Effect of thickness on the performance parameters of modified 1–3 piezoelectric composites

In this study, a modified 1–3 piezoelectric composite was designed to investigate the relationship between its thickness and properties of piezoelectric composites. First, the modified 1–3 piezoelectric composite was simulated using COMSOL to obtain the resonant and anti-resonant frequencies of each piezoelectric composite thickness, and the electromechanical coupling coefficient, acoustic impedance, acoustic velocity, and frequency difference of the corresponding thickness were calculated. Second, the modified 1–3 piezoelectric composite was simplified using series-parallel theory and uniform field theory, and the relevant piezoelectric performance parameters of the piezoelectric composites of different thicknesses were calculated. The above results were verified experimentally, and the experimental results were in good agreement with the simulation results. Although the theoretical calculation results deviated slightly from the experimental results, the overall trend was consistent with the experimental results. Finally, the performance parameters of the modified 1–3 piezoelectric composite and traditional 1–3 piezoelectric composite with a thickness of 7.5 mm were compared. It was found that the acoustic impedance of this modified 1–3 piezoelectric composite was smaller than that of the traditional 1–3 piezoelectric composite, and the electromechanical coupling coefficient was larger than that of the traditional 1–3 piezoelectric composite. Therefore, this modified 1–3 piezoelectric composite has great potential for the preparation of high-performance piezoelectric ultrasonic transducers.