A wireless sensor system for structural health monitoring with guided ultrasonic waves and piezoelectric transducers

Piezoelectric transducers are widely used for structural health monitoring (SHM) applications. Low weight and small dimensions are only two of the several advantages of piezoelectric transducers. However, these advantages are weakened by using wired connections for supplying the piezoelectric transducers. Besides the additional weight, a long wire connection can have an influence on the measured capacitance. Due to the aforementioned disadvantages, researchers developed different wireless solutions for SHM applications in the last 10 years. In this paper, we present a wireless SHM system, which is designed for SHM applications with piezoelectric transducers and guided ultrasonic waves (GUW). The first part in this paper describes the different parts of the wireless SHM system. One novelty ofthe proposed wireless system is that every wireless signal-processing unit (SPU) in the network can be used for exciting the piezoelectric transducer and also for measuring the voltage signals coming from the piezoelectric transducer. Finally, the paper presents a laboratory test on an aluminium/hardfoam sandwich plate with a removable artificial defect to accurately assess the performance merits and weaknesses of the wireless sensor network.