Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Graphite”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,495 records · Page 83
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Development of advanced composite rocket motor chambers using boron and graphite fibers.

Four 71-cm-diameter rocket motor chambers were designed and fabricated with advanced composite materials. The first three chambers were filament wound from boron/epoxy tape, and the fourth from graphite/epoxy tape. The first boron/epoxy chamber was 74 cm in length and was successfully hydroburst tested. The other three chambers were 57.6 cm in length for a smaller propellant load. The first shortened boron/epoxy chamber failed in proof test as a result of fabrication deficiencies. The last boron/epoxy and the graphite/epoxy chambers were successfully proof tested.

Jensen, W. M.↗
NASA NTRS1974

Graphite-polyimide composite for application to aircraft engines

A combined experimental and theoretical investigation was performed in order to (1) demonstrate that high quality angleplied laminates can be made from HT-S/PMR-RI (PMR in situ polymerization of monomeric reactants), (2) characterize the PMR-PI material and to determine the HT-S unidirectional composite properties required for composite micro and macromechanics and laminate analyses, and (3) select HT-S/PMR-PI laminate configurations to meet the general design requirements for high-tip-speed compressor blades. The results of the investigation showed that HT-S/PMR laminate configurations can be fabricated which satisfy the high-tip-speed compressor blade design requirements when operating within the temperature capability of the polymide matrix.

Hanson, M. P.↗
NASA NTRS1977

The application of thermally stable graphite composites to a space telescope structure

An optical bench and associated mirror support structural components were designed and fabricated for the HEAO-B satellite. Stringent dimensional stability criteria dictated the use of a graphite/epoxy composite as the basic structural material. Design, analysis, and fabrication aspects are discussed for the resulting structures, which pioneer the use of advanced composite materials for significant applications to orbital flight hardware.

Prunty, J.↗
NASA NTRS1978

The effect of impact damage and circular holes on the compressive strength of a graphite-epoxy laminate

Specimens were impacted by 1.27-cm-diameter aluminum spheres with speeds ranging from 52 to 101 m/s. Some specimens were impacted without any applied compressive load and then loaded to failure to determine their residual strength. Other specimens were loaded to a prescribed axial compressive strain and impacted while at that applied load. Loaded specimens that did not fail catastrophically on impact were subsequently loaded to failure to determine their residual strength. Low-velocity impact damage was found to degrade seriously the laminate static compressive strength. Low-strain compression-compression cyclic loading was found to degrade further the compressive strength of impact-damaged specimens. Specimens with circular holes having diameters up to a third of the specimen width were loaded to failure in compression. It was found that circular holes can also degrade the static compressive strength of the laminate. The effects of circular holes and impact damage on the compressive strength of the laminate are compared.

Starnes, J. H., Jr.↗
NASA NTRS1979

Assessment of state-of-the-art of in-service inspection methods for graphite epoxy composite structures on commercial transport aircraft

A survey was conducted to determine current in-service inspection practices for all types of aircraft structure and particularly for advanced composite structures. The survey consisted of written questionnaires to commercial airlines, visits to airlines, aircraft manufacturers, and government agencies, and a literature search. Details of the survey including visits, questions asked, a bibliography of reviewed literature and details of the results are reported. From the results, a current in-service inspection baseline and a preliminary inspection program for advanced composite structures is documented as appendices to the report.

Phelps, M. L.↗
NASA NTRS1978

Reproducibility of PMR-15 graphite polymide material

Investigation was made into the reproducibility of PMR polyimide/graphite prepreg reinforcement and the influence of these variabilities on processing characteristics and final composite properties. The purpose of these investigations was to establish specification controls and limits of acceptance/rejection on incoming materials. Prepreg samples were chemically analyzed and the results compared to the processing and property results of the resulting composites. The findings from these comparisons are discussed.

Hoggatt, J. T.↗
NASA NTRS1978

Structural development of the Nimbus-G/Seasat-A SMMR graphite epoxy antenna reflector

Specific details concerning the structural design, analysis, fabrication and testing of the Nimbus-G/Seasat-A Scanning Multichannel Microwave Radiometer (SMMR) are presented. Design requirements are illustrated and trade-off considerations discussed in terms of flight project requirements. It is shown that the application of graphite/epoxy material results in a lightweight, stiff, thermally stable antenna structure fully qualified for mission application.

Knoell, A.↗
NASA NTRS1979

Low-velocity impact damage in graphite-fiber reinforced epoxy laminates

An experimental investigation was conducted to identify the failure mechanisms and to understand damage propagation in compression-loaded composite structures. The tests were conducted on several laminates of different ply orientation with thickness that ranged from 0.56 to 0.75 cm. The panels were damaged by 1.27-cm-diameter aluminum spheres propelled normal to the specimen surface at velocities ranging from 30 m/s to 140 m/s. Results indicate that there is significant internal laminate damage due to low-velocity impact with no surface damage. The internal damage consists of delamination and intraply cracking. Three damage propagation modes were identified as causing specimen failure; which are delamination, axial load-lateral deformation coupling, and local shear failure.

Rhodes, M. D.↗