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
  • Data
  • Other Sources  (343)
  • COMPOSITE MATERIALS  (343)
  • 2000-2004
  • 1980-1984  (343)
  • 1925-1929
  • 1982  (155)
  • 1980  (188)
  • 1926
  • 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
    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
  • 11
    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
  • 12
    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
  • 13
    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
  • 14
    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
  • 15
    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
  • 16
    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
  • 17
    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
  • 18
    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
  • 19
    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
  • 20
    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
  • 21
    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
  • 22
    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
  • 23
    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
  • 24
    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
  • 25
    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
  • 26
    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
  • 27
    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
  • 28
    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
  • 29
    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
  • 30
    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
  • 31
    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
  • 32
    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
  • 33
    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
  • 34
    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
  • 35
    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
  • 36
    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
  • 37
    facet.materialart.
    Unknown
    Environmental effects on graphite fiber reinforced PMR-15 polyimide (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Studies were conducted to establish the effects of thermo-oxidative and hydrothermal exposure on the mechanical properties of T300 graphite fabric reinforced PMR-15 composites. The effects of hydrothermal exposure on the mechanical properties of HTS-2 continuous graphite fiber composites were also investigated. The thermo-oxidative stability characteristics of T300 fabric and T300 fabric/PMR-15 composites were determined. Flexural strengths of specimens were determined. The useful lifetime of T300 fabric/PMR-15 composites in air at 316 C was found to be about 100 hours. The useful lifetimes in air at 228 and 260 C were determined to be 500 and 1000 hours, respectively. Absorbed moisture was found to reduce the elevated temperature properties of both the T300 fabricate and HTS-2 continuous fiber composites. The moisture effect was found to be reversible. Previously announced in STAR as N81-32194
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 38
    facet.materialart.
    Unknown
    Micromechanical predictions of crack initiation, propagation and crack growth resistance in boron/aluminum composites (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: An elastoplastic, axisymmetric finite element model has been used to predict the initiation and propagation of a crack in a composite model consisting of a single broken boron fiber embedded in an annular sheath of aluminum matrix. The accuracy of the axisymmetric finite element model for crack problems has been established by solving the classical problem of a penny-shaped crack in a thick cylindrical rod under axial tension. Also, the stress intensity factors predicted by the present numerical model are compared with continuum results. A constant displacement boundary condition applied during an increment of crack growth permits a substantial amount of stable crack growth in the matrix material. The concept of Crack Growth Resistance Curves (KR-curves) has been used to determine the point of crack instability
    Keywords: COMPOSITE MATERIALS
    Type: Journal of Composite Materials; 16; Nov. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 39
    facet.materialart.
    Unknown
    Current and projected use of carbon composites in United States aircraft (1980)
    In:  CASI
    Details
    Publication Date: 2017-10-02
    Description: Carbon composite materials are finding limited use in both civil and military aircraft structures to exploit their weight saving potential for improved performance or fuel efficiency. Since these needs are growing, and a manufacturing cost savings potential is also recognized, wider use of composites in the near future may be expected. Carbon composites generally involve fiber volume fractions in excess of 60 percent in a variety of orthotropic sandwich or solid laminates. Bidirectional woven carbon cloth, common in recently designed structure, may provide higher, more uniform laminate conductivities than tape.
    Keywords: COMPOSITE MATERIALS
    Type: AGARD Electromagnetic Effects of (Carbon) Composite Mater. Upon Avionics Systems; 19 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 40
    facet.materialart.
    Unknown
    The potential for damage from the accidental release of conductive carbon fibers from aircraft composites (1980)
    In:  CASI
    Details
    Publication Date: 2017-10-02
    Description: Carbon and graphite fibers are known to be electrically conductive. The rapidly accelerating use of carbon fibers as the reinforcement in filamentary composite materials brought up the possibility of accidental release of carbon fibers from the burning of crashed commercial airliners with carbon composite parts. Such release could conceivably cause widespread damage to electrical and electronic equipment. The experimental and analytical results of a comprehensive investigation of the various elements necessary to assess the extent of such potential damage in terms of annual expected costs and maximum losses at low probabilities of occurrence are presented. A review of NASA materials research program to provide alternate or modified composite materials to overcome any electrical hazards from the use of carbon composites in aircraft structures is described.
    Keywords: COMPOSITE MATERIALS
    Type: AGARD Effect of Serv. Environ. on Composite Mater.; 21 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 41
    facet.materialart.
    Unknown
    Erosion of composite materials (1980)
    In:  CASI
    Details
    Publication Date: 2017-10-02
    Description: A model for describing the response of uncoated and coated fiber reinforced composites subjected to repeated impingements of liquid (rain) droplets is presented. The model is based on the concept that fatigue is the dominant factor in the erosion process. Algebraic expressions are provided which give the incubation period, the rate of mass loss past the incubation period, and the total mass loss of the material during rain impact. The influence of material properties on erosion damage and the protection offered by different coatings are discussed and the use of the model in the design in the design of structures and components is illustrated.
    Keywords: COMPOSITE MATERIALS
    Type: AGARD Effect of Serv. Environ. on Composite Mater.; 9 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 42
    facet.materialart.
    Unknown
    Graphite-epoxy panel compression strength reduction due to local impact (1980)
    In:  CASI
    Details
    Publication Date: 2017-10-02
    Description: The effects of low velocity impact on the compressive strength of graphite/epoxy structures are reviewed. Extensive tests were conducted on sandwich beams, laminated plates and stiffened panels. Conditions for failures were investigated by impact tests on statically loaded test specimens. Lightly loaded graphite structures (such as aircraft secondary structure) were insensitive to impact damage. In more heavily loaded structures, (such as wing panels), appreciable reductions in compressive strength occurred. The implications of the tests for structural design are discussed by comparing panel masses for designs where ultimate strains were reduced due to impact considerations with the masses of designs with higher ultimate strains. Preliminary test data are presented to show the possibility of improvements in damage to tolerance achievable by using an alternate matrix material.
