A study performs estimation of fatigue safety that is considering cross-sectional loss of cable by applying foreign regulatory review. Because of steel cable-stayed bridge cable`s corrosion which is occurred after construction completion more than 30 years. Analysis result, all cable members secure fatigue safety considering cross-sectional loss of cable.

This large diameter cable NDE technique was based on the direct current (DC) magnetization technique and a search coil-based magnetic flux measurement. A total flux sensor head was fabricated that was consisted by a magnetization part to magnetize the specimen and a sensing part to measure the total magnetic flux. The magnetization part was consisted by an electro-magnet yoke that fabricated by winding a coil. The magnetic field for magnetizing the main cable was generated by applying the low frequency DC voltage to the winded coil. The sensing part was configured by two semi-circular search coils, and it measures the electromotive force that pass through the search coil by using the faraday’s law of induction. Total flux was calculated by integrating the measured magnetic flux. Then, B-H curve was extracted using the total flux, and cross-sectional loss can be detected using variation of features from the B-H curve.

This large diameter cable NDE technique was based on the direct current (DC) magnetization technique and a search coil-based magnetic flux measurement. A total flux sensor head was fabricated that was consisted by a magnetization part to magnetize the specimen and a sensing part to measure the total magnetic flux. The magnetization part was consisted by an electro-magnet yoke that fabricated by winding a coil. The magnetic field for magnetizing the main cable was generated by applying the low frequency DC voltage to the winded coil. The sensing part was configured by two semi-circular search coils, and it measures the electromotive force that pass through the search coil by using the faraday’s law of induction. Total flux was calculated by integrating the measured magnetic flux. Then, B-H curve was extracted using the total flux, and cross-sectional loss can be detected using variation of features from the B-H curve.

Steel cables are frequently used for various infrastructures. Especially the steel cables in long span bridges are critical members Damage at cable members can occur in the form of cross sectional loss caused by corrosion and fracture. Therefore, NDE of steel cable is needed to measure the cross-sectional damage. In this study, Total Magnetic Flux sensor system was applied to monitor the condition of cables. This system measures total magnetic flux to detect the loss of metallic cross section area(LMA) of steel cable. To verify the feasibility of this study, 2 types of steel bar were fabricated and their output values measured by the search coil in total flux sensor.