A Micromechanical Damage Model for Uniaxially Reinforced Composites Weakened by Interfacial Arc Microcracks

Abstract

A micromechanical anisotropic damage model is presented for uniaxially reinforced (brittle matrix) composites weakened by an ensemble of (fiber/matrix) interfacial microcracks. All microcracks are assumed to occur along the fiber/matrix interfaces, and are modeled as arc microcracks under “cleavage 1” deformation processes. Microcrack-induced strains and overall elastic-damage compliances are analytically derived based on micromechanical bimaterial (interfacial) arc-microcrack opening displacements and mesostructural probabilistic distributions. Both “stationary ” and “evolutionary ” damage models are given. In particular, microcrack kinetic equations are constructed based on micromechanical fracture criterion and mesostructural geometry in a representative volume element. Simple and efficient computational algorithms as well as some numerical uniaxial tension tests are also presented. Finally, it is noted that not a single arbitrary (fitted) “material constant” is employed in the present work.