Restrained Thermal Growth of Carbon Phenolics and Its Relevance to the STS-8A Event,
SOUTHERN RESEARCH INST BIRMINGHAM AL
Pagination or Media Count:
The across-ply response of carbon phenolics under uniform rapid heating 10-30 degsec has been measured under varying degrees of across ply restraint, particularly with the boundary condition such that across-ply strain 0. These tests have been conducted on various carbon phenolics. The response shows a rather dramatic difference from that predicted from E alpha Delta T using the measured free expansion, which has previously been attributed to an effect of load on the free expansion giving a different, lower, effective expansion. A dramatic failure mode is seen in some materials. A hypothesis is presented, which accounts for this, both the change in response and the failure, based on a micromechanical model of the material. The correlation of these tests and model with the vent seen in STS-8A is shwon and the implications of this response on carbon phenolic design are discussed.