Design and Analyses of a Novel Two-axis Flexure Hinge with Elliptical Transverse Cross-sections
Two-axis flexure hinges with orthogonally-collocated notches comprised rectangular transverse cross-sections which increased the stress concentration on the sharp edges.In addition,such effects could not be avoided through notch optimization.Consequently,a novel kind of two-axis flexure hinge with elliptical transverse cross-sections was developed herein.Firstly,the parametric model of the flexure hinges with circular notches was established.Then,the compliance and stress models of the flexure hinges were developed based on the Castigliano's second theorem.The analytical models were verified through finite element analyses and the parametric simulations were performed to evaluate the characteristics of compliances and stress concentration.Finally,the compliances of a flexure specimen were tested through experiments.The results show that the ETC flexure hinges have two-dimensional anisotropic compliances.The sharp-edge structures are avoided.Therefore,the stress concentration effects are reduced and the motion capability is increased.Compared to exiting two-axis flexure hinges with identical notch profiles but rectangular transverse cross-sections,the motion capa-bility of the ETC type flexures hinges is increased by 47.9%.The ETC type two-axis flexure hinges expand the design spaces of the primary flexure structures.
flexure hingeflexure mechanismelliptical transverse cross-section(ETC)two-axis flexure hinge