Compression and energy absorption properties of the novel truss-like lightweight material based on space group P6mm

Abstract

Truss-like lightweight materials (TLMs) are a type of porous materials which have been widely used in aeronautics and astronautics because of excellent mechanical property and superior energy absorption capability, and these properties could be influenced by its meso-structure. Therefore, the meso-structure design is a critical task to develop high-performance TLMs. A novel meso-structure of TLM was deduced based on the symmetric operations of the space group P6mm. The mechanical model of the novel TLM was established to theoretically investigate its compression property, and it was found that the relative density and compression property of the novel TLM could be increased with the diameter-to-length ratio (d/l) and inclination angle (α) of strut. The equivalent elastic modulus, yield load and yield stress of the novel TLM could be predicted by theoretical analysis and verified by finite element analysis. The simulation results showed that the novel TLMs with varied relative densities have different loading capacity but the same failure mode. The compression and energy absorption properties of the novel TLM could be improved by increasing the structural relative density. In addition, this study indicated the novel TLM has better compression and energy absorption properties at the same relative density compared with other TLMs such as BCC and FCC, and its equivalent elastic modulus at the same relative density increased by 324.3% and 15.5%, respectively.