A continuum damage model for thick composite materials subjected to high-rate dynamic loading

A continuum damage model (CDM) is developed to study the response of thick laminated composite materials subjected to high-rate loading processes. A vector damage description is used to represent evolving modes of damage associated with certain orientations of brittle cracking of the matrix material. A simple maximum strain criterion is used for fiber breakage with no allowance for evolution. Phenomenological damage evolution equations are postulated in terms of the current state of damage, stress above a current threshold, and material properties controlling evolution rates, resulting in implicitly rate-dependent response. Specific threshold and evolution functions are postulated and used to illustrate the predictive capability of the model for homogeneous deformation fields. A comparison of results to available experimental data for rate-dependent behavior of graphite/epoxy laminated composites shows good agreement.