基于尾波干涉的含缺陷焊缝损伤发展监测  

Monitoring of damage development of defective weld based on coda wave interferometry

作　　者：霍林生[1] 周德田 杨卓栋 刘洋 HUO Linsheng;ZHOU Detian;YANG Zhuodong;LIU Yang(State Key Laboratory of Coastal&.Offshore Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China;Liaoning Transportation Research Institute Co.Ltd,Shenyang 110015,Liaoning,China)

机构地区：[1]大连理工大学,海岸与近海工程国家重点实验室,辽宁大连116024 [2]辽宁省交通科学研究院有限责任公司,辽宁沈阳110015

出　　处：《实验力学》2022年第4期455-464,共10页Journal of Experimental Mechanics

基　　金：国家自然科学基金项目(52178274);中央高校基本科研业务费项目(DUT19TD26)资助。

摘　　要：当焊缝中存在未焊透缺陷时,焊接试件在循环荷载作用下,焊缝处会出现微小的塑性变形并影响焊接强度,因此对未焊透缺陷在早期的损伤发展进行有效的监测十分重要。然而目前的一些检测方法精度较低,无法实现长期的监测。本文提出了一种基于压电传感器的尾波干涉方法,针对这种带有未焊透缺陷的焊缝,设计了循环加载实验使其产生塑性变形,对焊接试件在循环荷载作用下的微小损伤变化进行监测。实验结果表明,在循环荷载作用下,试件出现微小的塑性变形并逐渐变大。根据尾波干涉监测结果,与直达波相比,尾波信号对微小变形更加敏感。使用波形伸缩法进行计算,最终得到平均伸缩系数(即尾波相对波速的变化值)随着循环次数的增加而上升的结论。When there is an incomplete penetration defect occurring in the weld,the test piece will have slight plastic deformation under the cyclic loading and affect the weld strength.Therefore,it is important to monitor the damage development of incomplete penetration effectively.However,current detection methods have low accuracy and cannot achieve the long term monitoring.In this paper,we proposed a Coda Wave Interferometry(CWI)monitoring method using piezoceramic transducers.Aiming at the defective weld with the incomplete penetration,a cyclic loading experiment was designed to generate the plastic deformation and then the small damage change of the welded specimen under the cyclic loading was monitored.Experimental results show that the slight plastic deformation was occurring in the weld and developed gradually under the cyclic loading.According to the monitoring results of the CWI method,the coda wave is more sensitive to the small deformation than the direct wave.The calculations are performed using the stretching method,which eventually leads to the conclusion that the average stretch coefficient(i.e.,the relative velocity variation value of the coda wave)increases gradually with the increasing cycles.

关 键 词：尾波干涉 压电传感器 焊缝缺陷监测 未焊透缺陷 

分 类 号：TG441.7[金属学及工艺—焊接]