【摘要】 在分析二维傅里叶变换原理的基础上,将快速傅里叶变换(FFT)和自回归(AR)参数估计相结合,采用混合谱二维傅里叶变换方法,对铝板中的兰姆波模式进行识别。试验结果表明,与二维快速傅里叶变换相比,混合谱估计方法能精确检测多模式超声兰姆波相速度,对兰姆波模式识别力大大提高。混合谱二维傅里叶变换方法在超声导波检测研究中具有广泛的应用前景。更多还原

【Abstract】 Based on the analysis of two-dimensional Fourier transform method(2-D FFT),a mixed-spectral estimation was proposed combined with FFT and AR model for the recognition of Lamb wave propagating model in aluminum plates.Experimental results showed that the mixed-spectral estimation could detect the ultrasonic phase velocity of multi-mode Lamb wave accurately,compared with the conventional two-dimensional Fourier transform methods,the resolving power of the new method was highly increased.The mixed-spectral estimation methods could be widely used for development of ultrasonic guided wave testing.更多还原