Explicit topology optimization of large deforming hyperelastic composite structures

In this study, we propose an explicit topology optimization approach for multi-material composite structures that considers both geometric and material nonlinearities. Our method identifies each material using moving morphable components, resulting in explicit geometric descriptions and fewer design variables. In finite-element analysis, redundant degrees of freedom are removed to prevent highly distorted elements and improve computational efficiency. A numerical example demonstrated the methodology’s validity and the importance of accounting for geometric and material nonlinearities when designing a multi-material structure. We also show that, even with the same objective function and structural volume, the optimal usage ratio of the constituent materials varies depending on the problem. Using the proposed method, optimized structures with superior performance that cannot be achieved with a single material can be obtained.