Topology optimization for energy absorption of quasi-brittle structures undergoing dynamic fractures

Abstract

In this paper, we introduce a topology optimization approach aimed at improving the energy absorption of quasi-brittle structures under impact loading. Our method focuses on incorporating dynamic fracture behavior throughout the impact process to maximize the energy acting on the structure. To achieve this, we integrate a dynamic phase field method into density-based topology optimization, enabling us to simulate the initiation and propagation of complex dynamic fractures. The optimization formulation aims to maximize the absorbed energy over a specified period while adhering to material volume and compliance constraints. Sensitivity analysis was originally provided to accelerate computations and optimization. Several numerical examples show that the incorporation of dynamic fracture effects leads to superior energy absorption of the optimized structure compared to static strategies or neglecting the fracture process. Moreover, the proposed scheme facilitates tailored designs for different impact loading rates.