Flaw detection of pipelines using low frequency electromagnetic technique

LI Jun-ru1， ZHONG Shun-cong2，3，4， YANG Xiao-xiang2， GONG Ling-zhu5， GUO Jin-quan2，
CHEN Shi-wang5， CHEN Xiao-han5， LIN Tong5， YE Fei-fei5， WEN Zhen-xing5， YANG Tian-xue5
（1. School of Chemistry and Chemical Engineering， Fuzhou University， Fuzhou 350108， China；
2. School of Mechanical Engineering and Automation， Fuzhou University， Fuzhou 350108， China；
3. Key Laboratory of Safety Science of Pressurized System of Ministry of Education， East China University
of Science and Technology， Shanghai 200237， China；
4. Fujian Key Lab of Medical Instrument and Pharmaceutical Technology， Fuzhou 350002， China；
5. Special Equipment Inspection and Research Institute of Fujian， Fuzhou 350001， China）

Abstract： In order to investigate low frequency electromagnetic technique（LFET） in pipeline flaw detection，a two-dimensional finite element（FE） model of LFET was employed. A series of LFET simulations were carried out with the ANSYS parametric design language（APDL）. Magnetic flux lleakage signals of different flaws were obtained from the established models. The magnetic flux leakage signal was processed by using differential algorithm and more useful hidden information about flaws was obtained. From the simulations and experimental results，the practicality of LFET-based pipe flaw detection is demonstrated， therefore， it can be recommended for the applications in non-destructive testing of pipelines such as boiler water wall etc..
Key words： low frequency electromagnetic technique（LFET）； finite element（FE）； pipeline flaw detection； ANSYS parametric design language（APDL）