ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Maps
  • Other Sources  (855)
  • COMPOSITE MATERIALS  (855)
  • 1980-1984  (855)
  • 1
    facet.materialart.
    Unknown
    An investigation of possible electrical hazards of carbon fiber composites (1980)
    In:  CASI
    Details
    Publication Date: 2006-06-26
    Description: Results of an assessment of the public risk associated with the release of carbon fibers from crash-fire accidents of civil aircraft having carbon composite structures are presented. The overall national impact is shown to be extremely low in 1993. Personal injury is found to be extremely unlikely. Based on these findings, the risk of electrical failure from carbon fibers should not prevent the exploitation of composites in aircraft, and additional protection of aircraft avionics to guard aginst carbon fibers is unnecessary.
    Keywords: COMPOSITE MATERIALS
    Type: Selected NASA Res. in Composite Mater. and Struct.; p 183-234
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Development of a laminate fatigue analysis (1980)
    In:  CASI
    Details
    Publication Date: 2006-06-26
    Description: A fatigue analysis technique developed to predict damage growth in notched laminates is described. Features of the analysis include: criteria to relate matrix failure to cyclic stresses in and between plies; correlation of delamination growth with strain-release rate; and in-plane shear modulus change is related to cyclic shear stresses. A simplified finite element model is used to determine stresses in laminates that contain matrix damage. Failure criteria are integrated with the finite element model to form the fatigue analysis.
    Keywords: COMPOSITE MATERIALS
    Type: Selected NASA Res. in Composite Mater. and Struct.; p 79-106
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Damage tolerance research on composite compression panels (1980)
    In:  CASI
    Details
    Publication Date: 2006-06-26
    Description: The damage tolerance of composites was investigated. Results show that severe degradation in material strength may occur due to impact damage and that reduced strain allowables should be considered to compensate for possible impact damage. The mechanisms of failure involved in impact so that local damage will be reduced and arrest of propagating fracture initiated at impact locations are examined. Compression strength reductions for damage due to impact by a 1.27 cm diameter spherical projectile in thick laminates representative of wing skin panels are presented. Also discussed are the results of concepts recently evaluated to improve damage tolerance. These concepts range from improvements at the materials level to advanced structural configurations designed to arrest or limit the growth of propagating fractures. The results indicate that substantial improvements in the damage tolerance of graphite-epoxy composite structures can be achieved through the proper combination of materials and structural design.
    Keywords: COMPOSITE MATERIALS
    Type: Selected NASA Res. in Composite Mater. and Struct.; p 107-142
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Buckling and postbuckling research on flat and curved composite panels (1980)
    In:  CASI
    Details
    Publication Date: 2006-06-26
    Description: Progress in the development of verified design technology for generic advanced-composite structural components loaded in compression is reported. Generic structural configurations material systems and load ranges of interest for a given application were investigated using structural procedures, structural analysis procedures, and laboratory testing of structural specimens. Both flat and curved composite compression panels that are designed either to be buckling resistant or to have postbuckling strength depending on the expected application of the panels were considered.
    Keywords: COMPOSITE MATERIALS
    Type: Selected NASA Res. in Composite Mater. and Struct.; p 35-78
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Failure prediction techniques for compression loaded composite laminates with holes (1980)
    In:  CASI
    Details
    Publication Date: 2006-06-26
    Description: The degree of notch sensitivity of composites in compression and whether their failures can be predicted over a wide range of plate and hole sizes. The notch sensitivity of composites is investigated by comparing actual failure loads of laminates with circular holes, with the extreme failure that would be expected from an ideal notch insensitive material and from an ideal notch sensitive material. The predictability question is addressed by applying the point stress failure criterion to a wide range of plate widths and hole sizes and comparing with available experimental data. The severity of impact is explored by comparing strength reductions resulting from impact with those resulting from comparable size circular holes. Finally, comparison is made of the differences to be expected from the effects of cracks and circular holes on failure strength.
    Keywords: COMPOSITE MATERIALS
    Type: Selected NASA Res. in Composite Mater. and Struct.; p 1-33
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Research on ultra-high-temperature materials, monolithic ceramics, ceramic matrix composites and carbon/carbon composites (1982)
    In:  CASI
    Details
    Publication Date: 2006-04-12
    Description: Research on three classes of materials that show potential for allowing significant increases in operating temperatures in gas turbine engines is discussed. Monolithic ceramics, ceramic matrix composites, and carbon-carbon composites are discussed. Sintering, hot pressing, and densification are discussed.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Advan. Mater. Technol.; p 275-292
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Processing composite materials (1982)
    In:  CASI
    Details
    Publication Date: 2006-04-12
    Description: The fabrication of several composite structural articles including DC-10 upper aft rudders, L-1011 vertical fins and composite biomedical appliances are discussed. Innovative composite processing methods are included.
    Keywords: COMPOSITE MATERIALS
    Type: Advan. Mater. Technol.; p 115-140
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Opportunities for composites in commercial transport structures (1982)
    In:  CASI
    Details
    Publication Date: 2006-04-12
    Description: Manufacturers are developing composite versions of structural components on existing aircraft. Development involves testing of various material options before selecting one and then extensive testing to develop an adequate data base of material strength and stiffness properties. Design options are narrowed through analysis and a varied spectrum of development tests on small and large subcomponents. In parallel with this, a suitable production process including economical ply preparation and cure at high temperature and pressure is evolved, tools are designed and fabricated, and full scale components are then manufactured for ground qualification tests, flight tests, and airline service. The various tests include many that are required by the FAA for flight certification, which must precede airline service. Inspection and repair methods to insure adequate maintenance in service are also developed.
    Keywords: COMPOSITE MATERIALS
    Type: Advan. Mater. Technol.; p 1-28
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Fatigue and fracture research in composite materials (1982)
    In:  CASI
    Details
    Publication Date: 2006-04-12
    Description: The fatigue, fracture, and impact behavior of composite materials are investigated. Bolted and bonded joints are included. The solutions developed are generic in scope and are useful for a wide variety of structural applications. The analytical tools developed are used to demonstrate the damage tolerance, impact resistance, and useful fatigue life of structural composite components. Standard tests for screening improvements in materials and constituents are developed.
    Keywords: COMPOSITE MATERIALS
    Type: Advan. Mater. Technol.; p 91-114
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    The effect of space environment exposure on the properties of polymer matrix composite materials (A0180) (1984)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The objective of this experiment is to determine the effect of various lengths of exposure to a space environment on the mechanical properties of selected commercial polymer matrix composite materials. Fiber materials will include graphite, boron, S-glass, and PRD-49. The mechanical properties to be investigated are orthotropic elastic constants, strength parameters (satisfying the tensor polynomial relation), coefficients of thermal expansion, impact resistance, crack propagation, and fracture toughness. In addition, the effect of laminate thickness on property changes will also be investigated.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Long Duration Exposure Facility (LDEF); p 41-43
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 11
    facet.materialart.
    Unknown
    The effect of the space environment on composite materials (A0138-9) (1984)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The objective is to test different types of materials (laminates, thermal coatings, and adhesives) to determine their actual useful lifetime. These experiments will also make is possible to integrate the histories of the thermal and mechanical characteristics into models of the composite structures. The experiment is passive and is located in one of the boxes in a 12-in.-deep peripheral tray with nine other experiments from France. The box will provide protection for the samples from contamination during the launch and reentry phases of the Long Duration Exposure Facility mission. The experiment revolves around four themes of study: thermal coatings, adhesives, dimensional stability, and mechanical characteristics. The various materials will be arranged in six levels within the box, so only the first level will be subjected to direct solar radiation. Each level will consist of plates from which test specimens will be cut after the mission.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Long Duration Exposure Facility (LDEF); p 32-34
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 12
    facet.materialart.
    Unknown
    Space environment effects on spacecraft materials (M0003) (1984)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The immediate objectives of this experiment are to understand changes in the properties and structure of materials after exposure to the space environment and to compare these changes with predictions based on laboratory experiments. The experiment consists of 19 subexperiments involving a number of DOD laboratories and contractor organizations. In general, the experimental approach with each of the subexperiments will involve comparison of preflight and postflight analyses. Typical analyses will include the measurement of optical properties (reflectance, transmittance, and refractive index), and macrophysical properties. In addition to measuring changes in the macroscopic properties of the returned specimens, microstructural properties will also be examined. Thus, it may be possible to increase our understanding of the changes induced by the environment. This increased understanding can then be used to predict the performance of materials based on knowledge of the space environment and the results of laboratory tests. This experiment will be a coopperative effort and will provide an opportunity for DOD space programs and laboratories to evaluate materials and components after long exposures to the space environment.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Long Duration Exposure Facility (LDEF); p 44-48
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 13
    facet.materialart.
    Unknown
    Evaluation of long-duration exposure to the natural space environment on graphite-polyimide and graphite-epoxy mechanical properties (A0175) (1984)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The primary objective of this experiment is to accumulate the needed operational data associated with the exposure of graphite-polyimide and graphite-epoxy material to the environments of space. The experiment will be mounted in two 3-in.-deep peripheral trays. Graphite-polyimide specimens will occupy 1 1/3 trays and the graphite-epoxy specimens will occupy two-thirds of a tray. The experiment approach requires two matched sets of specimens with traceable records that are maintained for materials processing and specimen quality. After fabrication, one set of each test specimen will be sectioned and structurally tested to serve as a data baseline. After the flight, the other set of specimens will undergo extensive measurements of mechanical properties for comparison with the original data baseline. Structural testing of the graphite-polyimide specimens will provide strength and elastic data in tension, compression, and shear. Transverse tension microcracking and crack propagation will be evaluated by photomicroscopy. Structural testing of the graphite-epoxy specimens will include verification of laminate, core, adhesive, and fatigue properties as applied to the design and analysis of the payload bay door. Microcracking and crack propagation will also be analyzed by photomicroscopy.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Long Duration Exposure Facility (LDEF); p 38-40
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 14
    facet.materialart.
