Theoretical and numerical analysis of a compact structure with cutting rings for energy absorption mechanism

Abstract

Structures designed based on the deformation and damage mechanisms of metals are extensively applied in the energy absorption field. Inspired by cutting metal structures, a compact energy absorption structure with cutting rings (ECR) is proposed in this paper, which absorbs energy via metal shearing, extrusion, and upsetting. To investigate the effect of the key geometrical parameters on energy absorption performances of the ECR, including ring thickness and spacing, a parametric study is conducted. The numerical model of the ECR is constructed and validated by the dropping weight impact test results. Combining the response mechanism and numerical analysis, it is found that ECRs with different structural parameters show three typical response modes during the energy absorption process. Mode B is superior to the other two modes, with a higher energy absorption EA and a lower uniformity ratio RU. Moreover, the ECR with a larger ring thickness has a higher peak contact force Fpecf, which changes Mode B to Mode C. Thus, the gradient configuration is introduced to reduce the peak and obtain a steady energy absorption process. It is demonstrated that the gradient ECR shows an approximate 16% reduction in RU and an approximate 9% reduction in Fpecf, as compared to a non-gradient ECR with a similar average ring thickness.