Wireless monitoring of cable tension of cable-stayed bridges using PVDF piezoelectric films

For cable-stayed bridges, cable tension and its variation are two of the most important factors for judging whether the bridges are functional or not. Therefore, the in-situ monitoring of the stayed cables' tension of the cable-stayed bridge is very important and necessary, from which we can determine the health of the bridge. However, how to acquire and retrieve the signal is the key problem to determine whether the method is suitable for in-situ monitoring of the cable tension of cable-stayed bridges. In this paper, polyvinylidene fluoride (PVDF) piezoelectric films are used as the sensors to acquire the dynamic responses of the stayed cables, from which the tension of the stayed cables can be determined. Signal retrieval front the PVDF film sensors via wireless transmission technology is developed, which could be used for the wireless in-situ monitoring of the cable tension. The principles, feasibility, and configuration of the wireless system for monitoring the stayed cable tension of cable-stayed bridges are investigated. Also the validating experiment is performed on a small-scale stayed cable model in the laboratory. Results show that the proposed wireless monitoring system is feasible for the in-situ monitoring of the stayed cable tension. The method and transmission system can be applied to wireless health monitoring of civil infrastructures with various sensors.