title: Fatigue Crack Length Sizing Using a Novel Flexible Eddy Current Sensor Array.
abstract: The eddy current probe, which is flexible, array typed, highly sensitive and capable of quantitative inspection is one practical requirement in nondestructive testing and also a research hotspot. A novel flexible planar eddy current sensor array for the inspection of microcrack presentation in critical parts of airplanes is developed in this paper. Both exciting and sensing coils are etched on polyimide films using a flexible printed circuit board technique, thus conforming the sensor to complex geometric structures. In order to serve the needs of condition-based maintenance (CBM), the proposed sensor array is comprised of 64 elements. Its spatial resolution is only 0.8 mm, and it is not only sensitive to shallow microcracks, but also capable of sizing the length of fatigue cracks. The details and advantages of our sensor design are introduced. The working principal and the crack responses are analyzed by finite element simulation, with which a crack length sizing algorithm is proposed. Experiments based on standard specimens are implemented to verify the validity of our simulation and the efficiency of the crack length sizing algorithm. Experimental results show that the sensor array is sensitive to microcracks, and is capable of crack length sizing with an accuracy within ±0.2 mm.
authors.affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. xieruifang2@163.com.
authors.forename: Ruifang
authors.initials: R
authors.lastname: Xie
authors.affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. chendixiang@163.com.
authors.forename: Dixiang
authors.initials: D
authors.lastname: Chen
authors.affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. pmc_nudt@vip.163.com.
authors.forename: Mengchun
authors.initials: M
authors.lastname: Pan
authors.affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. twg_1978@163.com.
authors.forename: Wugang
authors.initials: W
authors.lastname: Tian
authors.affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. xzwu@nudt.edu.cn.
authors.forename: Xuezhong
authors.initials: X
authors.lastname: Wu
authors.affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. zwhgfkd@163.com.
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhou
authors.affiliation: College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha 410073, China. tangyingtiger@163.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Tang
keywords: crack sizing; flexible eddy current array; high sensitive; quantitative nondestructive evaluation; spatial resolution