Hidden damage detection for main cables of suspension bridges incorporating DC magnetization with a search coil-based B-H loop measurement

Recently, there have been lots of research and development activities to confirm the reliability in terms of the healthy condition for hanger cables of suspension bridges. However, little research about non-destructive evaluation (NDE) techniques for main cable of the suspension bridges has been carried out. In this context, this study proposes a new methodology incorporating DC magnetization with a search coil-based total flux measurement to investigate the loss of the cross section of the main cable due to corrosion damage. From the hysteresis curve of the magnetized main cable measured at the search coil of the proposed NDE equipment, a quantification algorithm to estimate the loss rate of the main cables' cross section is induced. The feasibility of the proposed NDE methodology is verified throughout an experimental study using a real scaled cable specimen with artificially inflicted broken wires.