Material Behavior of Structural Reaction Injection Molded Composites under Thermomechanical Loading

Abstract

The damage initiation and growth in discontinuous random fiber composites is explored with a representative volume element (RVE). Atensile loading condition is used to illustrate the effect of thermal processing on damage initiation and progression. The RVE utilizes a moderate strain elasto-plastic-fracture constitutive formulation for the resin as a function of temperature. The constitutive response of the fiber is modeled as linear elastic with fracture. The constitutive formulation is implemented into a commercial finite element program, ABAQUS®, as a user material subroutine to track damage initiation and growth within the RVE. This allows the designer to develop an understanding between the resin and fiber properties (coefficient of linear thermal expansion, yield stress, fracture strain, modulus) on the mechanical performance of random fiber composites.