基于PAUT与ACFM的钢桥疲劳裂纹检测试验研究

Experimental Study on Fatigue Crack Detection of Steel Bridge Based on PAUT and ACFM Technique

为准确检测疲劳裂纹尖端位置和裂纹长度,采用超声相控阵检测(PAUT)与交流电磁场检测(ACFM)技术对预制疲劳裂纹进行了测试,比较了超声相控阵与交流电磁场在疲劳裂纹识别与长度定量测试的准确性。分析了涂层对交流电磁场检测识别的影响,并通过实桥测试进行了验证。结果表明:超声相控阵和交流电磁场能够准确识别疲劳裂纹尖端位置,裂纹长度量化评估精度在95%以上;交流电磁场检测不受涂层影响,能在不去除涂层条件下实现疲劳裂纹检测和定量评估;超声相控阵和交流电磁场检测为疲劳裂纹尖端定位提供了新方法,可为疲劳裂纹的处治提供良好基础。

In order to accurately detect the position and length of fatigue crack,the ultrasonic phased array and alternating current field were used to test the preformed fatigue crack.The accuracy of ultrasonic phased array and alternating current field on fatigue crack detection and length quantification was verified.The influence of coating system on alternating current field detection and identification was analyzed.And it was verified by the actual bridge test.The results show that the ultrasonic phased array and alternating current field have high accuracy in fatigue crack detection and quantitative evaluation.The position of fatigue crack tip can been accurately identified,and the accuracy of quantitative evaluation for crack length is over 95%.Alternating current field detection is not affected by the coating,and the fatigue crack detection and quantitative evaluation can be realized without removing the coating.Ultrasonic phased array and alternating current field test provide a new way to locate the fatigue crack tip,and provide a good basis for treatment of fatigue crack.