    Unknown
    Effect of space exposure of some epoxy matrix composites on their thermal expansion and mechanical properties (A0138-8) (1984)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: This experiment has three objectives. The first and main objective is to detect a possible variation in the coefficient of thermal expansion of composite samples during a 1-year exposure to the near-Earth orbital environment. A second objective is to detect a possible change in the mechanical integrity of composite products, both simple elements and honeycomb sandwich assemblies. A third objective is to compare the behavior of two epoxy resins commonly used in space structural production. The experimental approach is to passively expose samples of epoxy matrix composite materials to the space environment and to compare preflight and postflight measurements of mechanical properties. The experiment will be located in one of the three FRECOPA (French cooperative payload) boxes in a 12-in.-deep peripheral tray that contains nine other experiments from France. The FRECOPA box will protect the samples from contamination during the launch and reentry phases of the mission. The coefficients of thermal expansion are measured on Earth before and after space exposure.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Long Duration Exposure Facility (LDEF); p 27-31
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 15
    facet.materialart.
    Unknown
    Space exposure of composite materials for large space structures (A0134) (1984)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: The objective of this experiment is to evaluate the effects of the near-Earth orbital environment on the physical and chemical properties of laminated continuous-filament composites and composites resin films for use in large space structures and advanced spacecraft. The experiment is passive and occupies about one-half of a 6-in.-deep peripheral tray. Specimens of composite materials and polymeric and resin films are arranged above and below the experiment mounting plate to enable both exposure and nonexposure to sunlight. This provides a comparison of the effects of ultraviolet plus vacuum plus thermal cycling and those of vacuum plus thermal cycling on these materials. The experiment tray is thermally isolated from the Long Duration Exposure Facility structure to allow the material specimens to experience a wide range of thermal cycles. Tensile and compression specimens will be used to evaluate the laminated composite materials. A number of the specimens are precut and ready for testing after space exposure, whereas other specimens will be prepared from larger samples.
    Keywords: COMPOSITE MATERIALS
    Type: Long Duration Exposure Facility (LDEF); p 24-26
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 16
    facet.materialart.
    Unknown
    Influence of extended exposure in space on mechanical properties of high-toughness graphite-epoxy composite material (A0019) (1984)
    In:  CASI
    Details
    Publication Date: 2006-02-14
    Description: Graphite-epoxy composites are promising candidates for structural use in space vehicles because of their high strength and elastic modulus properties. The problem of low fracture toughness was solved by use of recently developed techniques of intermittent interlaminar bonding. Before this material can be adapted for space use, however, confidence must be gained that its mechanical properties are not degraded by exposure to the space environment. The objective of this experiment is to test the effect of extended exposure to a space environment on the mechanical properties of a specially toughened T300/5208 graphite-epoxy composite material. Specimens made by recently developed techniques of intermittent interlaminar bonding will be exposed and afterward tested for fracture toughness, tensile strength, and elastic modulus. The approach of this experiment is to provide a frame on which the specimens can be mounted with their flat sides normal to the Long Duration Exposure Facility radius, each specimen with an unobstructed exposure of about 2 pi sr. The specimens will be mounted so that they neither fracture from high stress nor fail from excessive heating during launch and return.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Long Duration Exposure Facility (LDEF); p 19-20
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 17
    facet.materialart.
    Unknown
    Durability of aircraft composite materials (1982)
    In:  CASI
    Details
    Publication Date: 2006-04-12
    Description: 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.
    Keywords: COMPOSITE MATERIALS
    Type: Advan. Mater. Technol.; p 335-356
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 18
    facet.materialart.
    Unknown
    Recent advances in carbon-carbon materials systems (1982)
    In:  CASI
    Details
    Publication Date: 2006-04-12
    Description: Carbon-carbon materials and new oxidation resistant coating developments are discussed. Potential areas of application are highlighted. A short bibliography of selected references is included that describe carbon-carbon materials and related technology in detail.
    Keywords: COMPOSITE MATERIALS
    Type: Advan. Mater. Technol.; p 293-312
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 19
    facet.materialart.
    Unknown
    Fire-resistant material (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Keywords: COMPOSITE MATERIALS
    Type: NASA Technol. Appl. Team; p 38
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 20
    facet.materialart.
    Unknown
    Simplified composite micromechanics equations of hygral, thermal, and mechanical properties (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A unified set of composite micromechanics equations of simple form is summarized and described. This unified set can be used to predict unidirectional composite (ply) geometric, mechanical, thermal and hygral properties using constituent material (fiber/matrix) properties. This unified set also includes approximate equations for predicting (1) moisture absorption; (2) glass transition temperature of wet resins; and (3) hygrothermal degradation effects. Several numerical examples are worked-out to illustrate ease of use and versatility of these equations. These numerical examples also demonstrate the interrelationship of the various factors (geometric to environmental) and help provide insight into composite behavior at the micromechanistic level.
    Keywords: COMPOSITE MATERIALS
    Type: SAMPE Quarterly (ISSN 0036-0821); 15; 14-23
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 21
    facet.materialart.
    Unknown
    Off-axis tensile properties and fracture in a unidirectional graphite/polyimide composite (Celion 6000/PMR 15) (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Tensile properties of unidirectional Celion 6000 graphite/PMR 15 polyimide composites prepared by hot molding and cold molding processes were measured at room temperature and 316 C, the upper use temperature of the polyimide resin, at both 45 and 90 deg to the fiber axis. The resulting fractures were characterized by scanning electron microscopy and materialographic techniques. Variation in tensile properties with processing history occurred in the elastic modulus and strain to failure for specimens loaded at 90 deg at 316 C, and in the fracture stress, and hence the in-plane shear stress, for those loaded at 45 deg at room temperature. Significant plastic deformation was observed in the 45 deg orientation at 316 C for material produced by both processing methods. In general, fracture occurred by both failure within the matrix and at the fiber-matrix interface; the degree of interfacial failure increased with temperature. Secondary cracking below the primary fracture surface was also observed.
    Keywords: COMPOSITE MATERIALS
    Type: Polymer Composites (ISSN 0272-8397); 5; 179-185
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 22
    facet.materialart.
    Unknown
    Metallurgical and tensile property analysis of several silicon carbide/titanium composite systems (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Several silicon-carbide fiber reinforced titanium matrix composite systems were investigated to determine composite degradation mechanisms and to develop techniques to minimize loss of mechanical properties during fabrication and in service. Emphasis was on interface control by fiber or matrix coatings. Fibers and matrix materials were sputter coated with various metals to determine the effects of the coatings on basic fiber properties, fiber-matrix interactions, and on composite properties. The effects of limited variations in fabrication temperature on composite properties were determined for composites consolidated by standard press-diffusion-bonding techniques.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 23
    facet.materialart.
    Unknown
    Effect of resin on impact damage tolerance of graphite/epoxy laminates (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Twenty-four different epoxy resin systems were evaluated by a variety of test techniques to identify materials that exhibited improved impact damage tolerance in graphite/epoxy composite laminates. Forty-eight-ply composite panels of five of the material systems were able to sustain 100 m/s impact by a 1.27-cm-diameter aluminum projectile while statically loaded to strains of 0.005. Of the five materials with the highest tolerance to impact, two had elastomeric additives, two had thermoplastic additives, and one had a vinyl modifier; all the five systems used bisphenol A as the base resin. An evaluation of test results shows that the laminate damage tolerance is largely determined by the resin tensile properties, and that improvements in laminate damage tolerance are not necessarily made at the expense of room-temperature mechanical properties. The results also suggest that a resin volume fraction of 40 percent or greater may be required to permit the plastic flow between fibers necessary for improved damage tolerance.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 24
    facet.materialart.
    Unknown
    Durability/life of fiber composites in hygrothermomechanical environments (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Statistical analysis and multiple regression were used to determine and quantify the significant hygrothermomechanical variables which influence the tensile durability/life (cycle loading, fatigue) of boron-fiber/epoxy-matrix (B/E) and high-modulus-fiber/epoxy-matrix (HMS/E) composites. The use of the multiple regression analysis reduced the variables from fifteen, assumed initially, to six or less with a probability of greater than 0.999. The reduced variables were used to derive predictive models for compression and intralaminar shear durability/life of B/E and HMS/E composites assuming isoparametric fatigue behavior. The predictive models were subsequently generalized to predict the durability/life of graphite/fiber-r generalized model is of simple form, predicts conservative values compared with measured data and should be adequate for use in preliminary designs. Previously announced in STAR as N82-14287
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 25
    facet.materialart.
    Unknown
    Strain rate characterization of unidirectional graphite/epoxy composite (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: For an investigation of problems of composites at high strain rates with dominant wave propagation effects, such as dynamically loaded composite jet engine blades, the longitudinal, transverse, and in-plane shear properties of unidirectional SP 288/AS graphite/epoxy were measured at various strain rates ranging from quasi-static to over 500/s. The test specimens were rings 10.16 cm in diameter, 2.54 cm long, 6 to 8 plies thick, and with fibers at 0, 90, and 10 deg off-axis. Quasi-static testing was conducted in a fixture which applies hydraulic pressure to the ring specimens, and dynamic testing was conducted by applying an internal pressure pulse through a liquid in a special fixture. Dynamic stress-strain curves are presented. For the 0-deg specimens, the modulus increases with strain up to 20 percent of the static value. The modulus and strength increase sharply in the 90-deg rings with strain rate reaching values two to three times the corresponding static rate.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 26
    facet.materialart.
