表面裂纹对Rayleigh波的滤波特性分析

表面裂纹是危害很大且普遍存在的一种缺陷,严重影响到特种设备的安全运行。对表面裂纹尺寸的测量一直未得到很好的解决,由于Raylegh波能量主要集中在深度一个波长的范围内,当传播过程中和裂纹相互作用时,其频谱会发生变化,一部分高频波将会被吸收,吸收频率的大小与裂纹的深度密切相关。此时裂纹起了一个类似低通滤波器的作用,这点对于裂纹深度检测具有指导意义。

The surface crack is a defect which is very dangerous and widespread, seriously affect the sate of special equipment. Measurement of surface crack size has not been satisfactorily resolved, because the energy of the Rayleigh wave is concentrated in the depth of a wavelength range, when encountering the crack and happening interaction, the spectrum of Rayleigh wave will change, part of the high-frequency wave will be absorbed, the absorbed frequency is closely related to the size of the crack depth. Crack is similar to a low-pass filter, it is useful to the detection of crack depth.