超声兰姆波二次谐波发生效应的理论、实验及应用研究进展  

Advances in theoretical,experimental and applied studies on second-harmonic generation of ultrasonic Lamb waves

作　　者：李卫彬 项延训[2] 邓明晰 Weibin Li;Yanxun Xiang;Mingxi Deng(School of Aerospace Engineering,Xiamen University,Xiamen 361102,China;School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China;College of Aerospace Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]厦门大学航空航天学院,厦门361102 [2]华东理工大学机械与动力工程学院,上海200237 [3]重庆大学航空航天学院,重庆400044

出　　处：《科学通报》2022年第7期583-596,共14页Chinese Science Bulletin

基　　金：国家自然科学基金(12134002,12074050,11974295,11834008)资助。

摘　　要：材料退化或微损伤的早期无损检测和评价可以保障关键结构的安全服役.因此,开展缺陷演化的早期评价,甚至缺陷产生前的早期检测是非常重要的.通常,线性超声检测方法对材料微观缺陷不敏感.非线性超声技术被广泛认为可以表征材料微观结构变化.二次谐波发生效应作为超声传播过程中的一种典型非线性声学效应,可以用来评价材料的性能退化程度和检测早期的微缺陷.此外,超声兰姆波被广泛应用于大型工业结构的健康监测及材料的无损检测和评价.基于超声兰姆波的无损检测方法能够检测出结构不可达或隐蔽区域,并具有低成本、高效率的优势.兰姆波二次谐波结合了兰姆波的优点和二次谐波对微损伤的高敏感特性,近年来受到越来越多的关注和研究.然而,由于兰姆波的频散和多模式特性,一般认为兰姆波传播过程中不存在强烈的非线性效应,实验上也很难对兰姆波二次谐波进行观察与测量.近年来,虽然兰姆波二次谐波的理论和实验研究取得了重要的进展,但该领域仍存在一系列科学和技术难题.本文系统梳理了超声兰姆波二次谐波发生效应的理论研究历程,综述了兰姆波二次谐波的实验研究进展以及在不同类型损伤评价中的应用,讨论了超声兰姆波二次谐波近年来研究中出现的争议问题,最后展望了兰姆波二次谐波的未来研究重点及发展趋势.Nondestructive evaluation and testing of material degradation or micro-damages in an early stage are essential for the maintenance of the safety-critical structures.Therefore,it is important to detect defects in a very early stage or even better to detect changes in the microstructure before the defect initiation even occurs.Linear ultrasonic characteristics are not sufficiently sensitive to the kind of microscopic degradation of the material.However,on the other hand,even very small imperfections can produce very significant excess nonlinearity,which can be orders of magnitude higher than the intrinsic nonlinearity of the intact material.The excess nonlinearity is produced mainly by the strong local nonlinearity of microcracks.In order to assess the damage in components at an early stage,the use of nonlinear acoustics has been shown to be the leading and one of the most promising techniques.Second harmonic generation is a typical acoustic nonlinear effect of ultrasonic waves,which can be used to assess the material degradation and detect the micro-defects in their early stages.Furthermore,ultrasonic Lamb wave has been widely used in large-scale industrial structures for health monitoring and material nondestructive testing.The possibility to inspect inaccessible or hidden areas and great cost-effectiveness are the key advantages of ultrasonic Lamb wave-based damage detection approaches.Second harmonic Lamb wave,which combines the advantages of Lamb waves and the high sensitivity of second harmonic waves to microdamage,is drawing increasing attention in recent years.The measurement of second harmonic Lamb waves is investigated as a promising feature extraction technique to characterize material nonlinearity in plate-like structures.However,the second harmonic fields of Lamb waves are much more complex due to the dispersion and multi-mode nature of propagating Lamb waves.In general,the effect of second harmonic generation is often very small and can easily be overlooked experimentally.Consequently,proper mode tuni

关 键 词：兰姆波 二次谐波 相速度匹配 群速度 无损评价 

分 类 号：TB553[理学—物理]