Accurate Equivalent Beam Model of a Planar Compliant Mechanism with Elliptical Flexure Hinges

An accurate and efficient equivalent beam model(EBM) for a planar compliant mechanism with ellipticalflexure hinges is presented. First, based on 3D finite element analysis (FEA) for one-eighth of a single elliptical flexure hinge, a set of fictitious beams with identical stress and stiffness characteristics is derived. Then the static and dynamic performances of an eight-bar compliant mechanism with elliptical flexure hinges are studied based on the EBM and 2D FEA under either the plane stress or plane strain assumptions. Compared with the results of 2D FEA, the EBM has the advantages of high efficiency and good accuracy.