On the thermo-elasto-statics of composites with coated randomly distributed inclusions

We consider a linearly elastic composite medium with stress free strains, w hich consists of a homogeneous matrix containing a homogeneous and statisti cally uniform random set of coated ellipsoidal inclusions having all the sa me form, orientation and mechanical properties. We are using the main hypot hesis of many micromechanical methods, according to which each inclusion is located inside a homogeneous so-called effective field, It is shown, in th e framework of the effective field hypothesis, that from a solution of the pure elastic problem (with zero stress free strains) for the composite the relations for effective thermal expansions, stored energy and average therm oelastic strains inside the components can be found. This way one obtains t he generalization of the classical formulae by Rosen and Hashin (1970, Int, J. Eng. Sci, 8, 157-173), which are exact for two-component composites. Th e proposed theory is applied to the example of composites reinforced with p articles with thin inhomogeneous (along inclusion surface! coatings. For a single coated inclusion the micromechanical approach is based on the Green function technique as well as on the interfacial Hill operators. (C) 2000 E lsevier Science Ltd. All rights reserved.