A parametric study of inclusion interaction in particulate- and fibre-reinforced materials using the boundary element technique

Abstract

The purpose of the present work is to analyse the effect of inclusion interaction within a composite material using the boundary element (BE) technique. The stress distributions have been examined as a function of the inter-fibre/particle separation distance, interfacial conditions and the relative moduli and size of neighbouring inclusions. In particular, the relative size of interacting inclusions detrimentally affects the localized stress concentrations (fully bonded), and in certain circumstances can result in a complete loss of contact within 'shielded’ inclusions (non-bonded). Furthermore, the analysis of inclusions with differing Young's moduli shows that, if one of them has a modulus greater than that of the matrix, and the other a modulus lower than that of the matrix, then there is a significant reduction in the local stress concentrations. Hence, microcracks, which often nucleate in and around second-phase materials, would have a lower probability of initiation, which in turn could lead to an improvement in the fracture strength of the bulk material. For verification, the results have been found to correlate well with the present authors' finite element (FE) simulations and, where possible, comparison of the results with analytical models shows good agreement.