A numerical micro-mechanical study on damage induced by the curing process in carbon/epoxy unidirectional material

A numerical framework for the determination of the damage, the stress and the inelastic strain field induced by the curing process for unidirectional carbon/epoxy composite material is proposed. The approach integrates a network model for the estimation of the matrix shrinkage and elastic properties evolution during curing with damageable elasto-plastic constitutive equations. Simulations of the curing process and of the cured material transverse mechanical response are carried out. A sensitivity study is realised for different volume fractions and matrix tensile strengths for single fiber models. Analyses of Representative Volume Elements (RVEs) with randomly distributed fibers are also performed and a comparison with the ideally cured version of the same model is used to highlight the importance of considering the curing process effects in micromechanical models. The proposed framework, with a proper calibration of the constituents, contributes to the enhancement of the fidelity of numerical micromechanics for this class of materials.