Mechanical behavior and damage development during cyclic fatigue at high-temperature of a 2.5D carbon/SiC composite

This article describes part of a project to investigate the high-temperature fatigue behavior of a 2.5D C/SiC multilayer composite. This material is particularly interesting since it has been found that damage exists in the as-supplied material owing to the residual stresses produced during cooling of the composite. This section of work describes the effect of the number of cycles and the temperature on the composite, and attempts to explain the behavior during testing. The parameters controlling damage development and therefore fatigue life, are believed to be both thermal constraint in the composite, and the damage produced. The nature of the damage is such that the material is best considered in terms of damage occuring on the scale of the yarns, lather than at the smaller fiber level. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.