Experimental case studies on wireless and wired sensors

Abstract

Performing full-scale structural testing is an important methodology for researchers and engineers in civil engineering industry. To conduct a full-scale structural testing, sensors are used for data acquisitions. Based upon their data communication strategies, sensors used for civil-structure testing could be divided into traditional wired sensors and wireless sensors. Compared to wired sensors, sensors that employ the wireless communication technology can potentially reduce implementation time and expenses, thus facilitating deployment of a dense network of sensors for structural health monitoring (SHM). This paper experimentally evaluates the advantages and disadvantages of wireless sensors versus wired sensors. Accelerometers are selected for case studies since they are one of the most widely used sensors in civil structure testing, primarily in system identification and SHM. Three different accelerometers studied in this paper include the piezoelectric wired accelerometer, the force balance tri-axial accelerometers, and the wireless smart sensing network sensor board based on the MEMS technology. These sensors were compared during a series of tests, which include free vibration testing of a laboratory scale steel frame, field ambient vibration testing of a building connection bridge, and full scale field monitoring of a 65-m high wind turbine tower vibration. The complete testing procedure (instruments deployment, data acquisition, and data processing) shows the advantages and disadvantages of different types of sensors. It is expected that the results of this study can help structural researchers and engineers get familiar with the wired and wireless sensing technologies and select the most effective testing instruments.