MODELING OF THE MECHANICAL-BEHAVIOR OF 4D CARBON CARBON COMPOSITE-MATERIALS/

Mechanisms of damage and other anelastic effects in 4D carbon/carbon m aterials, comprising four reinforcement directions are modelled at the macroscopic scale for any loading at ambient temperature. The materia l was fabricated by Societe Europeenne de Propulsion (S.E.P.). The dam age theory is used to describe mechanisms of degradation. Anelastic st rains are taken into account by a plastic model with isotropic hardeni ng. The behaviour is linear-brittle in each direction of reinforcement . Only these remarkable experimentally observed properties and the mat erial microstructure are taken into account in constructing the mathem atical equations for the model..A formulation using a type of 'barycen tric coordinates' is used which allows us to define precisely, the cho ice of the damage kinematics as well as the form of the threshold func tion of anelasticity, Identification of the parameters of the model is effected by tension tests in two different directions. Simulations of the behaviour in different directions are presented and compared to e xperimental results. (C) 1998 Published by Elsevier Science Ltd. All r ights reserved.