

    Full Text Available Composite materials composing of fusing two materials or more are disaccorded in mechanical and physical characteristics, The studied the effect of changing in the reinforcement percentage by Hydroxyapatite Prepared nano world via the size of the nanoscale powder manufacturing manner chemical precipitation and microwave powders were two types their preparations have been from natural sources: the first type of eggshells and the other from the bones of fish in mechanical Properties which include the tensile strength, elastic modulus, elongation, hardness and tear for composite material consisting of Silicone rubber (SIR reinforced by (µ-n-HA, after strengthening silicone rubber Protect proportions (5,10,15,20 wt% of Article achieved results that increase the additive lead to increased hardness while tougher and modulus of elasticity decreases with added as shown in the diagrams.

  13. Mechanical characterization of composite materials by optical techniques: A review

    Bruno, Luigi

    2018-05-01

    The present review provides an overview of work published in recent years dealing with the mechanical characterization of composite materials performed by optical techniques. The paper emphasizes the strengths derived from the employment of full-field methods when the strain field of an anisotropic material must be evaluated. This is framed in contrast to the use of conventional measurement techniques, which provide single values of the measured quantities unable to offer thorough descriptions of deformation distribution. The review outlines the intensity and articulation of work in this research field to date and its ongoing importance not only in the academy, but also in industrial sectors where composite materials represent a strategic resource for development.

  14. Nanomodified composite magnetic materials and their molding technologies

    I. Timoshkov

    2018-05-01

    Full Text Available Advanced electro-magnetic machines and systems require new materials with improved properties. Heterogeneous 3D nanomodified soft magnetic materials could be efficiently applied. Multistage technology of iron particle surface nanomodification by sequential oxidation and Si-organic coatings will be reported. The thickness of layers is 0.5-5 nm. Compaction and annealing are the final steps of magnetic parts and components shaping. The soft magnetic composite material shows the features: resistivity is controlled by insulating coating thickness and equals up to ρ =10-4 Ω⋅m for metallic state and ρ =104 Ω⋅m for insulator state, maximum magnetic permeability is μm = 2500 and μm = 300 respectively, induction is up to Bm=2.1 T. These properties of composite soft magnetic material allow applying for transformers, throttles, stator-rotor of high-efficient and powerful electric machines in 10 kHz–1MGz frequency range. For microsystems and microcomponents application, good opportunity to improve their reliability is the use of nanocomposite materials. Electroplating technology of nanocomposite magnetic materials into the ultra-thick micromolds will be presented. Co-deposition of the soft magnetic alloys with inert hard nanoparticles allows obtaining materials with magnetic permeability up to μm=104, magnetic induction of Bs=(0.62–1.3 T. Such LIGA-like technology will be applied in MEMS to produce high reliable devices with advanced physical properties.

  15. Nanomodified composite magnetic materials and their molding technologies

    Timoshkov, I.; Gao, Q.; Govor, G.; Sakova, A.; Timoshkov, V.; Vetcher, A.

    2018-05-01

    Advanced electro-magnetic machines and systems require new materials with improved properties. Heterogeneous 3D nanomodified soft magnetic materials could be efficiently applied. Multistage technology of iron particle surface nanomodification by sequential oxidation and Si-organic coatings will be reported. The thickness of layers is 0.5-5 nm. Compaction and annealing are the final steps of magnetic parts and components shaping. The soft magnetic composite material shows the features: resistivity is controlled by insulating coating thickness and equals up to ρ =10-4 Ωṡm for metallic state and ρ =104 Ωṡm for insulator state, maximum magnetic permeability is μm = 2500 and μm = 300 respectively, induction is up to Bm=2.1 T. These properties of composite soft magnetic material allow applying for transformers, throttles, stator-rotor of high-efficient and powerful electric machines in 10 kHz-1MGz frequency range. For microsystems and microcomponents application, good opportunity to improve their reliability is the use of nanocomposite materials. Electroplating technology of nanocomposite magnetic materials into the ultra-thick micromolds will be presented. Co-deposition of the soft magnetic alloys with inert hard nanoparticles allows obtaining materials with magnetic permeability up to μm=104, magnetic induction of Bs=(0.62-1.3) T. Such LIGA-like technology will be applied in MEMS to produce high reliable devices with advanced physical properties.

  16. Stress and Damage in Polymer Matrix Composite Materials Due to Material Degradation at High Temperatures

    McManus, Hugh L.; Chamis, Christos C.

    1996-01-01

    This report describes analytical methods for calculating stresses and damage caused by degradation of the matrix constituent in polymer matrix composite materials. Laminate geometry, material properties, and matrix degradation states are specified as functions of position and time. Matrix shrinkage and property changes are modeled as functions of the degradation states. The model is incorporated into an existing composite mechanics computer code. Stresses, strains, and deformations at the laminate, ply, and micro levels are calculated, and from these calculations it is determined if there is failure of any kind. The rationale for the model (based on published experimental work) is presented, its integration into the laminate analysis code is outlined, and example results are given, with comparisons to existing material and structural data. The mechanisms behind the changes in properties and in surface cracking during long-term aging of polyimide matrix composites are clarified. High-temperature-material test methods are also evaluated.

  17. Dual-nanoparticulate-reinforced aluminum matrix composite materials

    Kwon, Hansang; Cho, Seungchan; Kawasaki, Akira; Leparoux, Marc

    2012-01-01

    Aluminum (Al) matrix composite materials reinforced with carbon nanotubes (CNT) and silicon carbide nanoparticles (nano-SiC) were fabricated by mechanical ball milling, followed by hot-pressing. Nano-SiC was used as an active mixing agent for dispersing the CNTs in the Al powder. The hardness of the produced composites was dramatically increased, up to eight times higher than bulk pure Al, by increasing the amount of nano-SiC particles. A small quantity of aluminum carbide (Al 4 C 3 ) was observed by TEM analysis and quantified using x-ray diffraction. The composite with the highest hardness values contained some nanosized Al 4 C 3 . Along with the CNT and the nano-SiC, Al 4 C 3 also seemed to play a role in the enhanced hardness of the composites. The high energy milling process seems to lead to a homogeneous dispersion of the high aspect ratio CNTs, and of the nearly spherical nano-SiC particles in the Al matrix. This powder metallurgical approach could also be applied to other nanoreinforced composites, such as ceramics or complex matrix materials. (paper)

  18. Fissure sealant materials: Wear resistance of flowable composite resins.

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm(2) and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm(2)of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

  19. On the composition and structure of nanoprecipitates in irradiated pressure vessel steels

    Odette, G.R.; Liu, C.L.; Wirth, B.D.

    1997-01-01

    Nanoscale Cu rich precipitates (CRPs) are widely believed to be the dominant hardening feature resulting in severe embrittlement in irradiated reactor pressure vessel (RPV) steels. However, this view has recently been challenged by interpretations of atom probe field ion microscopy (APFIM) measurements that describe the dominant nanofeatures as dilute solute atmospheres (DSAs). The practical impact of these differing views is very significant. This work compares and contrasts the CRP versus DSA descriptions to a wide variety of pertinent data. Mechanical property trends as well as small angle neutron scattering (SANS) and field emission scanning transmission electron microscopy (FEGSTEM) measurements support the presence of CRPs. CRPs are also consistent with the fundamental thermodynamic and kinetic laws. However, standard theory cannot provide the atomic level resolution needed to fully understand the nanofeatures. Therefore, a new Lattice Monte Carlo (LMC) atomistic method is used to simulate the complex chemical structures of the CRPs. The LMC method unifies the SANS/FEGSTEM and APFIM data within a well founded physical framework

  20. Heavy-Section Steel Irradiation Program on irradiation effects in light-water reactor pressure vessel materials

    Nanstad, R.K.; Corwin, W.R.; Alexander, D.J.; Haggag, F.M.; Iskander, S.K.; McCabe, D.E.; Sokolov, M.A.; Stoller, R.E.

    1995-01-01

    The safety of commercial light-water nuclear plants is highly dependent on the structural integrity of the reactor pressure vessel (RPV). In the absence of radiation damage to the RPV, fracture of the vessel is difficult to postulate. Exposure to high energy neutrons can result in embrittlement of radiation-sensitive RPV materials. The Heavy-Section Steel Irradiation (HSSI) Program at Oak Ridge National Laboratory, sponsored by the US Nuclear Regulatory Commission (USNRC), is assessing the effects of neutron irradiation on RPV material behavior, especially fracture toughness. The results of these and other studies are used by the USNRC in the evaluation of RPV integrity and regulation of overall nuclear plant safety. In assessing the effects of irradiation, prototypic RPV materials are characterized in the unirradiated condition and exposed to radiation under varying conditions. Mechanical property tests are conducted to provide data which can be used in the development of guidelines for structural integrity evaluations, while metallurgical examinations and mechanistic modeling are performed to improve understanding of the mechanisms responsible for embrittlement. The results of these investigations, in conjunction with results from commercial reactor surveillance programs, are used to develop a methodology for the prediction of radiation effects on RPV materials. This irradiation-induced degradation of the materials can be mitigated by thermal annealing, i.e., heating the RPV to a temperature above that of normal operation. Thus, thermal annealing and evaluation of reirradiation behavior are major tasks of the HSSI Program. This paper describes the HSSI Program activities by summarizing some past and recent results, as well as current and planned studies. 30 refs., 8 figs., 1 tab

  1. Enhancement of the quality of the reactor pressure vessel used in light water power plants by advanced material fabrication and testing technoligies

    Kussmaul, K.; Ewald, J.

    1977-01-01

    The fracture safe assessment of nuclear pressure vessels (RPV) is based upon: (i) an adequate stress analysis, (ii) reliable material characteristics, (iii) acceptable defects sizes. There may arise problems which are related to the inhomogeneity, low toughness and crack phenomena sometimes observed in the base material and heat affected zone (HAZ). Due to this it is difficult and in some respects even impossible to measure the decisive values of (fracture-) toughness and defects. Apart from the significance of those facts for existing RPVs, all efforts were directed to provide a steel which should be non-susceptible to embrittlement and/or cracking in the HAZ and simultaneously yielding in a higher upper shelf toughness of base and HAZ material. These objections were pursued in cooperation with manufacturers, vendors and inspection authorities by the following activities. (i) Detailed investigations to obtain information on: occurrence and size of inhomogeneities and defects, especially stress relief cracking (SCR), toughness properties adjacent to defects; (ii) improvement of: chemical composition, steel making processes, welding procedures, optimum temperature cycle and level for stress relief heat-treatment. In order to solve these tasks it was necessary to develop additional tools and to correlate all partial results which were newly elaborated. (Auth.)

  2. Automated Manufacture of Damage Detecting, Self-Healing Composite Cryogenic Pressure Vessels, Phase II

    National Aeronautics and Space Administration — After successfully demonstrating the basic functionality of a damage-detecting, self-healing 'smart' material system in Phase I, Aurora and UMass Lowell aim to...

  3. Hybrid fiber reinforcement and crack formation in Cementitious Composite Materials

    Pereira, E.B.; Fischer, Gregor; Barros, J.A.O.

    2011-01-01

    reinforcement systems. The research described in this paper shows that the multi-scale conception of cracking and the use of hybrid fiber reinforcements do not necessarily result in an improved tensile behavior of the composite. Particular material design requirements may nevertheless justify the use of hybrid......- to the macroscale. In this study, the performance of different fiber reinforced cementitious composites is assessed in terms of their tensile stress-crack opening behavior. The results obtained from this investigation allow a direct quantitative comparison of the behavior obtained from the different fiber...

