Ladder models for the constitutive behavior of heterogeneous materials with damage (Q675419)

We describe a procedure in which simplified constitutive models for random composites can be defined from the mechanical behavior of each component. The derivation of the overall properties does not rely on a linear elastic analysis of the microstructure but, as it is done in a more refined way in finite element studies, the parameters governing the interaction between the different phases are obtained from a purely topological description of the material. In the second part of this work, attention is devoted to the constitutive behavior of concrete, which is a binary composite with random distribution of phases. Some of the features characterizing the softening response of this material are incorporated in a new constitutive model for the matrix phase (mortar). Finally, some results are given for a binary composite incorporating a softening and a linearly elastic phase for two simple loading histories.