    Keywords: COMPOSITE MATERIALS
    Type: AGARD Effect of Serv. Environ. on Composite Mater.; 13 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 43
    facet.materialart.
    Unknown
    Self-lubricating composite materials (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The mechanical properties of two types of self lubricating composites (polymer matrix composites and inorganic composites) are discussed. Specific emphasis is given to the applicability of these composites in the aerospace industry.
    Keywords: COMPOSITE MATERIALS
    Type: Impact for the 80's: Proc. of a Conf. on Selected Technol. for Business and Ind.; p 75-95
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 44
    facet.materialart.
    Unknown
    Dissemination, resuspension, and filtration of carbon fibers (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Carbon fiber transport was studied using mathematical models established for other pollution problems. It was demonstrated that resuspension is not a major factor contributing to the risk. Filtration and fragmentation tests revealed that fiber fragmentation shifts the fiber spectrum to shorter mean lengths in high velocity air handling systems.
    Keywords: COMPOSITE MATERIALS
    Type: Assessment of Carbon Fiber Elec. Effects; p 59-71
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 45
    facet.materialart.
    Unknown
    Effects of carbon/graphite fiber contamination on high voltage electrical insulation (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The contamination mechanics and resulting failure modes of high voltage electrical insulation due to carbon/graphite fibers were examined. The high voltage insulation vulnerability to carbon/graphite fiber induced failure was evaluated using a contamination system which consisted of a fiber chopper, dispersal chamber, a contamination chamber, and air ducts and suction blower. Tests were conducted to evaluate the effects of fiber length, weathering, and wetness on the insulator's resistance to carbon/graphite fibers. The ability of nuclear, fossil, and hydro power generating stations to maintain normal power generation when the surrounding environment is contaminated by an accidental carbon fiber release was investigated. The vulnerability assessment included only the power plant generating equipment and its associated controls, instrumentation, and auxiliary and support systems.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Res. Center Assessment of Carbon Fiber Elec. Effects; p 235-263
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 46
    facet.materialart.
    Unknown
    Release of carbon fibers from burning composites (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The results of a burn/explosion test program are presented. The amount of fiber released and the physical characteristics of the fibers are among the data reported.
    Keywords: COMPOSITE MATERIALS
    Type: Assessment of Carbon Fiber Elec. Effects; p 29-57
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 47
    facet.materialart.
    Unknown
    Approach to the assessment of the hazard (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: An overview of the carbon fiber hazard assessment is presented. The potential risk to the civil sector associated with the accidental release of carbon fibers from aircraft having composite structures was assessed along with the need for protection of civil aircraft from carbon fibers.
    Keywords: COMPOSITE MATERIALS
    Type: Assessment of Carbon Fiber Elec. Effects; p 11-27
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 48
    facet.materialart.
    Unknown
    Risk Assessment of Carbon Fiber Composite in Surface Transportation (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The vulnerability of surface transportation to airborne carbon fibers and the national risk associated with the potential use of carbon fibers in the surface transportation system were evaluated. Results show airborne carbon fibers may cause failure rates in surface transportation of less than one per year by 1995. The national risk resulting from the use of carbon fibers in the surface transportation system is discussed.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Res. Center Assessment of Carbon Fiber Elec. Effects; p 276-282
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 49
    facet.materialart.
    Unknown
    Assessment of risk due to the use of carbon fiber composites in commercial and general aviation (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The development of a national risk profile for the total annual aircraft losses due to carbon fiber composite (CFC) usage through 1993 is discussed. The profile was developed using separate simulation methods for commercial and general aviation aircraft. A Monte Carlo method which was used to assess the risk in commercial aircraft is described. The method projects the potential usage of CFC through 1993, investigates the incidence of commercial aircraft fires, models the potential release and dispersion of carbon fibers from a fire, and estimates potential economic losses due to CFC damaging electronic equipment. The simulation model for the general aviation aircraft is described. The model emphasizes variations in facility locations and release conditions, estimates distribution of CFC released in general aviation aircraft accidents, and tabulates the failure probabilities and aggregate economic losses in the accidents.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Res. Center Assessment of Carbon Fiber Elec. Effects; p 183-211
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 50
    facet.materialart.
    Unknown
    Evaluation of Equipment Vulnerability and Potential Shock Hazards (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The vulnerability of electric equipment to carbon fibers released from aircraft accidents is investigated and the parameters affecting vulnerability are discussed. The shock hazard for a hypothetical set of accidents is computed.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Res. Center Assessment of Carbon Fiber Elec. Effects; p 73-99
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 51
    facet.materialart.
    Unknown
    Perspective on the results (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The results of studies on the risk due to the use of carbon fibers in aircraft are assessed. Assumptions such as additional fire protection in the aircraft, new structural concepts, and the development of unique carbon composites are evaluated. Some findings from the national risk profile including equipment vulnerability and economic impact are discussed.
    Keywords: COMPOSITE MATERIALS
    Type: Assessment of Carbon Fiber Elec. Effects; p 213-223
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 52
    facet.materialart.
    Unknown
    Large-scale fiber release and equipment exposure experiments (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: Outdoor tests were conducted to determine the amount of fiber released in a full scale fire and trace its dissemination away from the fire. Equipment vulnerability to fire released fibers was assessed through shock tests. The greatest fiber release was observed in the shock tube where the composite was burned with a continuous agitation to total consumption. The largest average fiber length obtained outdoors was 5 mm.
    Keywords: COMPOSITE MATERIALS
    Type: Assessment of Carbon Fiber Elec. Effects; p 101-136
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 53
    facet.materialart.
    Unknown
    Surveys of facilities for the potential effects from the fallout of airborne graphite fibers (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The impact of the entry of graphite fibers into workplaces in the United States is discussed. Areas where an electrical failure could cause major problems include process and production systems, hospitals, and police/fire emergency communication systems.
    Keywords: COMPOSITE MATERIALS
    Type: NASA. Langley Res. Center Assessment of Carbon Fiber Elec. Effects; p 137-149
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 54
    facet.materialart.
