Micro-mechanical failure analysis of a uni-directional fiber reinforced composite ply – Cohesive elements & a ductile fracture mechanics approach

Abstract

The failure behavior of a uni-directional (UD) carbon fiber reinforced epoxy composite ply subjected to transverse tension, compression and shear loads is studied using computational micromechanics. In order to capture the effect of the random fiber distributions on the average stress–strain behavior of a composite ply, three-dimensional Representative Volume Element (RVE) model is created. For modeling the fiber–matrix interface interactions, cohesive elements are used. In order to capture the epoxy matrix plastic deformations and the subsequent failure, a ductile fracture criterion is used in combination with the linear Drucker-Prager plasticity model. Finally, to avoid the stress concentrations at the boundaries, Periodic Boundary Conditions (PBCs) are applied to the faces, edges, and vertices of the RVE. The stress–strain and the failure behavior of the composite ply are estimated that is both qualitatively and quantitatively comparable to the experimental results.