Group Velocity Measurement of Piezo-Actuated Lamb Waves Using Hilbert-Huang Transform Method

This paper reports the application of Hilbert Huang transform (HHT) to analyze piezo-actuated Lamb waves simulated numerically using finite element method. Pure Aomicron mode, pure Somicron mode and mixed Aomicron and Somicron modes have been actuated and their responses in different flight distances are recorded. Energy-time spectra of HHT are used to extract the arrival times of these signals, from which, group velocities of Aomicron and Somicron modes can be computed. The results are close to their theoretical values, which demonstrate the effectiveness of HHT in analyzing Lamb waves.