Realistic micromechanical modeling of discontinuously reinforced composites

Finite element based multi-phase 3D micromechanical modeling is utilized to study the effects of porosity and reinforcement particle clustering on the mechanical properties of extruded discontinuously reinforced aluminum alloy composites possessing non-uniform microstructures with long-range spatial correlations. Microstructural attributes such as the shape, size, volume fraction, and spatial distribution of the reinforcement phase and porosity in these composites are incorporated in the models without any simplifying assumptions. The analyses are performed on representative volume elements that capture the short- and long-range heterogeneity of the composites. It is shown that the spatial clustering of the reinforcement particles reduces the strain-hardening capacity of the composites while the porosity significantly lowers the 0.2% offset yield strength.