CHARACTERISATION AND MODELLING OF THE RESPONSE OF ADDITIVELY-MANUFACTURED LATTICE STRUCTURES TO STATIC AND DYNAMIC DEFORMATION

Abstract

Lightweight lattice structures comprise unit open cells defined by interconnected struts, and possess a low relative density and high compressibility. This endows them with favourable energy absorption characteristics when subjected to gross crushing, and thus they are increasingly employed in automobile and aerospace industries for impact protection applications. Tailoring the topology of constituent unit cells is a key approach to enhance the energy absorption capability of a lattice, and additive manufacturing techniques that enable fabrication of lattices with complex cell architectures have made this possible. A novel Hybrid Structure (HS) is proposed to address the limitations associated with conventional octet and rhombic dodecahedron (RD) lattices, and therefore achieve superior performance – a both high and relatively stable post-yield stress plateau. The influence of deformation rate and the additive manufacturing process adopted on the resulting mechanical response of lattices is also investigated.