THERMAL-STRESSES IN ELASTODYNAMICS OF COMPOSITE-MATERIALS

The elastic composite materials are usually investigated using the mic romechanical approaches in which the micro-periodic heterogeneity of t he composite is scaled down and hence the microstructure length-scale effect on the macro-behaviour of the composite body is neglected. Howe ver, in elastodynamics of composite materials the length-scale effect can play a crucial role, and hence also thermal stresses in dynamic pr oblems 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 effe cts and is simple enough to use in calculations of thermal stresses in non-stationary processes. The considerations are carried out in the f ramework of the general non-linear elastodynamics; the non-linear theo ry for small strains as well as the linearized approximation are deriv ed as special cases. It is shown that the distribution of thermal stre sses in non-stationary problems, obtained from the proposed length-sca le model, is quite different than those obtained from the known effect ive modulus theories, where the effect of the microstructure size on t he body behaviour is neglected. Copyright (C) 1997 Elsevier Science Lt d.