Wireless impedance sensor nodes for functions of structural damage identification andsensor self-diagnosis

Abstract

Economic and reliable online health monitoring strategies are very essential for safeoperation of civil, mechanical and aerospace structures. This study presents onlinestructural health monitoring (SHM) techniques using wireless impedance sensor nodesequipped with both functions of structural damage identification and sensor self-diagnosis.The wireless impedance sensor node incorporating a miniaturized impedance measuringchip, a microcontroller and radio-frequency (RF) telemetry is equipped with thecapabilities for temperature sensing, multiplexing of several sensors, and local dataanalysis. The feasibility of the sensor node for structural damage identification is firstlyinvestigated through a series of experimental studies inspecting loosened bolt damage andcut damage cases. Additionally, a temperature effects-free sensor self-diagnosis algorithm isembedded into the sensor node and its feasibility is examined from the experimentsmonitoring the integrity of each piezoelectric sensor on a wireless sensor network.