A partially hollow BCC lattice structure with capsule-shaped cavities for enhancing load-bearing and energy absorption properties

Lattice structures have gained larger design space and wider application in aerospace, automobile, civil and other engineering fields due to the advancements in additive manufacturing (AM) technology. Seeking the optimal lattice structure configuration for the purpose of enhancing mechanical performance holds paramount importance. The hollow lattice structure possesses high material utilization efficiency, but often suffers from premature failure at the node interconnections. In this paper we propose a partially hollow lattice structure (PHBCC) with solidified nodes and capsule-shaped cavities in the middle of truss components. Quasi-static compression tests were performed on the partially hollow body-centered cubic (BCC) lattices manufactured via selective laser melting technology (SLM). The effects of various geometric parameters were analyzed through finite element simulations. The findings demonstrate that the introduced PHBCC lattice exhibits enhanced mechanical properties. Specifically, there is an observed increase of 92%, 51.9%, and 22.8% in terms of specific stiffness, specific strength, and specific energy absorption, respectively, in comparison to the conventional BCC and hollow BCC (HBCC) structure. Notably, the proposed PHBCC lattice displays superior energy absorption capacity compared to a majority of existing lattice structures.