Overall Instantaneous Viscoplastic Properties of Composites

Abstract

A computer procedure was developed to analyze viscoplasticity and strain rate effects of continuous fiber reinforced composite materials. The procedure provides the overall instantaneous moduli, coefficients of thermal expansion and micromechanical stresses and strains. It was implemented with the help of a displacement formulation of the finite element method and a periodic hexagonal array microstructural model. It also can be adapted to evaluate instantaneous overall viscoplastic properties at integration points in finite element analyses of composite structures. This procedure was primarily developed to simulate the viscoplastic response of an aramid/epoxy laminate, used in the production of ARALL®laminates, in an off-axis tension test.