厚壁管道轴向裂纹对C-SH_(0)模态反射特性的影响  

The effect of axial cracks in a thick-walled pipe on the reflection characteristics of C-SH_(0) mode

作　　者：赵华民[1] 郑明方 ZHAO Huamin;ZHENG Mingfang(College of Engineering,Shanxi Agricultural University,Jinzhong 030801,China;School of Environment and Civil Engineering,Dongguan University of Technology,Dongguan 523808,China)

机构地区：[1]山西农业大学工学院,晋中030801 [2]东莞理工大学环境与土木工程学院,东莞523808

出　　处：《无损检测》2021年第4期40-45,共6页Nondestructive Testing

基　　金：山西农业大学博士科研启动基金项目(P2018YJ43);国家自然基金青年科学基金项目(51905099)。

摘　　要：采用有限元方法分析了激励信号的中心频率、轴向裂纹长度、缺陷深度和缺陷位置对周向超声导波反射的影响。利用时域反射系数R评价了轴向裂纹反射回波强度随缺陷尺寸和中心频率的变化趋势。对于一定尺寸的非贯通轴向裂纹,当中心频率从55kHz增加到110kHz时,周向水平剪切模态(C-SH_(0))的R略有增加。在给定的中心频率下,随着裂纹长度的增加,R先增大后减小,再进入振荡区,最后趋于稳定。因此,得出C-SH_(0)模态对内部缺陷和外部缺陷具有相同的敏感性的结论。最后确定了不同轴向范围内R的最大值和最小值,可用于缺陷尺寸的定量分析。The effects of the center frequency of excitation signal,axial crack length,depth,and positions of defects on circumferential ultrasonic guided wave reflection were analyzed.Time-domain reflection coefficient(R)was used to evaluate the variation trend of the reflection strength with the defect size and the center frequency for axial crack.For a given size of non-through-wall axial crack,the R of circumferential shear horizontal(C-SH_(0))mode increased slightly when the center frequency was increased from 55 kHz to 110 kHz.At a given center frequency,for through-wall axial crack,the R firstly increased linearly,then decreased,subsequently entered an oscillatory regime,and finally became stable with the increase in the crack length.Therefore,the conclusion of C-SH_(0) mode had the same sensitivity to internal and external defects was given.The maximum and minimum values of R at varying axial extents were identified and can be used for defect sizing.

关 键 词：厚壁管道 周向导波 反射系数 轴向裂纹 

分 类 号：TB553[理学—物理] TG115.28[理学—声学]