    Unknown
    Buffer strips in composites at elevated temperature (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The composite material 'buffer strip' concept is presently investigated at elevated temperatures for the case of graphite/polyimide buffer strip panels using a (45/0/45/90)2S layup, where the buffer strip material was 0-deg S-glass/polyimide. Each panel was loaded in tension until it failed, and radiographs and crack opening displacements were recorded during the tests to determine fracture onset, fracture arrest, and the extent of damage in the buffer strip after crack arrest. At 177 + or - 3 C, the buffer strips increased the panel strength by at least 40 percent in comparison with panels without buffer strips. Compared to similar panels tested at room temperature, those tested at elevated temperature had lower residual strengths, but higher failure strains.
    Keywords: COMPOSITE MATERIALS
    Type: Journal of Composite Materials (ISSN 0021-9983); 17; 549-560
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 27
    facet.materialart.
    Unknown
    Processing of fused silicide coatings for carbon-based materials (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The processing and oxidation resistance of fused Al-Si and Ni-Si slurry coatings on ATJ graphite was studied. Ni-Si coatings in the 70 to 90 percent Si range were successfully processed to melt, wet, and bond to the graphite. The molten coatings also infiltrated the porosity in graphite and reacted with it to form SiC in the coating. Cyclic oxidation at 1200 C showed that these coatings were not totally protective because of local attack of the substrate, due to the extreme thinness of the coatings in combination with coating cracks. Previously announced in STAR as N83-27019
    Keywords: COMPOSITE MATERIALS
    Type: Ceramic Engineering and Science Proceedings (ISSN 0196-6219); 4; 757-783
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 28
    facet.materialart.
    Unknown
    Cyclic debonding of adhesively bonded composites (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: To analyze the fatigue behavior of a simple composite-to-composite bonded joint, a combined experimental and analytical study of the cracked-lap-shear specimen subjected to constant-amplitude cyclic loading was undertaken. Two bonded systems were studied: T300/5208 graphite/epoxy adherends bonded with adhesives EC 3445 and with FM-300. For each bonded system, two specimen geometries were tested: (1) a strap adherend of 16 plies bonded to a lap adherend of 8 plies, and (2) a strap adherend of 8 plies bonded to a lap adherend of 16 plies. In all specimens tested, the fatigue failure was in the form of cyclic debonding with some 0 deg fiber pull-off from the strap adherend. The debond always grew in the region of adhesive that had the highest mode I (peel) loading and that region was close to the adhesive-strap interface. Furthermore, the measured cyclic debond growth rates correlated well with total strain energy release rates G(T) as well as with its components G(I) (peel) and G(II) (shear) for the mixed-mode loading in the present study.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 29
    facet.materialart.
    Unknown
    PMR polyimide composites for aerospace applications (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: A novel class of addition-type polyimides has been developed in response to the need for high temperature polymers with improved processability. The new plastic materials are known as PMR (for in situ polymerization of monomer reactants) polyimides. The highly processable PMR polyimides have made it possible to realize much of the potential of high temperature resistant polymers. Monomer reactant combinations for several PMR polyimides have been identified. The present investigation is concerned with a review of the current status of PMR polyimides. Attention is given to details of PMR polyimide chemistry, the processing of composites and their properties, and aerospace applications of PMR-15 polyimide composites.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 30
    facet.materialart.
    Unknown
    Prediction of composite hygral behavior made simple (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A convenient procedure is described to determine the hygral behavior (moisture expansion coefficients and moisture stresses) of angleplied fiber composites using a pocket calculator. The procedure consists of equations and appropriate graphs for various (+ or - theta) ply combinations. These graphs present reduced stiffness and moisture expansion coefficients as functions of (+ or - theta) in order to simplify and expedite the use of the equations. The procedure is applicable to all types of balanced, symmetric fiber composites including interply and intraply hybrids. The versatility and generality of the procedure is illustrated using several step-by-step numerical examples. Previously announced in STAR as N82-16181
    Keywords: COMPOSITE MATERIALS
    Type: SAMPE Quarterly (ISSN 0036-0821); 14; 30-39
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 31
    facet.materialart.
    Unknown
    Thermal and mechanical properties of advanced, high temperature ceramic-composite insulation (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: It is found that the mechanical properties of fibrous refractory composite insulation (FRCI) can be improved if a higher calcination temperature is used before final processing. The results also reveal that a higher density FRCI containing 60 wt pct aluminoborosilicate fibers will exhibit minimal surface recession at 1480 C in a convective-heating environment. Another finding is that the material performance in the convective-heating environment is limited by the coating and the temperature capability of its emittance agent. A table is included giving the coating compositions used with the composite insulation and tested in the convectively heated environment at a surface temperature of 1480 C.
    Keywords: COMPOSITE MATERIALS
    Type: Ceramic Engineering and Science Proceedings (ISSN 0196-6219); 4; 551-563
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 32
    facet.materialart.
    Unknown
    Environmental and high strain rate effects on composites for engine applications (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Previously cited in issue 13, p. 2034, Accession no. A82-30118
    Keywords: COMPOSITE MATERIALS
    Type: AIAA Journal (ISSN 0001-1452); 22; 128-134
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 33
    facet.materialart.
    Unknown
    Mechanical properties of a fiberglass prepreg system at cryogenic and other temperatures (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Previously cited in issue 13, p. 2024, Accession no. A82-30099
    Keywords: COMPOSITE MATERIALS
    Type: AIAA Journal (ISSN 0001-1452); 21; 1722-172
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 34
    facet.materialart.
    Unknown
    Interlaminar fracture of random short-fiber SMC composite (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: In the experimental phase of the present study of the interlaminar fracture behavior of a randomly oriented short fiber sheet molding compound (SMC) composite, the double cantilever beam fracture test is used to evaluate the mode I interlaminar fracture toughness of different composite thicknesses. In the analytical phase of this work, a geometrically nonlinear analysis is introduced in order to account for large deflections and nonlinear load deflection curves in the evaluation of interlaminar fracture toughness. For the SMC-R50 material studied, interlaminar toughness is an order of magnitude higher than that of unreinforced neat resin, due to unusual damage mechanisms ahead of the crack tip, together with significant fiber bridging across crack surfaces. Composite thickness effects on interlaminar fracture are noted to be appreciable, and a detailed discussion is given on the influence of SMC microstructure.
    Keywords: COMPOSITE MATERIALS
    Type: Journal of Composite Materials (ISSN 0021-9983); 18; 574-594
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 35
    facet.materialart.
    Unknown
    Phosphorus-containing imide resins - Modification by elastomers (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: The syntheses and general features of addition-type maleimide resins based on bis(m-aminophenyl)phosphine oxide and tris(m-aminophenyl)phosphine oxide have been reported previously. These resins have been used to fabricate graphite cloth laminates having excellent flame resistance. These composites did not burn even in pure oxygen. However, these resins were somewhat brittle. This paper reports the modification of these phosphorus-containing resins by an amine-terminated butadiene-acrylonitrile copolymer (ATBN) and a perfluoroalkylene diaromatic amine elastomer (3F). An approximately two-fold increase in short beam shear strength and flexural strength was observed at 7 percent ATBN concentration. The tensile, flexural, and shear strengths were reduced when 18 percent ATBN was used. Anaerobic char yields of the resins at 800 C and the limiting oxygen indexes of the laminates decreased with increasing ATBN concentration. The perfluorodiamine (3F) was used with both imide resins at 6.4 percent concentration. The shear strength was doubled in the case of the bisimide with no loss of flammability characteristics. The modified trisimide laminate also had improved properties over the unmodified one. The dynamic mechanical analysis of a four-ply laminate indicated a glass transition temperature above 300 C. Scanning electron micrographs of the ATBN modified imide resins were also recorded.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 36
    facet.materialart.
    Unknown
    Chemical feasibility of lithium as a matrix for structural composites (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: The chemical compatibility of lithium with tows of carbon and aramid fibers and silicon carbide and boron monofilaments was investigated by encapsulating the fibers in liquid lithium and also by sintering. The lithium did not readily wet the various fibers. In particular, very little lithium infiltration into the carbon and aramid tows was achieved and the strength of the tows was seriously degraded. The strength of the boron and silicon carbide monofilaments, however, was not affected by the liquid lithium. Therefore lithium is not feasible as a matrix for carbon and aramid fibers, but a composite containing boron or silicon carbide fibers in a lithium matrix may be feasible for specialized applications.
    Keywords: COMPOSITE MATERIALS
    Type: Composites (ISSN 0010-4361); 15; 305-309
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 37
    facet.materialart.
    Unknown
    Investigating compression failure mechanisms in composite laminates with a transient fiberglass-epoxy birefringent material (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: An experimental study is reported in which a nondestructive technique involving the use of a transparent fiberglass-epoxy composite birefringent material has been used to investigate compression failure mechanisms in graphite-epoxy laminates. It is shown that the birefringency and transparency of the fiberglass-epoxy material permits regions of high stress to be located and the mechanisms of local failure propagation to be identified within the laminate. The material may also be useful for studying stress fields and for identifying failure initiation and propagation mechanisms in a wide variety of composite-structure problems.
    Keywords: COMPOSITE MATERIALS
    Type: Experimental Techniques (ISSN 0732-8818); 8; 24
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 38
    facet.materialart.
    Unknown
    Carbon/graphite composite material study. Appendix C: NASA studies on modification of carbon/graphite fibers and alternative materials (1981)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The feasibility of modifying resin matrix composites to reduce the potential of electrical shorting from fire released fiber was explored. The effort included modifications to or coatings for graphite fibers, alternative fibers, modifications to matrix materials, and hybrid composites. The objectives included reduction of the conductivity of the graphite fiber, char formation to reduce fiber release, glass formation to prevent fiber release, catalysis to assure fiber consumption in a fire, and replacement of the graphite fibers with nonconductive fibers of similar mechanical potential.
