摘要
采用ANSYS软件,针对1块表面有长9.0 mm、宽0.2 mm、深度分别为0.1,0.2,0.5,1.0,1.5,2.0和5.0mm裂纹的钢板建立涡流检测模型,仿真计算表面裂纹深度与磁感应强度的关系,得到近似服从指数关系的拟合曲线。在实验室制作钢轨表面裂纹试块,钢轨表面垂直裂纹试块的裂纹深度分别为0.5,1.0,2.0和5.0mm,钢轨表面斜裂纹试块的等效垂直深度分别为1.0和2.0mm且倾角分别为15°,30°,45°和60°;按照指数关系对试块表面裂纹深度与涡流检测信号电压幅值的关系进行拟合,得到可靠度高的指数函数式。截取1段表面带有自然裂纹的钢轨进行涡流检测试验,再利用拟合得到的指数函数式计算钢轨表面裂纹的深度,并与实际测量结果进行对比。结果表明:利用拟合的指数函数式评估深度约为2mm以内的钢轨表面裂纹时,表面裂纹深度的计算误差不超过10%,但是随后误差越来越大,因此采用涡流检测方法能够对2mm以内深度的钢轨表面裂纹进行有效检测及定量评估。
Based on ANSYS software, eddy current testing model was established for a steel plate with the cracks of 9.0 mm long, 0.2 mm wide and 0. 1, 0. 2, 0.5, 1.0, 1.5, 2.0, 5.0 mm deep respectively. The fitting curve of approximate exponential relation between surface crack depth and magnetic induction inten- sity was obtained by simulation. The test specimens of crack on rail surface were made in laboratory. The crack depth of vertical crack test specimen on rail surface was 0. 5, 1.0, 2.0 and 5.0 mm respectively. The equivalent vertical depth of inclined crack test specimen on rail surface was 1.0 and 2.0 mm respectively, and the inclination angle was 15°, 30°, 45° and 60°respectively. The relationship between the depth of crack surface and the voltage amplitude of the eddy current detection signal was fitted by exponential rela- tionship, and the exponential function formula with high reliability was obtained. The eddy current testing of a section of rail with natural crack was carried through. The crack depth of rail surface was calculated by using the fitting exponential function formula, and the results were compared with actual measurement re- sults. Results show that, when the crack on rail surface with a depth of about 2 mm is evaluated by the fitting exponential function formula, the calculation error the surface crack depth is no more than 10%. However, the error is getting bigger, so eddy current testing method can be used to effectively detect and quantitatively evaluate the rail surface crack within 2 mm in depth.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2017年第2期28-33,共6页
China Railway Science
基金
中国铁道科学研究院行业服务技术创新项目(2015YJ077)
关键词
钢轨探伤
表面裂纹
涡流检测
指数函数
非接触无损检测
Rail flaw inspection
Surface crack
Eddy current testing
Exponential function
Non-contact nondestructive testing