  4. Behavior of Fiber-Reinforced Smart Soft Composite Actuators According to Material Composition

    Han, Min-Woo; Kim, Hyung-Il; Song, Sung-Hyuk; Ahn, Sung-Hoon [Seoul Nat’l Univ., Seoul (Korea, Republic of)

    2017-02-15

    Fiber-reinforced polymer composites, which are made by combining a continuous fiber that acts as reinforcement and a homogeneous polymeric material that acts as a host, are engineering materials with high strength and stiffness and a lightweight structure. In this study, a shape memory alloy(SMA) reinforced composite actuator is presented. This actuator is used to generate large deformations in single lightweight structures and can be used in applications requiring a high degree of adaptability to various external conditions. The proposed actuator consists of numerous individual laminas of the glass-fiber fabric that are embedded in a polymeric matrix. To characterize its deformation behavior, the composition of the actuator was changed by changing the matrix material and the number of the glass-fiber fabric layers. In addition, current of various magnitudes were applied to each actuator to study the effect of the heating of SMA wires on applying current.

  5. Adaptive, Active and Multifunctional Composite and Hybrid Materials Program: Composite and Hybrid Materials ERA

    2014-04-01

    590 . SMASIS2011-4934. L. D. Peel, J. Baur, D. Phillips, and A. McClung, “The Effect of Scaling on the Performance of Elastomer Composite Actuators...fragility of the fibers it was also not possible to extract some of them from their adhesive paper mountings without breakage. For Raman ... Raman spectroscopy and microscopy (SEM), the nanocomposites were evaluated for their thermal analytical properties using TGA. Electrical

  6. The aqueous corrosion behavior of technetium - Alloy and composite materials

    Jarvinen, G.; Kolman, D.; Taylor, C.; Goff, G.; Cisneros, M.; Mausolf, E.; Poineau, F.; Koury, D.; Czerwinski, K.

    2013-01-01

    Metal waste forms are under study as possible disposal forms for technetium and other fission products. The alloying of Tc is desirable to reduce the melting point of the Tc-containing metal waste form and potentially improve its corrosion resistance. Technetium-nickel composites were made by mixing the two metal powders and pressing the mixture to make a pellet. The as-pressed composite materials were compared to sintered composites and alloys of identical composition in electrochemical corrosion tests. As-pressed samples were not robust enough for fine polishing and only a limited number of corrosion tests were performed. Alloys and composites with 10 wt% Tc appear to be more corrosion resistant at open circuit than the individual components based on linear polarization resistance and polarization data. The addition of 10 wt% Tc to Ni appears beneficial at open circuit, but detrimental upon anodic polarization. Qualitatively, the polarizations of 10 wt% Tc alloys and composites appear like crude addition of Tc plus Ni. The 1 wt% Tc alloys behave like pure Ni, but some effect of Tc is seen upon polarization. Cathodic polarization of Tc by Ni appears feasible based on open circuit potential measurements, however, zero resistance ammetry and solution measurements are necessary to confirm cathodic protection

  7. The aqueous corrosion behavior of technetium - Alloy and composite materials

    Jarvinen, G.; Kolman, D.; Taylor, C.; Goff, G.; Cisneros, M. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mausolf, E.; Poineau, F.; Koury, D.; Czerwinski, K. [Department of Chemistry, University of Nevada, Las Vegas, Las Vegas, NV 89154 (United States)

    2013-07-01

    Metal waste forms are under study as possible disposal forms for technetium and other fission products. The alloying of Tc is desirable to reduce the melting point of the Tc-containing metal waste form and potentially improve its corrosion resistance. Technetium-nickel composites were made by mixing the two metal powders and pressing the mixture to make a pellet. The as-pressed composite materials were compared to sintered composites and alloys of identical composition in electrochemical corrosion tests. As-pressed samples were not robust enough for fine polishing and only a limited number of corrosion tests were performed. Alloys and composites with 10 wt% Tc appear to be more corrosion resistant at open circuit than the individual components based on linear polarization resistance and polarization data. The addition of 10 wt% Tc to Ni appears beneficial at open circuit, but detrimental upon anodic polarization. Qualitatively, the polarizations of 10 wt% Tc alloys and composites appear like crude addition of Tc plus Ni. The 1 wt% Tc alloys behave like pure Ni, but some effect of Tc is seen upon polarization. Cathodic polarization of Tc by Ni appears feasible based on open circuit potential measurements, however, zero resistance ammetry and solution measurements are necessary to confirm cathodic protection.

  8. Multiple shell pressure vessel

    Wedellsborg, B.W.

    1988-01-01

    A method is described of fabricating a pressure vessel comprising the steps of: attaching a first inner pressure vessel having means defining inlet and outlet openings to a top flange, placing a second inner pressure vessel, having means defining inlet and outlet opening, concentric with and spaced about the first inner pressure vessel and attaching the second inner pressure vessel to the top flange, placing an outer pressure vessel, having inlet and outlet openings, concentric with and spaced apart about the second inner pressure vessel and attaching the outer pressure vessel to the top flange, attaching a generally cylindrical inner inlet conduit and a generally cylindrical inner outlet conduit respectively to the inlet and outlet openings in the first inner pressure vessel, attaching a generally cylindrical outer inlet conduit and a generally cylindrical outer outlet conduit respectively to the inlet and outlet opening in the second inner pressure vessel, heating the assembled pressure vessel to a temperature above the melting point of a material selected from the group, lead, tin, antimony, bismuth, potassium, sodium, boron and mixtures thereof, filling the space between the first inner pressure vessel and the second inner pressure vessel with material selected from the group, filling the space between the second inner pressure vessel and the outer pressure vessel with material selected from the group, and pressurizing the material filling the spaces between the pressure vessels to a predetermined pressure, the step comprising: pressurizing the spaces to a pressure whereby the wall of the first inner pressure vessel is maintained in compression during steady state operation of the pressure vessel

  9. Development of metallic system multi-composite materials for compound environment and corrosion monitoring technology

    Kiuchi, Kiyoshi

    1996-01-01

    For the structural materials used for the pressure boundary of nuclear power plants and others, the long term durability over several decades under the compound environment, in which the action of radiation and the corrosion and erosion in the environment of use are superposed, is demanded. To its controlling factors, the secular change of materials due to irradiation ageing and the chemical and physical properties of extreme compound environment are related complicatedly. In the first period of this research, the development of the corrosion-resistant alloys with the most excellent adaptability to environments was carried out by the combination of new alloy design and alloy manufacturing technology. In the second period, in order to heighten the adaptability as the pressure boundary materials between different compound environments, the creation of metallic system multi-composite materials has been advanced. Also corrosion monitoring technique is being developed. The stainless steel for water-cooled reactors, the wear and corrosion-resistant superalloy for reactor core, the corrosion-resistant alloy and the metallic refractory material for reprocessing nitric acid reaction vessels are reported. (K.I.)

  10. Compendium of Material Composition Data for Radiation Transport Modeling

    McConn, Ronald J.; Gesh, Christopher J.; Pagh, Richard T.; Rucker, Robert A.; Williams III, Robert

    2011-03-04

    Introduction Meaningful simulations of radiation transport applications require realistic definitions of material composition and densities. When seeking that information for applications in fields such as homeland security, radiation shielding and protection, and criticality safety, researchers usually encounter a variety of materials for which elemental compositions are not readily available or densities are not defined. Publication of the Compendium of Material Composition Data for Radiation Transport Modeling, Revision 0, in 2006 was the first step toward mitigating this problem. Revision 0 of this document listed 121 materials, selected mostly from the combined personal libraries of staff at the Pacific Northwest National Laboratory (PNNL), and thus had a scope that was recognized at the time to be limited. Nevertheless, its creation did provide a well-referenced source of some unique or hard-to-define material data in a format that could be used directly in radiation transport calculations being performed at PNNL. Moreover, having a single common set of material definitions also helped to standardize at least one aspect of the various modeling efforts across the laboratory by providing separate researchers the ability to compare different model results using a common basis of materials. The authors of the 2006 compendium understood that, depending on its use and feedback, the compendium would need to be revised to correct errors or inconsistencies in the data for the original 121 materials, as well as to increase (per users suggestions) the number of materials listed. This 2010 revision of the compendium has accomplished both of those objectives. The most obvious change is the increased number of materials from 121 to 372. The not-so-obvious change is the mechanism used to produce the data listed here. The data listed in the 2006 document were compiled, evaluated, entered, and error-checked by a group of individuals essentially by hand, providing no library

  11. Wetting, superhydrophobicity, and icephobicity in biomimetic composite materials

    Hejazi, Vahid

    Recent developments in nano- and bio-technology require new materials. Among these new classes of materials which have emerged in the recent years are biomimetic materials, which mimic structure and properties of materials found in living nature. There are a large number of biological objects including bacteria, animals and plants with properties of interest for engineers. Among these properties is the ability of the lotus leaf and other natural materials to repel water, which has inspired researchers to prepare similar surfaces. The Lotus effect involving roughness-induced superhydrophobicity is a way to design nonwetting, self-cleaning, omniphobic, icephobic, and antifouling surfaces. The range of actual and potential applications of superhydrophobic surfaces is diverse including optical, building and architecture, textiles, solar panels, lab-on-a-chip, microfluidic devices, and applications requiring antifouling from biological and organic contaminants. In this thesis, in chapter one, we introduce the general concepts and definitions regarding the wetting properties of the surfaces. In chapter two, we develop novel models and conduct experiments on wetting of composite materials. To design sustainable superhydrophobic metal matrix composite (MMC) surfaces, we suggest using hydrophobic reinforcement in the bulk of the material, rather than only at its surface. We experimentally study the wetting properties of graphite-reinforced Al- and Cu-based composites and conclude that the Cu-based MMCs have the potential to be used in the future for the applications where the wear-resistant superhydrophobicity is required. In chapter three, we introduce hydrophobic coating at the surface of concrete materials making them waterproof to prevent material failure, because concretes and ceramics cannot stop water from seeping through them and forming cracks. We create water-repellant concretes with CA close to 160o using superhydrophobic coating. In chapter four, experimental

  12. Multimaterial magnetically assisted 3D printing of composite materials

    Kokkinis, Dimitri; Schaffner, Manuel; Studart, André R.

    2015-10-01

    3D printing has become commonplace for the manufacturing of objects with unusual geometries. Recent developments that enabled printing of multiple materials indicate that the technology can potentially offer a much wider design space beyond unusual shaping. Here we show that a new dimension in this design space can be exploited through the control of the orientation of anisotropic particles used as building blocks during a direct ink-writing process. Particle orientation control is demonstrated by applying low magnetic fields on deposited inks pre-loaded with magnetized stiff platelets. Multimaterial dispensers and a two-component mixing unit provide additional control over the local composition of the printed material. The five-dimensional design space covered by the proposed multimaterial magnetically assisted 3D printing platform (MM-3D printing) opens the way towards the manufacturing of functional heterogeneous materials with exquisite microstructural features thus far only accessible by biological materials grown in nature.

