The bolt is considered as a four-end network of the equivalent circuit in the transducer.The resonance frequency equation of the transducer,whose displacement node is located at the metal, is derived. The effects of the position, the diameter and length of the bolt on the resonance frequency, the anti-resonance frequency and effective electro-mechanical coupling coefficient are studied. Uhe results show that changing the length,the position and diameter of the bolt appropriately can make the efffective electro-mechanical coupling coefficient of the transducer increase, thus optimize the performance of the piezoelectric transducer.

piezoelectric transducer; bolt; resonance frequency; anti-resonance frequency; electro-mechanical coupling coefficient