Multiscale Modeling of Failure Mechanisms in Multidirectional Double-Edge Notch Compression Specimens

Abstract

This study presents the use of a multiscale computational model for laminated composites in a double-edge notch compression (DENC) configuration. Analysis of in-situ and post-test DENC experiment results indicates the presence of multiple failure mechanisms, including ply splitting, delamination, and compression kink bands. In order to understand the onset, growth, and interplay of the critical and subcritical damage mechanisms, a nonlocal multiscale kink band model is incorporated alongside splitting and delamination models to simulate the compression behavior. The kink band model used in this study explicitly tracks the microstructural failure mechanisms that lead to the formation and propagation of kink bands. Cohesive zone models are used to describe the initiation and progression of ply splitting and delamination in the specimen. The splitting model was implemented using implicit finite element simulations and deployed with a pre-crack insertion technique to reduce simulation time while preserving prediction accuracy. Deterministic calibration of model parameters is performed using experiment measurements, and the effects of split location and growth characteristics on model predictions are also studied. The predicted positions of damage initiation and progression through the thickness of the laminate agree well with experiment results which include quantified characterization of the initiation and growth of both kink bands and surface ply splitting as a function of applied load level.