文献类型：期刊文献

英文题名：Symmetry properties of second harmonics generated by antisymmetric Lamb waves

作者：Zhu, Wujun[1];Xiang, Yanxun[1];Liu, Chang-Jun[1];Deng, Mingxi[2];Xuan, Fu-Zhen[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety MOE, Shanghai 200237, Peoples R China;[2]Logist Engn Univ, Dept Phys, Chongqing 401331, Peoples R China

年份：2018

卷号：123

期号：10

外文期刊名：JOURNAL OF APPLIED PHYSICS

收录：;EI(收录号：20181204920068);WOS:【SCI-EXPANDED(收录号:WOS:000427516000027)】；

基金：This work was supported by the National Natural Science Foundation of China (Grant Nos. 11474093, 11474361, and 11622430), the National Key Research and Development Program of China (2016YFC0801903), and the Fundamental Research Funds for the Central Universities (Grant Nos. 222201717005 and 222201718005).

语种：英文

外文关键词：Harmonic analysis - Time domain analysis - Ultrasonic waves - Wave propagation - Acoustic fields

摘要：Symmetry properties of second harmonics generated by antisymmetric primary Lamb waves are systematically studied in this work. In theory, the acoustic field of second harmonic Lamb waves is obtained by using the perturbation approximation and normal modal method, and the energy flux transfer from the primary Lamb waves to second harmonics is mainly explored. Symmetry analyses indicate that either the symmetric or antisymmetric Lamb waves can merely generate the symmetric second harmonics. Finite element simulations are performed on the nonlinear Lamb wave propagation of the antisymmetric A0 mode in the low frequency region. The signals of the second harmonics and the symmetric second harmonic s0 mode are found to be exactly equivalent in the time domain. The relative acoustic nonlinearity parameter A(2)/A(1)(2) oscillates with the propagation distance, and the oscillation amplitude and spatial period are well consistent with the theoretical prediction of the A0-s0 mode pair, which means that only the second harmonic s0 mode is generated by the antisymmetric primary A0 mode. Experiments are further conducted to examine the cumulative generation of symmetric second harmonics for the antisymmetric-symmetric mode pair A3-s6. Results show that A(2)/A(1)(2) increases linearly with the propagation distance, which means that the symmetric second harmonic s6 mode is generated cumulatively by the antisymmetric primary A3 mode. The present investigation systematically corroborates the proposed theory that only symmetric second harmonics can be generated accompanying the propagation of antisymmetric primary Lamb waves in a plate. Published by AIP Publishing.