  13. POLYMER COMPOSITES MODIFIED BY WASTE MATERIALS CONTAINING WOOD FIBRES

    Bernardeta Dębska

    2016-11-01

    Full Text Available In recent years, the idea of sustainable development has become one of the most important require-ments of civilization. Development of sustainable construction involves the need for the introduction of innovative technologies and solutions that will combine beneficial economic effects with taking care of the health and comfort of users, reducing the negative impact of the materials on the environment. Composites obtained from the use of waste materials are part of these assumptions. These include modified epoxy mortar containing waste wood fibres, described in this article. The modification consists in the substitution of sand by crushed waste boards, previously used as underlays for panels, in quantities of 0%, 10%, 20%, 35% and 50% by weight, respectively. Composites containing up to 20% of the modifier which were characterized by low water absorption, and good mechanical properties, also retained them after the process of cyclic freezing and thawing.

  14. Peridynamics for analysis of failure in advanced composite materials

    Askari, A.; Azdoud, Yan; Han, Fei; Lubineau, Gilles; Silling, S.

    2015-01-01

    Peridynamics has been recently introduced as a way to simulate the initiation and propagation of multiple discontinuities (e.g. cracks). It is an alternative to classical continuum damage mechanics and fracture mechanics and is based on a nonlocal rewriting of the equilibrium equation. This new technique is particularly promising in the case of composite materials, in which very complex mechanisms of degradation must be described. We present here some fundamental aspects of peridynamics models for composite materials, and especially laminates. We also propose an approach to couple peridynamics domains with classical continuum mechanics (which relies on the concept of contact forces) by the use of a recently introduced coupling technique: the morphing technique, that appears to be a very versatile and powerful tool for coupling local to nonlocal descriptions.

  15. Nanodiamond composite as a material for cold electron emitters

    Arkhipov, A V; Sominski, G G; Uvarov, A A; Gordeev, S K; Korchagina, S B

    2008-01-01

    Characteristics of field-induced electron emission were investigated for one of newly designed all-carbon materials - nanodiamond composite (NDC). The composite is comprised by 4-6 nm diamond grains covered with 0.2-1 nm-thick graphite-like shells that merge at grain junctions and determine such properties as mechanical strength and high electric conductivity. Large number of uniformly distributed sp 3 -sp 2 interfaces allowed to expect enhanced electron emission in electric field. Combination of these features makes NDC a promising material for cold electron emitters in various applications. Experimental testing confirmed high efficiency of electron emission from NDC. In comparison with previousely tested forms of nanocarbon, NDC emitters demonstrated better stabily and tolerance to performance conditions. Unusual activation scenarios and thermal dependencies of emission characteristics observed in experiments with NDC can add new background for explanation of facilitated electron emission from nanocarbons with relatively 'smooth' surface morphology

  16. Peridynamics for analysis of failure in advanced composite materials

    Askari, A.

    2015-08-14

    Peridynamics has been recently introduced as a way to simulate the initiation and propagation of multiple discontinuities (e.g. cracks). It is an alternative to classical continuum damage mechanics and fracture mechanics and is based on a nonlocal rewriting of the equilibrium equation. This new technique is particularly promising in the case of composite materials, in which very complex mechanisms of degradation must be described. We present here some fundamental aspects of peridynamics models for composite materials, and especially laminates. We also propose an approach to couple peridynamics domains with classical continuum mechanics (which relies on the concept of contact forces) by the use of a recently introduced coupling technique: the morphing technique, that appears to be a very versatile and powerful tool for coupling local to nonlocal descriptions.

  17. Nanodiamond composite as a material for cold electron emitters

    Arkhipov, A V; Sominski, G G; Uvarov, A A [St.Petersburg State Polytechnic University, 29 Politchnicheskaya, St.Petersburg, 195251 (Russian Federation); Gordeev, S K; Korchagina, S B [FSUE ' Central Research Institute for Materials' , 8 Paradnaya Street, St.Petersburg, 191014 (Russian Federation)], E-mail: arkhipov@rphf.spbstu.ru

    2008-03-15

    Characteristics of field-induced electron emission were investigated for one of newly designed all-carbon materials - nanodiamond composite (NDC). The composite is comprised by 4-6 nm diamond grains covered with 0.2-1 nm-thick graphite-like shells that merge at grain junctions and determine such properties as mechanical strength and high electric conductivity. Large number of uniformly distributed sp{sup 3}-sp{sup 2} interfaces allowed to expect enhanced electron emission in electric field. Combination of these features makes NDC a promising material for cold electron emitters in various applications. Experimental testing confirmed high efficiency of electron emission from NDC. In comparison with previousely tested forms of nanocarbon, NDC emitters demonstrated better stabily and tolerance to performance conditions. Unusual activation scenarios and thermal dependencies of emission characteristics observed in experiments with NDC can add new background for explanation of facilitated electron emission from nanocarbons with relatively 'smooth' surface morphology.

  18. Micromechanics of Composite Materials Governed by Vector Constitutive Laws

    Bednarcyk, Brett A.; Aboudi, Jacob; Arnold, Steven M.

    2017-01-01

    The high-fidelity generalized method of cells micromechanics theory has been extended for the prediction of the effective property tensor and the corresponding local field distributions for composites whose constituents are governed by vector constitutive laws. As shown, the shear analogy, which can predict effective transverse properties, is not valid in the general three-dimensional case. Consequently, a general derivation is presented that is applicable to both continuously and discontinuously reinforced composites with arbitrary vector constitutive laws and periodic microstructures. Results are given for thermal and electric problems, effective properties and local field distributions, ordered and random microstructures, as well as complex geometries including woven composites. Comparisons of the theory's predictions are made to test data, numerical analysis, and classical expressions from the literature. Further, classical methods cannot provide the local field distributions in the composite, and it is demonstrated that, as the percolation threshold is approached, their predictions are increasingly unreliable. XXXX It has been observed that the bonding between the fibers and matrix in composite materials can be imperfect. In the context of thermal conductivity, such imperfect interfaces have been investigated in micromechanical models by Dunn and Taya (1993), Duan and Karihaloo (2007), Nan et al. (1997) and Hashin (2001). The present HFGMC micromechanical method, derived for perfectly bonded composite materials governed by vector constitutive laws, can be easily generalized to include the effects of weak bonding between the constituents. Such generalizations, in the context of the mechanical micromechanics problem, involve introduction of a traction-separation law at the fiber/matrix interface and have been presented by Aboudi (1987), Bednarcyk and Arnold (2002), Bednarcyk et al. (2004) and Aboudi et al. (2013) and will be addressed in the future.

  19. Ultrasonic and radiographic evaluation of advanced aerospace materials: Ceramic composites

    Generazio, Edward R.

    1990-01-01

    Two conventional nondestructive evaluation techniques were used to evaluate advanced ceramic composite materials. It was shown that neither ultrasonic C-scan nor radiographic imaging can individually provide sufficient data for an accurate nondestructive evaluation. Both ultrasonic C-scan and conventional radiographic imaging are required for preliminary evaluation of these complex systems. The material variations that were identified by these two techniques are porosity, delaminations, bond quality between laminae, fiber alignment, fiber registration, fiber parallelism, and processing density flaws. The degree of bonding between fiber and matrix cannot be determined by either of these methods. An alternative ultrasonic technique, angular power spectrum scanning (APSS) is recommended for quantification of this interfacial bond.

  20. Application of electron and Bremsstrahlung beams for composite materials processing

    Zalyubovsky, I.I.; Avilov, A.M.; Popov, G.F.; Rudychev, V.G.

    1998-01-01

    In Kharkiv University the radiation process of obtaining composite polymer materials, CPM, with high strength properties and corrosion resistance was studied. CPM are manufactured by vacuum impregnating capillary-porous materials with synthetic monomers and oligomers or by molding granular waste and resins which are further treated by relativistic electron or Bremsstrahlung beam. Such radiation treatment yields new CPM in which capillary-porous structure acting as reinforcement is filled with polymer. The results of the applied research with industrial electron accelerator in the field of thick CPM formation are presented

  1. Conformal growth method of ferroelectric materials for multifunctional composites

    Bowland, Christopher Charles

    Multifunctional composites are the next generation of composites and aim to simultaneously meet multiple performance objectives to create system-level performance enhancements. Current fiber-reinforced composites have offered improved efficiency and performance through weight reduction and increased strength. However, these composites satisfy singular performance objectives. Therefore, the concept of multifunctional composites was developed as an approach to create components in a system that serve multiple functions. These composites aim to reduce the required components in a system by integrating unifunctional components together thus reducing the weight and complexity of the system as a whole. This work offers an approach to create multifunctional composites through the development of a structural, multifunctional fiber. This is achieved by synthesizing a ferroelectric material on the surface of carbon fiber. In this work, a two-step hydrothermal reaction is developed for synthesizing a conformal film of barium titanate (BaTiO3) on the surface of carbon fiber. A fundamental understanding of this hydrothermal process is performed on planar substrates leading to the development of processing parameters that result in epitaxial-type growth of highly-aligned BaTiO3 nanowires. This work establishes the hydrothermal reaction as a powerful synthesis technique for generating nanostructured BaTiO3 on carbon fiber creating a novel, multifunctional fiber. A reaction optimization process leads to the development of parameters that stabilize tetragonal phase BaTiO3 without the need for subsequent heat treatments. The application potential of these fibers is illustrated with both single fibers and woven fabrics. Single fiber cantilever beams are fabricated and subjected to vibrations to determine its voltage output with the ultimate goal of producing an air flow sensor. Carbon fiber reinforced composite integration is carried out by scaling up the hydrothermal reaction to

  2. Modeling Lightning Impact Thermo-Mechanical Damage on Composite Materials

    Muñoz, Raúl; Delgado, Sofía; González, Carlos; López-Romano, Bernardo; Wang, De-Yi; LLorca, Javier

    2014-02-01

    Carbon fiber-reinforced polymers, used in primary structures for aircraft due to an excellent strength-to-weight ratio when compared with conventional aluminium alloy counterparts, may nowadays be considered as mature structural materials. Their use has been extended in recent decades, with several aircraft manufacturers delivering fuselages entirely manufactured with carbon composites and using advanced processing technologies. However, one of the main drawbacks of using such composites entails their poor electrical conductivity when compared with aluminium alloy competitors that leads to lightning strikes being considered a significant threat during the service life of the aircraft. Traditionally, this problem was overcome with the use of a protective copper/bronze mesh that added additional weight and reduced the effectiveness of use of the material. Moreover, this traditional sizing method is based on vast experimental campaigns carried out by subjecting composite panels to simulated lightning strike events. While this method has proven its validity, and is necessary for certification of the structure, it may be optimized with the aid provided by physically based numerical models. This paper presents a model based on the finite element method that includes the sources of damage observed in a lightning strike, such as thermal damage caused by Joule overheating and electromagnetic/acoustic pressures induced by the arc around the attachment points. The results of the model are compared with lightning strike experiments carried out in a carbon woven composite.

  3. Contact problem for a composite material with nacre inspired microstructure

    Berinskii, Igor; Ryvkin, Michael; Aboudi, Jacob

    2017-12-01

    Bi-material composites with nacre inspired brick and mortar microstructures, characterized by stiff elements of one phase with high aspect ratio separated by thin layers of the second one, are considered. Such microstructure is proved to provide an efficient solution for the problem of a crack arrest. However, contrary to the case of a homogeneous material, an external pressure, applied to a part of the composite boundary, can cause significant tensile stresses which increase the danger of crack nucleation. Investigation of the influence of microstructure parameters on the magnitude of tensile stresses is performed by means of the classical Flamant-like problem of an orthotropic half-plane subjected to a normal external distributed loading. Adequate analysis of this problem represents a serious computational task due to the geometry of the considered layout and the high contrast between the composite constituents. This difficulty is presently circumvented by deriving a micro-to-macro analysis in the framework of which an analytical solution of the auxiliary elasticity problem, followed by the discrete Fourier transform and the higher-order theory are employed. As a result, full scale continuum modeling of both composite constituents without employing any simplifying assumptions is presented. In the framework of the present proposed modeling, the influence of stiff elements aspect ratio on the overall stress distribution is demonstrated.

