Material modeling of the CVI-infiltrated carbon felt I: Basic formulae, theory and numerical experiments

A material model for predicting the unknown elastic properties of the chemical vapor infiltrated carbon felts is proposed. Representative volume element of the studied material includes pyrolytic carbon matrix, randomly distributed carbon fibers (carbon felt) and pores. The homogenization procedure for this composite consists of two steps: (1) homogenization of material response without pores, i.e., homogenization of a media consisting of carbon fibers randomly distributed in an isotropic pyrolytic carbon matrix; (2) homogenization of material response with presence of pores, i.e., homogenization of a media consisting of three-dimensional pores embedded in the homogenized matrix from the previous step. The proposed model constitutes a theoretical basis for the numerical analysis of various carbon/carbon material systems that will be presented in the consecutive publications.