The parameter mapping of power ultrasonic transducer model

The vibration and electrical characteristics of transducer is determined by material coefficients and geometry, with material coefficients being susceptible to factors including frequency, pressure, and temperature, which leads to poor repeatability of transducer characteristics. Consequently, it is challenging to provide an accurate theoretical model to predict the characteristics based on the current material coefficients. To achieve a more accurate transducer model, a measurement method is proposed based on the mapping between material coefficients and transducer characteristic parameters to obtain accurate coefficients under working conditions with simple equipment and lower costs. The mapping is analyzed based on the transducer model, identifying five key coefficients. An iterative optimization method is then developed to measure these coefficients. Additionally, the genetic algorithm (GA) method is utilized for cross-checking. Transducers made from seven different materials and with varying lengths are measured, and the coefficients are obtained by both methods. With the obtained coefficients, the vibration and electrical characteristics of multi-material transducers is predicted and found to be in good agreement with the measured values, validating the transducer model and the coefficient measurement method. These coefficients are then compared with results obtained from a dynamic mechanical analyzer (DMA) and reference values. The results demonstrate that theoretical coefficients obtained by the proposed method lead to more accurate predictions for the vibration and electrical characteristics compared to those obtained from the DMA and reference values. Furthermore, the influence of frequency on the coefficients is studied by the method. The iterative method and GA method are compared in terms of their relative errors.