  4. Application of Composite Materials in the Fire Explosion Suppression System

    REN Shah

    2012-01-01

    In order to lighten the weight of the special vehicles and improve their mobility and flexibility, the weight of all subsystems of the whole vehicle must be reduced in the general planning. A fire explosion suppression system is an important subsystem for the self-protection of vehicle, protection of crews and safety of a vehicle. The performances of the special vehicles determine their survival ability and combat capability. The composite bottle is made of aluminum alloy with externally wrapped carbon fiber ; it has been proven by a large number of tests that the new type explosion suppression fire distinguisher made of such composite materials applied in the special vehicle has reliable performance, each of its technical indexes is higher or equal to that of a steel distinguisher, and the composites can also optimize the assembly structure of the bottle, and improve the reliability and corrosion resistance. Most important is that the composite materials can effectively lighten the weight of the fire explosion suppression system to reach the target of weight reduction of the subsystem in general planning.

  5. FIBROUS CERAMIC-CERAMIC COMPOSITE MATERIALS PROCESSING AND PROPERTIES

    Naslain , R.

    1986-01-01

    The introduction of continuous fibers in a ceramic matrix can improve its toughness, if the fiber-matrix bonding is weak enough, due to matrix microcracking and fiber pull-out. Ceramic-ceramic composite materials are processed according to liquid or gas phase techniques. The most important are made of glass, carbide, nitride or oxide matrices reinforced with carbon, SiC or Al2O3 fibers.

  6. Producing New Composite Materials by Using Tragacanth and Waste Ash

    Yasar Bicer; Serif Yilmaz

    2013-01-01

    In present study, two kinds of thermal power plant ashes; one the fly ash and the other waste ash are mixed with adhesive tragacanth and cement to produce new composite materials. 48 new samples are produced by varying the percentages of the fly ash, waste ash, cement and tragacanth. The new samples are subjected to some tests to find out their properties such as thermal conductivity, compressive strength, tensile strength and sucking capability of water. It is found that; the thermal conduct...

  7. COMPOSITION AND METHOD FOR DEGRADATION OF KERATINACEOUS MATERIALS

    2015-01-01

    materials (such as e.g. feather and pig bristles). (FR)L'invention concerne une composition dégradant la kératine qui comprend au moins deux différentes kératinases actives isolées issues d'au moins deux familles de protéases MEROPS différentes, au moins une sérine endo-kératinase active appartenant à la...

  8. Radiation embrittlement of WWER-1000 reactor vessel steels

    Nikolaeva, A.V.; Nikolaev, Yu.A.; Kevorkyan, Yu.R.

    2001-01-01

    Results obtained on the blank samples of materials of the WWER-1000 vessels irradiated by low density neutron flux are discussed. Chemical composition of the materials is characterized by the low content of the impurities (copper and phosphorus) and high content of nickel. Dependence of the radiation embrittlement of the WWER-1000 vessel materials on metallurgic variables and damage dose is treated. The research showed that nickel largely enhanced the radiation embrittlement. New dependences for determination of the radiation embrittlement real rate of the WWER-1000 vessel materials and its conservative estimation were developed [ru

  9. Autonomic composite hydrogels by reactive printing: materials and oscillatory response.

    Kramb, R C; Buskohl, P R; Slone, C; Smith, M L; Vaia, R A

    2014-03-07

    Autonomic materials are those that automatically respond to a change in environmental conditions, such as temperature or chemical composition. While such materials hold incredible potential for a wide range of uses, their implementation is limited by the small number of fully-developed material systems. To broaden the number of available systems, we have developed a post-functionalization technique where a reactive Ru catalyst ink is printed onto a non-responsive polymer substrate. Using a succinimide-amine coupling reaction, patterns are printed onto co-polymer or biomacromolecular films containing primary amine functionality, such as polyacrylamide (PAAm) or poly-N-isopropyl acrylamide (PNIPAAm) copolymerized with poly-N-(3-Aminopropyl)methacrylamide (PAPMAAm). When the films are placed in the Belousov-Zhabotinsky (BZ) solution medium, the reaction takes place only inside the printed nodes. In comparison to alternative BZ systems, where Ru-containing monomers are copolymerized with base monomers, reactive printing provides facile tuning of a range of hydrogel compositions, as well as enabling the formation of mechanically robust composite monoliths. The autonomic response of the printed nodes is similar for all matrices in the BZ solution concentrations examined, where the period of oscillation decreases in response to increasing sodium bromate or nitric acid concentration. A temperature increase reduces the period of oscillations and temperature gradients are shown to function as pace-makers, dictating the direction of the autonomic response (chemical waves).

  10. Characterization of Triaxial Braided Composite Material Properties for Impact Simulation

    Roberts, Gary D.; Goldberg, Robert K.; Biniendak, Wieslaw K.; Arnold, William A.; Littell, Justin D.; Kohlman, Lee W.

    2009-01-01

    The reliability of impact simulations for aircraft components made with triaxial braided carbon fiber composites is currently limited by inadequate material property data and lack of validated material models for analysis. Improvements to standard quasi-static test methods are needed to account for the large unit cell size and localized damage within the unit cell. The deformation and damage of a triaxial braided composite material was examined using standard quasi-static in-plane tension, compression, and shear tests. Some modifications to standard test specimen geometries are suggested, and methods for measuring the local strain at the onset of failure within the braid unit cell are presented. Deformation and damage at higher strain rates is examined using ballistic impact tests on 61- by 61- by 3.2-mm (24- by 24- by 0.125-in.) composite panels. Digital image correlation techniques were used to examine full-field deformation and damage during both quasi-static and impact tests. An impact analysis method is presented that utilizes both local and global deformation and failure information from the quasi-static tests as input for impact simulations. Improvements that are needed in test and analysis methods for better predictive capability are examined.

  11. Magnetomechanical local-global effects in magnetostrictive composite materials

    Elhajjar, Rani F.; Law, Chiu T.

    2015-10-01

    A constitutive model for magnetostrictive composite materials (MCMs) that describes the relations among stress, strain, magnetic field, and magnetization Liu and Zheng (2005 Acta Mech. Sin. 21 278-85) is implemented for multiphysics simulation for analysis of non-periodic or non-uniform microstructure effects. The multiphysics models that capture designed and actual microstructural details are used for predicting the responses of magnetostrictive composite materials under various mechanical and magnetic loading conditions. The approach overcomes the limitation with strain gages in the investigation of magnetostrictive strain due to stress localization around magnetostrictive phases. Three-dimensional digital image correlation (3D-DIC) is used to measure the displacements and strain in the composites under fluctuating magnetic fields. The specimens are prepared using epoxy and particulate magnetostrictive materials with the particles in the range of approximately 20 to 300 microns range. We examine the displacement and strain fields obtained and compare the results to those obtained from fiber Bragg grating (FBG) measurements. The coupling coefficients obtained from this method were in agreement with those measured using other techniques. The validated model allows us to predict the effect of curing, preload, microstructure alignment and particle shape on the magnetostrictive strains.

  12. Magnetomechanical local-global effects in magnetostrictive composite materials

    Elhajjar, Rani F; Law, Chiu T

    2015-01-01

    A constitutive model for magnetostrictive composite materials (MCMs) that describes the relations among stress, strain, magnetic field, and magnetization Liu and Zheng (2005 Acta Mech. Sin. 21 278–85) is implemented for multiphysics simulation for analysis of non-periodic or non-uniform microstructure effects. The multiphysics models that capture designed and actual microstructural details are used for predicting the responses of magnetostrictive composite materials under various mechanical and magnetic loading conditions. The approach overcomes the limitation with strain gages in the investigation of magnetostrictive strain due to stress localization around magnetostrictive phases. Three-dimensional digital image correlation (3D-DIC) is used to measure the displacements and strain in the composites under fluctuating magnetic fields. The specimens are prepared using epoxy and particulate magnetostrictive materials with the particles in the range of approximately 20 to 300 microns range. We examine the displacement and strain fields obtained and compare the results to those obtained from fiber Bragg grating (FBG) measurements. The coupling coefficients obtained from this method were in agreement with those measured using other techniques. The validated model allows us to predict the effect of curing, preload, microstructure alignment and particle shape on the magnetostrictive strains. (paper)

  13. Microencapsulated Phase Change Composite Materials for Energy Efficient Buildings

    Thiele, Alexander

    This study aims to elucidate how phase change material (PCM)-composite materials can be leveraged to reduce the energy consumption of buildings and to provide cost savings to ratepayers. Phase change materials (PCMs) can store thermal energy in the form of latent heat when subjected to temperatures exceeding their melting point by undergoing a phase transition from solid to liquid state. Reversibly, PCMs can release this thermal energy when the system temperature falls below their solidification point. The goal in implementing composite PCM walls is to significantly reduce and time-shift the maximum thermal load on the building in order to reduce and smooth out the electricity demand for heating and cooling. This Ph.D. thesis aims to develop a set of thermal design methods and tools for exploring the use of PCM-composite building envelopes and for providing design rules for their practical implementation. First, detailed numerical simulations were used to show that the effective thermal conductivity of core-shell-matrix composites depended only on the volume fraction and thermal conductivity of the constituent materials. The effective medium approximation reported by Felske (2004) was in very good agreement with numerical predictions of the effective thermal conductivity. Second, a carefully validated transient thermal model was used to simulate microencapsulated PCM-composite walls subjected to diurnal or annual outdoor temperature and solar radiation flux. It was established that adding microencapsulated PCM to concrete walls both substantially reduced and delayed the thermal load on the building. Several design rules were established, most notably, (i) increasing the volume fraction of microencapsulated PCM within the wall increases the energy savings but at the potential expense of mechanical properties [1], (ii) the phase change temperature leading to the maximum energy and cost savings should equal the desired indoor temperature regardless of the climate

  14. After-operating properties of nuclear reactor vessel materials of Lenin atomic ice breaker and prospective of reactor vessels radiation life prolongation

    Platonov, P.A.; Shtrombakh, Ya.I.; Amaev, A.D.; Krasikov, E.A.; Korolev, Yu.N.; Zabusov, O.O.; Glushakov, G.M.

