A predictive measure of thermomechanical coupling in elasto-viscoplastic composites

A set of thermo-elasto-viscoplastic analyses are performed to examine the e ffects of thermomechanical coupling in advanced composite materials. The co nstitutive equations for the orthotropic materials are formulated by adopti ng the unmixing-mixing scheme that is based on the micromechanics of compos ites. Then, considering restrictions from the second law of thermodynamics, the energy balance equation is derived for a class of orthotropic composit es. As numerical examples, the temperature histories of off-axis specimens subjected to quasi-static cyclic loads are evaluated under adiabatic therma l conditions. In addition, as a measure of thermomechanical coupling effect s, the irreversible viscoplastic energy developed in the specimens is caref ully monitored. As a result, the numerical study shows that heating effects may be significant depending on the viscoplastic energy accumulated in a c ycle. (C) 1999 Elsevier Science Ltd. All rights reserved.