Research Interests

Vibroacoustics studies the interaction between sound waves and structural vibrations. Efficient modeling of complex vibroacoustic systems is usually challenging. Although commercial FEM and BEM software packages are available, they lack the efficiency and flexibility for optimization purposes. To solve these challenges, we developed sub-structuring Patch Transfer Function (PTF) approach and Iso-geometric modeling method for efficient modeling of vibroacoustic systems. The accuracy and efficiency have been demonstrated through representative vibroacoustic systems.

The advent of acoustic metamaterials and meta-structures brings about fascinating opportunities for acoustic wave manipulation and noise control. Our research enabled new design concepts of advanced acoustic materials/structures and revealed predominant underlying mechanisms. Using the developed numerical methods, salient features of several metamaterial systems including tunable acoustic resonators, metamaterial ventilation windows and gratings, inertial amplification systems, and sonic black holes have been investigated with their detailed physical mechanisms revealed. The research findings are conducive to acoustic wave manipulation and the exploration of new functionalities, as showcased by a few successful applications in engineering noise control projects.

This research addresses the critical challenge of pipe inspection by focusing on the identification of leakage locations and conditions using a robotic platform. We propose novel methodologies that integrate LiDAR and microphone array to construct a high-precision leakage map. The degradation of LiDAR SLAM performance is improved by incorporating acoustic localization cues. Our work aims to facilitate non-destructive and autonomous structural health monitoring for effective pipe inspection.

Musical instruments, such as the violin and erhu, are highly complex vibro-acoustic systems. Their sound response and quality are determined by the intricate interactions between structural vibrations, acoustic resonances, sound radiation, and the surrounding environment. We conduct studies to investigate the effects of materials used in instrument construction, providing scientific insights into their acoustic properties. Our research involves accurate sound recording in an anechoic chamber and vibration testing using a laser Doppler vibrometer.

Sound barriers, commonly used to limit noise transmission, are often seen enveloping construction sites and road traffics. While effective, they are heavy, rigid and require significant manpower to assemble. Seeking to overcome these restrictions, we are borrowing concepts from origami, the art of paper folding. Our work offers fundamental insights into how folding would affect the acoustic performance of sound barriers, and opens up new opportunities for designing innovative acoustic devices.

The sound absorption performances of various types of porous materials are investigated. Acoustic characterization typically uses RUC based model to determine the micro-fluid parameters, then predicts the sound absorption using flow-resistivitybased DB/JCA model.

Material fabrication and experimental work are conducted by Prof. Zhai Wei's group at the National University of Singapore: https://blog.nus.edu.sg/zhaigroup/