    2001-01-01

    A post-operational state of the icebreaker Lenin reactor vessel metal is investigated. It is shown that a base metal of the icebreaker Lenin reactor vessel is of high quality as by an initial value of critical temperature of embrittlement, so by its radiation resistance. The weld metal possesses a sufficient radiation resistance but has an insufficient initial ductile-brittle transition temperature (approximately 63 Deg C). It is necessary to note that the final stage of operation for nuclear steam-generating plant should be carried out at the coolant temperature as high as possible [ru

  15. Continued Development of Meandering Winding Magnetometer (MWM (Register Trademark)) Eddy Current Sensors for the Health Monitoring, Modeling and Damage Detection of Composite Overwrapped Pressure Vessels

    Russell, Richard; Wincheski, Russell; Jablonski, David; Washabaugh, Andy; Sheiretov, Yanko; Martin, Christopher; Goldfine, Neil

    2011-01-01

    Composite Overwrapped Pressure Vessels (COPVs) are used in essentially all NASA spacecraft, launch. vehicles and payloads to contain high-pressure fluids for propulsion, life support systems and science experiments. Failure of any COPV either in flight or during ground processing would result in catastrophic damage to the spacecraft or payload, and could lead to loss of life. Therefore, NASA continues to investigate new methods to non-destructively inspect (NDE) COPVs for structural anomalies and to provide a means for in-situ structural health monitoring (SHM) during operational service. Partnering with JENTEK Sensors, engineers at NASA, Kennedy Space Center have successfully conducted a proof-of-concept study to develop Meandering Winding Magnetometer (MWM) eddy current sensors designed to make direct measurements of the stresses of the internal layers of a carbon fiber composite wrapped COPV. During this study three different MWM sensors were tested at three orientations to demonstrate the ability of the technology to measure stresses at various fiber orientations and depths. These results showed good correlation with actual surface strain gage measurements. MWM-Array technology for scanning COPVs can reliably be used to image and detect mechanical damage. To validate this conclusion, several COPVs were scanned to obtain a baseline, and then each COPV was impacted at varying energy levels and then rescanned. The baseline subtracted images were used to demonstrate damage detection. These scans were performed with two different MWM-Arrays. with different geometries for near-surface and deeper penetration imaging at multiple frequencies and in multiple orientations of the linear MWM drive. This presentation will include a review of micromechanical models that relate measured sensor responses to composite material constituent properties, validated by the proof of concept study, as the basis for SHM and NDE data analysis as well as potential improvements including

  16. Assessment of weld heat-affected zones in a reactor vessel material

    Marston, T.U.; Server, W.

    1978-01-01

    The mechanical properties of weld heat-affected zones (HAZ's) associated with the heavy section, nuclear quality weldments are evaluated and found to be superior to those of the parent base material. The nil ductility transition temperature (NDTT), Charpy impact and static and dynamic fracture toughness properties of a HAZ associated with a submerged arc weld and one associated with a manual metal arc weld are directly compared with those of the parent base material. It is concluded that the stigma normally associated with HAZ is not justified for this grade and quality of material and weld procedure

  17. Composite material pedestrian bridge for the Port of Bilbao

    Gorrochategui, I.; Manteca, C.; Yedra, A.; Miguel, R.; del Valle, F. J.

    2012-09-01

    Composite materials in comparison to traditional ones, steel and concrete, present advantages in civil works construction: lower weight, higher corrosion resistance (especially in the marine environment), and ease of installation. On the other hand, fabrication costs are generally higher. This is the reason why this technology is not widely used. This work illustrates the process followed for the design, fabrication and installation of a composite material pedestrian bridge in the Port of Bilbao (Northern Spain). In order to reduce the price of the bridge, the use of low cost materials was considered, therefore polyester resin was selected as the polymeric matrix, and glass fibres as reinforcement. Two material choices were studied. Currently in the market there is high availability of carbon nanoparticles: carbon nanotubes (CNT) and carbon nanofibres (CNF), so it was decided to add this kind of nanoparticles to the reference material with the objective of improving its mechanical properties. The main challenge was to transfer the CNT and CNF excellent properties to the polymeric matrix. This requires dispersing the nanoreinforcements as individual particles in the polymeric matrix to avoid agglomerates. For this reason, an advanced high shear forces dispersion technique (called "three roll mills") was studied and implemented. Also surface functionalization of the nanoreinforcements by chemical treatment was carried out. Herein, a comparison is performed between both materials studied, the explanation of the employment of the reference material (without nanoreinforcement) as the one used in the fabrication of the pedestrian bridge is justified and, finally, the main characteristics of the final design of the structural element are described.

  18. Composite material pedestrian bridge for the Port of Bilbao

    Gorrochategui, I; Manteca, C; Yedra, A; Miguel, R; Valle, F J del

    2012-01-01

    Composite materials in comparison to traditional ones, steel and concrete, present advantages in civil works construction: lower weight, higher corrosion resistance (especially in the marine environment), and ease of installation. On the other hand, fabrication costs are generally higher. This is the reason why this technology is not widely used. This work illustrates the process followed for the design, fabrication and installation of a composite material pedestrian bridge in the Port of Bilbao (Northern Spain). In order to reduce the price of the bridge, the use of low cost materials was considered, therefore polyester resin was selected as the polymeric matrix, and glass fibres as reinforcement. Two material choices were studied. Currently in the market there is high availability of carbon nanoparticles: carbon nanotubes (CNT) and carbon nanofibres (CNF), so it was decided to add this kind of nanoparticles to the reference material with the objective of improving its mechanical properties. The main challenge was to transfer the CNT and CNF excellent properties to the polymeric matrix. This requires dispersing the nanoreinforcements as individual particles in the polymeric matrix to avoid agglomerates. For this reason, an advanced high shear forces dispersion technique (called 'three roll mills') was studied and implemented. Also surface functionalization of the nanoreinforcements by chemical treatment was carried out. Herein, a comparison is performed between both materials studied, the explanation of the employment of the reference material (without nanoreinforcement) as the one used in the fabrication of the pedestrian bridge is justified and, finally, the main characteristics of the final design of the structural element are described.

  19. A Critique of a Phenomenological Fiber Breakage Model for Stress Rupture of Composite Materials

    Reeder, James R.

    2010-01-01

    Stress rupture is not a critical failure mode for most composite structures, but there are a few applications where it can be critical. One application where stress rupture can be a critical design issue is in Composite Overwrapped Pressure Vessels (COPV's), where the composite material is highly and uniformly loaded for long periods of time and where very high reliability is required. COPV's are normally required to be proof loaded before being put into service to insure strength, but it is feared that the proof load may cause damage that reduces the stress rupture reliability. Recently, a fiber breakage model was proposed specifically to estimate a reduced reliability due to proof loading. The fiber breakage model attempts to model physics believed to occur at the microscopic scale, but validation of the model has not occurred. In this paper, the fiber breakage model is re-derived while highlighting assumptions that were made during the derivation. Some of the assumptions are examined to assess their effect on the final predicted reliability.

  20. Characterization of the weld HAZ properties of nuclear reactor pressure vessel materials

    Kim, Joo Hag; Shin, H. S.; Moon, J. G. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-12-01

    This work contains an investigation on the microstructure and toughness in the weld heat-affected zone (HAZ) of a quenched and tempered SA 508 Cl. 3 reactor pressure vessel (RPV) steel. In order to evaluate systematically the notch toughness and microstructural alterations, a unit HAZ concept was applied to the multipass weld HAZ of RPV steel. Seven typical positions were selected to evaluate the spatial distribution of notch toughness and microstructure in the unit HAZ. As a result of notch toughness evaluation, three coarse-grained regions and two fine-grained regions of SA 508 Cl. 3 RPV steel HAZ showed relatively good toughness. On the contrary, an intercritically reheated and a subcritically reheated region showed lower toughness than the base metal. The region which first and second peak temperatures are 700 deg C showed the lowest toughness among the low toughness region because of carbide coarsening. Therefore, it was proposed that the notch position in the surveillance HAZ specimen should be placed to the boundary between the HAZ and the base metal. The method, which evaluates the fracture toughness in the transition region of ferritic steel, was effectively applicable to the various HAZ regions of RPV steel. The fracture toughness test results were nearly same as the notch toughness test results. The volume fraction of tempered martensite phase was revealed as the most dominant factor that determines fracture toughness. 59 refs., 29 figs., 10 tabs. (Author)

  1. A perspective on thermal annealing of reactor pressure vessel materials from the viewpoint of experimental results

    Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K.

    1996-01-01

    It is believed that in the next decade or so, several nuclear reactor pressure vessels (RPVs) may exceed the reference temperature limits set by the pressurized thermal shock screening criteria. One of the options to mitigate the effects of irradiation on RPVs is to thermally anneal them to restore the toughness properties that have been degraded by neutron irradiation. This paper summarizes recent experimental results from work performed at the Oak Ridge National Laboratory to study the annealing response, or ''recovery'' of several irradiated RPV steels. The fracture toughness is one of the important properties used in the evaluation of the integrity of RPVs. Optimally, the fracture toughness is measured directly by fracture toughness specimens, such as compact tension or precracked Charpy specimens, but is often inferred from the results of Charpy V-notch impact specimens. The experimental results are compared to the predictions of models for embrittlement recovery which have been developed by Eason et al. Some of the issues in annealing that still need to be resolved are discussed

  2. To the application of TV and optical equipment for in-service inspection of reactor vessel and primary circuit component materials

    Afonin, Eh.M.; Bachelis, I.M.; Tokarev, E.A.; Yastrebov, V.E.

    1985-01-01

    Some problems of application of TV and optical equipment for inspection of reactor vessel and primary circuit component materials are considered taking the most widespread WWER-440 type reactor as an example. The most advanrageous objects of the inspection and typical zones of equipment arrangement are shown. Methods and peculiarities of the inspection with the use of TV and optical equipment are presented. Recommendations on rational application of the equipment for the inspection of WWER-440 reactor vessel components are given

  3. Using the Steel Vessel Material-Cost Index to Mitigate Shipbuilder Risk

    Keating, Edward G; Murphy, Robert; Schank, John F; Birkler, John

    2008-01-01

    This paper describes how the US Navy structures fixed-price and fixed-price, incentive-fee shipbuilding contracts and how labor- and material-cost indexes can mitigate shipbuilder risk in either type of contract...

  4. Utilization of Construction Waste Composite Powder Materials as Cementitious Materials in Small-Scale Prefabricated Concrete

    Cuizhen Xue; Aiqin Shen; Yinchuan Guo; Tianqin He

    2016-01-01

    The construction and demolition wastes have increased rapidly due to the prosperity of infrastructure construction. For the sake of effectively reusing construction wastes, this paper studied the potential use of construction waste composite powder material (CWCPM) as cementitious materials in small-scale prefabricated concretes. Three types of such concretes, namely, C20, C25, and C30, were selected to investigate the influences of CWCPM on their working performances, mechanical properties, ...

  5. Standard Test Methods for Constituent Content of Composite Materials

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 These test methods determine the constituent content of composite materials by one of two approaches. Method I physically removes the matrix by digestion or ignition by one of seven procedures, leaving the reinforcement essentially unaffected and thus allowing calculation of reinforcement or matrix content (by weight or volume) as well as percent void volume. Method II, applicable only to laminate materials of known fiber areal weight, calculates reinforcement or matrix content (by weight or volume), and the cured ply thickness, based on the measured thickness of the laminate. Method II is not applicable to the measurement of void volume. 1.1.1 These test methods are primarily intended for two-part composite material systems. However, special provisions can be made to extend these test methods to filled material systems with more than two constituents, though not all test results can be determined in every case. 1.1.2 The procedures contained within have been designed to be particularly effective for ce...

  6. Metal/graphite-composite materials for fusion device

    Kneringer, G.; Kny, E.; Fischer, W.; Reheis, N.; Staffler, R.; Samm, U.; Winter, J.

