In order to realize nondestructive cracks testing of aircraft wheel hub

an eddy-current probe is designed which is placed on the wheel hub surface plate.The probe consists of a detecting coil and a reference coil.The faint crack signals are picked up by the electric bridge.The orthogonal phase-lock amplification is adopted to obtain the orthogonal decomposition signals.Two-path DC component

which contain amplitude and phase information are utilized to inspect the cracks.According to the conclusion obtained from numerical simulation and guide design of pratical probe

and the test results for the aircraft wheel hub show that the proposed probe can be used for detecting aperture’s crack accurately and it has high sensitivity.