Effect of drilling-induced defects on progressive damage of open-hole composite laminates under compression

Abstract

In this study, the effect of drilling-induced defects on open-hole compression progressive failure and buckling and post-buckling behavior of composite laminates was investigated numerically. First, drilling-induced defects were identified from X-ray computed tomography data using image processing software, from which delamination and fiber pull-out defects were quantified on the specimen. These defects were then incorporated into finite element mesh, and numerical analyses simulating ASTM open-hole compression tests were performed in Abaqus. Hashin failure criterion and energy-based linear softening law were employed to determine in-plane failure initiation and evolution. Interlaminar failure was accounted for by cohesive zone modelling inserting cohesive elements at delaminated interfaces. The numerical model with defects was validated against experimental results and very good agreement was obtained. Next, simulations were performed on both defect-free and defective open-hole composite laminate models to study the effect of drilling-induced defects on compressive strength and progressive failure behavior. Finally, analyses were performed with buckling deformation allowed and the effect of buckling and post-buckling on compression failure behavior was investigated.