Research on Multi-scale Collaborative Design Method of Lightweight Bionic Structure Based on Topological Optimization and Additive Manufacturing

Abstract

In response to the growing demands for structural performance and lightweighting in high-end equipment, traditional design methods face performance limitations and efficiency bottlenecks. This paper proposes a multi-scale collaborative design approach integrating
bionics principles, topology optimization theory, and additive manufacturing technology, aiming to achieve integrated innovation in both macroscopic structural configurations and microscopic material distribution. The research extracts core principles such as "material on-demand
distribution, " "functional gradients, " and "multi-level coupling" from biological multi-scale structures (e.g., avian bones, plant stems) as
the biological foundation for optimization design. By constructing a microstructure unit library containing typical biomimetic configurations
like honeycombs and three-period minimal surfaces, and establishing mapping relationships between macroscopic and microscopic design
variables, an improved variable-density topology optimization model was developed to simultaneously optimize macroscopic topology and
microscopic material distribution. To address the disconnect between design and manufacturing, process constraints of additive manufacturing
(e.g., minimum feature size, maximum overhang angle) were incorporated as penalty functions into the optimization cycle, enabling manufacturability iteration of design results. Finally, a case study was conducted on a drone load-bearing bracket. Results demonstrate that compared
to traditional single-scale topology optimization, the structures generated by this method achieved 48% weight reduction while significantly
improving stress concentration phenomena, with maximum equivalent stress reduced by approximately 15%, exhibiting superior mechanical performance and biomimetic characteristics. This study provides a systematic new approach for the design and manufacturing of highperformance lightweight structures.