The influence of introducing the cohesive zone model in simulating the impact of stratified composites

Abstract

This paper presents a comparison of two models for an impact with a projectile 9 mm FMJ (full metal jacket), having 373 m/s on stratified composites, at meso level. The models contain yarn with the geometry similar to the actual yarns of glass fibers, used in an experimental test. The yarns’ orientation is a repeated (0°/90°). The model includs 8 layers of yarns. One model is done including only friction among yarns and between yarn and projectile and the second model introduces both friction and delamination properties (as in the coehesive zone model). The paper reports the differences between the two simulations with the same geometry of the models and the same constitutive material models for yarn and projectile materials, but one with conditioned bonds as in the cohesive zone models. Applying the cohesive zone model (CZM) with zero thickness makes the impact to have a more localized action, reduce bending of the broken yarns. The models are compared to an actual panel made of stratified layers of glass fibers with similar properties of the yarns and the simulation with cohesive zone model gives a closer aspect of the failure as compared to the actual one.