On the numerical synthesis of a contact-aided branch hinge (CABH) with variable stiffness

Abstract

Based on the mortise-and-tenon structure, this paper proposes a Contact-Aided Branch Hinge (CABH) with variable stiffness. The equivalent spring model (ESM) and the chain pseudo-rigid body model (CPRBM) of the hinge are derived respectively, and the applicability of these two models is analyzed by the finite element method and experimental tests. Therefore, a compliant-element-based dimensional synthesis (CEBDS) method is proposed. Taking the CABH as an example, three derivative mechanisms are synthesized to meet the complex working requirements. The finite element analysis (FEA) results are consistent with the kinematic requirements, which verifies the correctness and feasibility of the synthesis method. In addition, the prototypes are fabricated. The potential applications of the CABH in robotics and medical devices can be increased by combining multiple derivative mechanisms.