    1995-01-01

    The utilization of graphite as a structural material depends to an important extent on the availability of a joining technique suitable for the production of reliable large scale metal/graphite-composites. This study has been conducted to evaluate vacuum brazes and procedures for graphite and metals which can be used in fusion applications up to about 1500 degree C. The braze materials included: AgCuTi, CuTi, NiTi, Ti, ZrTi, Zr. Brazing temperatures ranged from 850 degree C to 1900 degree C. The influence of graphite quality on wettability and pore-penetration of the braze has been investigated. Screening tests of metal/graphite-assemblies with joint areas exceeding some square-centimeters have shown that they can only successfully be produced when graphite is brazed to a metal, such as tungsten or molybdenum with a coefficient of thermal expansion closely matching that of graphite. Therefore all experimental work on evaluation of joints has been concentrated on molybdenum/graphite brazings. The tensile strength of molybdenum/graphite-composites compares favorably with the tensile strength of bulk graphite from room temperature close to the melting temperature of the braze. In electron beam testing the threshold damage line for molybdenum/graphite-composites has been evaluated. Results show that even composites with the low melting AgCuTi-braze are expected to withstand 10 MW/m 2 power density for at least 10 3 cycles. Limiter testing in TEXTOR shows that molybdenum/graphite-segments with 3 mm graphite brazed on molybdenum-substrate withstand severe repeated TEXTOR plasma discharge conditions without serious damage. Results prove that actively cooled components on the basis of a molybdenum/graphite-composite can sustain a higher heat flux than bulk graphite alone. (author)

  7. Experimental identification of smart material coupling effects in composite structures

    Chesne, S; Jean-Mistral, C; Gaudiller, L

    2013-01-01

    Smart composite structures have an enormous potential for industrial applications, in terms of mass reduction, high material resistance and flexibility. The correct characterization of these complex structures is essential for active vibration control or structural health monitoring applications. The identification process generally calls for the determination of a generalized electromechanical coupling coefficient. As this process can in practice be difficult to implement, an original approach, presented in this paper, has been developed for the identification of the coupling effects of a smart material used in a composite curved beam. The accuracy of the proposed identification technique is tested by applying active modal control to the beam, using a reduced model based on this identification. The studied structure was as close to reality as possible, and made use of integrated transducers, low-cost sensors, clamped boundary conditions and substantial, complex excitation sources. PVDF (polyvinylidene fluoride) and MFC (macrofiber composite) transducers were integrated into the composite structure, to ensure their protection from environmental damage. The experimental identification described here was based on a curve fitting approach combined with the reduced model. It allowed a reliable, powerful modal control system to be built, controlling two modes of the structure. A linear quadratic Gaussian algorithm was used to determine the modal controller–observer gains. The selected modes were found to have an attenuation as strong as −13 dB in experiments, revealing the effectiveness of this method. In this study a generalized approach is proposed, which can be extended to most complex or composite industrial structures when they are subjected to vibration. (paper)

  8. Metallurgy of steels for PWR pressure vessels

    Kepka, M.; Mocek, J.; Barackova, L.

    1980-01-01

    A survey and the chemical compositions are presented of reactor pressure vessel steels. The metallurgy is described of steel making for pressure vessels in Japan and the USSR. Both acidic and alkaline open-hearth steel is used for the manufacture of ingots. The leading world manufacturers of forging ingots for pressure vessels, however, exclusively use electric steel. Vacuum casting techniques are exclusively used. Experience is shown gained with the introduction of the manufacture of forging ingots for pressure vessels at SKODA, Plzen. The metallurgical procedure was tested utilizing alkaline open hearths, electric arc furnaces and facilities for vacuum casting of steel. Pure charge raw materials should be used for securing high steel purity. Prior to forging pressure vessel rings, not only should sufficiently big bottoms and heads be removed but also the ingot middle part should be scrapped showing higher contents of impurities and nonhomogeneous structure. (B.S.)

  9. Metallurgy of steels for PWR pressure vessels

    Kepka, M; Mocek, J; Barackova, L [Skoda, Plzen (Czechoslovakia)

    1980-09-01

    A survey and the chemical compositions are presented of reactor pressure vessel steels. The metallurgy is described of steel making for pressure vessels in Japan and the USSR. Both acidic and alkaline open-hearth steel is used for the manufacture of ingots. The leading world manufacturers of forging ingots for pressure vessels, however, exclusively use electric steel. Vacuum casting techniques are exclusively used. Experience is shown gained with the introduction of the manufacture of forging ingots for pressure vessels at SKODA, Plzen. The metallurgical procedure was tested utilizing alkaline open hearths, electric arc furnaces and facilities for vacuum casting of steel. Pure charge raw materials should be used for securing high steel purity. Prior to forging pressure vessel rings, not only should sufficiently big bottoms and heads be removed but also the ingot middle part should be scrapped showing higher contents of impurities and nonhomogeneous structure.

  10. Ferrocement: A versatile composite structural material - A Review

    Memon, N. A.; Sumadi, S. R.

    2006-01-01

    The use of-based composites for structural application is becoming more popular with the introduction of new high performance materials. Ferrocement as a structural material has evolved from an appropriate technology applied for rural development to high performance and high durability construction material. The efficient use of ferrocement technology as per the requirements of the structures must be studied and developed in order to assist all the concerned parties concerned with structural activities. This paper is aimed to present the research made continuously to improve the ferrocement properties and performance and its uses in the different application and to encourage practical application of ferrocement especially in developing countries like Pakistan. This paper covers the theoretical, experimental and numerical studies conducted by several researchers to investigate the mechanical and structural properties of ferrocement. Also the efforts made to develop the design code offerrocement have been reviewed. (author)

  11. Corrosion and tribological properties of basalt fiber reinforced composite materials

    Ha, Jin Cheol; Kim, Yun-Hae; Lee, Myeong-Hoon; Moon, Kyung-Man; Park, Se-Ho

    2015-03-01

    This experiment has examined the corrosion and tribological properties of basalt fiber reinforced composite materials. There were slight changes of weight after the occurring of corrosion based on time and H2SO4 concentration, but in general, the weight increased. It is assumed that this happens due to the basalt fiber precipitate. Prior to the corrosion, friction-wear behavior showed irregular patterns compared to metallic materials, and when it was compared with the behavior after the corrosion, the coefficient of friction was 2 to 3 times greater. The coefficient of friction of all test specimen ranged from 0.1 to 0.2. Such a result has proven that the basalt fiber, similar to the resin rubber, shows regular patterns regardless of time and H2SO4 concentration because of the space made between resins and reinforced materials.

  12. The TPX vacuum vessel and in-vessel components

    Heitzenroeder, P.; Bialek, J.; Ellis, R.; Kessel, C.; Liew, S.

    1994-01-01

    The Tokamak Physics Experiment (TPX) is a superconducting tokamak with double-null diverters. TPX is designed for 1,000-second discharges with the capability of being upgraded to steady state operation. High neutron yields resulting from the long duration discharges require that special consideration be given to materials and maintainability. A unique feature of the TPX is the use of a low activation, titanium alloy vacuum vessel. Double-wall vessel construction is used since it offers an efficient solution for shielding, bakeout and cooling. Contained within the vacuum vessel are the passive coil system, Plasma Facing Components (PFCs), magnetic diagnostics, and the internal control coils. All PFCs utilize carbon-carbon composites for exposed surfaces

  13. A new silver based composite material for SPA water disinfection.

    Tartanson, M A; Soussan, L; Rivallin, M; Chis, C; Penaranda, D; Lapergue, R; Calmels, P; Faur, C

    2014-10-15

    A new composite material based on alumina (Al2O3) modified by two surface nanocoatings - titanium dioxide (TiO2) and silver (Ag) - was studied for spa water disinfection. Regarding the most common microorganisms in bathing waters, two non-pathogenic bacteria Escherichia coli (Gram-negative) and Staphylococcus epidermidis (Gram positive) were selected as surrogates for bacterial contamination. The bactericidal properties of the Al2O3-TiO2-Ag material were demonstrated under various operating conditions encountered in spa water (temperature: 22-37 °C, presence of salt: CaCO3 or CaCl2, high oxygen content, etc.). Total removal of 10(8) CFU mL(-1) of bacteria was obtained in less than 10 min with 16 g L(-1) of material. Best results were observed for both conditions: a temperature of 37 °C and under aerobic condition; this latest favouring Reactive Oxygen Species (ROS) generation. The CaCO3 salt had no impact on the bactericidal activity of the composite material and CaCl2 considerably stabilized the silver desorption from the material surface thanks to the formation of AgCl precipitate. Preliminary tests of the Al2O3-TiO2-Ag bactericidal behaviour in a continuous water flow confirmed that 2 g L(-1) of material eliminated more than 90% of a 2.0 × 10(8) CFU mL(-1) bacterial mixture after one water treatment recycle and reached the disinfection standard recommended by EPA (coliform removal = 6 log) within 22 h. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Adhesion of resin composite core materials to dentin.

    O'Keefe, K L; Powers, J M

    2001-01-01

    This study determined (1) the effect of polymerization mode of resin composite core materials and dental adhesives on the bond strength to dentin, and (2) if dental adhesives perform as well to dentin etched with phosphoric acid as to dentin etched with self-etching primer. Human third molars were sectioned 2 mm from the highest pulp horn and polished. Three core materials (Fluorocore [dual cured], Core Paste [self-cured], and Clearfil Photo Core [light cured]) and two adhesives (Prime & Bond NT Dual Cure and Clearfil SE Bond [light cured]) were bonded to dentin using two dentin etching conditions. After storage, specimens were debonded in microtension and bond strengths were calculated. Scanning electron micrographs of representative bonding interfaces were analyzed. Analysis showed differences among core materials, adhesives, and etching conditions. Among core materials, dual-cured Fluorocore had the highest bond strengths. There were incompatibilities between self-cured Core Paste and Prime & Bond NT in both etched (0 MPa) and nonetched (3.0 MPa) dentin. Among adhesives, in most cases Clearfil SE Bond had higher bond strengths than Prime & Bond NT and bond strengths were higher to self-etched than to phosphoric acid-etched dentin. Scanning electron micrographs did not show a relationship between resin tags and bond strengths. There were incompatibilities between a self-cured core material and a dual-cured adhesive. All other combinations of core materials and adhesives produced strong in vitro bond strengths both in the self-etched and phosphoric acid-etched conditions.

  15. Structural health monitoring in composite materials using frequency response methods

    Kessler, Seth S.; Spearing, S. Mark; Atalla, Mauro J.; Cesnik, Carlos E. S.; Soutis, Constantinos

    2001-08-01

    Cost effective and reliable damage detection is critical for the utilization of composite materials in structural applications. Non-destructive evaluation techniques (e.g. ultrasound, radiography, infra-red imaging) are available for use during standard repair and maintenance cycles, however by comparison to the techniques used for metals these are relatively expensive and time consuming. This paper presents part of an experimental and analytical survey of candidate methods for the detection of damage in composite materials. The experimental results are presented for the application of modal analysis techniques applied to rectangular laminated graphite/epoxy specimens containing representative damage modes, including delamination, transverse ply cracks and through-holes. Changes in natural frequencies and modes were then found using a scanning laser vibrometer, and 2-D finite element models were created for comparison with the experimental results. The models accurately predicted the response of the specimems at low frequencies, but the local excitation and coalescence of higher frequency modes make mode-dependent damage detection difficult and most likely impractical for structural applications. The frequency response method was found to be reliable for detecting even small amounts of damage in a simple composite structure, however the potentially important information about damage type, size, location and orientation were lost using this method since several combinations of these variables can yield identical response signatures.

  16. Novel SiO2-C composite adsorptive material

    Volzone, C.

