Topology optimisation of periodic structures with multiple materials using BESO

Periodic structures have been used extensively in many engineering fields due to their unique advantages, including being easy to manufacture and assemble. A combination of multiple materials can provide a more favourable performance for periodic structures. This study aims to optimise multi-material periodic structures by using bi-directional evolutionary structural optimisation (BESO). Firstly, a topology optimisation framework for multiple materials is developed to design periodic structures using BESO. Then, a material interpolation model is adopted to display the overall layouts of multiple materials in the design domain. Finally, three numerical examples are investigated to illustrate the feasibility and effectiveness of the proposed design framework, regarding obtaining periodic structures with multiple materials.