Sequential topology and shape optimization framework to design compliant mechanisms with boundary stress constraints

We present a sequential topology and shape optimization framework to design compliant mechanisms with boundary stress constraints. In our approach, a density-based topology optimization method is used to generate the configuration of the mechanisms. Afterwards, a node-based shape optimization is invoked to obtain an exact boundary representation. A specialized, optimality criteria-based design update is formulated for the shape optimization. To avoid impractical hinges with point connections, stress constraints are imposed. The stress constraints are imposed using two strategies: Local stress constraints on the nodes of the boundary or global P-norm stress constraints in the domain. Further, an adaptive shape refinement strategy is adopted to increase the design space of shape optimization and to capture the fine-scale details of the geometry. Finally, numerical experiments are presented, showing that the proposed approach can be effectively applied to the design of compliant mechanisms with stress constraints.

Automated summary

We propose a sequential topology and shape optimization framework for designing compliant mechanisms with boundary stress constraints. Our approach utilizes a density-based topology optimization method to generate the configuration of the mechanisms and a node-based shape optimization method for obtaining an exact boundary representation. Stress constraints are imposed to avoid impractical hinges with point connections, either locally on the nodes of the boundary or globally using P-norm stress constraints in the domain. Moreover, our method incorporates an adaptive shape refinement strategy to increase the design space and capture fine-scale geometry details. Numerical experiments demonstrate the effectiveness of our approach in designing compliant mechanisms with stress constraints.