    Keywords: COMPOSITE MATERIALS
    Type: Executive Office of the President Carbon(Graphite Composite Material Study; p 101-105
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 39
    facet.materialart.
    Unknown
    Carbon-fiber technology (1980)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The state of the art of PAN based carbon fiber manufacture and the science of fiber behavior is surveyed. A review is given of the stabilization by oxidation and the subsequent carbonization of fibers, of the apparent structure of fibers deduced from scanning electron microscopy, from X-ray scattering, and from similarities with soft carbons, and of the known relations between fiber properties and heat treatment temperature. A simplified model is invoked to explain the electrical properties of fibers and recent quantum chemical calculations on atomic clusters are used to elucidate some aspects of fiber conductivity. Some effects of intercalation and oxidative modification of finished fibers are summarized.
    Keywords: COMPOSITE MATERIALS
    Type: American Chemical Society The 16th Natl. Symp. on Polymers in the Serv. of Man; p 125-130
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 40
    facet.materialart.
    Unknown
    Preparation of cast aluminum alloy-mica particle composites (1980)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: A method for making aluminum-mica particle composites is presented in which mica particles are stirred in molten aluminum alloys followed by casting in permanent molds. Magnesium is added either as an alloying element or in the form of pieces to the surface of the alloy melts to disperse up to 3 wt% mica powders in the melts and to obtain high recoveries of mica in the castings. The mechanical properties of the aluminum alloy-mica composite decrease with increasing mica content; however, even at 2.2% it has a tensile strength of 14.22 kg/sq mm with 1.1% elongation, a compression strength of 42.61 kg/sq mm, and an impact strength of 0.30 kgm/sq cm. Cryogenic and self-lubricating bearing are mentioned applications.
    Keywords: COMPOSITE MATERIALS
    Type: Journal of Materials Science; 15; May 1980
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 41
    facet.materialart.
    Unknown
    Ultrasonic and mechanical characterizations of fatigue states of graphite epoxy composite laminates (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Results of an exploration of the relationship between ultrasonic attenuation and fatigue survivability of graphite fiber epoxy composites fabricated under different cure conditions are reported. A total of 9 27 x 40 cm eight-ply graphite epoxy laminated specimens were formed, and fatigue tests were run on five partial samples at 73.5 N varying at 30 Hz, with tests ending at a 1.27 cm deflection. A pulsed oscillator generated sinusoidal waves and transducers recorded the passage of the ultrasonic waves for display on oscilloscopes. Cure pressures ranged from 0.52-0.85 MPa and cure temperatures were in the 150-200 C interval. Ultrasonic through-transmission at 4 MHz was performed prior to and during fatigue testing. The minimum void volume fraction occurred at 175 C and 0.86 MPa. The flexural stiffness decreased with the number of fatigue cycles past 10,000, when the attenuation also increased. Correlations were found between the 4.0 MHz signal attenuation and the void volume fraction, and between the number of fatigue cycles to failure and the 4.0 MHz signal attenuation.
    Keywords: COMPOSITE MATERIALS
    Type: Materials Evaluation; 40; Apr. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 42
    facet.materialart.
    Unknown
    Property changes of a graphite/epoxy composite exposed to nonionizing space parameters (1980)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A study has been made of the changes in the mass, thickness and flexural properties of initially wet and dry specimens of graphite/epoxy composite material due to the equivalent of eight weeks of exposure to nonionizing space environmental parameters. The parameters were near and middle solar UV irradiance, high vacuum, and temperature. The flexural properties were not affected by the exposures. Changes occurred to the mass, dimensions, and surface morphology of the specimens which varied with individual and combined parameter exposures. The combined UV and elevated thermal environment had synergistic effects on the properties of the specimens.
    Keywords: COMPOSITE MATERIALS
    Type: Journal of Composite Materials; 14; Oct. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 43
    facet.materialart.
    Unknown
    Positron annihilation studies of moisture in graphite-reinforced composites (1980)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The positron lifetime technique of monitoring absorbed moisture is applied to several composites, including graphite/polymides which are candidates for high-temperature (over 260 C) applications. The experimental setup is a conventional fast-slow coincidence system wherein the positron lifetime is measured with respect to a reference time determined by the detection of a nuclear gamma ray emitted simultaneously with the positron. From the experiments, a rate of change of positron mean lifetime per unit mass of water can be determined for each type of specimen. Positron lifetime spectra are presented for a graphite/polyimide composite and for a pure polyimide.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 44
    facet.materialart.
    Unknown
    Carbon/graphite composite material study, appendix A and appendix B (1981)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A comprehensive assessment of the possible damage to electrical and electronic equipment caused by accidental release of carbon fibers from burning civil aircraft with carbon composite parts was completed. The study concluded that the amount of fiber likely to be released is much lower than initially predicted. Carbon fiber released from an aircraft crash fire was found (from atmospheric dissemination models) to disperse over a much larger area than originally estimated, with correspondingly lower fiber concentrations. Long term redissemination of fiber was shown to be insignificant if reasonable care is exercised in accident cleanup. The vulnerability of electrical equipment to structural fibers in current use was low. Consumer appliances, industrial electronics, and avionics were essentially invulnerable to carbon fibers. Shock hazards (and thus potential injury or death) were found to be extremely unlikely.
    Keywords: COMPOSITE MATERIALS
    Type: Executive Office of the President Carbon(Graphite Composite Material Study; p 48-100
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 45
    facet.materialart.
    Unknown
    Carbon/graphite composite material study. 3: Agency program activities. National Aeronautics and Space Administration (NASA) (1981)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The accidental release of carbon fibers from civil aircraft and the need for protection of civil aircraft systems from such fibers were studied. It was concluded that the electrical hazard from carbon fibers accidentally released in an aircraft crash fire pose no threat to human life. Overall costs associated with carbon fiber release are predicted to be extremely low. The risk of electrical or electronic failures due to carbon fibers is so minimal that future exploitation of carbon composites in aircraft should be continued. Additional protection of aircraft avionics to guard against carbon fibers is unnecessary. A program to develop alternate materials specifically to overcome the potential electrical hazard is not justified.
    Keywords: COMPOSITE MATERIALS
    Type: Executive Office of the President Carbon(Graphite Composite Material Study; p 6-10
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 46
    facet.materialart.
    Unknown
    Advanced resin systems for graphite epoxy composites (1980)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The value of resin/carbon fiber composites as lightweight structures for aircraft and other vehicle applications is dependent on many properties: environmental stability, strength, toughness, resistance to burning, smoke produced when burning, raw material costs, and complexity of processing. A number of woven carbon fiber and epoxy resin composites were made. The epoxy resin was commercially available tetraglycidylmethylene dianiline. In addition, composites were made using epoxy resin modified with amine and carboxyl terminated butadiene acrylonitrile copolymer. Strength and toughness in flexure as well as oxygen index flammability and NBS smoke chamber tests of the composites are reported.
    Keywords: COMPOSITE MATERIALS
    Type: American Chemical Society The 16th Natl. Symp. on Polymers in the Serv. of Man; p 131-135
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 47
    facet.materialart.
    Unknown
    Dynamic crack propagation and arrest in orthotropic DCB fiber composite specimens (1981)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: An orthotropic double cantilever beam (DCB) model is used to study dynamic crack propagation and arrest in 90 deg unidirectional Hercules AS/3501-6 graphite fiber epoxy composites. The dynamic fracture toughness of the composite is determined from tests performed on the long-strip specimen and DCB crack arrest experiments are conducted. By using the dynamic fracture toughness in a finite-difference solution of the DCB governing partial differential equations, a numerical solution of the crack propagation and arrest events is computed. Excellent agreement between the experimental and numerical crack arrest results are obtained.
    Keywords: COMPOSITE MATERIALS
    Type: Engineering Fracture Mechanics; 14; 2, 19; 1981
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 48
    facet.materialart.
    Unknown
    Ultrasonic attenuation and velocity in AS/3501-6 graphite fiber composite (1980)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The ultrasonic group velocity and attenuation were measured as a function of frequency for longitudinal and shear waves in the Hercules epoxy matrix (3501-6) and in the principal directions of the unidirectional Hercules graphite fiber epoxy composite (AS/3501-6). Tests were conducted in the frequency ranges 0.25-14 MHz and 0.5-3 MHz for longitudinal and shear wave modes, respectively. While the attenuation increased with frequency for all wave modes, the group velocity was independent of frequency for all wave modes. In studying the effects of transducer-specimen interface couplant and pressure, it was found that for each transducer, there exists a frequency-dependent 'saturation pressure' corresponding to the maximum output amplitude of the signal.
    Keywords: COMPOSITE MATERIALS
    Type: Journal of Nondestructive Evaluation; 1; June 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 49
    facet.materialart.
    Unknown
    Thermal expansion and swelling of cured epoxy resin used in graphite/epoxy composite materials (1980)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The paper presents results of experiments in which the thermal expansion and swelling behavior of an epoxy resin system and two graphite/epoxy composite systems exposed to water were measured. It was found that the cured epoxy resin swells by an amount slightly less than the volume of the absorbed water and that the swelling efficiency of the water varies with the moisture content of the polymer. Additionally, the thermal expansion of cured epoxy resin that is saturated with water is observed to be more than twice that of dry resin. Results also indicate that cured resin that is saturated with 7.1% water at 95 C will rapidly increase in moisture content to 8.5% when placed in 1 C water. The mechanism for this phenomenon, termed reverse thermal effect, is described in terms of a slightly modified free-volume theory in conjunction with the theory of polar molecule interaction. Nearly identical behavior was observed in two graphite/epoxy composite systems, thus establishing that this behavior may be common to all cured epoxy resins.
