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

Damage mechanisms and inelastic mechanical phenomena are modeled to the macroscopic 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 loading as a consequence of some remarkable experimentally observed properties and the material geometry. The anisotropic continuum damage theory introduced by Ladevèze is used. To identify the material constants and functions characterizing the studied 4D C/C material is a rather difficult task: fiber debonding near the edges is very important for tensile tests. To go further in the test analysis, large finite element computations have been done introducing a mesomodelling of the composite specimen, the meso-constituents being the fiber yarns, the matrix blocks and the interfaces. Finally, the identified material model has been checked on various experiments.