Accession Number : ADA305262

Title :   Preliminary Burn and Impact Tests of Hybrid Polymeric Composites.

Descriptive Note : Technical memo.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CEN TER

Personal Author(s) : Tompkins, Stephen S. ; Brewer, William D.

PDF Url : ADA305262

Report Date : JUL 1978

Pagination or Media Count : 27

Abstract : Recent studies have shown that free graphite fibers released into the environment from resin matrix composite components, as a result of fire and/or explosion, pose a potential hazard to electrical equipment. An approach to prevent the fibers from becoming airborne is to use hybrid composite materials which retain the fibers at the burn site. Test results are presented for three hybrid composites that were exposed to a simulation of an aircraft fire and explosion. The hybrid systems consisted of 16 plies of graphite-epoxy with two plies of Kevlar-, S-glass-, or boron-epoxy on each face. Two different test environments were used. In one environment, specimens were heated by convection only, and then impacted by a falling mass. In the other environment, specimens were heated by convection and by radiation, but were not impacted. The convective heat flux was about 100-120 kW/sq m in both environments and the radiative flux was about 110 kW/sq m. A large quantity of graphite fibers was airborne upon impact of graphite epoxy and the Kevlar-graphite hybrid specimens which had been subjected to the burn tests. Significantly fewer airborne graphite fibers resulted from the impact of burned boron- and glass-graphite hybrid specimens. The relative performance of each hybrid was the same in the two environments. jg

Descriptors :   *HAZARDS, *POLYMERS, *COMPOSITE MATERIALS, *IMPACT TESTS, *HYBRID SYSTEMS, *ELECTRICAL EQUIPMENT, TEST AND EVALUATION, SIMULATION, RADIATION, ENVIRONMENTS, FLUX(RATE), MASS, AIRBORNE, EXPLOSIONS, CARBON FIBERS, MATRIX MATERIALS, GLASS, COMBUSTION, FIRES, CONVECTION(HEAT TRANSFER), HEAT FLUX, BORON, AIRCRAFT FIRES, PLASTICS, GRAPHITE EPOXY COMPOSITES, FALLING BODIES.

Subject Categories : Laminates and Composite Materials
      Polymer Chemistry
      Electricity and Magnetism
      Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE