摘要
交变磁场测量法通常要求检测探头的扫查方向与裂纹走向平行,但构件实际裂纹走向难以判断;在激励电流和频率为2.3A、1000Hz时,利用U型磁轭探头,对铝板不同深度的矩形槽缺陷进行不同扫查模式的检测,研究了探头扫查方向、感应涡流场方向分别与裂纹走向相垂直和平行时对检测信号的影响规律;实验结果表明:探头扫查方向与其两脚连线垂直时仅BX或By分量变化,难以表征缺陷,而探头扫查方向与两脚连线平行时,无论检测横向或纵向裂纹,都可依据BX和BZ变化量评价其深度和长度,但检测灵敏度有一定差异;上述结论有助于人们认识扫查方向对交变磁场测量法检测结果的影响。
The scanning direction o;t testing probe is usually required to be parallel wlin cracks in atternatmg current lield measurement （ACFM） technique, but the alignment of cracks in components is generally unknown. U-shape inducer was used to detect rectangular slot of various depths with different scanning modes when the inducing current and frequency is 2. 3A and 1000Hz, general rules between scan- ning direction and testing signals were researched. The experiment results show that the flaws are difficult to be characterized for only Bx or Bymagnetic field changes when scanning direction is vertical with the connection of the feet, but the depth and length of the longitudinal or transverse cracks could be evaluated by Bx and Bz when scanning direction is parallel with the connection of the feet, though the sensitivity is different. The conclusion above is useful to realize the affection of scanning direction on ACFM testing signals.
出处
《计算机测量与控制》
北大核心
2013年第7期1750-1752,共3页
Computer Measurement &Control
基金
国家自然科学基金项目(51265041)
江西省教育厅科技项目(GJJ12406
GJJ12444)
无损检测技术教育部重点实验室基金项目(ZD201029003)
南昌航空大学研究生创新基金项目(YC2011015)
