Topology optimization of compliant mechanisms using pairs of curves

Abstract

The structural topology optimization approach can be used to generate compliant mechanisms for some desired input–output requirements. The success of the optimization depends on the structural geometry representation scheme used. In this paper, a novel representation scheme is proposed. The representation scheme is characterized by pairs of curves that are used to connect Input/Ouput (I/O) regions of the structure. Each pair of curves includes a normal curve and a fat curve. The areas bounded by the pair of curves define the material distribution between them. All I/O regions are connected to one another (either directly or indirectly) by pairs of curves in order to form one single connected load-bearing structure. A genetic algorithm for constrained and multiobjective optimization is then applied with the representation scheme of the structure in the form of a graph. Simulation results from a displacement inverter and a displacement redirector indicate that the presented representation scheme is appropriate.

Keywords:

• topology optimization
• genetic algorithm
• structural optimization
• compliant mechanism

Funding

This work is supported by the National Natural Science Foundation of China [grant nos. 51205134 and 91223201]; the Doctoral Fund of the Ministry of Education of China [grant no. 20120172120001]; the Science and Technology Program of Guangzhou [grant no. 20l3JA300008]; the Research Project of the State Key Laboratory of Mechanical System and Vibration [grant no. MSV201405]; the Natural Science Foundation of Guangdong Province [grant no. S2013030013355]; the Fundamental Research Funds for the Central Universities [grant no. 2013ZM012].