LATTICE MODEL EVALUATION OF PROGRESSIVE FAILURE IN DISORDERED PARTICLE COMPOSITES

Results from experimental and numerical investigation on the fractal p roperties of particle composites are presented. Splitting tests on con crete were carried out and the fractal dimension of the crack patterns detected on microscope images was measured. Numerical simulations of the tests were performed by means of a lattice model, and non-integer dimensions were measured on the predicted lattice damage patterns. The ability of the model to reproduce realistic statistical interactions and self-organization in the propagation of the cracks is discussed. I n particular, an increasing Hausdorff dimension was measured during da mage development in the lattice network. It is concluded that, next to the stable crack growth provided by fractality in disordered material s, an optimal choice of the percentages of weak and strong microstruct ural elements, together with their particle-like distribution, may lea d to improved mechanical performance of the considered materials. (C) 1997 Elsevier Science Ltd.