Irreversible Hygrothermomechanical Behavior and Numerical Analysis in Anisotropic Materials

Abstract

Diffusion of moisture and heat transfer through epoxy-fiber composites contribute to degradation of the material. The constitutive theory and gov erning equations incorporate Duffour and Soret effects and irreversibility due to both temperature and moisture. In addition, the possibility of two- phase diffusion, free and bound, has been taken into account. The resulting governing equations lead to the rigorous and practical method of analysis capable of determining the correct state of stress. A simple case of two- dimensional epoxy-graphite fiber composites is analyzed and the numerical results are presented. With appropriate experimental data relating the material properties, the analysis is expected to provide reliable design criteria to insure the composite structures freee from unacceptable degradation due to environmental effects including moisture and heat transfer.