    2001-08-01

    Full Text Available The present work is about the development of a Novel Composite that has several properties in only one material. This material is composed by a silica network with a sharpened pore size distribution - diameter near 1000 Å - intercrossed with another carbon network that has carbonaceous microdomains of high activity. The first network facilitates the entrance of big molecules to the interior of the material grains so they quickly reach the active sites of the carbonous network, minimizing the diffusional resistance observed when high performance activated carbons are used in adsorption processes or catalytic applications. These two intercrossed structures are self-supporting and independent among them, so one from the other can be isolated without losing the original shape and volume of the starting composite, then, their possible uses may be multiplied. The Novel Composite is stable with respect to other support or adsorbent materials due to its high obtention temperature (1550 ºC. The obtention methods of the composite and its isolated structures are described. The material was characterized by different techniques (XRD, IR, Loss on ignition, pore size distribution, specific surface area, adsorption desorption isotherms, methylene blue adsorption and SEM.En el presente trabajo se describe el desarrollo de un nuevo material compuesto que reúne distintas propiedades en un solo material. Dicho material está formado por una red de sílice con distribución de tamaño de poro estrecha - diámetro cercano a los 1000 Å - entrecruzada con otra red de carbón pseudografítica donde los microdominios carbonosos son de alta actividad. La primer red facilita la entrada de grandes moléculas al interior de los granos del material permitiendo su rápido acceso a los sitios activos de la red carbonosa, esto minimiza la resistencia difusional observada cuando se utilizan carbones activados de alto rendimiento en los procesos de adsorción o aplicaciones

  17. In-situ change and repairing method of armour tile made of carbon fiber composite material in divertor

    Ishiyama, Shintaro.

    1994-01-01

    A joint portion of a damaged armour tile of a carbon fiber composite material and a divertor substrate is locally heated spontaneously to re-melt the soldering. Then, the damaged tile is removed and the portion where the tile is removed is heated again to melt the soldering, then a tile for exchange is joined. Alternatively, a thermosetting type adhesive is coated on the surface of the damaged armour tile made of carbon fiber composite material on the divertor, and a tile for repairing is adhered thereon then the joint surface is locally heated to cure the adhesive. For local heating, for example, high frequency heating or dielectric heating is used. It is preferably conducted by remote handling by using robot arms under vacuum in an vacuum vessel of the thermonuclear device. The operations of the heating and pressurization for the joint surface are preferably repeated for several times. (N.H.)

  18. Mechanical and thermophysical properties of graphite/polyimide composite materials

    Rummler, D. R.; Clark, R. K.

    1979-01-01

    An on-going program to characterize advanced composites for up to 50,000 hours of exposure to simulated supersonic cruise environments is summarized. Results are presented for up to 25,000 hours of thermal exposure and 10,000 hours of flight simulation at temperatures up to 560K (550 F) with emphasis on HTS/710 graphite/polyimide composite material. Results to date indicate that the maximum use temperature for HTS/710 may be reduced to 505K (450 F) for long-time (1000 hours) application such as the supersonic transport. Preliminary thermophysical properties data for HTS/PMR15 graphite/polyimide were generated. These data include thermal conductivity, thermal expansion, and specific heat from 115K (-252 F) to 590K (600 F) and emittance at room temperature and 590K (600 F). The purpose in generating these data was to validate use of state-of-the-art property measurement methods for advanced graphite fiber reinforced resin matrix composites. Based on results to this point, thermal expansion measurements for composites are most difficult to perform. A high degree of caution in conducting thermal expansion tests and analyzing results is required to produce reliable data.

  19. Estimation and analysis of the sensitivity of monoenergetic electron radiography of composite materials with fluctuating composition

    Rudenko, V.N.; Yunda, N.T.

    1978-01-01

    A sensitivity analysis of the electron defectoscopy method for composite materials with fluctuating composition has been carried out. Quantitative evaluations of the testing sensitivity depending on inspection conditions have been obtained, and calculations of the instrumental error are shown. Based on numerical calculations, a comparison of error has been carried out between high-energy electron and X-ray testings. It is shown that when testing composite materials with a surface density of up to 7-10 g/cm 2 , the advantage of the electron defectoscopy method as compared to the X-ray one is the higher sensitivity and lower instrumental error. The advantage of the electron defectoscopy method over the X-ray one as regards the sensitivity is greater when a light-atom component is predomenant in the composition. A monoenergetic electron beam from a betatron with an energy of up to 30 MeV should be used for testing materials with a surface density of up to 15 g/cm 2

  20. Cyclic stress effects on transport properties of superconducting composite materials

    Fisher, E.S.; Kim, S.H.; Turner, A.P.L.

    1976-01-01

    The effects of cyclic stresses at 4.2 0 K on the conductor materials for large superconducting magnets are being investigted in samples of unalloyed copper and of composites containing Nb--Ti or Nb 3 Sn wires in a copper matrix. The samples are constant-strain cycled in pure tension-compression modes. The increase in electrical resistivity of different grades of copper with number and amplitude of cycles is described. The increases can be of the order of the magnetoresistance for 1000 to 2000 cycles at 0.20 percent strain per cycle. The facility for measuring critical current changes with composite cycling is described and the initial results indicate significant I/sub c/ changes as well as unexpected filament fractures. 10 fig

  1. Aerogel Hybrid Composite Materials: Designs and Testing for Multifunctional Applications

    Williams, Martha K.; Fesmire, James E.

    2016-01-01

    This webinar will introduce the broad spectrum of aerogel composites and their diverse performance properties such as reduced heat transfer to energy storage, and expands specifically on the aerogel/fiber laminate systems and testing methodologies. The multi-functional laminate composite system, AeroFiber, and its construction is designed by varying the type of fiber (e.g. polyester, carbon, Kevlar®, Spectra® or Innegral(TradeMark) and combinations thereof), the aerogel panel type and thickness, and overall layup configuration. The combination and design of materials may be customized and tailored to achieve a range of desired properties in the resulting laminate system. Multi-functional properties include structural strength, impact resistance, reduction in heat transfer, increased fire resistance, mechanical energy absorption, and acoustic energy dampening. Applications include aerospace, aircraft, automotive, boating, building and construction, lightweight portable structures, liquefied natural gas, cryogenics, transportation and energy, sporting equipment, and military protective gear industries.

  2. Engineering of oriented carbon nanotubes in composite materials

    Beigmoradi, Razieh; Mohebbi-Kalhori, Davod

    2018-01-01

    The orientation and arrangement engineering of carbon nanotubes (CNTs) in composite structures is considered a challenging issue. In this regard, two groups of in situ and ex situ techniques have been developed. In the first, the arrangement is achieved during CNT growth, while in the latter, the CNTs are initially grown in random orientation and the arrangement is then achieved during the device integration process. As the ex situ techniques are free from growth restrictions and more flexible in terms of controlling the alignment and sorting of the CNTs, they are considered by some as the preferred technique for engineering of oriented CNTs. This review focuses on recent progress in the improvement of the orientation and alignment of CNTs in composite materials. Moreover, the advantages and disadvantages of the processes are discussed as well as their future outlook. PMID:29515955

  3. Designing magnetic composite materials using aqueous magnetic fluids

    Galicia, J A; Cousin, F; Guemghar, D; Menager, C; Cabuil, V

    2003-01-01

    In this paper, we report on how to take advantage of good knowledge of both the chemistry and the stability of an aqueous magnetic colloidal suspension to realize different magnetic composites. The osmotic pressure of the magnetic nanoparticles is set prior to the realization of the composite to a given value specially designed for the purpose for each hybrid material: magnetic particles in polymer networks, particles as probes for studying the structure of clay suspensions and shape modification of giant liposomes. First, we show that the introduction of magnetic particles in polyacrylamide gels enhances their Young modulus and reduces the swelling caused by water. The particles cause both a mechanical and an osmotic effect. The latter is strongly dependent on the ionic strength and is attributed to an attraction between particles and the polymeric matrix. In the second part, we determine the microscopic structure of suspensions of laponite as a function of concentration, by combining SANS and magneto-optica...

  4. Compositions for enhancing hydroysis of cellulosic material by cellulolytic enzyme compositions

    Quinlan, Jason; Xu, Feng; Sweeney, Matthew; Johansen, Katja Salomon

    2014-09-30

    The present invention relates to compositions comprising a GH61 polypeptide having cellulolytic enhancing activity and an organic compound comprising a carboxylic acid moiety, a lactone moiety, a phenolic moiety, a flavonoid moiety, or a combination thereof, wherein the combination of the GH61 polypeptide having cellulolytic enhancing activity and the organic compound enhances hydrolysis of a cellulosic material by a cellulolytic enzyme compared to the GH61 polypeptide alone or the organic compound alone. The present invention also relates to methods of using the compositions.

  5. Structural Behaviour of Strengthened Composite Materials. Experimental Studies

    Vlad Munteanu

    2007-01-01

    Full Text Available Masonry represents one of the earliest structural materials used by mankind. A lot of the ancient building structures were made using masonry. A large number of these buildings have been stated historical monuments. Most commonly masonry elements which are able to cover large spans was masonry arches. The paper makes a detailed presentation on structural behaviour and failure mechanisms of a horizontally loaded masonry arch. The arch model was built at a 1 : 1 scale using solid bricks and M10Z mortar. It was firstly loaded with vertically acting dead loads and with horizontal load acting in its plane. In this loading hypothesis, a plastic hinge occurred leading to the failure of the arch and loss of load bearing capacity. In the next stage of the experimental program, the arch was strengthened using a composite material membrane at the upper face. The membrane consisted in a continuous, glass-fiber fabric and epoxy resin. After proper curing, the same loading hypothesis was used. The failure mechanisms changed and a larger horizontal loading level was noticed. Further on, the arch was rehabilitated using a different composite material layout, the membrane was applied both on upper and bottom faces as well as partially on the lateral faces of the arch. This new rehabilitation layout leads to a significant increase in the load bearing capacity of the arch. The failure mechanisms were changed causing a significantly better overall structural behaviour of the arch.

  6. Flexible Multibody Systems Models Using Composite Materials Components

    Neto, Maria Augusta; Ambr'osio, Jorge A. C.; Leal, Rog'erio Pereira

    2004-01-01

    The use of a multibody methodology to describe the large motion of complex systems that experience structural deformations enables to represent the complete system motion, the relative kinematics between the components involved, the deformation of the structural members and the inertia coupling between the large rigid body motion and the system elastodynamics. In this work, the flexible multibody dynamics formulations of complex models are extended to include elastic components made of composite materials, which may be laminated and anisotropic. The deformation of any structural member must be elastic and linear, when described in a coordinate frame fixed to one or more material points of its domain, regardless of the complexity of its geometry. To achieve the proposed flexible multibody formulation, a finite element model for each flexible body is used. For the beam composite material elements, the sections properties are found using an asymptotic procedure that involves a two-dimensional finite element analysis of their cross-section. The equations of motion of the flexible multibody system are solved using an augmented Lagrangian formulation and the accelerations and velocities are integrated in time using a multi-step multi-order integration algorithm based on the Gear method

  7. Micro-Scale Experiments and Models for Composite Materials with Materials Research

    Zike, Sanita

    Numerical models are frequently implemented to study micro-mechanical processes in polymer/fibre composites. To ensure that these models are accurate, the length scale dependent properties of the fibre and polymer matrix have to be taken into account. Most often this is not the case, and material...... properties acquired at macro-scale are used for micro-mechanical models. This is because material properties at the macro-scale are much more available and the test procedures to obtain them are well defined. The aim of this research was to find methods to extract the micro-mechanical properties of the epoxy...... resin used in polymer/fibre composites for wind turbine blades combining experimental, numerical, and analytical approaches. Experimentally, in order to mimic the stress state created by a void in a bulk material, test samples with finite root radii were made and subjected to a double cantilever beam...

