Automated Monitoring of Cable-Anchorage Force by Imote2-Platformed Impedance Sensor Node

摘要

For prestressed structures such as cable-stayed bridges and pretressed concrete bridges, it is very important to ensure prestress force of cable or tendon for the safety of these structures. The loss of prestress force could significantly reduce load carrying capacity of the structure and even result in structural collapse. This study presents an automated system to monitor cable-anchorage force using Imote2-platformed impedance sensor node. The following approaches are carried out to achieve the objective. Firstly, wireless impedance sensor node is designed for automated impedance-based monitoring technique. The sensor node is mounted on the high-performance Imote2 sensor platform to fulfill high operating speed, low power requirement and large storage memory. Secondly, a PZT-interface is designed to monitor prestress force of cable-anchorage by variation of impedance signatures. A linear regression model is established to predict prestress force with regarding to RMSD and frequency-shift. Finally, the system of PZT-interface and wireless sensor node is evaluated its performance on a lab-scale cable-anchorage model.