Delamination Prediction of Uni-Directional Composite Laminates using Shell Elements and a Strain Rate Dependent Micro-mechanical Material Model

The effectiveness of studying inter-laminar delamination in composites with the help of newly formulated thickness-stretch shell elements (ELFORM=25) as compared to the traditional plane-stress shell elements (ELFORM=2) has been investigated using LS-DYNA ® . A strain-rate dependent micro-mechanical material model using ply-level progressive failure criteria has been used to simulate the initiation and propagation of delamination. The numerical delamination growth has been qualitatively analyzed against the experimental C-scan images for multiple impact events on a T800H/3900-2 CFRP plate. As an addition to the capability of the micro-mechanical material model, a methodology of assigning physical significance to the choice of damage parameters has been presented.