Energy absorption of SMC/balsa sandwich panels with geometrical triggering features

The influence of triggering topologies on the peak load and energy absorption of sandwich panels loaded in in-plane compression is investigated. Sandwich panels with different geometrical triggering features are manufactured and tested experimentally. Damage initiation in panels with grooves is investigated using finite element models. As expected the investigated triggering features reduce the extreme load peaks. A less expected result is that the plateau load following peak load tends to be higher for panels with triggering features. Both results are judged favourable for crash performance of panels in vehicle applications. Analysis suggests that there is a transition in failure mode for the studied panels, where the peak load for panels containing no or few grooves seems to be governed by principles of fracture mechanics while for panels with a high number of grooves it appears to be limited by the average stress.