ON OVERALL PROPERTIES OF ELASTIC HETEROGENEOUS BODIES SMALLER THAN THE REPRESENTATIVE VOLUME

The problem of experimental evaluation of effective and overall properties of heterogeneous elastic bodies smaller than the representative volume is considered in terms of apparent characteristics. The uniform boundary conditions (static, kinematic and mixed) are introduced as essential solutions of the classic Hill condition. The case of mixed boundary conditions is studied in detail. The concept of orthogonal mixed boundary conditions is elaborated and its possibilities to give the bounds on the effective and overall properties of heterogeneous building materials are analysed. Testing and FEM study results are presented for specimens of concrete, to confirm the analytically established order relationships. A phenomenological model for mixed apparent properties is proposed. It is verified by experimental and numerical data.