Thermal stresses in elastodynamics of composite materials

The elastic composite materials are usually investigated using the micromechanical approaches in which the micro-periodic heterogeneity of the composite is scaled down and hence the microstructure length-scale effect on the macro-behaviour of the composite body is neglected. However, in elastodynamics of composite materials the length-scale effect can play a crucial role, and hence also thermal stresses in dynamic problems have to be investigated using a certain length-scale model of a composite. The main aim of the contribution is to propose a new model of elastic periodic composites, which describes the length-scale effects and is simple enough to use in calculations of thermal stresses in non-stationary processes. The considerations are carried out in the framework of the general non-linear elastodynamics; the non-linear theory for small strains as well as the linearized approximation are derived as special cases. It is shown that the distribution of thermal stresses in non-stationary problems, obtained from the proposed length-scale model, is quite different than those obtained from the known effective modulus theories, where the effect of the microstructure size on the body behaviour is neglected. Copyright © 1997 Elsevier Science Ltd.