THERMOMECHANICAL MODELING OF IRRADIATED POLYMER COMPOSITES

Thermoelastic models are presented to evaluate constitutive response o f fiber-reinforced polymer composites subjected to irradiation and tem perature exposure. These models are based upon thermodynamic considera tions involving Helmholtz and Gibbs free energy functions, and micro-m echanical models involving Eshelby's modified approach. The proposed u nion between the energy functions and micro-mechanics provides a unify ing framework that can deal with the potential property changes in fib ers, matrix and at the fiber-matrix interface. The results for a graph ite/epoxy (T300/934) composite show a good agreement with the availabl e experimental data. The parametric study for all the principal elasti c constants involving matrix stiffening as well as matrix softening ex hibit a number of interesting results.