The radial composite cylindrical piezoelectric ultrasonic transducer

The radial vibration of a new kind of ternary radial composite cylindrical piezoelectric transducer is studied. Based on the elastic mechanics theory and the electromechanical analogy,the electromechanical equivalent circuits of the segmented radially polarized piezoelectric ceramic tube in quasi-thickness vibration and a thin-walled metal pipe in radial vibration are obtained.By considering the continuous boundary conditions of the radial force and vibration velocity on the each interface of the transducer,the radial vibration equivalent circuit of the radial composite cylindrical piezoelectric transducer is derived and the resonance frequency equation is obtained.The relationship between the resonance frequency,the effective electro-mechanical coupling coefficient and the geometrical dimensions is analyzed.It is illustrated that the radial resonance frequency and the effective electro-mechanical coupling coefficient of the transducer are decreased with the radius of the inner core and the wall thickness of the prestress pipe of it increased.Finally,the radial resonance frequencies of some radial composite cylindrical piezoelectric transducers are tested.It is shown that the theoretical radial resonance frequencies are in a good agreement with the measured results.