ON A FIRST CREEP MODEL FOR A 2D SICF-SIC COMPOSITE

For ceramic matrix composites, damage is generally of a highly complex nature, with several damage mechanisms and strong unilateral features depending on whether microcracks are open or closed. During high temp erature, inelasticity or viscoplasticity can occur. This paper deals w ith the application of a damage mechanics approach, based on continuum mechanics, to solve these problems of inelasticity and damage. The mo dels are constitutive relationships able to describe and predict the d amage state of a structure at any time, and at any point, up to the fi nal fracture. These equations include all physical information coming from the micro-, meso- and macro-scales. Using microscopic observation of the tested specimens, the possible mechanisms involved in the meas ured inelasticity are discussed, in order to establish the evolution o f the chosen viscoplastic potential. (C) 1998 Elsevier Science S.A. Al l rights reserved.