Macro–microscale topological design for compliant mechanisms with special mechanical properties

Abstract

This paper proposes a macro–microscale topology optimization approach for constructing compliant mechanisms with deterministic mechanical characteristics based on the essential properties of structural materials. The topology optimization process is divided into two scales: in macroscale optimization, the flexibility matrix factor is used as the constraint function, and the Augmented Lagrangian method is used to transform the constrained optimization problem into an unconstrained model, and the free materials optimization approach is used to generate a compliant mechanism with multiple material attribute elements at the macroscale. In microscale optimization, each microstructures are optimized to obtain special mechanical properties issued from macroscale optimized results. Within the allowable elastic deformation range, the compliant mechanism with arbitrary mechanical properties can be designed, and several numerical examples demonstrate that the compliant mechanisms have expected motion characteristics. The proposed method solved the quantitative design of mechanical properties of compliant mechanisms and can be extended to other fields of compliant mechanisms using macro–microscale topology optimization.