裂纹方向对脉冲涡流激励热成像的影响  

Analysis of the Crack Orientation Effect on Pulsed Eddy Current Stimulated Thermography

作　　者：常东[1,2] 左宪章[1] 田贵云[3] 钱苏敏[1] 

机构地区：[1]军械工程学院无人机工程系 [2]中国人民解放军71602部队 [3]英国纽卡斯尔大学电子与计算机工程学院

出　　处：《上海交通大学学报》2013年第5期779-785,共7页Journal of Shanghai Jiaotong University

摘　　要：通过建立不同方向裂纹的有限元模型,对利用脉冲涡流热成像技术检测铁磁和非铁磁金属材料的裂纹缺陷进行分析,讨论了不同方向裂纹对裂纹附近涡流场和温度场的影响,并提取试件表面温度最大值作为特征量来对裂纹方向角与几何尺寸的关系进行分析.同时,通过实验对数值分析结果进行验证.结果表明:在铁磁材料中,具有各种方向角的裂纹都可以检测到;而在非铁磁材料中,当方向角较小时难以检测出其裂纹.根据试件表面温度分布的对称特点,可对裂纹的走向进行初步判断;根据试件表面最大温度随着裂纹方向角的增大而呈线性增加,可进一步识别裂纹方向角.Finite element models of crack with different direction angle were established to analyse the cracks detection using the pulsed eddy current thermography in ferromagnetic and non-ferromagnetic metal materials. It was discussed the impact of different direction angle of cracks to the distribution of eddy field and temperature field. Extracting the maximum value of the surface temperature of the specimen as the feature, the relationship between the orientation angles and the geometric dimensions of the different crack was analyzed. In ferromagnetic materials, cracks can be detected in any directions angle. But it is difficult to achieve detection to the small direction in non-ferromagnetic material. According to the symmetric char- acteristics of the surface temperature distribution of the specimen, crack orientation can be initially judged. The surface maximum temperature value along the crack direction angle increases linearly with the increase of crack direction angle. It can be used for further identification.

关 键 词：脉冲涡流热成像 裂纹检测 裂纹方向 

分 类 号：TG115.28[金属学及工艺—物理冶金]