关键词: 激光超声/
有限元法/
近表面黏性性质/
衰减
English Abstract
Propagation characteristics of laser-generated surface acoustic waves in composite plate with gradient changes of near-surface viscous moduli
Guan Yi-Jun1,Sun Hong-Xiang1,2,
Yuan Shou-Qi1,
Ge Yong1,
Xia Jian-Ping1
1.Faculty of Science, Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, China;
2.State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China
Fund Project:Project supported by the Major Program of National Natural Science Foundation of China (Grant No. 51239005), the National Natural Science Foundation of China (Grant No. 11404147), the Natural Science Foundation of Jiangsu Province of China (Grant No. BK20140519), the China Postdoctoral Science Foundation (Grant No. 2015M571672), the Research Fund for Advanced Talents of Jiangsu University, China (Grant No. 13JDG106), and the Training Project of Young Backbone Teachers of Jiangsu University, China.Received Date:07 June 2016
Accepted Date:18 August 2016
Published Online:05 November 2016
Abstract:Taking into account the gradient change of the near-surface viscous property, we develop a finite element model of laser-generated surface acoustic wave in composite plate. The propagation characteristics of the surface acoustic wave in the composite plate are studied in detail, and the influences of the near-surface viscous modulus, thickness, and Lam constant on the attenuation characteristics of the surface acoustic wave are discussed. In addition, the propagation characteristics of the surface acoustic wave are verified by the theoretical calculations of the dispersion and attenuation curves. The results show that the near-surface viscous modulus and thickness are related to the attenuations of the surface shear wave and the Rayleigh wave, but have no influence on the propagation velocity. Furthermore, the imaginary part of the Lam constant has great influence on the attenuations of the surface shear wave and the Rayleigh wave, whereas the imaginary part of has no effect on the attenuation characteristics of the two waves, which indicates that the attenuation of the surface acoustic wave is related to the near-surface shear viscous modulus. The study gives theoretical basis for evaluating the near-surface mechanical properties of the composite plates by the laser ultrasound technique. Besides, it provides a feasible way to study the surface micro-cracks on the composite plates.
Keywords: laser ultrasound/
finite element method/
near-surface viscous property/
attenuation
