Rate-dependent constitutive modelling and micro-mechanical analysis of fibre-reinforced metal-matrix composites

A rate-dependent elastic-plastic constitutive model is presented which was implemented into a finite element code. As an illustration, this model is used in a micro-mechanical analysis of a fibre-reinforced metal matrix composite laminate. The matrix (a titanium alloy) is a rate-dependent material while the fibre behaves elastically. The residual stresses due to mismatch of the thermal expansion of the matrix and fibre are determined first. The three-dimensional finite element prediction of the representative volume element, which includes a debonding criterion, is found to be in good agreement with the experimental data in the linear and nonlinear regimes as well as the unloading part of the stress-strain curve. This success is attributed to the accurate representation of the matrix material properties by the rate-dependent constitutive model, and proper simulation of the fibre/matrix interface debonding. (C) 2001 Elsevier Science Ltd. All rights reserved.