Investigation of Delamination Modeling Capabilities for Thin Composite Structures in LS-DYNA®

Predictive capabilities to simulate the initiation and propagation of delamination in thin composite laminates have been investigated. Different element formulations (3D solids, 2D shells, and 3D thick shells), cohesive fracture models (commercially available in LS-DYNA 971 v6.1 and *USER_DEFINED constitutive behavior) and stacking procedures have been applied to representative composite models of increasing complexity to demonstrate their response, delamination failure modes and computational efficiency. It has been shown that stacks of 2D shell elements with nodal offsets with a user-defined constitutive model for cohesive elements can retain many of the necessary predictive attributes of delamination dominated failure while providing superior computational efficiency and flexibility required for industrial component scale design.