    Keywords: COMPOSITE MATERIALS
    Type: Journal of Materials Science; 15; July 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 50
    facet.materialart.
    Unknown
    Effect of processing on Polymer/Composite structure and properties (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Advances in the vitality and economic health of the field of polymer forecasting are discussed. A consistent and rational point of view which considers processing as a participant in the underlying triad of relationships which comprise materials science and engineering is outlined. This triad includes processing as it influences material structure, and ultimately properties. Methods in processing structure properties, polymer science and engineering, polymer chemistry and synthesis, structure and modification and optimization through processing, and methods of melt flow modeling in processing structure property relations of polymer were developed. Mechanical properties of composites are considered, and biomedical materials research to include polymer processing effects are studied. An analysis of the design technology of advances graphite/epoxy composites is also reported.
    Keywords: COMPOSITE MATERIALS
    Type: The Mater. Process. Res. Base of the Mater. Process. Center; p 185-197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 51
    facet.materialart.
    Unknown
    Modification of epoxy-reinforced glass-cloth composites with a perfluorinated alkyl ether elastomer (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A perfluorinated alkyl ether diacyl fluoride prepolymer (molecular weight about 1500) was coreacted with Epon 828 epoxy resin and diamino diphenyl sulfone to obtain an elastomer-toughened, glass-cloth composite. Improvements in flexural toughness, impact resistance, and water resistance, without loss of strength, modulus of elasticity or a lowering of the glass-transition temperature, were realized over those of the unmodified composite. Factors concerning optimization of the process are discussed. Results suggest that a simultaneously interpenetrating polymer network may be formed which gives rise to a measured improvement in composite mechanical properties.
    Keywords: COMPOSITE MATERIALS
    Type: Polymer Composites (ISSN 0272-8397); 5; 198-201
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 52
    facet.materialart.
    Unknown
    Simplified composite micromechanics equations for strength, fracture toughness and environmental effects (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A unified set of composite micromechanics equations of simple form is summarized and described. This unified set includes composite micromechanics equations for predicting: (1) ply in-plane uniaxial strengths; (2) through-the-thickness strength (interlaminar and flexural); (3) in-plane fracture toughness; (4) in-plane impact resistance; and (5) through-the-thickness (interlaminar and flexural) impact resistance. Equations are also included for predicting the hygrothermal effects on strength, fracture toughness and impact resistance. Several numerical examples are worked out to illustrate the ease of use of the various composite micromechanics equations.
    Keywords: COMPOSITE MATERIALS
    Type: SAMPE Quarterly (ISSN 0036-0821); 15; 41-55
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 53
    facet.materialart.
    Unknown
    Thermogravimetric analysis of silicon carbide-silicon nitride fibers at ambient to 1000 C in air (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Thermogravimetric analysis of silicon carbide-silicon nitride fibers was carried out at ambient to 1000 C in air. The weight loss over this temperature range was negligible. In addition, the oxidative stability at high temperature for a short period of time was determined. Fibers heated at 1000 C in air for fifteen minutes showed negligible weight loss (i.e., less than 1 percent).
    Keywords: COMPOSITE MATERIALS
    Type: SAMPE Quarterly (ISSN 0036-0821); 15; 39
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 54
    facet.materialart.
    Unknown
    Processing and flammability parameters of bismaleimide and some other thermally stable resin matrices for composites (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The effect of processing variables on the flammability and mechanical properties of state-of-the-art and advanced resin matrices for graphite composites were studied. Resin matrices which were evaluated included state-of-the-art epoxy, phenolic-novolac, phenolic-Xylok, two types of bismaleimides, benzyl, polyethersulfone, and polyphenylsulfone. Comparable flammability and thermochemical data on graphite-reinforced laminates prepared with these resin matrices are presented, and the relationship of some of these properties to the anaerobic char yield of the resins is described.
    Keywords: COMPOSITE MATERIALS
    Type: Polymer Composites (ISSN 0272-8397); 5; 143-150
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 55
    facet.materialart.
    Unknown
    Optimization of composite structures (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Structural optimization is introduced and examples which illustrate potential problems associated with optimized structures are presented. Optimized structures may have very low load carrying ability for an off design condition. They tend to have multiple modes of failure occurring simultaneously and can, therefore, be sensitive to imperfections. Because composite materials provide more design variables than do metals, they allow for more refined tailoring and more extensive optimization. As a result, optimized composite structures can be especially susceptible to these problems. Previously announced in STAR as N83-10447
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 56
    facet.materialart.
    Unknown
    Tungsten-fiber-reinforced superalloy composite, high-temperature component design considerations (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Tungsten fiber reinforced superalloy composites (TFRS) are intended for use in high temperature turbine components. Current turbine component design methodology is based on applying the experience, sometimes semiempirical, gained from over 30 years of superalloy component design. Current composite component design capability is generally limited to the methodology for low temperature resin matrix composites. Often the tendency is to treat TFRS as just another superalloy or low temperature composite. However, TFRS behavior is significantly different than that of superalloys, and the high environment adds consideration not common in low temperature composite component design. The methodology used for preliminary design of TFRS components are described. Considerations unique to TFRS are emphasized. Previously announced in STAR as N82-21259
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 57
    facet.materialart.
    Unknown
    Factors influencing the thermally-induced strength degradation of B/Al composites (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Literature data related to the thermally-induced strength degradation of B/Al composites were examined in the light of fracture theories based on reaction-controlled fiber weakening. Under the assumption of a parabolic time-dependent growth for the interfacial reaction product, a Griffith-type fracture model was found to yield simple equations whose predictions were in good agreement with data for boron fiber average strength and for B/Al axial fracture strain. The only variables in these equations were the time and temperature of the thermal exposure and an empirical factor related to fiber surface smoothness prior to composite consolidation. Such variables as fiber diameter and aluminum alloy composition were found to have little influence. The basic and practical implications of the fracture model equations are discussed. Previously announced in STAR as N82-24297
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 58
    facet.materialart.
    Unknown
    Thermal degradation of the tensile properties of undirectionally reinforced FP-Al2O3/EZ 33 magnesium composites (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The effects of isothermal and cyclic exposure on the room temperature axial and transverse tensile strength and dynamic flexural modulus of 35 volume percent and 55 volume percent FP-Al203/EZ 33 magnesium composites were studied. The composite specimens were continuously heated in a sand bath maintained at 350 C for up to 150 hours or thermally cycled between 50 and 250 C or 50 and 350 C for up to 3000 cycles. Each thermal cycle lasted for a total of six minutes with a hold time of two minutes at the maximum temperature. Results indicate no significant loss in the room temperature axial tensile strength and dynamic flexural modulus of composites thermally cycled between 50 and 250 C or of composites isothermally heated at 350 C for up to 150 hours from the strength and modulus data for the untreated, as-fabricated composites. In contrast, thermal cycling between 50 and 350 C caused considerable loss in both room temperature strength and modulus. Fractographic analysis and measurement of composite transverse strength and matrix hardness of thermally cycled and isothermally heated composites indicated matrix softening and fiber/matrix debonding due to void growth at the interface and matrix cracking as the likely causes of the strength and modulus loss behavior. Previously announced in STAR as N82-21260
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 59
    facet.materialart.
    Unknown
    The effect of a coating on the thermo-oxidative stability of Celion 6000 graphite fiber/PMR 15 polyimide composites (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The thermooxidative stability in air at 316 C of unidirectional, uncoated and aluminum-coated Celion 6000 graphite fiber/PMR 15 polyimide composites has been determined for exposure times up to nominally 2000 h. Comparison of the weight loss data and microstructural integrity reveals that a thin aluminum-foil coating can provide significant protection from oxidation. A quantitative description of the average depth of the reaction zone and the maximum length of cracks produced during oxidation as a function of time in uncoated Celion 6000/PMR 15 are given.
    Keywords: COMPOSITE MATERIALS
    Type: Composites Technology Review; 5; 109-114
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 60
    facet.materialart.
    Unknown
    Application of a gripping system to test a uniaxial graphite fiber reinforced composite /PMR 15/Celion 6000/ in tension at 316 C (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A gripping system has been developed to test uniaxial, 0 deg orientation PMR 15/Celion 6000 composites at elevated temperatures. The method involves compression of grit-blasted laminate between grit-blasted metal to give a non-slipping interface for load transfer. Tensile testing at both 316 C and room temperature indicated that deformation was elastic to fracture and that the variation in tensile properties for one laminate is the same as that for several panels. In addition, the tensile properties for uniaxial PMR 15/Celion 6000 are identical at 316 C and room temperature. For nominally 51 volume percent fiber, the elastic modulus is 119.6 GPa, the fracture stress is 1370 MPa, and the strain to fracture is about 1.15 percent. In addition, data are presented which indicate that the gripping system can be used for long term, elevated temperature testing of composite materials.
    Keywords: COMPOSITE MATERIALS
    Type: Polymer Composites; 3; Apr. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 61
    facet.materialart.
    Unknown
    The properties of novel bisimide amine cured epoxy/Celion 6000 graphite fiber composites (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The study is concerned with the further development of bisimide amine cured epoxy resins first reported by Serafini et al. (1979). Attention is given to properties of the neat resins and composites made with these novel epoxy resins and Celion 6000 graphite fibers. The use of bisimide amine hardeners to cure epoxy resins causes a significant improvement in the char-forming characteristics of the cured resin. Compared to epoxy resins cured with a conventional amine, such as 4,4'-diaminodiphenylsulfone, the bisimide cured epoxies exhibit about a twofold improvement in the aerobic char yield at 800 C. The levels of moisture absorption exhibited by the bisimide amine cured epoxies were found to be considerably lower than those exhibited by state-of-the-art epoxies (0.5 wt.% versus 2.0%).
