Experiments and numerical simulations of low‐velocity impact of sandwich composite panels

This article investigates the response of composite sandwich panel with Nomex honeycomb core subjected to low-velocity impact and compression after impact (CAI) by using the methods of experiments and numerical simulations. Low-velocity impact of sandwich panels at five energy levels is carried out to research the damage resistance and tolerance. A failure model based on Hashin failure criterion is implemented to model the intralaminar damage behavior of laminated plies in the numerical simulation. The cohesive zone model is used to simulate the delamination damage between adjacent laminated plies. The honeycomb core behavior is defined as an elastic-plastic material. Good agreements, in terms of contact-force histories, damage shapes, and indentation depths of the sandwich panels, are observed between the experimental and numerical results. During CAI analysis, the damaged panels present a phenomenon of quick crack propagation from impact indentation location to each unloaded side after the structural strength reached. It is found that the in-plane compressive strength of damaged sandwich panels is almost 25-35% reduction than that of undamaged panels. POLYM. COMPOS., 38:646-656, 2017. (c) 2015 Society of Plastics Engineers