Effect of boundary conditions on plasticity and creep behavior analysis of particle reinforced composites by representative volume element approach

In the present study, the plasticity and creep behaviors of heterogeneous composites containing randomly distributed particles were considered to predict the effect of boundary conditions (BCs) numerically derived solutions. Modeling was performed using two dimensional representative volume elements (RVEs) with different sizes and particle volume fraction. Structural heterogeneity along the model boundaries considerably influenced the overall numerical solutions that developed stress/strain fluctuations, while inner part of the model showed almost the same strain fields. In both plasticity and creep models, the thickness of BC-affected region was larger in plastic or creep strain fields than in elastic strain fields when dividing the total strain of volume elements into elastic, and plastic or creep strain. When the particle volume fraction increased, the thickness of the BC-affected region reached a critical size with the exception of the plasticity model. Comparing the results of the linear and nonlinear problems, the thickness was larger in the nonlinear problem than the linear one. The results suggested that the mechanism proposed for the elasticity model could be applied to nonlinear models to determine the size of the RVE for the specific research purposes or predicting potential errors to estimate the effective properties. (C) 2014 Elsevier B.V. All rights reserved.