    Unknown
    Heatshield material selection for advanced ballistic reentry vehicles (1980)
    In:  CASI
    Details
    Publication Date: 2016-06-07
    Description: The Performance of staple rayon fiber and AVTEX continuous rayon fiber was evaluated as precursor materials for heatshields. The materials studied were referenced to the IRC FM5055A heatshield materials flown during the past decade. Three different arc jet facilities were used to simulate portions of the reentry environment. The IRC FM5055A and the AVTEX FM5055G, both continuous rayon fiber woven materials having the phenolic impregnant filled with carbon particles were compared. The AVTEX continuous fiber, unfilled material FM5822A was also examined to a limited extent. Test results show that the AVTEX FM5055G material provided a close substitute for the IRC FM5055A material both in terms of thermal protection and roll torque performance.
    Keywords: COMPOSITE MATERIALS
    Type: The 11th Space Simulation Conf.; p 410-426
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 55
    facet.materialart.
    Unknown
    Durability of commercial aircraft and helicopter composite structures (1982)
    In:  Other Sources
    Details
    Publication Date: 2019-01-25
    Description: The development of advanced composite technology during the past decade is discussed. Both secondary and primary components fabricated with boron, graphite, and Kevlar composites are evaluated. Included are spoilers, rudders, and fairings on commercial transports, boron/epoxy reinforced wing structure on C-130 military transports, and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on commercial helicopters. The development of composite structures resulted in advances in design and manufacturing technology for secondary and primary composite structures for commercial transports. Design concepts and inspection and maintenance results for the components in service are reported. The flight, outdoor ground, and controlled laboratory environmental effects on composites were also determined. Effects of moisture absorption, ultraviolet radiation, aircraft fuels and fluids, and sustained tensile stress are included. Critical parameters affecting the long term durability of composite materials are identified.
    Keywords: COMPOSITE MATERIALS
    Type: Army Materials and Mechanics Research Center Proc. of the Critical Rev.; p 423-452
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 56
    facet.materialart.
    Unknown
    High Temperature Resin Matrix Composites for Aerospace Structures (1980)
    In:  CASI
    Details
    Publication Date: 2018-10-20
    Description: Accomplishments and the outlook for graphite-polyimide composite structures are briefly outlined. Laminates, skin-stiffened and honeycomb sandwich panels, chopped fiber moldings, and structural components were fabricated with Celion/LARC-160 and Celion/PMR-15 composite materials. Interlaminar shear and flexure strength data obtained on as-fabricated specimens and specimens that were exposed for 125 hours at 589 K indicate that epoxy sized and polyimide sized Celion graphite fibers exhibit essentially the same behavior in a PMR-15 matrix composite. Analyses and tests of graphite-polyimide compression and shear panels indicate that utilization in moderately loaded applications offers the potential for achieving a 30 to 50 percent reduction in structural mass compared to conventional aluminum panels. Data on effects of moisture, temperature, thermal cycling, and shuttle fluids on mechanical properties indicate that both LARC-160 and PMR-15 are suitable matrix materials for a graphite-polyimide aft body flap. No technical road blocks to building a graphite-polyimide composite aft body flap are identified.
    Keywords: COMPOSITE MATERIALS
    Type: Selected NASA Research in Composite Materials and Structures; 143-182
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 57
    facet.materialart.
    Unknown
    Acousto-ultrasonic characterization of fiber reinforced composites (1982)
    In:  Other Sources
    Details
    Publication Date: 2019-01-25
    Description: The advantageous aspects of acoustic emission and ultrasonic methodologies are combined in a technique which operates by introducing a repeating series of ultrasonic pulses into a material. The waves introduced simulate the spontaneous stress waves that would arise if the material were put under stress as in the case of acoustic emission measurements. These benign stress waves are detected by an acoustic emission sensor. The physical arrangement of the ultrasonic (input) transducer and acoustic emission (output) sensor is such that the resultant waveform carries an imprint of morphological factors that govern or contribute to material performance. The output waveform is quite complex, but it can be quantitized in terms of a "stress wave factor". The stress wave factor, which can be defined in a number of ways, is essentially a relative measure of the efficiency of energy dissipation in a material. If flaws or other material anomalies exist in the volume being examined, their combined effect will appear in the stress wave factor.
    Keywords: COMPOSITE MATERIALS
    Type: Army Materials and Mechanics Research Center Proc. of the Critical Rev.; p 231-242
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 58
    facet.materialart.
    Unknown
    Thermophysical properties data on graphite/polyimide composite materials (1982)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Experimental data for the thermal conductivity, thermal expansion, specific heat, and emittance of laminates of HTS/NR 150B2 and HTS/PMR 15 are presented. Measurements were made over the temperature range 116 K to 588 K. Results for the two materials were similar with some differences attributable to laminate quality. Higher expansion coefficients for the HTS/PMR 15 specimens in the resin-dominated directions indicate a higher coefficient for PMR 15 than NR 150B2. Previously announced in STAR as N80-14197
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 59
    facet.materialart.
    Unknown
    Influence of quality control variables on failure of graphite/epoxy under extreme moisture conditions (1982)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Tension tests on graphite/epoxy composites were performed to determine the influence of various quality control variables on failure strength as a function of moisture and moderate temperatures. The extremely high and low moisture contents investigated were found to have less effect upon properties than did temperature or the quality control variables of specimen flaws and prepreg batch to batch variations. In particular, specimen flaws were found to drastically reduce the predicted strength of the composite, whereas specimens from different batches of prepreg displayed differences in strength as a function of temperature and extreme moisture exposure. The findings illustrate the need for careful specimen preparation, studies of flaw sensitvity, and careful quality control in any study of composite materials. Previously announced in STAR as N80-33493
    Keywords: COMPOSITE MATERIALS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 60
    facet.materialart.
