FEA-based optimization and experimental verification of a typical flexure-based constant force module

Abstract

To solve the problem of insufficient constant-force stroke of the compliant constant force mechanism (CFM), a FEA-based optimization method based on structural parameters is proposed in this paper. Firstly, a flexure-based constant force module (FBCFM) combined with a Z-shaped beam and a bi-stable beam is designed. By analyzing the force-displacement relationship of the two kind beams, the architectural parameters related to the constant force characteristic of the FBCFM are derived. Then, the initial constant-force stroke with 2.2 mm and output constant force with 13.8 N of the FBCFM are obtained by experimental studies. Furthermore, to explore the parametric effects for the designed FBCFM, parametric evaluation is conducted via MATLAB. Finally, the optimal solution set of architecture parameters is obtained with FEA-based optimization method. Through experimental verification, the constant-force stroke of the optimized FBCFM is 4.5 mm with constant force 8.5 N. The optimization results show the effectiveness and feasibility of the proposed FEA-based optimization method.