摘要
水平剪切(SH)波电磁超声换能器(EMAT)具有非接触、无需耦合剂、对表面油污涂层不敏感、单点激励大范围检测等优点,在航空不锈钢薄板快速导波检测中具有重要的技术优势。首先建立了含缺陷的不锈钢薄板SH导波传播有限元模型,分析了不同设计参数EMAT对应缺陷的距离-波幅曲线(DAC),并对DAC进行实验验证。然后建立了不锈钢薄板中SH导波声场分析有限元模型,研究了周期性永磁体电磁超声换能器(PPM EMAT)中永磁体宽度、长度和对数对SH导波辐射声场特性的影响,得到了EMAT的轴线声压分布,并在此基础上获取了EMAT的最优设计参数组合。结果表明增大永磁体长度和对数都能提高EMAT轴线辐射声场强度,使EMAT在远距离检测具有较好的声压分布均匀性。当永磁体对数、长度、宽度分别为6对、25mm、7mm时,对应的EMAT具有较高的轴线辐射声场强度和较平稳的DAC,更适合对航空不锈钢薄板进行远距离快速导波检测。
The Shear Horizontal(SH)wave Electromagnetic Ultrasonic Transducer(EMAT)has the advantages of non-contact,no coupling agent,insensitivity to surface oil coating,single point excitation and wide range detection.It has important technical advantages in rapid guided wave detection of aviation stainless steel sheet.A finite element model of SH guided wave propagation in stainless steel sheet with defects is established.The Distance Amplitude Curve(DAC)of the defects corresponding to different design parameters of EMAT is analyzed,and the DAC was verified by experiments.A finite element model for the acoustic field analysis of SH guided waves in stainless steel plates is established.The effects of the width,length and logarithm of the Permanent Magnet in Periodic-Permanent-Magnet Electromagnetic Acoustic Transducer(PPM EMAT)on the acoustic field characteristics of SH guided waves are studied.The axial sound pressure distribution of EMAT is obtained.On this basis,the optimal design parameter combination of EMAT is obtained.The results show that increasing the length and logarithm of permanent magnet can improve axial radiation acoustic field intensity of the EMAT,which makes the EMAT have good uniformity of sound pressure distribution in remote detection.When the number,length and width of permanent magnet are 6pairs,25mm and 7mm respectively,the corresponding EMAT has higher axial radiation acoustic field intensity and more stable DAC,and is more suitable for long-distance rapid guided wave detection of aviation stainless steel sheet.
作者
吴锐
石文泽
卢超
李秋锋
陈果
WU Rui;SHI Wenze;LU Chao;LI Qiufeng;CHEN Guo(Key Laboratory of Nondestructive Testing,Ministry of Education,Nanchang Hangkong University,Nanchang 330063,China;State Key Laboratory of Acoustic Field and Acoustic Information,Academy of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;Key Laboratory of Simulation and Numerical Modeling Technology of Jiangxi Province,Gannan Normal University,Ganzhou 341000,China)
出处
《航空学报》
EI
CAS
CSCD
北大核心
2022年第9期727-740,共14页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(12064001,52065049,51705231)
江西省自然科学基金重点项目(20192ACBL20052)
江西省科技厅科技计划(20204BCJL22039,20192BCD40028)
江西省青年科学基金(20181BAB216020)
南昌航空大学研究生创新专项资金(YC2020057)。