    Unknown
    Advanced manufacturing development of a composite empennage component for L-1011 aircraft (1982)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: This is the final report of technical work conducted during the fourth phase of a multiphase program having the objective of the design, development and flight evaluation of an advanced composite empennage component manufactured in a production environment at a cost competitive with those of its metal counterpart, and at a weight savings of at least 20 percent. The empennage component selected for this program is the vertical fin box of the L-1011 aircraft. The box structure extends from the fuselage production joint to the tip rib and includes front and rear spars. During Phase 4 of the program, production quality tooling was designed and manufactured to produce three sets of covers, ribs, spars, miscellaneous parts, and subassemblies to assemble three complete ACVF units. Recurring and nonrecurring cost data were compiled and documented in the updated producibility/design to cost plan. Nondestruct inspections, quality control tests, and quality acceptance tests were performed in accordance with the quality assurance plan and the structural integrity control plan. Records were maintained to provide traceability of material and parts throughout the manufacturing development phase. It was also determined that additional tooling would not be required to support the current and projected L-1011 production rate.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-165885 , NAS 1.26:165885
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 61
    facet.materialart.
    Unknown
    Full-scale testing, production and cost analysis data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2 (1982)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The development, testing, production activities, and associated costs that were required to produce five-and-one-half advanced-composite stabilizer shipsets for Boeing 737 aircraft are defined and discussed.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-166012 , NAS 1.26:166012 , D6-46038-2-VOL-2
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 62
    facet.materialart.
    Unknown
    Design, ancillary testing, analysis and fabrication data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2 (1982)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Results of tests conducted to demonstrate that composite structures save weight, possess long term durability, and can be fabricated at costs competitive with conventional metal structures are presented with focus on the use of graphite-epoxy in the design of a stabilizer for the Boeing 737 aircraft. Component definition, materials evaluation, material design properties, and structural elements tests are discussed. Fabrication development, as well as structural repair and inspection are also examined.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-166011 , NAS 1.26:166011 , D6-46037-2-VOL-2
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 63
    facet.materialart.
    Unknown
    Creep rupture behavior of unidirectional advanced composites (1980)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: A 'material modeling' methodology for predicting the creep rupture behavior of unidirectional advanced composites is proposed. In this approach the parameters (obtained from short-term tests) required to make the predictions are the three principal creep compliance master curves and their corresponding quasi-static strengths tested at room temperature (22 C). Using these parameters in conjunction with a failure criterion, creep rupture envelopes can be generated for any combination of in-plane loading conditions and ambient temperature. The analysis was validated experimentally for one composite system, the T300/934 graphite-epoxy system. This was done by performing short-term creep tests (to generate the principal creep compliance master curves with the time-temperature superposition principle) and relatively long-term creep rupture tensile tests of off-axis specimens at 180 C. Good to reasonable agreement between experimental and analytical results is observed.
    Keywords: COMPOSITE MATERIALS
    Type: Materials Science and Engineering; 45; Oct. 198
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 64
    facet.materialart.
    Unknown
    SPAR VI Technical Report for Experiment 76-22: Directional Solidification of Magnetic Composites (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Samples of eutectic Bi/MnBi were directionally solidified during a low-g interval aboard the SPAR 6 flight and in a l-g environment under identical furnace velocity and thermal conditions. The Bi/MnBi eutectic is characterized by a regular rod eutectic whose morphology may be sensitive to thermo-solutal convection and by its components, MnBi, which is ferromagnetic. Morphological analyses on samples show statistically smaller interrod spacings and rod diameters with respect to samples grown under identical solidification furnace conditions in l-g. An adjustment between the interrod spacing, growth velocity, and total undercooling at the solidification interface is proposed. Morphological analyses on samples grown in l-g indicate little difference between results for different growth orientations with respect to the gravity vector. The magnetic properties are significantly affected, however, by the presence of a nonequilibrium magnetic phase and the nonequilibrium phase transforms to the equilibrium ferromagnetic phase during isothermal heat treatment.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-161671 , RE-602
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 65
    facet.materialart.
    Unknown
    Microwave limb sounder, graphite epoxy support structure (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The manufacturing and processing procedures which were used to fabricate a precision graphite/epoxy support structure for a spherical microwave reflecting surface are described. The structure was made fromm GY-70/930 ultra high modulus graphite prepreg, laminated to achieve an isotropic in plane thermal expansion of less than + or - 0.1 PPM/F. The structure was hand assembled to match the interface of the reflective surface, which was an array of 18 flexure supported, aluminum, spherically contoured tiles. Structural adhesives were used in the final assembly to bond the elements into their final configuration. A eutectic metal coating was applied to the composite surface to reduce dimensional instabilities arising from changes in the composite epoxy moisture content due to environmental effects. Basic materials properties data are reported and the results of a finite element structural analysis are referenced.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-163929 , COI-1180-0104 , JPL-9950484
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 66
    facet.materialart.
    Unknown
    Method for alleviating thermal stress damage in laminates (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A method is provided for alleviating the stress damage in metallic matrix composites, such as laminated sheet or foil composites. Discontinuities are positively introduced into the interface between the layers so as to reduce the thermal stress produced by unequal expansion of the materials making up the composite. Although a number of discrete elements could be used to form one of the layers and thus carry out this purpose, the discontinuities are preferably produced by simply drilling holes in the metallic matrix layer or by forming grooves in a grid pattern in this layer.
    Keywords: COMPOSITE MATERIALS
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 67
    facet.materialart.
    Unknown
    Graphite fiber surface treatment to improve char retention and increase fiber clumping (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Composites containing carbon and graphite fibers can release fibers into the atmosphere during a fire. This release can potentially cause failure in some types of electrical equipment. Reduced fiber dispersion during and after combustion will reduce risks. Epoxidized char forming systems were synthesized which will react with commercially available surface treated carbon fiber. Fibers modified with these char formers retained adhesion in a specific epoxy matrix resin. Small scale combustion testing indicates that using these char former modified fibers in laminates will help to reduce the dispersement of fibers resulting from exposure to fire without sacrificing resin to fiber adhesion.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-159357
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 68
    facet.materialart.
