Damage modelling of a 4D carbon/carbon composite for high temperature application

Damage mechanisms and inelastic mechanical phenomena are modeled to the mac roscopic scale for multiaxial loading. The studied material is a 4D carbon- carbon composite comprising therefore four reinforcement directions. A very simple mathematical material model has been first derived for multiaxial l oading as a consequence of some remarkable experimentally observed properti es and the material geometry. The anisotropic continuum damage theory intro duced by Ladeveze is used. To identify the material constants and functions characterizing the studied 4D C/C material is a rather difficult task: fib er debonding near the edges is very important for tensile tests. To go furt her in the test analysis, large finite element computations have been done introducing a meso-modelling of the composite specimen, the meso-constituen ts being the fiber yarns, the matrix blocks and the interfaces. Finally, th e identified material model has been checked on various experiments. (C) 20 00 Elsevier Science Ltd and Techna S.r.l. All rights reserved.