Crushing performance of 3D-printed sandwich panels with mathematical waveform-based core topologies

In this study, the mechanical performance of 3D-printed sandwich panels with waveform-based cores under compression is investigated. For this purpose, first, a nonlinear finite element model is developed and validated against experimental tests. Then, sixteen sandwich panels with various uni and bi-directional wavy cores are systematically examined through numerical simulations. All the core topologies have been developed based on mathematical waveform equations, including sinusoidal and triangular waveforms. At the same time, additional geometrical modifications have also been introduced to generate modified wavy core topologies. By comparing the specific absorbed energies of the sandwich panels, the performance of each core topology has been examined. Among all the studied geometries, a novel clipped one-sided bi-directional core geometry has shown the best energy absorption capacity, with its specific energy absorption being 340% higher than that of the sandwich panel with simple uni-directional sinusoidal corrugation. The results also show that the core topologies obtained by applying the clipping and absolute value functions to the base waveform equations perform significantly better. It was also found that the primary failure mode of the 3D printed sandwich panels with uni-directional corrugations is elastic buckling, whereas yielding is the primary failure mode in those with bi-directional corrugations.