on the plate cracks in a wagon wheel

 

 

SUN Zhen guo1, CAI Dong1, LI Dong1, 2, ZHANG Wen zeng1, CHEN Qiang1

 

(1. Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;

2. College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China)

 

 

Abstract: Aiming at the lift off effect during the inspection of plate cracks using eddy current, the probe was optimized, which can ensure the high signal noise ratio and suppress the lift off effect with the increase of sensitivity,  to realize the accurate detection of the cracks in the rough surface. A side by side type probe with small size, suitable for the detection of plate crack, was proposed. The magnetic field induced by the probe was calculated with the numerical analysis of probes based on field circuit coupling. Experiments were conducted to compare the performance of the proposed probe with traditional one. The results indicate that the probe with a closed magnetic circuit can suppress the lift off effect more effective than the traditional differential probe, and side by side type probe can effectively detect the plate cracks in a wagon wheel and realize the quantitative measurement of crack length.

 

Key words: plate cracks; eddy current testing; lift off effect; probe optimization