Influence of strain rate effect on energy absorption characteristics of bio-inspired honeycomb column thin-walled structure under impact loading

In this paper, we studied the internal structure of beetle elytra, i.e., three different structural forms of bio-inspired honeycomb column thin-walled structure (BHTS) to make the honeycomb sandwich structure commonly applied in engineering have better mechanical and lightweight performance. We choose the AlSi10Mg aluminum alloy as material specimens for fabrication using selective laser melting of additive manufacturing (AM-SLM) and testing. Considering the influence of strain rate effect (SRE) on the structure during impact loading, the numerical model was verified by uniaxial compression tests and numerical simulations. Then the effects of five different strain rates (100 s(-1), 200 s(-1), 300 s(-1), 400 s(-1) and 500 s(-1)) were discussed on the loading process of BHTSs specimens. The experimental results show that the energy absorption (EA) indexes of each BHTS are greatly improved by SRE in the out-of-plane compression test of AM-SLM AlSi10Mg: the initial peak crushing force (PCF), mean crushing force (MCF) and specific energy absorption (SEA) of the specimen average increased by 120.64 %, 8.74 % and 10.61 %, respectively. Finally, according to the evaluation of each EA indexes, the design of BHTS-III has better comprehensive performance. These results can provide important assist for the design, manufacture and modeling of BHTS-based materials.