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

Abstract

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.

Keywords:

• structural health monitoring
• wireless sensor network
• piezoelectric transducer
• guided waves
• artificial delamination

Acknowledgements

This research is partially funded by Nano-Tera.ch, Swiss scientific initiative in health/security/environment systems. The authors would like to express their gratitude to Mr. Specker and Mr. Brühwiler from the Interstate University of Applied Sciences of Technology Buchs for developing the main parts of the wireless System, Mr. Lemuel Agostinelli for performing the experimental measurements, Mr. Lorenzo De Boni for technical support and Dr.Andreas J. Brunner and Dr. Andrea Battisti for proofreading this paper and for their support and helpful discussions.