Wireless Impedance Sensor Node and Interface Washer for Damage Monitoring in Structural Connections

In this study, a technique using wireless impedance sensor node and interface washer is proposed for monitoring damage in structural connections of bridges. In order to achieve the objective, the following approaches are implemented. First, a wireless impedance sensor node is designed for automated and cost-efficient monitoring in structural connections. Second, impedance-based algorithms are embedded in the wireless impedance sensor node for autonomous monitoring of structural connections. Third, a tensile-force monitoring technique-using an interface washer is proposed to overcome limitations of the wireless impedance sensor node such as measureable ranges with narrow frequency band, and the proposed technique is numerically validated. Finally, the performance of the wireless impedance sensor node and the interface washer is experimentally evaluated in cable-anchor connection and bolted connection models.