Teoria ośrodków wielofazowych

The paper provides a survey of the present state and basic trends of the theory. Following topics are dealt with: basic definitions (grain, phase, etc.), field of research (in particular, macroscopic constitutive equations), fundamental assumptions. Apart from some special methods (e.g. dilute suspensions, fluctuating inhomogeneities), main attention is focused on (1) variational approach (approximate solutions, closing inequalities for effective quantities), (2) probabilistic approach (exact solutions in the form of series according to correlation functions of increasing order). Problems are mainly tackled in the context of the theory of elasticity, other fields of applications, however, being also pointed out. Some possible future trends are discussed, especially the wave problem, theory of micro- and macro-plasticity, relations to chemical physics of manufacturing of materials.