A micromechanical cyclic constitutive model for ratchetting deformation of polymeric composites with imperfect interface

Abstract

In this study, a micromechanical cyclic constitutive model for accurately describing the ratchetting deformation of polymeric composites is proposed. The model is based on the mean‐field homogenization method and incorporates the nonlinear viscoelastic‐viscoplastic (VE‐VP) cyclic constitutive model of the polymeric matrix and the imperfect interface. First, the nonlinear VE‐VP model was linearized using the incremental affine method and then was introduced into the homogenization process. The imperfect interface was represented using a linear spring model. A modified Mori‐Tanaka model was developed to incorporate the nonlinear VE‐VP model and imperfect interface into the micromechanical constitutive model. To implement the proposed micromechanical model, a numerical algorithm was developed. The model is capable of capturing the influence of the imperfect interface on the ratchetting deformation of polymeric composites. Furthermore, it is applicable to simulate various loading histories, including monotonic tension, stress relaxation, creep, and uniaxial ratchetting loads. The proposed model was validated by comparing its simulations with those obtained from the full‐field finite element method (FEM) model. The proposed model can predict the ratchetting deformation of polymeric composites and promote the practical application of these material in structures.Highlights A micromechanical cyclic constitutive model is developed to describe the ratchetting deformation of polymeric composites with imperfect interface. Nonlinear viscoelastic‐viscoplastic deformation of polymeric matrix is considered. A modified Mori‐Tanaka method is employed to incorporate the nonlinear constitutive model and imperfect interface into the process of homogenization. Good agreement between simulations of the proposed model and the full‐field FEM model under various loading histories.