Capturing subtle features of delamination shapes in cross-ply laminates due to low speed impact

The present paper is to enhance the understanding of general delamination problem by addressing a few basic phenomena which have been well-observed repeatedly, but hardly comprehended, let alone being captured via the theoretical modelling. Specifically, in cross-ply laminates, the shape of delamination areas, which form due to low velocity impact, has two subtle features, which have been captured consistently in numerous experiments, but have not been reproduced consistently through numerical modelling. Those are the pointed delamination tips and the intact zone between the lobes of delamination. Out of the present investigation, these features have been subjected to close examination. In each case, a key and unique reason has been identified.