Microcrack localization using a collinear Lamb wave frequency-mixing technique in a thin plate  

作　　者：Ji-Shuo Wang Cai-Bin Xu You-Xuan Zhao Ning Hu Ming-Xi Deng 王积硕;许才彬;赵友选;胡宁;邓明晰(College of Aerospace Engineering,Chongqing University,Chongqing,400044,China;School of Mechanical Engineering,Hebei University of Technology,Tianjin 300401,China)

机构地区：[1]College of Aerospace Engineering,Chongqing University,Chongqing,400044,China [2]School of Mechanical Engineering,Hebei University of Technology,Tianjin 300401,China

出　　处：《Chinese Physics B》2022年第1期364-373,共10页中国物理B（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.12074050,52005058,11834008,and 11632004);the China Postdoctoral Science Foundation(Grant No.2020M673119);the Fund for Innovative Research Groups of Natural Science Foundation of Hebei Province,China(Grant No.A2020202002).

摘　　要：A novel Lamb wave frequency-mixing technique is proposed for locating microcracks in a thin plate,which does not require the resonance condition of Lamb wave mixing and can accurately locate the microcracks through only one-time sensing.Based on the bilinear stress-strain constitutive model,a two-dimensional finite element(FE)model is built to investigate the frequency-mixing response induced by the interaction between two primary Lamb waves and a microcrack.When two primary Lamb waves of A0 and S0 modes with different frequencies excited on the same side of the plate simultaneously impinge on the examined microcrack,under the modulation of the contact acoustic nonlinearity,the microcrack itself can be deemed as the secondary sound source and it will radiate the Lamb waves of new combined frequencies.Based on the time of flight of the generated A0 mode at difference frequency,an indicator named normalized amplitude index(NAI)is defined to directly locate the multi-microcracks in the given plate.It is found that the number and location of the microcracks can be intuitively visualized by using the NAI based frequency-mixing technique.It is also demonstrated that the proposed frequency mixing technique is a promising approach for the microcrack localization.

关 键 词：frequency-mixing of Lamb waves contact acoustic nonlinearity bilinear stress-strain constitutive model microcrack localization 

分 类 号：O346.1[理学—固体力学]