Precision vibration suppression design for composite piezoelectric actuator based on coupled mechanism of leverage and triangular principle

Limited by their inherent structural characteristics, conventional piezoelectric stack actuators only produce micro-scale output displacements, which fail to satisfy the large-stroke working demands of precision mechanical systems. To overcome this technical limitation, this paper proposes a flexible hinge actuator integrating the lever and triangular amplification principles. The symmetric structural configuration is designed to combine the high displacement gain of lever mechanisms and the high linearity advantage of triangular structures, effectively resolving the inherent trade-off among output stroke, motion trajectory accuracy and structural stiffness in traditional displacement amplification designs. Based on the elastic mechanics theory, theoretical models for the displacement amplification ratio and equivalent stiffness of the proposed actuator are established. Finite element simulation is conducted to further validate its structural strength and dynamic performance. A prototype of the actuator is manufactured through wire electrical discharge machining, and systematic experimental tests are performed for performance verification. The test results demonstrate that the actuator achieves an output displacement of 85.360 μm under a driving voltage of 80 V, with a measured amplification gain of approximately 4.500. The experimental data exhibits a consistent variation trend with the theoretical value of 5.400 and the simulated value of 4.774. Benefiting from the advantages of large output stroke and superior structural stiffness, the proposed actuator provides a promising technical approach for high-precision actuation and vibration suppression applications.