Space Node Topology Optimization Design Considering Anisotropy of Additive Manufacturing

Abstract

Featured Application: In this paper, the anisotropy of the mechanical properties of additively manufactured products was investigated. When carrying out a lightweight design, considering the anisotropy during manufacturing, it can provide accurate performance estimates for subsequent manufacturing. The research object of this paper was the space node, which is very suitable for lightweight design because of its complex force. However, this method can also be used for those products that need to consider the performance after manufacture, especially in mass production, whereby the most suitable molding direction can be found using this method. At present, a large number of scholars have conducted related research on topology optimization for additive manufacturing (AM). However, there are few relevant research reports on the impact of different directions of additive manufacturing on the optimal design and manufacturing results. In this paper, using the bidirectional evolutionary optimization (BESO) method, anisotropic optimization analysis was carried out on space nodes that are currently popular in the field of additive manufacturing and topology optimization. The elastic constants in different directions were used as anisotropic material properties for optimization research in this paper through tensile testing, which was carried out on 316L stainless-steel specimens fabricated using Selective Laser Melting (SLM) technology. In addition, SEM analyses were performed to explore the microscopic appearance of the material. The study found that additive manufacturing is affected by the printing direction in terms of both macroscopic mechanical properties and microscopic material structure; the deformation obtained by anisotropic optimization was about 1.1–2.3% smaller than that obtained by isotropic optimization.