Mechanical analysis of fiber-reinforced plastics using an elastoplastic-damage constitutive equation considering asymmetric material behavior

Abstract

Mechanical modeling of fiber-reinforced plastics to predict nonlinear mechanical behavior along the off-axis direction is very complex due to tension-compression asymmetry. This study aimed aims to develop a generalized constitutive model for different types of unidirectional and woven composites, considering tension-compression asymmetry in various deformation ranges from elastic to plastic, and finally to failure. To capture the asymmetry effectively, a new multivariable plastic model was proposed with additional dilatational components and different elastic moduli for tension and compression. Finally, asymmetric failure criteria and a damage evolution law were introduced for strength prediction. The proposed model was implemented in a finite element analysis software via a user material subroutine, and experimentally validated in terms of off-axis tension and compression tests in various loading directions. The experimental results were accurately predicted using a multi-parameter plastic model in this study compared to previous other models with few parameters.