Modeling and analysis of bridge-type compliant mechanism with elliptical shell

This paper investigates a bridge-type compliant mechanism with elliptical shell for amplified piezoelectric actuators. Compared with the traditional bridge-type mechanism using the notch flexure hinges, this kind of mechanism has advantages of high stiffness, low stress and high resonant frequency. An analytical model for the calculations of displacement amplification ratio and input stiffness is established based on the strain energy and Castigliano's displacement theorem. The analytical model is then verified by the finite element method. The influences of the geometric parameters on the performances of the compliant mechanism are also deeply analyzed using the analytical model. The conclusion of this paper provides an accurate analytical method for the design of bridge-type compliant mechanism with elliptical shell, and has a great practical significance.