Seminar by Xun Wang

Ultrasonic guided wave, a tool for structural health monitoring (SHM): presentation of latest work

Dr. Xun Wang is now a professor at Beihang University, Beijing, China. He received his Ph.D. in "Estimation of multiple sound sources with data and model uncertainties" in Dec 2014 from the University of Technology of Compiègne, France. He was a postdoctoral fellow at Aix-Marseille University, France, and a Research Associate at Hong Kong University of Science and Technology from 2015 to 2020. He joined Beihang University in 2020 and has been a Full Professor since 2022. Dr. Xun Wang has published over 50 research papers in leading journals in acoustics and signal processing such as MSSP, JSV, and JASA. He has been awarded more than 10 research grants as PI, including three grants from the National Natural Science Foundation of China. His research interests include acoustical inverse problems, structural health monitoring, and acoustic imaging.

Abstract:
The ultrasonic guided wave is an efficient tool for structural health monitoring (SHM) due to its large inspection distance and high sensitivity to structural properties. However, the active guided wave method requires a wave generator and a power amplifier, which, in many scenarios of online monitoring, reduce the structural integrity and reliability and are also a heavy burden for power consumption. Flow-induced and mechanical random vibrations occur naturally during the flight of an aircraft and automatically produce passive guided waves with no need for wave excitation equipment, which thus have great potential for online SHM. This talk will show how random ambient guided waves can be used for passive icing detection. Recent progress by our research group on this topic will be introduced, including the dispersion curve and attenuation models for icing structures, passive extraction of dispersion curve and attenuation coefficients, passive icing detection and warning algorithms, numerical study of ambient noise distribution in wing structures, and manipulation of passive guided wave propagation. The proposed passive detection methods are verified via both laboratory and wind tunnel experiments.