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 62
    facet.materialart.
    Unknown
    High-temperature resins (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The basic chemistry, cure processes, properties, and applications of high temperature resins known as polyimides are surveyed. Condensation aromatic polymides are prepared by reacting aromatic diamines with aromatic dianhydrides, aromatic tetracarboxylic acids, or with dialkyl esters of aromatic tetracarboxylic acids, depending on the intended end use. The first is for coatings or films while the latter two are more suitable for polyimide matrix resins. Prepreg solutions are made by dissolving reactants in an aprotic solvent, and advances in the addition of a diamine on the double bond and radical polymerization of the double bond are noted to have yielded a final cure product with void-free characteristics. Attention is given to properties of the Skybond, Pyralin, and NR-150B polyimide prepreg materials and characteristics of aging in the NP-150 polyimides. Finally, features of the NASA-developed PMR polyimides are reviewed.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 63
    facet.materialart.
    Unknown
    On determination of fibre fraction in continuous fibre composite materials (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: It is pointed out that the fiber volume fraction is probably the most important parameter influencing the properties of fibrous composite materials. The present investigation is concerned with questions regarding the accurate determination of this parameter. It is found that an estimate of the fiber volume fraction based on determinations from several coupons taken from different regions of a laminate is not accurate. At present fiber volume fractions are not directly measured but rather are calculated from the fiber weight fraction and densities of the composite and fiber. Image analysis techniques can and should be applied to determine fiber volume fraction. However, several factors have to be considered in this connection. It is necessary to make many measurements of the local fiber area fractions, and the preparation of representative planar cross sections parallel to the fiber axis may be difficult.
    Keywords: COMPOSITE MATERIALS
    Type: Journal of Materials Science Letters; 1; June 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 64
    facet.materialart.
    Unknown
    General Electric composite ring-disk flywheel: Recent and potential developments (1984)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Recent developments of the General Electric hybrid rotor design are described. The relation of the hybrid rotor design to flywheel designs that are especially suitable for spacecraft applications is discussed. Potential performance gains that can be achieved in such rotor designs by applying latest developments in materials, processing, and design methodology are projected. Indications are that substantial improvements can be obtained.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center An Assessment of Integrated Flywheel System Technol.; p 209-231
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 65
    facet.materialart.
    Unknown
    Flexible matrix composite laminated disk/ring flywheel (1984)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: An energy storage flywheel consisting of a quasi-isotropic composite disk overwrapped by a circumferentially wound ring made of carbon fiber and a elastometric matrix is proposed. Through analysis it was demonstrated that with an elastomeric matrix to relieve the radial stresses, a laminated disk/ring flywheel can be designed to store a least 80.3 Wh/kg or about 68% more than previous disk/ring designs. at the same time the simple construction is preserved.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center An Assessment of Integrated Flywheel System Technol.; p 193-207
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 66
    facet.materialart.
    Unknown
    Generic composite flywheel designs (1984)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Fiber reinforced composites belong to a new class of materials and allow great flexibility in flywheel design. The most efficient flywheel may no longer have the classic Stodola taper and indeed, may not even be round. Some of the flywheel designs that have been developed in the past are discussed. Although choice of material, mounts and service requirements often dictate the final design choice for a particular application, the composite flywheels in this paper are classified within a geometric framework, a simple stress analysis of a circular disk is carried out.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center An Assessment of Integrated Flywheel System Technol.; p 169-179
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 67
    facet.materialart.
    Unknown
    Inorganic composites for space applications (1984)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The development of inorganic composite materials for space applications is reviewed. The composites do not contain any organic materials, and therefore, are not subject to degradation by ultraviolet radiation, volatilization of constituents, or embrittlement at low temperatures. The composites consist of glass, glass/ceramics or ceramic matrices, reinforced by refractory whiskers or fibers. Such composites have the low thermal expansion, refractories, chemical stability and other desirable properties usually associated with the matrix materials. The composites also have a degree of toughness which is extraordinary for refractory inorganic materials.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Marshall Space Flight Center 2nd Symp. on Space Industrialization; p 321-332
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 68
    facet.materialart.
    Unknown
    Studies of noise transmission in advanced composite material structures (1983)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Noise characteristics of advanced composite material fuselages were discussed from the standpoints of applicable research programs and noise transmission theory. Experimental verification of the theory was also included.
    Keywords: COMPOSITE MATERIALS
    Type: ACEE Composite Struct. Technol.; p 161-178
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 69
    facet.materialart.
    Unknown
    Development of a Heterogeneous Laminating Resin (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-17
    Description: The feasibility of toughening the common types of matrix resins such as Narmco 5208 by utilizing a heterogeneous additive was examined. Some basic concepts and principles in the toughening of matrix resins for advanced composites were studied. The following conclusions were advanced: (1) the use of damage volume as a guide for measurement of impact resistance appears to be a valid determination; (2) short beam shear is a good test to determine the effect of toughening agents on mechanical properties; (3) rubber toughening results in improved laminate impact strength, but with substantial loss in high temperature dry and wet strength; (4) in the all-epoxy systems, the polycarbonate toughening agent seemed to be the most effective, although hot-wet strength is sacrificed; ABS was not as effective; and (5) in general, the toughened all-epoxy systems showed better damage tolerance, but less hot-wet strength; toughened bismaleimides had better hot-wet strength.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Tough Composite Mater.; p 261-272
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 70
    facet.materialart.
    Unknown
    Fundamental Studies of Composite Toughness (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-17
    Description: Evaluation of drop weight impact testing of neat resin and crossplied graphite fiber reinforced composites resulted in three conclusions: (1) during impact of cross-ply laminates, resin properties appear to influence the extent and mechanism of damage propagation; (2) by itself, neat resin strain to fracture is not a controlling influence on resin or composite fracture toughness; and (3) impact failure energy of neat resin plates can give a misleading indication of the resin contribution to composite impact behavior because of differences in the magnitude of diaphragm action in the two systems. Both geometric and composite constituent materials properties influence the drop weight impact resistance of crossplied composite plates. The matrix influence appears to be reflected in the incipient damage mechanism and the propagation of damage.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Tough Composite Mater.; p 125-136
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 71
    facet.materialart.
    Unknown
    Accurate Measurement of Heat Capacity by Differential Scanning Calorimetry (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-16
    Description: Experience with high quality heat capacity measurement by differential scanning calorimetry is summarized and illustrated, pointing out three major causes of error: (1) incompatible thermal histories of the sample, reference and blank runs; (2) unstable initial and final isotherms; (3) incompatible differences between initial and final isotherm amplitudes for sample, reference and blank runs. Considering these problems, it is shown for the case of polyoxymethylene that accuracies in heat capacity of 0.1 percent may be possible.
    Keywords: COMPOSITE MATERIALS
    Type: Composite Struct. Mater.; p 127-145
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 72
    facet.materialart.
    Unknown
    Variation of Resin Properties Through the Thickness of Cured Samples (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-16
    Description: It is the purpose of this work to gain knowledge of the glassy materials used as matrices in composites and to study the homogeneity resulting from the curing process. An attempt is made to link the glass transition quantitatively with the presence of a given material. Expoxy resins containing various amounts of hardener (TGDDM/DDS system) were cured in a muffle furnace at 473 K for seven hours. The glass transition temperature, T sub g versus weight minus percent of hardener in the epoxy resin were measured. A limit was rapidly reached in T sub g at only two percent hardener. Thus, the glass transition of the fully cured epoxy-amine matrix seems not much different from the epoxide-epoxide cure. The T sub g versus cure-time for the epoxide-epoxide reaction was also studied. My 720 was cured by itself in an oil bath at 473 K for different lengths of time. The T sub g was found to increase exponentially with the cure time, and a maximum T sub g of about 450 K was reached after eleven hours. The reaction was found to be inhibited by running the sample under argon.
    Keywords: COMPOSITE MATERIALS
    Type: Composite Struct. Mater.; p 101-126
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 73
    facet.materialart.
    Unknown
    Chemical Modification of the Surface of High Modulus Carbon Fibers (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-16
    Description: The deposition of selected monomers on the surface of high modulus carbon fibers was studied. The fundamental principles which provide the basis for the design of a predictable interfacial bond between carbon fibers and polymeric matrices are described.
    Keywords: COMPOSITE MATERIALS
    Type: Composite Struct. Mater.; p 11-25
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 74
    facet.materialart.
    Unknown
    Solvent Resistant Thermoplastic Composite Matrices (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-16
    Description: The following approaches improved the solvent resistance and raised the Tg of thermoplastics: end-capping aligomers with ethynyl groups; incorporating ethynyl groups pendent along the polymer chain; and correcting polymers containing pendent ethynyl groups with a low molecular weight diethynyl compound. The following conclusions were reached: (1) film and composite properties off an ethynyl-terminated sulfone were better than those of UDEL (trademark); (2) fracture energy of an ethynyl-terminated sulfone was lower than that of UDEL (trademark); (3) residual palladium in the cured ethynyl-terminated sulfone lower the thermooxidative stability of the cured resin; (4) the properties of a phenoxy resin were altered considerably by placing pendent ethynyl groups along the polymer chain; and (5) property trade-offs must be considered when thermoplastics are modified via reactant groups.
    Keywords: COMPOSITE MATERIALS
    Type: Tough Composite Mater.; p 317-335
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 75
    facet.materialart.
    Unknown
    Newer Carbon Fibers and Their Properties (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-16
    Description: The newer carbon fibers that are either on the market or coming in the near future are described. The structure of carbon fibers is discussed along with the relationship between structure and physical property. Finally, how different types of structure are designed by control of process parameters is described.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Tough Composite Mater.; p 245-257
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 76
    facet.materialart.