    Unknown
    Contact law and impact responses of laminated composites (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Static identation tests were performed to determine the law of contact between a steel ball and glass/epoxy and graphite/epoxy laminated composites. For both composites the power law with an index of 1.5 was found to be adequate for the loading curve. Substantial permanent deformations were noted after the unloading. A high order beam finite element was used to compute the dynamic contact force and response of the laminated composite subjected to the impact of an elastic sphere. This program can be used with either the classical Hertzian contact law or the measured contact law. A simple method is introduced for estimating the contact force and contact duration in elastic impacts.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-159884 , CML-80-1
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 69
    facet.materialart.
    Unknown
    Experimental investigation of graphite/polyimide sandwich panels in edgewise compression (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The local and general buckling behavior of graphite/polyimide sandwich panels simply supported along all four edges and loaded in uniaxial edgewise compression was investigated. Material properties of adhesive and facings were determined from flatwise tension and sandwich beam flexure tests. Tensile and compressive material properties of the facings were determined at 116, R.T., and 589 K (-250, R.T., and 600 F) using the sandwich beam flexure test method. Results indicate that Gr/PI is a usable structural material for short term use at temperatures as high as 589 K (600 F). Buckling specimens were 30.5 X 33.0 cm (12 x 13 in.), had quasi-isotropic symmetric facings and a glass/polyimide honeycomb core. Core thicknesses varied and three panels of each thickness were tested in edgewise compression at room temperature to investigate failure modes and corresponding buckling formulas. Specimens 0.635 cm (0.25 in.) thick failed by overall buckling at loads close to the analytically predicted buckling load; all other panels failed by face wrinkling. Results of the winkling tests indicate that several buckling formulas were unconservative and therefore not suitable for design purposes; recommended wrinkling equations are presented.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-81895
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 70
    facet.materialart.
    Unknown
    Laminates and reinforced metals (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A selective review is presented of the state of the art of metallic laminates and fiber reinforced metals called metallic matrix laminates (MMLs). Design and analysis procedures that are used for, and typical structural components that have been made from MMLs are emphasized. Selected MMLs, constituent materials, typical material properties and fabrication procedures are briefly described, including hybrids and superhybrids. Advantages, disadvantages, and special considerations required during design, analysis, and fabrication of MMLs are examined. Tabular and graphical data are included to illustrate key aspects of MMLs. Appropriate references are cited to provide a selective bibliography of a rapidly expanding and very promising research and development field.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-81591 , E-570
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 71
    facet.materialart.
    Unknown
    Fiber release from impacted graphite reinforced epoxy composites (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Carbon fibers released from composites by aircraft fires and crashes can cause electrical shorts and consequent equipment damage. This report investigates less vigorous release mechanisms than that previously simulated by explosive burn/blast tests. When AS/3501-6 composites are impacted by various head and weight configurations of a pendulum impactor, less than 0.2 percent by weight of the original sample is released as single fibers. Other fiber release mechanisms studied were air blasts, constant airflow, torsion, flexural, and vibration of composite samples. The full significance of the low single fiber release rates found here is to be evaluated by NASA in their aircraft vulnerability studies.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-163684 , AD-A090112 , NSWC/TR-80-216
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 72
    facet.materialart.
    Unknown
    Fracture toughness of boron/aluminum laminates with various proportions of 0 deg and plus or minus 45 deg (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The fracture toughness of boron/aluminum laminates was measured on sheet specimens containing central slits of various lengths that represent cracks. The specimens were loaded axially and had various widths. The sheets were made with five laminate orientation. Fracture toughness was calculated for each laminate orientation. Specimens began failing at the ends of the slit with what appeared to be tensile failures of fibers in the primary load carrying laminae. A general fracture toughness parameter independent of laminate orientation was derived on the basis of fiber failure in the principal load carrying laminae. The value of this parameter was proportional to the critical value of the stress intensity factor. The constant of proportionality depended only on the elastic constants of the laminates.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TP-1707 , L-13880
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 73
    facet.materialart.
    Unknown
    A probabilistic analysis of electrical equipment vulnerability to carbon fibers (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The statistical problems of airborne carbon fibers falling onto electrical circuits were idealized and analyzed. The probability of making contact between randomly oriented finite length fibers and sets of parallel conductors with various spacings and lengths was developed theoretically. The probability of multiple fibers joining to bridge a single gap between conductors, or forming continuous networks is included. From these theoretical considerations, practical statistical analyses to assess the likelihood of causing electrical malfunctions was produced. The statistics obtained were confirmed by comparison with results of controlled experiments.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-80217
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 74
    facet.materialart.
    Unknown
    Three dimensional inelastic finite element analysis of laminated composites (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Formulations of the inelastic response of laminated composites to thermal and mechanical loading are used as the basis for development of the computer NALCOM (Nonlinear Analysis of Laminated Composites) computer program which uses a fully three dimensional isoparametric finite element with 24 nodes and 72 degrees of freedom. An incremental solution is performed with nonlinearities introduced as pseudoloads computed for initial strains. Equilibrium iteration may be performed at every step. Elastic and elastic-plastic response of boron/epoxy and graphite/epoxy graphite/epoxy and problems of curing 0/90 sub s Gr/Ep laminates with and without circular holes are analyzed. Mechanical loading of + or - 45sub s Gr/Ep laminates is modeled and symmetry conditions which exist in angle-ply laminates are discussed. Results are compared to experiments and other analytical models when possible. All models are seen to agree reasonably well with experimetnal results for off-axis tensile coupons. The laminate analyses show the three dimensional effects which are present near holes and free corners.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-163712 , VPI-E-80-28
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 75
    facet.materialart.
