施加水平磁场下电磁声发射与裂纹指向特征分析  

Characteristics analysis for EMAE and crack orientation under a horizontal magnetic field

作　　者：蔡智超[1] 刘素贞[2] 张闯[2] 张严伟[2] 杨庆新[2,3] 

机构地区：[1]华东交通大学电气与自动化工程学院,南昌330013 [2]河北工业大学电磁场与电器可靠性省部共建重点实验室,天津300130 [3]天津工业大学电工电能新技术天津市重点实验室,天津300387

出　　处：《振动与冲击》2017年第5期238-245,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51307043)

摘　　要：声发射检测方法对金属构件进行健康检测的关键问题:通过合适的载荷使得构件产生声发射信号。现阶段大部分声发射检测均采用接触式离线加载,声发射检测采用可在线检测的非接触式电磁加载。从电致位错、自由电子运动理论出发,在微观层面探究电磁声发射的机理特征;研究静磁场与涡流分布作用下电磁声发射特征差异;基于声发射信号的非平稳特征,利用希尔伯特黄变换方法分析电磁声发射特征。通过改变水平磁场激励方向,实现本征模态函数的能量比值、互相关系数、特征本征模态函数时频图与裂纹指向特征之间的关系联立。The key problem for the metallic structures ^ health monitoring using the acoustic emission （AE） method is to establish a relationship between a suitable load and structures＇ AE signals excited. But the current AE tests mostly use an offline loading on structures with the contact method. Here, an AE testing method using a contactless local electromagnetic online loading was proposed. Firstly, the mechanism of electromagnetically induced acoustic emission （EMAE） was studied at a microscopic level based on the electro induced dislocation and free electron movement theory. Secondly, the characteristic differences of EMAE signals under various electromagnetic loading conditions were studied, the emission characteristics of the collected nonstationary EMAE signals were studied with Hilbert-Huang transformation. Finally, the relationships among the energy percentage of intrinsic mode functions （ IMFs ） , the cross-correlation coefficients of IMFs, the time-frequency figures of IMFs and crack orientation were established through changing the excitation direction of horizontal magnetic field.

关 键 词：电磁声发射 水平磁场 希尔伯特黄变换 裂纹指向性 

分 类 号：TM153[电气工程—电工理论与新技术]