    Unknown
    Experimental and Theoretical Studies of Moisture and Temperature Effects on the Mechanical Properties of Graphite/Epoxy Laminates and Neat Resins (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-16
    Description: The properties of high performnce composites which are strongly dependent on the physical properties of the matrix resin were studied. Moisture adversely affect the properties of both neat epoxy resin and epoxy matrix composites. Inhomogeneous swelling as to the moisture degradation of mechanical properties, both in the neat resin and the composite. It is postulated that the postcuring process can change structure/moisture interactions and partially alleviate its adverse effects. The study is directed toward are understanding of the physical/mechanical/thermodynamic aspects of this problem.
    Keywords: COMPOSITE MATERIALS
    Type: Composite Struct. Mater.; p 35-38
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 77
    facet.materialart.
    Unknown
    The Chemical Nature of the Fiber/resin Interface in Composite Materials (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-13
    Description: Carbon fiber/epoxy resin composites are considered. The nature of the fiber structure and the interaction that occurs at the interface between fiber and matrix are emphasized. Composite toughness can be improved by increased axial tensile and compressive strengths in the fibers. The structure of carbon fibers indicates that the fiber itself can fail transversely, and different transverse microstructures could provide better transverse strengths. The higher surface roughness of lower modulus and surface-treated carbon fibers provides better mechanical interlocking between the fiber and matrix. The chemical nature of the fiber surface was determined, and adsorption of species on this surface can be used to promote wetting and adhesion. Finally, the magnitude of the interfacial bond strength should be controlled such that a range of composites can be made with properties varying from relatively brittle and high interlaminar shear strength to tougher but lower interlaminar shear strength.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Tough Composite Mater.; p 209-225
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 78
    facet.materialart.
    Unknown
    Composites for Increased Wear Resistance: Current Achievements and Future Prospects (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-11
    Description: The various ways in which reductions in wear and/or friction can be achieved by the use of composite materials are reviewed. Reinforced plastics are emphasized and it is shown that fillers and fibers reduce wear via several mechanisms additional to their role of increasing overall mechanical strength, preferential transfer, counter face abrasion, preferential load support, or third-body formation on either the composite or its counterface. Examples are given from recent work on thin layer composites of the type widely used as dry bearings in aircraft flight control mechanisms. Developments in metal based composites and carbon-carbon composites for high energy brakes are discussed. The aspects which could benefit by increased fundamental understanding identified and the types of composites which appear to have greatest potential for further growth are indicated.
    Keywords: COMPOSITE MATERIALS
    Type: NASA Lewis Research Center Tribology in the 80's. Vol. 1; p 333-356
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 79
    facet.materialart.
    Unknown
    Mechanical Property Characterization of F-100/934 Graphite-Epoxy Composite Material (1983)
    In:  CASI
    Details
    Publication Date: 2014-09-11
    Description: Procedures for quality control, fabrication techniques, specimen machining, test methodologies, and data collection and interpretation were defined using Thornel P-100 carbon fiber combined with Fiberite's 934 epoxy resin in unidirectional tape form. Tests on the prepreg material, including gel time, resin solids content, tack, volatile content, and flow are detailed. The steps of the fabrication and machining processes are described. Both destructive and nondestructive techniques were employed to assess the properties of the cured laminates. Tests to determine tensile strength and modulus, compressive strength and modulus, interlaminar and inplane shear strength, and flexural strength and modulus are discussed. The results of these experiments are compared with data generated by other researchers.
    Keywords: COMPOSITE MATERIALS
    Type: Alabama Univ. Res. Rept.: 1983 NASA(ASEE Summer Faculty Fellowship Program; 28 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 80
    facet.materialart.
    Unknown
    Quantification of Saint-Venant's Principle for a General Prismatic Member (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-17
    Description: A semi-analytic finite element method for finding the decay rates of edge effects in anisotropic layered plates was extended to the treatment of prismatic members of an arbitrary cross section composed of any number of anisotropic elements. The displacement fields corresponding to the decay rates with positive real part were determined for a homogenous graphite/epoxy plate two units thick. The behavior of a rectangular beam is also considered.
    Keywords: COMPOSITE MATERIALS
    Type: Composite Struct. Mater.; p 67-88
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 81
    facet.materialart.
    Unknown
    Composite Property Dependence on the Fiber, Matrix, and the Interphase (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-17
    Description: The matrix properties of a difunctional epoxy, Epon 828, were varied. The Hercules type A fiber was also utilized in this investigation. The fiber and the interface between fiber and matrix were examined in terms of shear strength. Micrographs of the epoxy matrix are presented.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Tough Composite Mater.; p 227-243
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 82
    facet.materialart.
    Unknown
    The Effect of Cross-Link Density on the Toughening Mechanism of Elastomer-Modified Epoxies (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-17
    Description: A DGEBA epoxide resin (EPON 828) was elastomer modified by using three different carboxyl terminated butadiene acrylonitrile copolymers. The fracture toughness of these elastomer modified epoxies was measured in terms of the critical strain energy release rate, G sub IC. The toughening mechanism was elucidated using a tensile dilatometry technique. A plot of volume strain versus longitudinal strain often reveals the types of micromechanical deformations occurring in the uniaxial tensile specimen up to yield. Several microscopy techniques were employed to corroborate the tensile dilatometry results. The role of matrix ductility on the toughening mechanism of elastomer modified epoxies was investigated. By reducing the cross link density with various equivalent weight epoxide resins. Fracture toughness was again measured in terms of G sub IC. The characterization of the toughening mechanism was performed using a uniaxial tensile dilatometry technique and corroborated using various microscopy techniques.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Tough Composite Mater.; p 173-194
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 83
    facet.materialart.
    Unknown
    Characterization of Interlaminar Crack Growth in Composites with the Double Cantilever Beam Specimen (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-17
    Description: A project to examine the double cantilever beam specimen as a quantitative test method to assess the resistance of various composite materials to interlaminar crack growth is discussed. A second objective is to investigate the micromechanics of failure for composites with tough matrix resins from certain generic types of polymeric systems: brittle thermosets, toughened thermosets, and thermoplastics. Emphasis is given to a discussion of preliminary results in two areas: the effects of temperature and loading rate for woven composites, and the effects of matrix toughening in woven and unidirectional composites.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Research Center Tough Composite Mater.; p 3-16
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 84
    facet.materialart.
    Unknown
    Improved Beam Theory for Anisotropic Materials (1984)
    In:  CASI
    Details
    Publication Date: 2014-09-17
    Description: The behavior of beams made of anisotropic material was investigated in order to develop an appropriate model of such behavior. Closed form solutions of the problem were derived using two alternative approaches. In the first approach, the axial displacements are expanded as a series of eigenwarpings. In the second approach, the axial stresses are expanded as a series of eigenwarpings. A finite element solution was also derived using the same displacement field as in the first approach.
    Keywords: COMPOSITE MATERIALS
    Type: Composite Struct. Mater.; p 89-99
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 85
    facet.materialart.
    Unknown
    Composite components on commercial aircraft (1980)
    In:  CASI
    Details
    Publication Date: 2012-05-18
    Description: Flight experience gained with numerous composite aircraft structures is discussed. Both commercial transports and helicopters are included. Design concepts with significant mass savings and appropriate inspection and maintenance procedures are among the factors considered. Also, a major NASA/U.S. industry technology program to reduce fuel consumption of commercial transport aircraft through the use of advanced composites is described, including preliminary results. Ground and flight environmental effects on the composite materials used in the flight service programs are also discussed.
    Keywords: COMPOSITE MATERIALS
    Type: AGARD Effect of Serv. Environ. on Composite Mater.; 22 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 86
    facet.materialart.
    Unknown
    A compliant, high failure strain, fibre-reinforced glass-matrix composite (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A glass-matrix composite reinforced by discontinuous graphite fibers was produced by hot pressing glass-powder-impregnated two-dimensional arrays of in-plane randomly oriented graphite fibers held together by approximately 5-10% by weight of organic binder (generally polyester). The composite tensile behavior is characterized by a highly nonlinear stress-strain curve which differs markedly from that of either unreinforced glass or a similarly reinforced epoxy-matrix composite. By virtue of this nonlinearity, the composite is able to redistribute applied stresses to achieve a high load-carrying capacity. The fibrous microstructure and the low fiber-matrix bond provide a mechanism for achieving high fracture toughness and unusually high compliance. For a 96%-silica-matrix composite, the strength is retained to over 1000 C.
    Keywords: COMPOSITE MATERIALS
    Type: Journal of Materials Science; 17; Dec. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 87
    facet.materialart.
    Unknown
    An equation for bolt clampup relaxation in transient environments (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: (Previously announced in STAR as N82-25327)
    Keywords: COMPOSITE MATERIALS
    Type: Composites Technology Review; 4; Winter 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 88
    facet.materialart.
    Unknown
    Performance properties of graphite reinforced composites with advanced resin matrices (1980)
    In:  Other Sources
    Details
    Publication Date: 2011-08-17
    Description: The contribution of the resin matrix to the performance of the composite is studied with particular emphasis on the flammability, and thermal and mechanical properties. Of the several thermoset and thermoplastic matrices examined, the lowest fire-resistant properties of the composite have been observed with epoxy matrices. Bismaleimide A composites exhibit high fire-resistant properties, low moisture absorption, and good mechanical properties at 23 C. Bismaleimide B and phenolic retain their mechanical properties at elevated temperatures but have lower mechanical properties than the epoxy composites at ambient temperatures. Phenolic-novolac, polyethersulfone, and polyphenylsulfone composites exhibit high oxygen index and low smoke evolution.
    Keywords: COMPOSITE MATERIALS
    Type: Plastics Design and Processing; Jan. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 89
    facet.materialart.
