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-tempe rature fatigue behavior of a 2.5D C/SiC multilayer composite. This mat erial is particularly interesting since it has been found that damage exists in the as-supplied material owing to the residual stresses prod uced during cooling of the composite. This section of work describes t he 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 believe d to be both thermal constraint in the composite, and the damage produ ced. The nature of the damage is such that the material is best consid ered in terms of damage occuring on the scale of the yarns, lather tha n at the smaller fiber level. (C) 1998 Published by Elsevier Science L td. All rights reserved.