On the nonlinear viscoelastic deformations of composites with prestressed inclusions

This study aims to understand the effect of prestressing the inclusion on the overall mechanical performance of composites having nonlinear viscoelastic constituents. Particle reinforced composites are considered and each non-overlapping particle is assumed to be fully surrounded by polymeric matrix. We study different responses of polymeric matrix with limiting strain and stress softening behaviors. In both models, linearized strain is given explicitly as a nonlinear function of stress and stress history and a justification for such a non-linear relationship is provided. A recursive-iterative algorithm is used to numerically solve the governing equations which are integrated within a displacement based finite element environment. Examples of composite responses with different particle contents are presented. A thermal process that could induce prestress in the inclusion is discussed. (C) 2016 Elsevier Ltd. All rights reserved.