Design and Implementation of an Accurate, Portable, and Time-Efficient Impedance-Based Transceiver for Structural Health Monitoring

Reducing maintenance costs while increasing the safety and reliability, especially in moving structures, needs a reliable nondestructive analyzer. The aim of this research is to provide a practical solution for this problem based on high-frequency excitation of stationary and moving structures by propagating standing Lamb waves in the range of 1 to 1000 kHz. The proposed solution comprises of a controlled frequency swept signal source, a number of piezoelectric sensors, a portable analyzer, and a rotary mechanism. Measuring the accurate electromechanical impedance (EMI) is made possible by monitoring the applied voltages, currents, and phase differences accurately. In this study, design and implementation of a low-cost, compact, and portable transceiver is explored for periodic structural health monitoring of a proposed rotary structure using EMI technique. The compactness of the proposed system is an essential requirement for rotary structures as compared with bulky, heavy, and expensive impedance analyzers. Challenges in design and development of such a system are discussed in this paper, together with mitigations to make the system functional and practical. An experimental study is carried out in frequency domain to measure the real and imaginary parts of impedance spectrum of piezo-transducers. The results show that the portable transceiver has the capability to detect structural incipient damages before any catastrophic failure, thus avoiding undesirable shut down during the operation.