Efficient design optimization of variable-density cellular structures for additive manufacturing: theory and experimental validation

• Published in: Rapid prototyping journal Vol. 23; no. 4; pp. 660 - 677
• Main Authors: Cheng, Lin, Zhang, Pu, Biyikli, Emre, Bai, Jiaxi, Robbins, Joshua, To, Albert
• Format: Journal Article
• Language: English
• Published: Bradford Emerald Publishing Limited 20.06.2017; Emerald Group Publishing Limited
• Subjects: Additive manufacturing; CAD; Cellular manufacture; Cellular structure; Colleges & universities; Computer aided design; Computer simulation; Density; Density distribution; Design optimization; Homogenization; Laboratories; Manufacturability; Materials science; Mechanical engineering; Mechanical properties; Methods; Rapid prototyping; Scale (ratio); Stiffness; Theory; Topology optimization; Reconstruction; Homogenization; Topology optimization; Additive manufacturing; Cellular structure
• ISSN: 1355-2546; 1758-7670
• DOI: 10.1108/RPJ-04-2016-0069

Purpose The purpose of the paper is to propose a homogenization-based topology optimization method to optimize the design of variable-density cellular structure, in order to achieve lightweight design and overcome some of the manufacturability issues in additive manufacturing. Design/methodology/approach First, homogenization is performed to capture the effective mechanical properties of cellular structures through the scaling law as a function their relative density. Second, the scaling law is used directly in the topology optimization algorithm to compute the optimal density distribution for the part being optimized. Third, a new technique is presented to reconstruct the computer-aided design (CAD) model of the optimal variable-density cellular structure. The proposed method is validated by comparing the results obtained through homogenized model, full-scale simulation and experimentally testing the optimized parts after being additive manufactured. Findings The test examples demonstrate that the homogenization-based method is efficient, accurate and is able to produce manufacturable designs. Originality/value The optimized designs in our examples also show significant increase in stiffness and strength when compared to the original designs with identical overall weight.