Effect Law Study of Geometric Characteristic of Steel Bridge Fatigue Crack on Eddy Current Testing Signal
Aiming at the problem that the conventional fatigue crack testing method of steel bridge deck can only fit the sur-face for testing,the eddy current testing method was introduced to realize the detection of fatigue cracks on the surface of steel bridge deck.A eddy current testing experimental platform was built,and an eddy current testing probe was designed and devel-oped to scan fatigue cracks of different sizes horizontally.The influence rule of fatigue cracks with different length,width and depth characteristics on the testing signal was studied.The finite element simulation model was established to simulate the fatigue crack scanning process,which verified the reliability of the eddy current detection method for fatigue crack of steel bridge deck,and provided a basis for accurate measurement of subsequent fatigue crack size.The experimental results show that the designed hollow cylindrical testing probe can realize the positioning detection of surface crack defects with a minimum size of 60 mm length,0.2 mm width and 5 mm depth.The amplitude variation of the detection signal is positively correlated with the crack length,width and depth within a certain range.The crack length and depth have a great influence on the testing signal,and the crack width has little effect on the testing signal.
eddy current testingsteel bridge fatigue crackgeometric characteristictesting signal