相速度近似匹配情况下的Lamb波非线性特征研究  

Nonlinear features of Lamb wave based on approximate phase velocity matching

作　　者：朱颖[1,2] 黄嘉诚 陈祎婷 陆铭慧 朱萍[3] Zhu Ying;Huang Jiacheng;Chen Yiting;Lu Minghui;Zhu Ping(Key Laboratory of Nondestructive Testing Ministry of Education Nanchang Hangkong Unirersily,Nanchang330063,China;Stale Key Laboratory ofAcoustics,Institule of Acousties,Chinese Academy of Sciences,Beijing 100190,China;AECC Shenyang Liming Aeroengine CorporationLd,Shenyang110043,China)

机构地区：[1]南昌航空大学无损检测技术教育部重点实验室,南昌330063 [2]中国科学院声学研究所声场声信息国家重点实验室,北京100190 [3]中国航发沈阳黎明航空发动机有限责任公司,沈阳110043

出　　处：《仪器仪表学报》2022年第4期263-270,共8页Chinese Journal of Scientific Instrument

基　　金：声场声信息国家重点实验室开放基金(SKLA202112);省教育厅科技项目(GJJ190513);无损检测技术教育部重点实验室开放基金(EW201908439)项目资助。

摘　　要：基频Lamb波模式的选择和激发条件的确定对非线性Lamb波技术起重要作用。利用积累距离定义二次谐波激发窗口,讨论谐波产生对基频Lamb波激发条件严苛性的要求。利用二次谐波表面位移振幅评价谐波激发效率,讨论相速度近似匹配对谐波激发效率的影响及不同模式Lamb波间二次谐波激发效率的大小。理论结果表明,在积累距离内,传播距离的增加,会提高二次谐波激发效率,却使谐波产生条件更为严苛;一定程度的相速度近似匹配,会使二次谐波的激发效率提高;激发模式不同,其谐波激发效率及对谐波产生条件的严苛性均不同。实验测量并比较了纵波型S;/S;模式对在90、150 mm传播距离下以及纵波型S;/S;、S;/S;模式对在150 mm传播距离时的激发窗口与相对非线性系数大小,测量结果与理论分析结论一致。本文对于相速度近似匹配情况下Lamb波非线性效应的讨论,为Lamb波实际应用提供了分析方法与依据。The choice of primary Lamb wave mode and the determination of excitation conditions play important roles in the nonlinear Lamb wave technology. The excitation window of the second-harmonic Lamb wave is defined by accumulation distance when the phase velocity is approximate matching. The strictness of the primary Lamb wave excitation condition is discussed. The excitation efficiency of the second-harmonic Lamb wave is evaluated by the amplitude of surface displacement. The influence of phase velocity approximate matching on the excitation efficiency as well as the excitation efficiency of different modes of Lamb wave is discussed. The theoretical results show that, within the accumulation distance, the increase of the propagation distance could improve the excitation efficiency of the second harmonic. But, the harmonic generation conditions are more strictly. A certain degree of phase velocity approximate matching will improve the excitation efficiency of second-harmonic Lamb wave. For different primary wave modes, the excitation efficiency and the strictness of the excitation condition of second-harmonic Lamb wave are different. The excitation window and the relative nonlinear coefficient of the longitudinal S;/S;mode at 90 and 150 mm propagation distance, as well as of longitudinal S;/S;and S;/S;mode at 150 mm propagation distance, are measured and compared. The measurement results are consistent with the theoretical analysis. In this article, the nonlinear effect of the Lamb wave in the case of approximate matching of phase velocity is discussed, which provides the analysis method and basis for the practical application of the Lamb wave.

关 键 词：非线性超声 LAMB波 二次谐波 模式选择 

分 类 号：TG115.28[金属学及工艺—物理冶金] TH878.2[金属学及工艺—金属学] TB553[机械工程—仪器科学与技术]