ABSTRACT
In the past few decades, bridge construction has developed rapidly around the world. As a result, how to ensure the safety and durability of these infrastructures has become an important issue in the field of bridge engineering. As one of the main load-bearing members in cable-supported bridge, the bridge cable is relatively easy to be damaged. The damage involves corrosion, broken wire, and even fracture, which threatens the safety of bridges and personnel. Therefore, a series of studies related to the method development of non-destructive testing and evaluation of cables are necessary for scientific management and safe operation of cable-supported bridges. This paper presents the work on investigating the magnetic performance of bridge cables for damage detection. At first, several experiments of the cable wire were carried out. For steel wire, both static magnetization curve and the magnetization curve under stress were tested on various samples. For cable model, the magnetic after-effect test was carried out. Based on the test results, the factors having a great influence on the magnetization curve of the steel wire were obtained. This could help to further improve the method of increasing magnetization of the steel wire and the signal-to-noise ratio in the damage detection. Based on the phenomenon and trend obtained in the experiments, a finite element model was built to analyze the demagnetization effect of the steel wire in detail. The main factors affecting the demagnetization effect can also be obtained. This research promotes better understanding of the process of magnetic evolution of the entire bridge cable system, and the results can support the development of relative theory and experimental studies of cable damage detection.
