作者：杨三虎¹, 周进节¹, 郑阳², 贾浩东¹

作者单位：1. 中北大学机械工程学院， 山西 太原 030051;
2. 中国特种设备检测研究院， 北京 100029

关键词：兰姆波S₀模态;模态控制;相控延时;阵列EMAT

摘要：

兰姆波具有频散、多模态特性，导致在检测过程中难以区分回波信号。针对这一问题，进行阵列EMAT相控延时实现单一模态兰姆波控制激励与增强的研究。在不改变EMAT配置方式、结构及参数的情况下，通过计算阵列EMAT频率响应取得最大值时的延迟时间，将其施加到各个阵元，实现单一模态兰姆波的激励与增强。同时，研究了激励频率对增强阵列EMAT单模态兰姆波幅值的影响，获得单模态控制与增强效果较好的激励频率。实验结果表明：通过调控阵列EMAT各阵元的延迟激励时间，可以较好地实现单一S₀模态控制与增强，S₀模态的幅值比提高8.3倍。该结果可验证相控延时对阵列EMAT S₀模态控制与增强是有效的。

Research on Lamb wave mode control and enhancement by phased delay excitation of array EMAT
YANG Sanhu¹, ZHOU Jinjie¹, ZHENG Yang², JIA Haodong¹
1. School of Mechanical Engineering, North University of China, Taiyuan 030051, China;
2. China Special Equipment Inspection and Research Institute, Beijing 100029, China
Abstract: Lamb wave has the characteristics of dispersion and multimode, which makes it difficult to distinguish the echo signal during detection. In order to solve this problem, the modulation and enhancement of single mode Lamb wave control for array EMAT phase delay are studied. Without changing the EMAT configuration mode, structure and parameters, the time delay when the EMAT frequency response of the array is maximized is calculated and applied to each array element to realize the excitation and enhancement of single mode Lamb wave. At the same time, the influence of excitation frequency on the amplitude of single-mode Lamb wave of EMAT is studied, and the excitation frequency with good single-mode control and enhancement effect is obtained. The experimental results show that the single S₀ mode control and enhancement can be well realized by adjusting the excitation time delay of each array EMAT element, and the amplitude ratio of S₀ mode is increased by 8.3 times. This result verifies that the phase-controlled delay is effective for array EMAT S₀ mode control and enhancement.
Keywords: Lamb wave S₀ mode;mode control;phase control delay;electromagnetic ultrasonic transducer array
2022, 48(1):101-107  收稿日期: 2021-01-29;收到修改稿日期: 2021-03-26
基金项目: 国家重点研发计划重点专项资助项目（2018YFC0809002）；国家自然科学基金（61601413）
作者简介: 杨三虎(1997-)，男，山西吕梁市人，硕士研究生，专业方向为电磁超声导波检测
参考文献
[1] 何存富, 郑明方, 吕炎, 等. 超声导波检测技术的发展, 应用与挑战[J]. 仪器仪表学报, 2016, 37(8): 1713-1726
[2] SU Z Q, YE L, LU Y. Guided Lamb waves for identification of damage in composite structures: A review[J]. Journal of Sound and Vibration, 2006, 295(3-5): 753-780
[3] SHEN W, LI D S, ZHANG S F, et al. Analysis of wave motion in one-dimensional structures through fast-Fourier-transform-based wavelet finite element method[J]. Journal of Sound and Vibration, 2017, 400: 369-386
[4] KHALILI P, CAWLEY P. Excitation of single-mode Lamb waves at high-frequency-thickness products[J]. IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2016, 63(2): 303-312
[5] KHALILI P, CAWLEY P. Relative ability of wedge-coupled piezoelectric and meander coil emat probes to generate single-mode Lamb waves[J]. IEEE Transactions on Ultrasonics Ferroelectrics & Frequency Control, 2018, 64(5): 648-656
[6] 徐煦源, 涂君, 张旭, 等. 用于钢板厚度测量的常用电磁超声线圈特性研究[J]. 中国测试, 2020, 46(4): 143-147
[7] 李建, 张斌, 马锦程, 等. Lamb波电磁超声换能器三维仿真研究[J]. 中国测试, 2020, 46(9): 90-95
[8] HUANG S L, WEI Z, ZHAO W, et al. A new omni-directional EMAT for ultrasonic Lamb wave tomography imaging of metallic plate defects[J]. Sensors, 2014, 14(2): 3458-3476
[9] LEE KYUNG J, KIM Y Y. Tuned double-coil EMATs for omnidirectional symmetric mode lamb wave generation[J]. NDT & E International, 2016, 83: 38-47
[10] LIU Z H, HU Y N, XIE M W, et al. Development of omnidirectional A0 mode EMAT employing a concentric permanent magnet pairs with opposite polarity for plate inspection[J]. NDT & E international, 2018, 94: 13-21
[11] LIU Z H, DENG L M, ZHANG Y C, et al. Development of an omni-directional magnetic-concentrator-type electromagnetic acoustic transducer[J]. NDT & E international, 2020, 109: 102193
[12] LIU Z H, DENG L M, ZHANG Y C, et al. Development of a mode-tuning magnetic-concentrator-type electromagnetic acoustic transducer[J]. Ultrasonics, 2020, 103: 106094
[13] ZHANG Y H, QIAN Z H, WANG B. Modes control of Lamb wave in plates using meander-line electromagnetic acoustic transducers[J]. Applied Sciences, 2020, 10(10): 3491
[14] 周进节, 贾浩东, 郑阳, 等. 跑道形线圈EMAT有限元建模与声场特性研究[J]. 机械工程学报, 2020, 56(2): 9-19
[15] ROSE J L. 固体中的超声波[M]. 何存富, 吴斌, 王秀彦, 译. 北京: 科学出版社, 2004: 82-86.
[16] LI J, ROSE J L. Implementing guided wave mode control by use of a phased transducer array[J]. Ultrasonics Ferroelectrics & Frequency Control IEEE Transactions on, 2001, 48(3): 761-768