Multi-Material and Multi-Joint Topology Optimization Considering Multiple Design Spaces

Abstract Today, automakers are focusing on cost reduction and lightweighting, by utilizing a combination of different materials in the vehicle design. Topology optimization is a numerical tool that provides more design freedom than other methods, such as size optimization and shape optimization. Multi-material topology optimization can optimize both material layout and material distribution to improve structural performance. However, these methods assume that dissimilar materials are perfectly bonded, which limits the manufacturability of the design. This work presents a multi-material and multi-joint topology optimization methodology that considers additional design variables for joints in the material interface region. The mechanical properties of joints are included in the analysis, which affects the overall structural behavior and the optimized result. This paper firstly introduces topology optimization methods and material interpolation functions for multiple design spaces. Then, the material interface region detection method is explained. After that, sensitivity analysis for different responses is conducted. Lastly, the results of some example models demonstrate this methodology can be used to control mass and joining cost in multiple design spaces within a structure.