The novelty design method in lightweight structures with low effective elastic modulus

Abstract

Lightweight structures are of great interest in industrial areas such as automotive, aerospace, and biomedical due to their lightness, and superior mechanical performance. The advantages of lightweight structures are increased with the spread of additive manufacturing and design them in various geometries. Beam-based structures and triply periodic minimal surface structures are currently used to extend these advantages. In this study, it is aimed to create die models of beam-based structures in order to contribute to the geometric diversity for lightweight structures. By designing the die lattice structures of the beam-based structures, the comparison of the mechanical performance of basic lattice and die lattice structures with the same porosity was carried out. For FCC, CFCC, and Octet-Truss lattice structures, basic lattice and die lattice structures are designed on scaffolds in 5x5x5 array with 50%, 60%, 70%, and 80% porosity. Numerical data were obtained for Ti6Al4V with compression tests simulated by applying pressure in the -y direction. According to numerical analyses, the effective elastic modulus decreased due to the increased porosity in both structure models. The CFCC and Octet Truss scaffolds have different force transmission performances. Likewise, this situation is observed in die lattice structures, but the force transmission with the surfaces reveals the difference of the structures. The effective elastic modulus of basic lattice structure with 80% porosity of the Octet Truss structure is approximately twice that of the die lattice structure. Thus, the use of die lattice structures will provide advantages for the design of lightweight structures with low elastic modulus.