Multi-material topology optimization of phononic crystals based on bandgap generation and control
摘要
This paper proposes a multi-material level set-based topology optimization method for designing phononic crystals with bandgaps. To facilitate bandgap formation and prevent convergence to local optima with zero bandgaps, we introduce a novel optimization formulation that penalizes band intersections using a constraint. The optimization process is conducted using the reaction-diffusion equation-based multi-material level set-based method, which represents multiple material phases without overlap and enables topological changes during the optimization process. Numerical examples confirmed that the proposed method can robustly generate non-zero bandgaps for different initial configurations. Moreover, under the same mass constraint, the maximum relative bandgap width (RBW) obtained in the three-material case exceeds that of the two-material case, suggesting the potential benefits of incorporating an additional material. At the same time, the results indicate that the final RBW remains sensitive to the initial design.