管道导波检测中的位移圆周分布调制方法

Angular-profile Tuning of Guided Waves in Pipe Inspection

在研究管道导波检测中的位移圆周分布调制聚焦技术时,将存在的缺陷看作一个新的导波源,提出通过截取阵列中各传感器获得的检测信号中的缺陷反射回波及转换模态波包信息,分析该波源造成的波场在检测位置的位移圆周分布,从而得到将检测能量重新聚焦于缺陷所在圆周任一位置所需要的各激励信号幅值系数和时间延迟参数。有限元分析及试验表明,应用该方法,不仅可以减少运用位移圆周分布调制聚焦技术检测时的计算量,还可以灵活地应对检测过程中管道参数、传感器阵列及检测频率的变化,有利于该方法的推广和应用。

When the angular-profile tuning method is used for the detection of small defects in a pipe, the defect is considered as a new passive guided wave source. The focusing phenomenon is analyzed by intercepting the defect reflected waves and conversion modes, which gives the information of the angular-profile for the passive wave source fields. Based on the information, the time delays and amplitude factors for a guided wave array are computed. The Finite Element Analysis and experimental results show that this method can be used to reduce the computation efforts and also to eater for the variations of the pipe parameters, the transducer array and the detection frequency during the detection processing, which can contribute to the popularization and application of this method.