基于传递函数法的兰姆波解析模拟

ANALYTICAL MODELING OF LAMB WAVES BASED ON TRANSFER FUNCTION METHOD

论文研究了兰姆波传播的解析模型.薄压电传感器(PZT)被用于兰姆波的激发.为模拟PZT的激励,采用PZT边缘的分布式点源等效PZT的激励,建立了解析模型的边界条件.结合三维傅里叶变换,在频率波数域求解了三维波动方程,得到了在单位周期激励下兰姆波的频域响应.结合传递函数法,可以得到任意激励下兰姆波的频域响应.利用傅里叶逆变换,进一步求解了兰姆波在时间-空间域的全局波场.为了验证解析模型,将解析模拟与实验进行了比对.试验测量值与解析模拟结果相吻合.

This analytical modeling of Lamb wave propagation excited by wafer type piezoelectric sensors （PZT） is studied. The PZT excitation is modeled by the distributed point sources at the PZT edge. By using the three-dimensional Fourier transform, the three-dimensional wave equation is solved in frequency- wavenumber domain. The frequency response of the Lamb wave propagation is achieved for the unit harmonic excitation. Further, the Lamb wave response is obtained with the transfer function method for any type of excitation. Using inverse Fourier transform, the time-space wavefield is obtained from the frequency response. Comparison between the analytical results and experimental measurements shows a good agree- ment between them is shown,which verifies the analytical modeling.