OVERALL PROPERTIES OF NONLINEAR COMPOSITE S - A MODIFIED SECANT MODULI THEORY AND ITS LINK WITH CASTANEDA,PONTE NONLINEAR VARIATIONAL PROCEDURE

This Note deals with the overall properties of composites made up of n onlinear incompressible phases. A modified secant moduli approach is p roposed. In the classical secant moduli approach, each individual nonl inear phase is replaced by a linear phase, the shear modulus of which is computed by means of the average strain of the phase. The modified approach makes use of the quadratic average of the strain over the pha se. It is shown that the resulting scheme coincides with Ponte Castane da's nonlinear variational procedure. A simple way of calculating this energetic norm is also given, which applies to every scheme predictin g the overall properties of linear composites.