INFLUENCE OF RANDOM GEOMETRY ON EFFECTIVE PROPERTIES AND DAMAGE FORMATION IN COMPOSITE-MATERIALS

We study the effective moduli and damage formation in out-of-plane ela sticity (i.e., two-dimensional conductivity) of matrix-inclusion compo site materials with either randomly or periodically distributed inclus ions (fibers). In this paper, we focus our attention on composites wit h isotropic phases, both of which have elastic-brittle response in dam age. The elastic-brittle behavior is modeled with the help of a fine m esh finite-difference system, whereby damage evolution is simulated by sequentially removing/breaking bonds in this lattice in accordance wi th the state of stress/strain concentrations. The composite systems ar e specified by two parameters: stiffness ratio and strength ratio of b oth phases. In particular, we investigate the following aspects: basic classification of effective constitutive responses, geometric pattern s of damage, varying degrees of randomness of the inclusions' arrangem ents, and mesh resolutions of continuum phases.