板材在生产、运输或使用过程中易产生缺陷，影响板材的使用并造成安全隐患。采用传感器阵列成像技术能够直观、清晰地显示出缺陷的相关信息。SH0模态在铝板中传播时无频散现象，波速恒定，在对信号进行处理时，不需要考虑频散特性带来的影响，有利于缺陷定位和成像。基于磁致伸缩换能机理，研制出一种能在板中激励接收SH波最低阶模态即SH0模态的磁致伸缩贴片型传感器，并测试其全向性。以工程中应用广泛的铝板作为研究对象，运用研制的全向性SH0模态磁致伸缩贴片型传感器布置成分布式传感器阵列。利用椭圆成像算法，实现了铝板中不同直径的模拟缺陷成像检测，探究了全向性SH0模态磁致伸缩贴片型传感器阵列的检测能力，并基于ROC曲线设定成像通用阈值，提高了缺陷成像质量。
刘增华
,
钟栩文
,
李欣
,
何存富
,
吴斌
. 基于全向性SH0模态磁致伸缩贴片型传感器阵列的铝板缺陷成像研究[J]. 机械工程学报, 2018
, 54(14)
: 8
-15
.
DOI: 10.3901/JME.2018.14.008
During the process of production, transportation and application, plates can easily appear damages which influence the performance of plates and cause potential safety hazard. Transducer array imaging technique lays the foundation for damage visualization. Damage information can be displayed through transducer array imaging technology intuitively and clearly. SH0 mode spreads in the aluminum plate with the characteristics of non-dispersion and constant velocity. The impact of dispersion cannot be considered during the signal processing which is helpful to damage location and imaging. A kind of magnetostrictive patch transducer based on the magnetostriction mechanism is made for generating and receiving the lowest mode of SH waves, i.e., SH0 mode, in plates. Furthermore, the omnidirectivity of magnetostrictive patch transducer is tested. Aluminum plates which are popular in engineering applications are taken as research objects. Omnidirectional SH0 mode magnetostrictive patch transducers are arranged as distributed transducers array. Imaging detection of simulated damages with different diameters in aluminum plates are realized by using ellipse algorithm. Furthermore, the detectability of omnidirectional SH0 mode magnetostrictive patch transducers array is studied and imaging common threshold is set for improving the damage imaging quality based on ROC curve.
[1] 杨守杰,戴圣龙. 航空铝合金的发展回顾与展望[J]. 材料导报,2005,19(2):76-80. YANG Shoujie,DAI Shenglong. A glimpse at the development and application of aluminum alloys in aviation industry[J]. Materials Review,2005,19(2):76-80.
[2] YE L,LU Y,SU Z,et al. Functionalized composite structures for new generation airframes:A review[J]. Composites Science and Technology,2005,65(9):1436-1446.
[3] 张胜俊,李辉. 汽车车身铝合金板材的应用及发展趋势[J]. 汽车工程师,2015(3):16-18. ZHANG Shengjun,LI Hui. Application and development of aluminum-alloy body of vehicle[J]. Auto Engineer,2015(3):16-18.
[4] 李瑶,王快社,刘长瑞. 金属板材表面缺陷检测发展现状[J]. 材料导报,2011,25(2):238-241. LI Yao,WANG Kuaishe,LIU Changrui. Development status of surface defects inspection for metal plants[J]. Materials Review,2011,25(2):238-241.
[5] SU Z,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):753-780.
[6] 刘增华,樊军伟,何存富,等. 基于全向型S0模态磁致伸缩传感器的无参考缺陷成像方法研究[J]. 机械工程学报,2015,51(10):8-16. LIU Zenghua,FAN Junwei,HE Cunfu,et al. Research on baseline-free damage imaging method employing omni-directional S0 mode magnetostrictive transducers[J]. Journal of Mechanical Engineering,2015,51(10):8-16.
[7] HAYASHI T,KAWASHIMA K. Multiple reflections of Lamb waves at a delamination[J]. Ultrasonics,2002,40(1):193-197.
[8] 黄松岭. 电磁超声导波理论与应用[M]. 北京:清华大学出版社,2013. HUANG Songlin. Theory and application of electromagnetic ultrasonic guided waves[M]. Beijing:Qsinghua University Press,2013.
[9] 刘增华,谢穆文,钟栩文,等. 超声导波电磁声换能器的研究进展[J]. 北京工业大学学报,2017,43(2):192-202. LIU Zenghua,XIE Muwen,ZHONG Xuwen,et al. Research progress of electromagnetic acoustic transducers for ultrasonic guided waves inspection[J]. Journal of Beijing University of Technology,2017,43(2):192-202.
[10] THOMPSON R B. Generation of horizontally polarized shear waves in ferromagnetic materials using magnetostrictively coupled meander-coil electromagnetic transducers[J]. Applied Physics Letters,1979,34(2):175-177.
[11] VASILE C F,THOMPSON R B. Excitation of horizontally polarized shear elastic waves by electromagnetic transducers with periodic permanent magnets[J]. Journal of Applied Physics,1979,50(4):2583-2588.
[12] CHO S H,LEE J S,KIM Y Y. Guided wave transduction experiment using a circular magnetostrictive patch and a figure-of-eight coil in nonferromagnetic plates[J]. Applied Physics Letters,2006,88:224101.
[13] RIBICHINI R,CEGLA F,NAGY P B,et al. Study and comparison of different EMAT configurations for SH wave inspection[J]. IEEE Transactions on Ultrasonics,Ferroelectrics,and Frequency Control,2011,58(12):2571-2581.
[14] LEE J S,KIM Y Y,CHO S H. Beam-focused shear-horizontal wave generation in a plate by a circular magnetostrictive patch transducer employing a planar solenoid array[J]. Smart Materials and Structures,2009,18(1):015009.
[15] LEE M K,LEE J S,KIM Y Y. An SH wave magnetostrictive patch transducer for ultrasonic inspection of a plate-like structures[C]//2010 IEEE International Ultrasonics Symposium,San Diego,California,USA. New York:IEEE,2010:1164-1165.
[16] SEUNG H M,KIM H W,KIM Y Y. Development of an omni-directional shear-horizontal wave magnetostrictive patch transducer for plates[J]. Ultrasonics,2013,53(7):1304-1308.
[17] HUANG S,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.
[18] 刘增华,穆云龙,宋国荣,等. 复合材料板Chirp激励的Lamb波成像技术研究[J]. 仪器仪表学报,2015,36(9):1961-1971. LIU Zenghua,MU Yunlong,SONG Guorong,et al. Research on Lamb wave imaging technique for composite plate based on chirp excitation[J]. Chinese Journal of Scientific Instrument,2015,36(9):1961-1971.
[19] MICHAELS J E,CROXFORD A J,WILCOX P D. Imaging algorithms for locating damage via in situ ultrasonic sensors[C]//2008 IEEE Sensors Applications Symposium,San Diego,California,USA. New York:IEEE,2008:63-67.
[20] BRADLEY A P. The use of the area under the ROC curve in the evaluation of machine learning algorithms[J]. Pattern Recognition,1997,30(7):1145-1159.
