  The local and overall responses of nonlinear composites are classically
investigated by the Finite Element Method. We propose an alternate method based
on Fourier series which avoids meshing and which makes direct use of
microstructure images. It is based on the exact expression of the Green
function of a linear elastic and homogeneous comparison material. First, the
case of elastic nonhomogeneous constituents is considered and an iterative
procedure is proposed to solve the Lippman-Schwinger equation which naturally
arises in the problem. Then, the method is extended to non-linear constituents
by a step-by-step integration in time. The accuracy of the method is assessed
by varying the spatial resolution of the microstructures. The flexibility of
the method allows it to serve for a large variety of microstructures. (C) 1998
Elsevier Science S.A.
