Research on Parametric Design and Mechanical Performance of Variable Cross-Section Diamond Lattice Structures

The diamond lattice structure is a type of lattice structure that exhibits excellent isotropic and mechanical properties. The variable section design can optimize the section size of the support rod of lattice structure and improve the mechanical properties of lattice structure. In this paper, a design method of variable section diamond lattice structure based on minimal surface parallel implicit function is proposed. The parametric variable section design of lattice structure can be realized by adjusting the variable section coefficient K. A functional relationship between the K value and the cross-sectional radius of the struts is established, and a mechanical analytical model of the variable cross-section diamond lattice structure is constructed based on Timoshenko beam theory. Using SLM (selective laser melting) technology, six lattice structure samples made of 316L stainless steel with a volume fraction of 5% were prepared and subjected to compression tests. The results show that the mechanical properties of the lattice structure first increase and then decrease with the increase of the variable cross section coefficient K. Compared to constant cross-section structures, the variable cross-section lattice structure’s effective elastic modulus can be increased by up to 20.23%, and the effective yield strength can be increased by up to 14.79%.