    Unknown
    Completion of evaluation of manufacturing processes for B/Al composites containing 0.2mm diameter boron fibers (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Four fabricators produced a total of 54 B/1100 Al, B/6061 Al, and B/2024 Al panels for evaluation. The 8 ply unidirectional, 45 to 50 volume percent, panels were made using 0.20 mm diameter boron fibers which were obtained from a single supplier. Hot press consolidation was carried out in vacuum except for one set of dry woven tape panels which were hot pressed in air. A single testing contractor conducted nondestructive inspection, metallography, fractography and mechanical property tests. The mechanical property tests included 21 and 260 C tensile tests and 21 C shear tests. Panel quality, as measured by nondestructive evaluation, was generally good as were the 21 C tensile properties. The panels hot pressed in air delaminated in the shear tests. Shear strength values were lower in these panels. But tensile strengths were not affected by the delaminations because of the relation between the tensile loading direction and the delaminations. Composite tensile strength was found to be proportional to the volume percent boron and the aluminum matrix rather than to the tape used or fabrication technique. Suitability of these composites for 260 C service was confirmed by tensile tests.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-81573 , E-543
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 76
    facet.materialart.
    Unknown
    Silicone modified resins for graphite fiber laminates (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Six silicone modified resins were selected for evaluation in unidirectional filament wound graphite laminates. Neat samples of these resins had 1,000 C char residues of 6-63%. The highest flexural values measured for the laminates were a strength of 1,220 MPa and a modulus of 105 GPa. The highest interlaminar shear strength was 72 MPa.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-165451 , REPT-80-9B7-SIMOD-R2
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 77
    facet.materialart.
    Unknown
    Spatial distribution of volatile compounds in graphite composites (1980)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The distribution of water and other volatile compounds such as acetone and phenol was measured as a function of depth in four graphite resin matrix composites. Precision abrasion mass spectrometry was used to qualitatively and quantitatively characterize the indigenous volatile compounds in the as received condition and after drying in an environmentally controlled oven. The total amount of water in the composites varied from 0.12 wt% to 1.1 wt% and the times required to dry the samples ranged from less than 96 h to much greater than 555 h.
    Keywords: COMPOSITE MATERIALS
    Type: American Chemical Society The 16th Natl. Symp. on Polymers in the Serv. of Man; p 141-147
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 78
    facet.materialart.
    Unknown
    Fire test methodology for aerospace materials. 1: Thermal and smoke toxicological assessments of graphite/bismaleimide and graphite/epoxy systems (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Both materials possess a high degree of thermal stability, with total heat release values being essentially identical under piloted ignition conditions over a range of 5 to 10 W/sq cm incident heat flux. The graphite/epoxy material had a tendency to auto-ignite at a lower heat flux (about 7 W/sq cm) and produced about 23 percent higher peak heat release rates, approximately 42 percent more carbon monoxide and considerably more smoke than the graphite/bismaleimide under conditions of piloted ignition. Toxicological potencies of smoke produced from the two composites were equivalent for 30 minute exposures. Potencies were also comparable to many common materials, such as wood. There was no evidence for the formation of an "unusual toxicant" nor for any short term post-exposure toxicological effects.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-166196 , SWRI-03-5565-001
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 79
    facet.materialart.
    Unknown
    Large-scale carbon fiber tests (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A realistic release of carbon fibers was established by burning a minimum of 45 kg of carbon fiber composite aircraft structural components in each of five large scale, outdoor aviation jet fuel fire tests. This release was quantified by several independent assessments with various instruments developed specifically for these tests. The most likely values for the mass of single carbon fibers released ranged from 0.2 percent of the initial mass of carbon fiber for the source tests (zero wind velocity) to a maximum of 0.6 percent of the initial carbon fiber mass for dissemination tests (5 to 6 m/s wind velocity). Mean fiber lengths for fibers greater than 1 mm in length ranged from 2.5 to 3.5 mm. Mean diameters ranged from 3.6 to 5.3 micrometers which was indicative of significant oxidation. Footprints of downwind dissemination of the fire released fibers were measured to 19.1 km from the fire.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-80218
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 80
    facet.materialart.
    Unknown
    Study and modification of the reactivity of carbon fibers (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The reactivity to air of polyactylonitrile-based carbon fiber cloth was enhanced by the addition of metals to the cloth. The cloth was oxidized in 54 wt% nitric acid in order to increase the surface area of the cloth and to add carbonyl groups to the surface. Metal addition was then achieved by soaking the cloth in metal acetate solution to effect exchange between the metal carbon and hydrogen on the carbonyl groups. The addition of potassium, sodium, calcium and barium enhanced fiber cloth reactivity to air at 573 K. Extended studies using potassium addition showed that success in enhancing fiber cloth reactivity to air depends on: extent of cloth oxidation in nitric acid, time of exchange in potassium acetate solution and the thoroughness of removing metal acetate from the fiber pore structure following exchange. Cloth reactivity increases essentially linearly with increase in potassium addition via exchange.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-164962 , FR-1 , JPL-9550-462
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 81
    facet.materialart.
    Unknown
    Risk to the public from carbon fibers released in civil aircraft accidents (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Because carbon fibers are strong, stiff, and lightweight, they are attractive for use in composite structures. Because they also have high electrical conductivity, free carbon fibers settling on electrical conductors can cause malfunctions. If released from the composite by burning, the fibers may become a hazard to exposed electrical and electronic equipment. As part of a Federal study of the potential hazard associated with the use of carbon fibers, NASA assessed the public risk associated with crash fire accidents of civil aircraft. The NASA study projected a dramatic increase in the use of carbon composites in civil aircraft and developed technical data to support the risk assessment. Personal injury was found to be extremely unlikely. In 1993, the year chosen as a focus for the study, the expected annual cost of damage caused by released carbon fibers is only $1000. Even the worst-case carbon fiber incident simulated (costing $178,000 once in 34,000 years) was relatively low-cost compared with the usual air transport accident cost. On the basis of these observations, the NASA study concluded that exploitation of composites should continue, that additional protection of avionics is unnecessary, and that development of alternate materials specifically to overcome this problem is not justified.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-SP-448
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 82
    facet.materialart.
