A novel design method based onmulti–objective optimization for graded lattice structure by additive manufacturing

• Published in: Rapid prototyping journal Vol. 30; no. 6; pp. 1170 - 1190
• Main Authors: Li, Xiangyun, Zhu, Liuxian, Fan, Shuaitao, Wei, Yingying, Wu, Daijian, Gong, Shan
• Format: Journal Article
• Language: English
• Published: Bradford Emerald Publishing Limited 01.07.2024; Emerald Group Publishing Limited
• Subjects: Additive manufacturing; Biomechanical engineering; Biomechanics; Biomedical engineering; Computational fluid dynamics; Design factors; Design optimization; Design parameters; Design techniques; Domains; Finite element method; Genetic algorithms; Geometry; Initial stresses; Iterative methods; Lattice design; Mechanical properties; Optimization; Performance enhancement; Permeability; Porous materials; Powder metallurgy; Rapid prototyping; Structural design; Struts; Tissue engineering; Topology optimization; Transplants & implants; Yield stress; Multi-objective optimization; Graded lattice structure; Additive manufacturing; Parametric design
• DOI: 10.1108/RPJ-09-2023-0330
• ISSN: 1355-2546

Purpose While performance demands in the natural world are varied, graded lattice structures reveal distinctive mechanical properties with tremendous engineering application potential. For biomechanical functions where mechanical qualities are required from supporting under external loading and permeability is crucial which affects bone tissue engineering, the geometric design in lattice structure for bone scaffolds in loading-bearing applications is necessary. However, when tweaking structural traits, these two factors frequently clash. For graded lattice structures, this study aims to develop a design-optimization strategy to attain improved attributes across different domains. Design/methodology/approach To handle diverse stress states, parametric modeling is used to produce strut-based lattice structures with spatially varied densities. The tailored initial gradients in lattice structure are subject to automatic property evaluation procedure that hinges on finite element method and computational fluid dynamics simulations. The geometric parameters of lattice structures with numerous objectives are then optimized using an iterative optimization process based on a non-dominated genetic algorithm. Findings The initial stress-based design of graded lattice structure with spatially variable densities is generated based on the stress conditions. The results from subsequent dual-objective optimization show a series of topologies with gradually improved trade-offs between mechanical properties and permeability. Originality/value In this study, a novel structural design-optimization methodology is proposed for mathematically optimizing strut-based graded lattice structures to achieve enhanced performance in multiple domains.