阵列EMAT相控延时激励实现兰姆波模态控制与增强的研究  

Research on Lamb wave mode control and enhancement by phased delay excitation of array EMAT

作　　者：杨三虎 周进节[1] 郑阳[2] 贾浩东 YANG Sanhu;ZHOU Jinjie;ZHENG Yang;JIA Haodong(School of Mechanical Engineering,North University of China,Taiyuan 030051,China;China Special Equipment Inspection and Research Institute,Beijing 100029,China)

机构地区：[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

出　　处：《中国测试》2022年第1期101-107,共7页China Measurement & Test

基　　金：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)。

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。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 singlemode 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.

关 键 词：兰姆波S0模态 模态控制 相控延时 阵列EMAT 

分 类 号：TB553[理学—物理]