Interrogating failure mechanisms of notched composites through a discrete crack modeling approach

Abstract

The prediction of compressive failure of composite laminates is generally more challenging than tensile failure, due to more complex failure mechanisms and nonlinear effects. This work presents an extension of a previously developed numerical framework utilizing discontinuous solid-shell elements and enriched cohesive elements for the simulation of damage growth of open-hole laminates under compression. Unlike tension, compressive loading may result in inclined matrix cracks due to localized shear damage. An approximate but efficient modeling technology was adopted by formulating an assumed vertical cohesive crack with the inclined crack coordinate system. The proposed approach explicitly represents damage as discrete cracks and leads to more accurate prediction of brittle and push-out failure patterns for sublaminate-scaled and ply-scaled laminates, respectively, including size and lay-up effects. These failure events of open-hole compression are believed to be captured with discrete crack analysis for the first time.