Experimental and numerical validation of impact mitigation capability of meta-panels

The unique stress wave mitigation capacity of meta-materials and meta-structures has been extensively investigated by many analytical studies but there has been very limited experimental verification on their favourable properties and performances, particularly the excellent stress wave mitigation of meta-panels. To address this research gap, the impact mitigation performances of meta-panels were experimentally and numerically investigated in this study. Firstly, an instrumented hammer impact test was conducted to verify the ability of the meta-truss bar in filtering out the incident stress. Then, impact tests using the gas gun system were implemented to examine the effectiveness of the meta-panel which is composed by the meta-truss bars on impact mitigation. It is experimentally proven that the meta-panel exhibited better dynamic performances, i.e., reductions in force transmission to the protected structure as well as in the back facesheet displacement, and an increase in energy absorption compared to the traditional panels made of hollow solid-truss bars. Furthermore, the effect of the impact velocity on the dynamic performance of meta-panels was also experimentally examined and discussed.