Nonlinear vibration in metal plate excited by high-power ultrasonic pulses
高功率超声脉冲激励下金属板的非线性振动现象研究

Nonlinear vibration phenomena including superharmonics, subharmonics, quasi-subharmonics and chaos in metal plate excited by intensive ultrasonic pulses are studied experimentally and theoretically. In the experiments, the plates are excited by the ultrasonic pulse modulated high frequency vibration, and the nonlinear vibration velocities of the plates are measured by laser vibrometer for different sizes and fixing conditions of the plates. The analysis of time series, frequency spectrum and phase space are also performed to characterize the nonlinear vibration of the plate. According to the experimental conditions, a vibro-impact model with nonlinear contact damping is presented to explore the generation mechanism of the complicated nonlinear vibration in the plate. In the dynamic model, the intermittent vibro-impact between the ultrasonic transducer horn and plate are considered as the main source for generating the strongly nonlinear vibration in the plate. The numerical calculation results are in agreement with the observed experimental phenomena.