With the development of aerospace and aeronautics, medical instruments, underwater sonar system. telecommunication, etc. PZT-metal composite structure can be applied in various ultrasonic and acoustic devices and structures, such as actuators, motors, transducers, pumps, telephones, sensors, etc. In this paper, a PZT-metal composite disk used in disk-type traveling wave ultrasonic motors, is given as an example to investigate its non-axisymmetric ultrasonic vibration, Although non-axisymmetric vibrating distribution can be tested by several methods, such as Doppler Laser Interferometer, numeric imaging, FEM, etc., theoretical arithmetic simulation is limited by the complex structure and non-axisymmetric distortion. According to Kirchhoffs assumptions, this paper establishes linear system of equations for solving frequency constants and mode shapes. Using engineering and numerical analysis software Matlab5.3 and coefficient determinant searching arithmetic, frequency constants and mode shapes of the vibrator are solved corresponding to inner/outer diameter of 0.1, 0.3, 0.35, 0.6 and different modes. It offers a valid theoretical foundation for optimum design of the vibrator of disk-type traveling wave motor.
