Simulation of interface damage in metal matrix composites under off-axis loading using cohesive zone model

Abstract

A finite element, micromechanical model is developed to predict the inelastic behavior of SiC/Ti composites subjected to off-axis loading using a three-dimensional representative volume element (RVE). The model includes the effects of manufacturing process thermal residual stresses together with interface damage and fiber coating. The cohesive zone model is used to consider the imperfect interface between the fiber and matrix. Introducing a unique failure criterion for various off-axis angles is the main novelty of this study. Apart from interface damage, plastic deformation of the matrix is also considered as another source of nonlinearity. Appropriate boundary conditions are imposed on the RVE to allow simultaneous application of a combined normal axial and transverse and axial shear loading plus thermal residual stresses. Results of the presented finite element model are compared with experimental data for stress–strain response, initiation of nonlinearity, and ultimate strength in various off-axis angles which show good agreement. Moreover, parametric studies are conducted to examine the effects of thermal residual stress and fiber volume fraction (FVF) on the mechanical response of the material.