频散补偿在导波缺陷形状辨识上的应用  

Application of dispersion compensation in defect identification using guided wave

作　　者：吴斌[1] 邓菲[1] 何存富[1] 李隆涛[1] 

机构地区：[1]北京工业大学机电学院,北京100022

出　　处：《仪器仪表学报》2006年第z3期2095-2097,共3页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金项目(10572009);北京市自然科学基金项目(4052008);北京市教委资助项目(4KM200410005003)

摘　　要：针对超声导波具有的频散特性,导致导波缺陷检测信号波包在结构中传播时发生的展宽及衰减现象,研究了如何利用频散补偿技术对检测信号进行处理,将被频散特性淹没的缺陷信息再现,以实现缺陷形状的辨识问题。在进行实验验证的过程中,利用导波检测管道中的双槽形人工缺陷,通过改变端面加载的压电传感器位置,接收一组时域回波信号,根据波数—频率关系对导波传播过程中的频散进行补偿后,再现缺陷的形状特征。The dispersive effect of ultrasonic guided wave leads to the spreading and attenuation of the wave-packet propagated in a structure. Inspective signals with some information about defects are polluted by the effect. Application of dispersion compensation are studied for defect identification in this paper. According to this method, a non-axis symmetry end loading transducer can be used to excite an L(0,2) guided mode and receive its echo at one end of the pipe. By rotating this transducer with a specific space in the circumferential direction, twenty-four signals are received for dispersion compensation using the relation of wavenumber and frequency. Finally, we conclude that it is effective to help identify the shape of defects.

关 键 词：超声导波 频散补偿 缺陷检测 反演 

分 类 号：TH7-55[机械工程—仪器科学与技术]