A Self-contained Active Sensor System for Health Monitoring of Civil Infrastructures

A self-contained active sensor system is proposed for the practical use of an electro-mechanical impedance-based structural health monitoring (SHM) technique for civil infrastructures. This system, which consists of a miniaturized impedance measuring chip (AD5933) and a self-sensing macro-fiber composite (MFC) patch, can be a powerful tool for a variety of in-situ SHM applications in civil, mechanical, and aerospace systems, since (1) the AD5933 is low-cost, portable, and readily combined with a wireless telemetry and (2) the MFC patch can be permanently attached to a structure and provide meaningful information regarding the structure's integrity through its self-sensing function. In this study, the effectiveness of the proposed active sensor device has been verified through a series of experimental studies: (a) inspecting loosening bolts in a bolt-jointed structure and (b) detecting corrosion in an aluminum beam.