The deformation mechanism, energy absorption behavior and optimal design of vertical-reinforced lattices

Abstract

As a typical hybrid lattice, vertical-reinforced lattices, i.e., adding vertical struts to traditional lattices, have not been extensively studied, especially from the aspects of deformation mechanism, energy absorption performance and structural optimization. In this paper, body-centered cubic (BCC), face-centered cubic (FCC), as well as vertical-reinforced BCC and FCC (VBCC and VFCC) lattices were established and fabricated by the selective laser melting technique to elucidate the influence of the vertical struts on the mechanical behavior of the lattices. Uniaxial quasi-static compression tests were conducted on lattice samples made of stainless steel 316L. Moreover, numerical simulations were performed to facilitate analysis of the deformation modes of the specimens and further optimization designs. The results show that the VBCC and VFCC lattices exhibit stronger stiffness and higher initial strength compared to the BCC and FCC lattices. Typically, the effective specific energy absorption of the vertical-reinforced lattices can be increased by about 60%–75% compared with those of non-reinforced lattices, since more plastic hinges are formed in the lattice via adding vertical struts to dissipate energy. The present study also demonstrates that increasing the diameter of the vertical struts plays a vital role in improving energy absorption capabilities of the vertical-reinforced lattice, and the highest effective specific energy absorption of optimized VBCC and VFCC lattices are 21.7 J/g and 27.9 J/g, notably far above the general trend of most metal lattices.