Designing particulate composites: The effect of variability of filler properties and filler spatial distribution

Abstract

A new perspective on structural design of particulate composites is presented in this chapter. The central concept is that by controlling multiple parameters describing the stochastic microstructure, such as allowing the filler properties to vary from filler to filler, or constructing spatially correlated filler distributions, significantly expands the design space which, in turn, is likely to lead to the development of more performant composites. We investigate the effect of two such parameters on the elastic-plastic and damping behavior of the composite. First, we consider microstructures containing fillers of same properties but which are spatially distributed in a correlated way. It is observed that composites with spatially correlated filler distributions are stiffer, strain harden more and lead to larger damping ratios relative to microstructures with random, uncorrelated filler distributions of same volume fraction. In the second part of the study we consider composites in which filler properties vary from filler to filler. It is observed that the composite modulus and its strain hardening rate decrease as the variance of the probability distribution function of filler elastic constants increases, while the mean of the distribution is kept constant. The damping ratio of the composite is not sensitive to the higher moments of the distribution function of damping coefficients within inclusions.