    Unknown
    Review and developments of dissemination models for airborne carbon fibers (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Dissemination prediction models were reviewed to determine their applicability to a risk assessment for airborne carbon fibers. The review showed that the Gaussian prediction models using partial reflection at the ground agreed very closely with a more elaborate diffusion analysis developed for the study. For distances beyond 10,000 m the Gaussian models predicted a slower fall-off in exposure levels than the diffusion models. This resulting level of conservatism was preferred for the carbon fiber risk assessment. The results also showed that the perfect vertical-mixing models developed herein agreed very closely with the diffusion analysis for all except the most stable atmospheric conditions.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-80216
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 83
    facet.materialart.
    Unknown
    Influence of quality control variables on failure of graphite/epoxy under extreme moisture conditions (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Tension tests on graphite/epoxy composites were performed to determine the influence of various quality control variables on failure strength as a function of moisture and moderate temperatures. The extremely high and low moisture contents investigated were found to have less effect upon properties than did temperature or the quality control variables of specimen flaws and prepreg batch to batch variations. In particular, specimen flaws were found to drastically reduce the predicted strength of the composite, whereas specimens from different batches of prepreg displayed differences in strength as a function of temperature and extreme moisture exposure. The findings illustrate the need for careful specimen preparation, studies of flaw sensitivity, and careful quality control in any study of composite materials.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-81246 , A-8382
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 84
    facet.materialart.
    Unknown
    Experimental and analytical studies for the NASA carbon fiber risk assessment (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Various experimental and analytical studies performed for the NASA carbon fiber risk assessment program are described with emphasis on carbon fiber characteristics, sensitivity of electrical equipment and components to shorting or arcing by carbon fibers, attenuation effect of carbon fibers on aircraft landing aids, impact of carbon fibers on industrial facilities. A simple method of estimating damage from airborne carbon fibers is presented.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-159214
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 85
    facet.materialart.
    Unknown
    Carbon/graphite fiber risk analysis and assessment study: Assessment of risk to the Lockheed Model L-1011 commercial transport aircraft (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The risk associated with the accidental release of carbon/graphite fibers (CF) from fires on commercial transport aircraft incorporating composite materials was assessed. Data are developed to evaluate the potential for CF damage to electrical and electronic equipment, assess the cost risk, and evaluate the hazard to continued operation. The subjects covered include identification of susceptible equipments, determination of infiltration transfer functions, analysis of airport operations, calculation of probabilities of equipment failures, assessment of the cost risk, and evaluation of the hazard to continued operation. The results show the risks associated with CF contamination are negligible through 1993.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-159201 , LR-29338
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 86
    facet.materialart.
    Unknown
    Effect of processing parameters on reaction bonding of silicon nitride (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Reaction bonded silicon nitride was developed. The relationship between the various processing parameters and the resulting microstructures was to design and synthesize reaction bonded materials with improved room temperature mechanical properties.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-165230
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 87
    facet.materialart.
    Unknown
    Stability optimization of laminated composite plates (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The optimum design of plates with orthotropic layers under axial compression and shear is discussed. The plates considered are the laminates of N orthotropic layers whose principal material axes coincide with the plate axes. Each layer is assumed to have the same thickness and an equal number of fibers in the direction of + alpha sub i and - alpha sub i with respect to the plate axis. The fiber directions which give the highest axial buckling stress and the highest shear buckling stress are found by utilizing a mathematical optimization technique for various aspect ratios of the plates. Inhomogeneity in the direction of the plate thickness (stacking sequence) is taken into account in this analysis.
    Keywords: COMPOSITE MATERIALS
    Type: ISAS-579-VOL-45-NO-4 , NASA-CR-163456
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 88
    facet.materialart.
    Unknown
    Coatings for graphite fibers (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Graphite fibers released from composites during burning or an explosion caused shorting of electrical and electronic equipment. Silicon carbide, silica, silicon nitride and boron nitride were coated on graphite fibers to increase their electrical resistances. Resistances as high as three orders of magnitude higher than uncoated fiber were attained without any significant degradation of the substrate fiber. An organo-silicone approach to produce coated fibers with high electrical resistance was also used. Celion 6000 graphite fibers were coated with an organo-silicone compound, followed by hydrolysis and pyrolysis of the coating to a silica-like material. The shear and flexural strengths of composites made from high electrically resistant fibers were considerably lower than the shear and flexural strengths of composites made from the lower electrically resistant fibers. The lower shear strengths of the composites indicated that the coatings on these fibers were weaker than the coating on the fibers which were pyrolyzed at higher temperature.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-159304 , R80-914212-22
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 89
    facet.materialart.
    Unknown
    A carbon fiber exposure test facility and instrumentation (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A facility to evaluate the risk associated with the exposure of electrical and electronic equipment to airborne carbon/graphite fibers was constructed. A wide variety of instrumentation is described and illustrated.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-80220
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 90
    facet.materialart.
    Unknown
    The vulnerability of electric equipment to carbon fibers of mixed lengths: An analysis (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: The susceptibility of a stereo amplifier to damage from a spectrum of lengths of graphite fibers was calculated. A simple analysis was developed by which such calculations can be based on test results with fibers of uniform lengths. A statistical analysis was applied for the conversation of data for various logical failure criteria.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-80215
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 91
    facet.materialart.
    Unknown
    Outgassing data for spacecraft materials (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A system for determining the mass loss in vacuum and for collecting the outgassed compounds was developed. Outgassing data, derived from tests at 398 K (125 degrees C) for 24 hours in vacuum as per ASTM E 59577, are compiled for numerous materials for spacecraft use. The data presented are the total mass loss (TML) and the collected volatile condensable materials (CVCM). The various materials are compiled by likely usage and alphabetically.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-RP-1061 , REPT-80-F-7000
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 92
    facet.materialart.
    Unknown
    Potential release of fibers from burning carbon composites (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A comprehensive experimental carbon fiber source program was conducted to determine the potential for the release of conductive carbon fibers from burning composites. Laboratory testing determined the relative importance of several parameters influencing the amounts of single fibers released, while large-scale aviation jet fuel pool fires provided realistic confirmation of the laboratory data. The dimensions and size distributions of fire-released carbon fibers were determined, not only for those of concern in an electrical sense, but also for those of potential interest from a health and environmental standpoint. Fire plume and chemistry studies were performed with large pool fires to provide an experimental input into an analytical modelling of simulated aircraft crash fires. A study of a high voltage spark system resulted in a promising device for the detection, counting, and sizing of electrically conductive fibers, for both active and passive modes of operation.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-80214
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 93
    facet.materialart.
