K. Z. Markov. Justification
of an effective field method in elasto-statics of heterogeneous solids. Journal
of the Mechanics and Physics of Solids,49, Issue 11, November 2001, Pages 2621-2634.
Abstract. A heuristic scheme for predicting the overall properties of composite
media has been proposed, explored and widely used in the last 25 years by Kanaun
and Levin. The numerous results and technical details are collected in the impressive
volume Kanaun and Levin (1993 Petrozavodsk: Izdatel'stvo Petrozavodskogo Universiteta
[in Russian]). The method is based on a certain old, natural and appealing physical
reasoning, which well explains its name effective field method (EFM). The
predictions of the methods agree very well with many experimental data. However,
no attempt has been made to justify the method, putting it into the frame of a
more rigorous theory of heterogeneous media. The present study represents such
an attempt. The main conclusion is that the EFM approach, at least in elasto-statics
when the effective moduli of the composite are looked for, is in essence a variational
procedure of Hashin-Shtrikman' type. Hence Kanaun-Levin's results provide, for
the microstructures treated by the authors, rigorous variational prescriptions.
The latter represent bounds on the effective moduli of the composites, if the
matrix is weaker or stiffer than the inclusions. Moreover, it is shown that in
the special, though quite general case of a matrix containing several kinds of
ellipsoidal inclusions, distributed with `ellipsoida'" symmetry, an obvious
generalization of the EFM method yields results that coincide with the variational
estimates, recently obtained by Ponte Castaneda and Willis (1995 J. Mech. Phys.
Solids 43, 1919-1951).
Keywords: heterogeneous solids, composite media, effective properties,
variational estimates