An integrated modeling method for piezo-actuated compliant mechanisms

Abstract

Piezo-actuated compliant mechanisms are widely employed in precision positioning and micro/nano manipulation due to their advantages of compact structure, high displacement resolution, and fast response. However, it is still challenging to accurately analyze the designed mechanisms due to the complicated coupled electromechanical behaviors of piezoelectric actuators and compliant mechanisms, which prevents further performance improvement by configuration design and optimization. A novel modeling method is developed in this paper for the kinetostatic and dynamic analyses of piezoelectric actuators and their comprised systems with compliant mechanisms. The electromechanical model of piezoelectric actuators is derived from linear piezoelectric vibration theory and further simplified as a practical equivalent model in the form of dynamic stiffness matrices. With the proposed actuator model, an integrated modeling method based on the dynamic stiffness matrix method is proposed for analyses of the piezo-actuated compliant mechanism with complicated configurations of piezoelectric actuators and flexible structures. Two case studies, including a piezoelectric actuator and a fast scanning stage, are analyzed to verify the effectiveness of the proposed approach. Both finite element analysis and experimental results validate that the presented modeling method can be used to resolve the kinetostatics and dynamics of complex piezo-actuated compliant mechanisms efficiently and effectively.