No abstract

No abstract

We discuss the Hill principle's role and applications in modern micromechanics of industrial composite materials. Uniform boundary conditions, fundamental in micromechanics, are introduced as a class of Hill solutions. Mixed uniform conditions, basic for experimental testing, are analysed. Domains of application of the Hill principle are reviewed, like homogeneization of heterogeneous media, de®nition of effective properties and size effect in heterogeneous materials. Generalization of the Hill condition is realized for arbitrary materials, in particular for nonlinear inelastic composites with imperfect interfaces.

Huet's model for overall properties of specimens smaller than the representative volume is generalized on nonlinear heterogeneous elastic materials with imperfect interfaces. A modified definition for the apparent properties of heterogeneous nonlinear elastic bodies is given. The size effect relationships are established between experimental results obtained on a big specimen and on an appropriate set of smaller specimens. Hierarchies between the apparent properties of the families of specimens of different sizes are constructed.

No abstract