A study on the flexible Bricard mechanisms with plane-symmetric structure

Abstract

The six-bar single-loop overconstrained Bricard linkages have been attracting continuous attention due to their special geometry and remarkable mobility. During the past century, a great number of papers have been published in various aspects, however, almost all of them focus on those only consisting of rigid links and joints. In this paper, the concept of ‘Flexible Bricard Mechanisms’ is introduced to extend these classical overconstrained linkages from the category of rigid-body systems to the scope of flexible ones. In these novel designs, slender elastic beams are used to replace the rigid links and joints, such that the mobility of flexible Bricard mechanisms is achieved not only via the relative motion from rigid joints, but also the large-scale deformations of elastic links. The plane-symmetric case is studied to demonstrate the realization, analysis methodology, and potential applications of this new type of Bricard mechanism. A candidate with a specialized structure is elaborated as a case study, about which a proof-of-concept prototype is developed. Preliminary experiments are conducted to verify the feasibility of the proposed idea.