Micromechanics-Based Elastoplastic Modeling of Functionally Graded Materials with Pairwise Particle Interactions

Abstract

To understand the inelastic behavior of functionally graded materials (FGMs) containing aluminum particles in high-density polyethylene (HDPE), a micromechanics-based elastoplastic model was developed. It was assumed that the particle phase was in a linearly elastic state while the matrix phase could be in a plastic stage. The corresponding yield function for the matrix phase was investigated, where the pairwise interaction term and probabilistic spatial distribution of particles were used to accommodate the gradation of particle volume fraction. Accordingly, the overall elastoplastic stress-strain response was established through homogenization of the stress and strain fields. The modeling prediction was validated with experiments on a specific functionally graded material. Good agreement was observed between the model and experimental results. In this paper, the effect of various particle distribution functions and relative material stiffness on the elastoplastic behavior of FGMs is addressed and discussed.