FINITE STRAIN MICROMECHANICAL MODELING OF THERMOVISCOELASTIC MATRIX COMPOSITES

A finite strain micromechanical analysis is generalized for the modeling of thermoviscoelastic matrix composites. The thermoviscoelastic matrix of the composite is represented by a finite thermoviscoelasticity theory that permits (in contrast to finite linear thermoviscoelasticity theories) large deviations away from thermodynamic equilibrium. As a result, it is possible to subject the composite to large thermomechanical loadings. In addition, the possibility of evolving damage in the matrix is included. The derived micromechanical model is applied to investigate the behavior of a thermoviscoelastic rubber-like matrix reinforced by steel fibers in various circumstances. By subjecting the composite to mechanical loading under isentropic conditions, the micromechanical model is employed for the prediction of thermoelastic inversion point at which the Gough-Joule phenomenon at the rubber-like phase occurs. Results are given that show the effect of damage, elevated temperature and viscoelasticity of the matrix on the global response of the composite including its creep and relaxation behavior.