Fatigue Evaluation of Piezo Impact Drive Mechanism

Impact drive mechanism (IDM) has been applied in many fields in recent years. As an important component, the piezoelectric element (multilayer actuator) influences the mechanism's performance to a large extent. After been used for a long time, fatigue of the element will occur undoubtedly, which may be disadvantageous to the motion characteristic of IDM. The relationship between the fatigue and the movement is investigated in this paper making use of three non-destructive evaluation (NDE) methods. The experiment result reveals that if the fatigue occurs in multilayer actuator, the movement performance of IDM will be affected to varying degrees. It is confirmed that the impedance curve, the capacitance and the hysteresis loop of piezo element can be utilized as effective tools to estimate the IDM's property. They can be regarded as a reference standard to design, fabrication and application of IDM.