Modelling damage in half-hole pin bearing cross-ply and angle-ply composite laminates

Abstract

This paper presents the development and validation of a mesoscale numerical model to predict the bearing failure of composite laminates reinforced by unidirectional continuous fibers, focusing on specimens that show a significant non-linear response prior to failure. Half-hole pin bearing tests were carried out with multiple instrumentation for the comprehensive characterization of the failure process. Three-dimensional finite element models were used for the simulation of plastic deformation and damage of the cross- and angle-ply specimens using fiber-aligned mesh for the composite plies. To consider the non-linear material behavior prior to crack propagation, the constitutive model proposed includes a bi-linear elastoplastic model to represent the non-linear response under longitudinal shear. For the prediction of the peak and post-peak behavior, 3D invariant-based failure criteria and mechanism-based continuum damage models were used for intralaminar damage, together with a discrete cohesive zone model for delamination. Thorough analyses and comparisons of the experimental and numerical results show a good correlation of the bearing strengths and overall deformation, as well as good agreement in terms of damage size and damage shape. Relevant limitations include difficulties in predicting the post-peak plateau stresses and the loading displacements in some configurations, setting the stage for additional future research.