Energy absorption diagram characteristic of metallic self-supporting 3D lattices fabricated by additive manufacturing and design method of energy absorption structure

Three-dimensional lattice structures have the advantages of light-weight and strong design ability, and have good prospects in the application for energy absorption. However, there are seldom design methods of three-dimensional lattice structures for energy absorption, especially a three-dimensional lattice structure design method for energy absorption based on energy absorption diagrams has not yet been proposed. The present study establishes a mechanical theoretical model of self-supporting lattice structures for additive manufacturing. The aluminum alloy self-supporting lattice structures are fabricated by selective laser melting (SLM). An improved characterization method on energy absorption diagram is proposed. Energy absorption diagram of self-supporting lattice structures is established based on finite element analysis (FEA) and uniaxial compression experiments. The results show that the envelope lines of shoulder points of three-dimensional lattice structures with various configurations are different, which varies from the foams. A design method of three-dimensional lattice structures for energy absorption is proposed for the first time on the basis of this energy absorption diagram, which is of great significance for the design of energy-absorbing structures in the fields of aerospace, aviation and transportation.