基于模态对称算法的直管道导波缺陷检测研究

Straight Pipe Ultrasonic Guided Wave Defect Detection Based on Modal Symmetric Algorithm

针对直管道超声导波检测较难靠近管道结构处缺陷的问题,研究并设计了模态对称算法用于抽离回波信号中的非对称模态,对处理得到的模态对称曲线信息进行分析并评估管道结构处的健康状况。同时,建立管道试验系统对管道近焊缝处的裂纹回波进行采集,通过处理发现带缺陷处的模态对称曲线出现明显升高,加大裂纹缺陷,发现模态对称曲线幅值随缺陷的圆周对称度的增大而升高。该方法为避免管道缺陷的漏检提供了新的技术支持,且实现了利用导波技术对直管道结构处的区域进行准确诊断。

A modal symmetric algorithm capable of pulling away asymmetric modal of echo signal is designed for detecting defects near straight pipe structure. The modal symmetric curve is used to evaluate pipe structure health. A pipe test system is built to collect the crack near weld. It is found that the amplitude of defect modal symmetric curve rise obviously with the percent of defect circumference symmetric. This method also realizes the straight pipe structure health detection using ultrasonic guided waves.