Thermo-Viscoelastic Constitutive Modeling of Polymer Composites Subjected to Space Irradiation

In this paper, a general linear constitutive theory of thermo-viscoelasticity for irradiated polymer composites is presented. The model is based upon thermodynamic considerations involving Helmholtz and Gibbs free energies, Clausius and Duhem inequality and micro-mechanical strain, and stress fields associated with the fiber and matrix materials. The results show that the transverse and shear creep compliances for a T300/934 graphite-epoxy composite increase as the volume fraction of matrix increases and/or the fiber-matrix interfacial debonding increases. The results, when compared with the available limited experimental data, exhibit good correlation.