    Unknown
    DC calibration of the strain sensitivity of a single mode optical fiber interferometer (1981)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The strain sensitivity of an optical fiber interferometer developed for the detection of pulsed ultrasonic waves in solids was calibrated. Light from the output ends of both fibers was superimposed to form an interference fringe pattern that was interrogated in the far field to give a signal proportional to the differential optical fiber path length. Strain sensitivity is determined by comparing data obtained by clamping and bending the bar at different lengths to simple cantilever beam theory. A minimum theoretical detectable strain of less than 10 to the minus 10th power is indicated.
    Keywords: COMPOSITE MATERIALS
    Type: Va. Polytech. Inst. and State Univ. Opt. Fiber Interferometer for the Study of Ultrasonic Waves in Composite Mater.; p 13-15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 90
    facet.materialart.
    Unknown
    Detection of ultrasonic waves in solids by an optical fiber interferometer (1981)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: An optical fiber interferometer was developed for the detection of ultrasonic waves in solids. The optical paths in both the signal and reference arms of the Mach-Zehnder interferometer are through the cores of similar lengths of single mode fiber mode stripped at both input and output. Instantaneous translation of the pattern is proportional to the localized strain produced by ultrasonic bulk waves generated in the disc and integrated along the fiber path. By spatially filtering the moving fringe pattern and synchronously demodulating the filtered optical intensity distirbution, a signal proportional to the integrated strain is obtained.
    Keywords: COMPOSITE MATERIALS
    Type: Va. Polytech. Inst. and State Univ. Opt. Fiber Interferometer for the Study of Ultrasonic Waves in Composite Mater.; p 7-11
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 91
    facet.materialart.
    Unknown
    Optical fiber interferometer for the study of ultrasonic waves in composite materials, discussion (1981)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Ultrasonic waves in composite materials using optical fiber waveguide as the detecting device were studied. The possibility of using embedded probes in composites for nondestructive evaluation is discussed. It is found that interferometric system is sensitive but requires accurate optical positioning at both fiber input and output.
    Keywords: COMPOSITE MATERIALS
    Type: Opt. Fiber Interferometer for the Study of Ultrasonic Waves in Composite Mater.; p 2-6
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 92
    facet.materialart.
    Unknown
    A unifying strain criterion for fracture of fibrous composite laminates (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Fibrous composite materials, such as graphite/epoxy, are light, stiff, and strong. They have great potential for reducing weight in aircraft structures. However, for a realization of this potential, designers will have to know the fracture toughness of composite laminates in order to design damage tolerant structures. In connection with the development of an economical testing procedure, there is a great need for a single fracture toughness parameter which can be used to predict the stress-intensity factor (K(Q)) for all laminates of interest to the designer. Poe and Sova (1980) have derived a general fracture toughness parameter (Qc), which is a material constant. It defines the critical level of strains in the principal load-carryng plies. The present investigation is concerned with the calculation of values for the ratio of Qc and the ultimate tensile strain of the fibers. The obtained data indicate that this ratio is reasonably constant for layups which fail largely by self-similar crack extension.
    Keywords: COMPOSITE MATERIALS
    Type: Engineering Fracture Mechanics; 17; 2, 19; 1983
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 93
    facet.materialart.
    Unknown
    Fatigue behavior of SiC reinforced Ti/6Al-4V/ at 650 C (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Axial, low cycle fatigue properties of 25 and 44 fiber vol pct SiC/Ti(6Al-4V) composites, measured at 650 C, were compared with the fatigue properties of unreinforced Ti(6Al-4V) at the same temperature. A prior study of the fatigue behavior of this composite system at room temperature indicated that the SiC fiber reinforcement did not provide the anticipated improvement of fatigue resistance of this alloy. At 650 C, the composite fatigue properties degraded somewhat from those at room temperature. However, these properties degraded more for the unreinforced matrix at 650 C with the result that the composite fatigue strength was two to three times the fatigue strength of the matrix alloy. The reasons for this reversal are discussed in terms of crack initiation at broken fibers and residual matrix stresses.
    Keywords: COMPOSITE MATERIALS
    Type: Metallurgical Transactions A - Physical Metallurgy and Materials Science; 13A; Nov. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 94
    facet.materialart.
    Unknown
    Mechanisms of fatigue damage in boron/aluminum composites (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: (Previously announced in STAR as N81-16135)
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 95
    facet.materialart.
    Unknown
    Acousto-ultrasonic measurements to monitor damage during fatigue of composites (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: An acousto-ultrasonic nondestructive testing method used to monitor damage during static and fatigue loading of thin graphite epoxy laminates is described. The experimental procedure, the signal analysis by the Fast Fourier Transform (FFT) algorithm, and the results of this analysis are discussed. Quasi-static tension tests showed a sharp decrease in the quantitative parameters when transverse cracks developed in the 90 degrees plies of a (0, 90/2/)s laminate. When internal micro-delaminations unite to form macro-delaminations, a sharp decrease in the parameters is also observed. The parameters are found to correlate well with other indications of damage development such as stiffness and degradation. The root mean square value of the moment is found to be more sensitive to damage than stiffness. Various signals and spectrums of graphite epoxy systems are presented.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 96
    facet.materialart.
    Unknown
    Ground exposure of composite materials for helicopters (1984)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: Residual strength results are presented on four composite material systems that were exposed for three years at locations on the North American Continent. The exposure locations are near the areas where Bell Model 206L Helicopters, that are in a NSA/U.S. Army sponsored flight service program, are flying in daily commercial service. The composite systems are: (1) Kevlar-49 fabric/F-185 epoxy; (2) Kevlar-49 fabric/LRF-277 epoxy; (3) Kevlar-49 fabric/CE-306 epoxy; and (4) T-300 Graphite/E-788 epoxy. All material systems exhibited good strength retention in compression and short beam shear. The Kevlar-49/LRF-277 epoxy retained 88 to 93 percent of the baseline strength while the other material systems exceeded 95 percent of baseline strength. Residual tensile strength of all materials did not show a significant reduction. The available moisture absorption data is also presented.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 97
    facet.materialart.
    Unknown
    Rubber-toughened polyfunctional epoxies - Brominated vs nonbrominated formulated for graphite composites (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: A new, commercially available, trifunctional epoxy resin (tris-(hydroxyphenyl)-methane triglycidyl ether) was modified with synthetic rubber to increase the impact resistance of epoxy/graphite composites. These composites were reinforced with commercially available satin-weave carbon cloth using two formulations of epoxies (brominated and nonbrominated) containing various amounts of carboxy-terminated butadience acrylonitrile (CTBN) rubber that had been prereacted with epoxy resin. The impact resistance was determined by measuring the interlaminar shear strength of the composites after impact. The mechanical properties, such as flexural strength and modulus at room temperature and at 93 C, were also determined. Measurements were taken of the flammability and glass transition temperature (Tg); and a thermal-gravimetric analysis was made.
    Keywords: COMPOSITE MATERIALS
    Type: SAMPE Quarterly (ISSN 0036-0821); 14; 34-38
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 98
    facet.materialart.
    Unknown
    Preliminary evaluation of large area bonding processes for repair of graphite/polyimide composites (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: It is pointed out that graphite/polyimide (Gr/PI) composites are potential candidates for primary and secondary structural components in the next generation of reusable space vehicles and supersonic aircraft which are to possess operational capabilities involving the temperature range from 400 to 600 F. In connection with the considered applications, it is necessary to establish economic and reliable methods for the repair of Gr/PI composite components which have been damaged. The present investigation is concerned with the results of research conducted to develop a bonding process applicable to the repair of large areas in Gr/PI composite structural components. Attention is given to five repair techniques for Gr/PI composite materials. The techniques were employed to fabricate large panels from which flexure and short-beam-shear specimens were machined.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 99
    facet.materialart.
    Unknown
    Polyfunctional epoxies - Different molecular weights of brominated polymeric additives as flame retardants in graphite composites (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The imparting of flame retardancy to graphite-reinforced composites without incurring mechanical property deterioration is investigated for the case of an experimental, trifunctional epoxy resin incorporating brominated polymeric additives (BPAs) of the diglycidyl type. Such mechanical properties as flexural strength and modulus, and short beam shear strength, were measured in dry and in hot/wet conditions, and the glass transition temperature, flammability, and water absorption were measured and compared with nonbromilated systems. Another comparison was made with a tetrafunctional epoxy system. The results obtained are explained in terms of differences in the polymeric backbone length of the bromine carrier polymer. BPAs are found to be a reliable bromine source for fire inhibition in carbon-reinforced composites without compromise of mechanical properties.
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 100
    facet.materialart.
    Unknown
    Forced torsional properties of PMR composites with varying nadic ester concentrations and processing histories (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: PMR polyimide resin was prepared from 4,4'-methylenedianiline, the dimethyl ester of 3,3',4,4'-benzophenonetetracarboxylic acid and the monomethyl ester of 5-norbornene-2,3-dicarboxylic acid (NE). The NE group serves as a chain terminator and crosslinking site. PMR/Celion 6000 composites were fabricated from resins having varying NE concentrations using two molding processes, and the laminates characterized in forced torsion. Glass transition temperatures (T(g)) of 360-390 C were observed in the crosslinked resins, as compared with the literature value of 284 C reported for the uncrosslinked system. T(g) did not decrease with decreasing NE concentrations over the range from 2.0 to 1.25 moles. Stoichiometry, within the range studied, showed little influence on shear properties; however, a 25% variation in matrix shear modulus with processing was observed. The G(12) values determined in forced torsion were in excellent agreement with those reported from tensile tests of + or - 45 deg laminates. A branching and possible secondary crosslink mechanism is proposed based on dynamic mechanical behavior and infrared spectra of the composites.
    Keywords: COMPOSITE MATERIALS
    Type: Polymer Composites; 3; July 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...