  8. Corrosion Assessment of Candidate Materials for the SHINE Subcritical Assembly Vessel and Components FY14 Report

    Pawel, Steven J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-10-01

    Laboratory corrosion testing of candidate alloys—including Zr-4 and Zr-2.5Nb representing the target solution vessel, and 316L, 2304, 304L, and 17-4 PH stainless steels representing process piping and balance-of-plant components—was performed in support of the proposed SHINE process to produce 99Mo from low-enriched uranium. The test solutions used depleted uranyl sulfate in various concentrations and incorporated a range of temperatures, excess sulfuric acid concentrations, nitric acid additions (to simulate radiolysis product generation), and iodine additions. Testing involved static immersion of coupons in solution and in the vapor above the solution, and was extended to include planned-interval tests to examine details associated with stainless steel corrosion in environments containing iodine species. A large number of galvanic tests featuring couples between a stainless steel and a zirconium-based alloy were performed, and limited vibratory horn testing was incorporated to explore potential erosion/corrosion features of compatibility. In all cases, corrosion of the zirconium alloys was observed to be minimal, with corrosion rates based on weight loss calculated to be less than 0.1 mil/year with no change in surface roughness. The resulting passive film appeared to be ZrO2 with variations in thickness that influence apparent coloration (toward light brown for thicker films). Galvanic coupling with various stainless steels in selected exposures had no discernable effect on appearance, surface roughness, or corrosion rate. Erosion/corrosion behavior was the same for zirconium alloys in uranyl sulfate solutions and in sodium sulfate solutions adjusted to a similar pH, suggesting there was no negative effect of uranium resulting from fluid dynamic conditions aggressive to the passive film. Corrosion of the candidate stainless steels was similarly modest across the entire range of exposures. However, some sensitivity to corrosion of the stainless steels was

  9. Vessel Operating Units (Vessels)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data for vessels that are greater than five net tons and have a current US Coast Guard documentation number. Beginning in1979, the NMFS...

  10. Composite Materials with Magnetically Aligned Carbon Nanoparticles Having Enhanced Electrical Properties and Methods of Preparation

    Hong, Haiping (Inventor); Peterson, G.P. (Bud) (Inventor); Salem, David R. (Inventor)

    2016-01-01

    Magnetically aligned carbon nanoparticle composites have enhanced electrical properties. The composites comprise carbon nanoparticles, a host material, magnetically sensitive nanoparticles and a surfactant. In addition to enhanced electrical properties, the composites can have enhanced mechanical and thermal properties.

  11. Composite Materials with Magnetically Aligned Carbon Nanoparticles and Methods of Preparation

    Hong, Haiping (Inventor); Peterson, G.P. (Bud) (Inventor); Salem, David R. (Inventor)

    2018-01-01

    The present invention relates to magnetically aligned carbon nanoparticle composites and methods of preparing the same. The composites comprise carbon nanoparticles, host material, magnetically sensitive nanoparticles and surfactant. The composites may have enhanced mechanical, thermal, and/or electrical properties.

  12. HTGR Base Technology Program. Task 2: concrete properties in nuclear environment. A review of concrete material systems for application to prestressed concrete pressure vessels

    Naus, D.J.

    1981-05-01

    Prestressed concrete pressure vessels (PCPVs) are designed to serve as primary pressure containment structures. The safety of these structures depends on a correct assessment of the loadings and proper design of the vessels to accept these loadings. Proper vessel design requires a knowledge of the component (material) properties. Because concrete is one of the primary constituents of PCPVs, knowledge of its behavior is required to produce optimum PCPV designs. Concrete material systems are reviewed with respect to constituents, mix design, placing, curing, and strength evaluations, and typical concrete property data are presented. Effects of extreme loadings (elevated temperature, multiaxial, irradiation) on concrete behavior are described. Finally, specialty concrete material systems (high strength, fibrous, polymer, lightweight, refractory) are reviewed. 235 references

  13. Development of neutron irradiation embrittlement correlation of reactor pressure vessel materials of light water reactors

    Soneda, Naoki; Dohi, Kenji; Nomoto, Akiyoshi; Nishida, Kenji; Ishino, Shiori

    2007-01-01

    A large amount of surveillance data of the RPV embrittlement of the Japanese light water reactors have been compiled since the current Japanese embrittlement correlation has been issued in 1991. Understanding on the mechanisms of the embrittlement has also been greatly improved based on both experimental and theoretical studies. CRIEPI and the Japanese electric power utilities have started research project to develop a new embrittlement correlation method, where extensive study of the microstructural analyses of the surveillance specimens irradiated in the Japanese commercial reactors has been conducted. The new findings obtained from the experimental study are that the formation of solute-atom clusters with little or no copper is responsible for the embrittlement in low-copper materials, and that the flux effect exists especially in high-copper materials and this is supported by the difference in the microstructure of the high-copper materials irradiated at different fluxes. Based on these new findings, a new embrittlement correlation method is formulated using rate equations. The new methods has higher prediction capability than the current Japanese embrittlement correlation in terms of smaller standard deviation as well as smaller mean value of the prediction error. (author)

  14. Materials technology and the energy problem : application to the reliability and safety of nuclear pressure vessels

    Garrett, G.G.

    1975-01-01

    In the U.S.A. over the past few months, widespread plant shutdowns because of cracking problems has produced considerable public pressure for a reappraisal of the reliability and safety of nuclear reactors. The awareness of such problems, and their solution, is particularly relevant to South Africa at this time. Some materials problems related to nuclear plant failure are examined in this paper. Since catastrophic failure (without prior warning from slow leakage) is in principle possible for light water (pressurised) reactors under operating conditions, it is essential to maintain rigorous manufacturing and quality control procedures, in conjunction with thorough and frequent examination by non-destructive testing methods. Although tests currently in progress in the U.S.A. on large-scale model reactors suggest that mathematical stress and failure analyses, for simple geometries at least, are sound, current in situ surveillance programmes aimed at categorizing the effects of irradiation are inadequate. In addition, the effects on materials properties and subsequent fracture resistance of the combined effects of irradiation and thermal shock (arising from the injection of emergency cooling water during a loss-of coolant accident) are unknown. The problem of stress corrosion cracking in stainless steel pipelines is considerable, and at present virtually impossible to predict. Much of the available laboratory data is inapplicable in that it cannot account for the complex interactions of stress state, temperature, material variations and segregation effects, and water chemistry, especially in conjunction with irradiation effects, that are experienced in an operating environment

  15. The bond of different post materials to a resin composite cement and a resin composite core material.

    Stewardson, D; Shortall, A; Marquis, P

    2012-01-01

    To investigate the bond of endodontic post materials, with and without grit blasting, to a resin composite cement and a core material using push-out bond strength tests. Fiber-reinforced composite (FRC) posts containing carbon (C) or glass (A) fiber and a steel (S) post were cemented into cylinders of polymerized restorative composite without surface treatment (as controls) and after grit blasting for 8, 16, and 32 seconds. Additional steel post samples were sputter-coated with gold before cementation to prevent chemical interaction with the cement. Cylindrical composite cores were bonded to other samples. After sectioning into discs, bond strengths were determined using push-out testing. Profilometry and electron microscopy were used to assess the effect of grit blasting on surface topography. Mean (standard deviation) bond strength values (MPa) for untreated posts to resin cement were 8.41 (2.80) for C, 9.61(1.88) for A, and 19.90 (3.61) for S. Prolonged grit blasting increased bond strength for FRC posts but produced only a minimal increase for S. After 32 seconds, mean values were 20.65 (4.91) for C, 20.41 (2.93) for A, and 22.97 (2.87) for S. Gold-coated steel samples produced the lowest bond strength value, 7.84 (1.40). Mean bond strengths for untreated posts bonded to composite cores were 6.19 (0.95) for C, 13.22 (1.61) for A, and 8.82 (1.18) for S, and after 32 seconds of grit blasting the values were 17.30 (2.02) for C, 26.47 (3.09) for A, and 20.61 (2.67) for S. FRC materials recorded higher roughness values before and after grit blasting than S. With prolonged grit blasting, roughness increased for A and C, but not for S. There was no evidence of significant bonding to untreated FRC posts, but significant bonding occurred between untreated steel posts and the resin cement. Increases in the roughness of FRC samples were material dependent and roughening significantly increased bond strength values (p<0.05). Surface roughening of the tested FRC posts is

  16. Metal Matrix Composite Material by Direct Metal Deposition

    Novichenko, D.; Marants, A.; Thivillon, L.; Bertrand, P. H.; Smurov, I.

    Direct Metal Deposition (DMD) is a laser cladding process for producing a protective coating on the surface of a metallic part or manufacturing layer-by-layer parts in a single-step process. The objective of this work is to demonstrate the possibility to create carbide-reinforced metal matrix composite objects. Powders of steel 16NCD13 with different volume contents of titanium carbide are tested. On the base of statistical analysis, a laser cladding processing map is constructed. Relationships between the different content of titanium carbide in a powder mixture and the material microstructure are found. Mechanism of formation of various precipitated titanium carbides is investigated.

  17. Composite material including nanocrystals and methods of making

    Bawendi, Moungi G.; Sundar, Vikram C.

    2010-04-06

    Temperature-sensing compositions can include an inorganic material, such as a semiconductor nanocrystal. The nanocrystal can be a dependable and accurate indicator of temperature. The intensity of emission of the nanocrystal varies with temperature and can be highly sensitive to surface temperature. The nanocrystals can be processed with a binder to form a matrix, which can be varied by altering the chemical nature of the surface of the nanocrystal. A nanocrystal with a compatibilizing outer layer can be incorporated into a coating formulation and retain its temperature sensitive emissive properties.

  18. Characterization of selected LDEF polymer matrix resin composite materials

    Young, Philip R.; Slemp, Wayne S.; Witte, William G., Jr.; Shen, James Y.

    1991-01-01

    The characterization of selected graphite fiber reinforced epoxy (934 and 5208) and polysulfone (P1700) matrix resin composite materials which received 5 years and 10 months of exposure to the LEO environment on the Long Duration Exposure Facility is reported. Resin loss and a decrease in mechanical performance as well as dramatic visual effects were observed. However, chemical characterization including infrared, thermal, and selected solution property measurements showed that the molecular structure of the polymeric matrix had not changed significantly in response to this exposure. The potential effect of a silicon-containing molecular contamination of these specimens is addressed.

  19. Materials Characterisation of Glass/epoxy Composites - Focusing on Process Conditions

    Jakobsen, Johnny; Lyckegaard, Anders; Jensen, Erik Appel

    2013-01-01

    Predicting the behaviour of fibre reinforced polymer composites taking the process conditions into account involves advanced modelling techniques and an extensive materials characterisation. The materials characterisation of a chopped strand mat glass/epoxy composite has been the focus...

  20. Thermal modelling of extrusion based additive manufacturing of composite materials

    Jensen, Mathias Laustsen; Sonne, Mads Rostgaard; Hattel, Jesper Henri

    One of the hottest topics regarding manufacturing these years is additive manufacturing (AM). AM is a young branch of manufacturing techniques, which by nature is disruptive due to its completely different manufacturing approach, wherein material is added instead of removed. By adding material...... layer by layer, mould and customised tooling requirements from the conventional manufacturing are reduced or removed, which leads to increased customisation options and enables new part complexities without increasing the manufacturing cost. AM hence enables customised small volume productions...... of composite parts not feasible by conventional manufacturing techniques. This sets up new requirements to the part verification and validation, while conventional destructive tests become too expensive. This initial study aims to investigate alternative options to this destructive testing by increasing...