Delamination Prediction and Non-local Averaging using a Composite Micro-Mechanical Model

Inter-laminar delamination in laminated composites has been studied with the help of thickness-stretch shell elements using a 3-D material model and compared against the traditional plane-stress shell elements. A strain-rate and pressure dependent micro-mechanical material model using ply-level progressive failure criteria has been used to simulate the initiation and propagation of delamination. The material parameters of the non-linear resin have been determined using LS-OPT®. The numerical delamination growth has been qualitatively analyzed against the experimental C-scan images for multiple impact events on different composite plates. In addition, a non-local model with an isotropic weight function has been implemented to work in conjunction with the composite micro-mechanical material model to alleviate strain softening typically seen in composite materials.