A NUMERICAL-METHOD FOR COMPUTING THE OVERALL RESPONSE OF NONLINEAR COMPOSITES WITH COMPLEX MICROSTRUCTURE

The local and overall responses of nonlinear composites are classicall y investigated by the Finite Element Method. We propose an alternate m ethod based on Fourier series which avoids meshing and which makes dir ect use of microstructure images. It is based on the exact expression of the Green function of a linear elastic and homogeneous comparison m aterial. First, the case of elastic nonhomogeneous constituents is con sidered and an iterative procedure is proposed to solve the Lippman-Sc hwinger equation which naturally arises in the problem. Then, the meth od is extended to non-linear constituents by a step-by-step integratio n in time. The accuracy of the method is assessed by varying the spati al resolution of the microstructures. The flexibility of the method al lows it to serve for a large variety of microstructures. (C) 1998 Else vier Science S.A.