Topic: Recent Advances in Quantitative Nonlinear Ultrasonics: From Analytical Modelling to Engineering Applications
Speaker: Prof. Zhongqing Su, The Hong Kong Polytechnic University (PolyU)
Time: Thursday, July 21, 2022, 2:30 - 3:45 pm
Live Streaming Platform: Tencent Meeting
Conference ID: 863-274-400
Nonlinear ultrasonics – a technique that makes use of nonlinear features of ultrasonic waves such as higher-order harmonic generation, subharmonic generation, nonlinear resonance, or mixed frequency response, has been a core of intensive study in the past decade, to break through the bottleneck of conventional damage detection and structural health monitoring approaches based on ultrasonic waves. In such a context, this talk recaps some recent advances in quantitative characterization of small-scale damage such as fatigue cracks (with dimensions smaller than 1/10 of the probing wavelength) via nonlinear ultrasonics. Based on the wave propagation theory and elastodynamic reciprocity theorem, a three-dimensional (3-D) analytical model is developed, to shed light on the nonlinear aspects of ultrasonic waves disturbed by a fatigue crack with “breathing” traits. With the model, generation of contact acoustic nonlinearity embodied in waves, subjected to the key parameters of a “breathing” crack (e.g., crack length, orientation), is scrutinized quantitatively. The developed approach facilitates early prognosis of engineering structures under cyclic loads. The talk also highlights some successful applications of the technique in real engineering world.
About the Speaker:
Prof. Zhongqing Su is Professor of Mechanical Engineering and Head of Department of Mechanical Engineering at the Hong Kong Polytechnic University (PolyU). His research interests focus on ultrasonics, structural health monitoring (SHM), wave propagation, sensors, non-destructive evaluation, smart materials and advanced composites. He is the current Editor-in-Chief of journal Ultrasonics, and Associate Editor of nine key international journals in his field, including Journal of Sound and Vibration, Structural Health Monitoring: An International Journal, Structural Engineering and Mechanics, and ASME Journal of NDE. He is the author/co-author of two research monographs, six book chapters, eight edited books/international conference proceedings, and over 330 academic journal articles and international conference papers. Prof. Su received Structural Health Monitoring – Person of the Year Award in 2012, Dragon-Star Innovation Award (1st Place) in 2015 from European Commission, and the Natural Science Award for Higher Education Outstanding Scientific Research Output in 2015 and 2020 respectively, from Ministry of Education China. In PolyU, he was a recipient of the President’s Award for Excellent Performance/Achievement in Research & Scholarly Activities in 2011, Faculty Award for Outstanding Performance in Research in 2011, and Faculty of Engineering Research Grant Achievement Award in 2014, 2017 and 2020.
School Reliability and System Engineering