Self-magnetic flux leakage-based detection and quantification for high-strength steel wires of bridge cables considering corrosion-fatigue coupling effect

Self-magnetic flux leakage (SMFL) detection has been applied to detect internal defects of bridge cables, which are subjected to the coupling of corrosion-fatigue. In order to evaluate the coupling effect, a platform was designed for detecting the SMFL signals in cables or high-strength steel wires. Subsequently, experiments considering alternating action of corrosion and fatigue loads were performed. Based on the experimental data and theoretical model, influence mechanism of the coupling effect on SMFL signal was investigated. Results show that the signals are enhanced with only fatigue loads, and variations of signals tend to be stable. The abnormal signals caused by corrosion is weaken and enhanced by the fatigue load applied after and before the corrosion, respectively. When the fatigue loads are applied after the action of fatigue (pre-fatigue load)-corrosion, the prefatigue load makes the abnormal signal weakening more serious. The range of random variations of signals is larger with longer corrosion duration, but does not change regularly with the fatigue loads. The results provide guidance for the application of SMFL in bridge engineering.