    Unknown
    Moisture determination in composite materials using positron lifetime techniques (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A technique was developed which has the potential of providing information on the moisture content as well as its depth in the specimen. This technique was based on the dependence of positron lifetime on the moisture content of the composite specimen. The positron lifetime technique of moisture determination and the results of the initial studies are described.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TP-1681 , L-13651
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 94
    facet.materialart.
    Unknown
    Evaluation of micron size carbon fibers released from burning graphite composites (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Quantitative estimates were developed of micron carbon fibers released during the burning of graphite composites. Evidence was found of fibrillated particles which were the predominant source of the micron fiber data obtained from large pool fire tests. The fibrillation phenomena were attributed to fiber oxidation effects caused by the fire environment. Analysis of propane burn test records indicated that wind sources can cause considerable carbon fiber oxidation. Criteria estimates were determined for the number of micron carbon fibers released during an aircraft accident. An extreme case analysis indicated that the upper limit of the micron carbon fiber concentration level was only about half the permissible asbestos ceiling concentration level.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-159217 , TRW-80-06
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 95
    facet.materialart.
    Unknown
    Composite materials research and education program: The NASA-Virginia Tech composites program (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Major areas of study include: (1) edge effects in finite width laminated composites subjected to mechanical, thermal and hygroscopic loading with temperature dependent material properties and the influence of edge effects on the initiation of failure; (2) shear and compression testing of composite materials at room and elevated temperatures; (3) optical techniques for precise measurement of coefficients of thermal expansion of composites; (4) models for the nonlinear behavior of composites including material nonlinearity and damage accumulation and verification of the models under biaxial loading; (5) compressive failure of graphite/epoxy plates with circular holes and the buckling of composite cylinders under combined compression and torsion; (6) nonlinear mechanical properties of borsic/aluminum, graphite/polyimide and boron/aluminum; (7) the strength characteristics of spliced sandwich panels; and (8) curved graphite/epoxy panels subjected to internal pressure.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-162719
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 96
    facet.materialart.
    Unknown
    Thermal expansion of composites using Moire interferometry (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An experimental technique for precise measurement of the thermal response of fiber-reinforced composite materials uses moire interferometry with fringe multiplication which yield a sensitivity of 833 nm (32.8 mu in.) per fringe. Results from the technique are compared with those obtained from electrical resistance strain gages, and also those predicted from classical lamination theory. Temperature dependent coefficients of thermal expansion for composite materials subjected to thermal cycling in the temperature range of 297 K (75 F) to 422 K (300 F) were determined for four laminate configurations (0, 90, 0/ + or - 45/90 sub s and 0/90/ + or - 45 sub s) of T300/5208 graphite epoxy, and ranged from -0.107 mu epsilon K/1 (-0.059 mu epsilon deg F/-) for the 0 laminate to 32.18 mu epsilon K/1 (17.88 mu epsilon F/1) for the 90 laminate. Moisture was found to greatly influence the thermal response of a quasi-isotropic laminate, resulting in hysteresis and residual compressive strain as the moisture content was reduced. Comparisons between moire and strain gage measurements were inconclusive with both techniques giving consistent but systematically different results. Differences of as much as 29% were observed.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-80788 , VPI-E-80-19 , IR-20
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 97
    facet.materialart.
    Unknown
    Polar symmetry in three-dimensional analysis of laminates with angle plies (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: An improved procedure for the three dimensional finite element analysis of an angle ply laminate with a circular hole is discussed. The procecure exploits polar symmetry and is the basis for a new finite element computer code. For the broad class of laminates that contain angle plies, this code requires only one half as much computing capacity as conventional codes.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-81852
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 98
    facet.materialart.
    Unknown
    Carbon fiber counting (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A method was developed for characterizing the number and lengths of carbon fibers accidentally released by the burning of composite portions of civil aircraft structure in a jet fuel fire after an accident. Representative samplings of carbon fibers collected on transparent sticky film were counted from photographic enlargements with a computer aided technique which also provided fiber lengths.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-80117
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 99
    facet.materialart.
    Unknown
    Development of a fire test facility for graphite fiber-reinforced composites (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: A number of modifications were added to the Model 25 facility to make it specifically applicable for composite material screening tests. Most significant was the development of hardware for trapping fibers released during test and isolating them for quantitative measurement. Capability was added for increasing test section velocities and increasing the range of air/fuel ratios available from very rich to very lean. A provision was added for agitation of the test specimen and the combustion gases by a pulsating gas supply. A variety of specimen configurations was evaluated by an extensive series of tests on a graphite-epoxy reference composite which is representative of material currently used in advanced aircraft. A standard test technique and specimen configuration were established which was satisfactory for the reference composite. A test program was then performed on several alternate composite materials to verify the validity of the test method for relative evaluation of a variety of composite materials.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-CR-159193
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 100
    facet.materialart.
    Unknown
    Effects of method of loading and specimen configuration on compressive strength of graphite/epoxy composite materials (1980)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Three test schemes were examined for testing graphite/epoxy (Narmco T300/5208) composite material specimens to failure in compression, including an adaptation of the IITRI "wedge grip" compression fixture, a face-supported-compression fixture, and an end-loaded-coupon fixture. The effects of specimen size, specimen support arrangement and method of load transfer on compressive behavior of graphite/epoxy were investigated. Compressive stress strain, strength, and modulus data obtained with the three fixtures are presented with evaluations showing the effects of all test parameters, including fiber orientation. The IITRI fixture has the potential to provide good stress/strain data to failure for unidirectional and quasi-isotropic laminates. The face supported fixture was found to be the most desirable for testing + or - 45 s laminates.
    Keywords: COMPOSITE MATERIALS
    Type: NASA-TM-81796
    Format: application/pdf
    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...