Micromechanical modeling of random short fiber reinforced polymer composites with progressive debonding damage

Abstract

In this study, we investigated the mechanical behavior of short fiber reinforced composite by using a computational approach for predicting damage evolution and mechanical properties according to the respective mechanical characteristics of the matrix, the fibers and the volume fraction. In this computational approach, for a more accurate calculation of the fiber/matrix interfacial stress, we proposed a combination of two models. The first model is an elastic-viscoelastic phenomenological model describing the nonlinear behavior of the polymeric matrix for predicting damage in polymers, used to predict the matrix damage and the interfacial stress (fiber/matrix). The second model is a Mori-Tanaka homogenization model with a probabilistic aspect used to predict the global damage in the composite by nonlinear laws based on the theory of Eshelby equivalent inclusion. The representative volume element (REV) chosen in the homogenization process, is constructed by assuming local 3D periodicity of the microstructure. The macroscopic stresses and strains are obtained by the average stress-strain field in the RVE. The validation of both homogenization procedure and the constitutive model is accomplished by a range of comparisons with experimental data for uniaxial traction and compression tests. A fair agreement is obtained between numerical and experimental results.