Analytical model and experimental verification of an elliptical bridge-type compliant displacement amplification mechanism
Haitao Wu, Leijie Lai, Limin Zhu
Abstract
In this paper, an analytical model of elliptical bridge-type compliant mechanism is established. Compared with the traditional bridge mechanism, the elliptical bridge-type compliant mechanism has the advantages of light weight, high natural frequency, and more uniform stress distribution. Based on the strain energy and Castigliano's displacement theorem, a static model for calculating the displacement amplification ratio and input stiffness is established. Then, the Lagrange equation is used to establish the dynamic model to calculate the natural frequency. After that, finite element simulation and experimental test are both used to verify the proposed analytical model. The results show that the maximum error between the analytical model and finite element simulation is within 8.25% and that of the experimental results is within 6.25%. The conclusion of this paper provides an accurate prediction analytical method for the mechanical performance index design of the elliptical compliant mechanism, which has important theoretical significance.