边界散射对超声水平剪切导波成像检测的影响  

Influence of Boundary Scattering on Imaging and Inspection of Ultrasonic Shear Horizontal-guided Waves

作　　者：朱新杰[1,2] 韩赞东[1,2] 都东[1,2] 陈以方[1,2] 原可义[1,2] 

机构地区：[1]清华大学先进成形制造教育部重点实验室,北京100084 [2]清华大学机械工程系,北京100084

出　　处：《机械工程学报》2011年第16期14-19,共6页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(60871101)

摘　　要：超声水平剪切(Shear horizontal,SH)导波在工业在役板材成像检测和结构健康监测(Structural health monitoring,SHM)中有重要的应用价值。基于合成孔径聚焦方法,对钢板中人工缺陷用超声SH导波进行成像,对边界散射条件下的成像检测阵列信号进行分析,探讨了边界散射对超声SH导波成像检测的影响。研究结果表明,基于合成孔径聚焦的超声SH导波成像方法用于板材缺陷成像检测时,超声边界散射使成像信号'双曲线'阵列特征弱化,缺陷声波信号衰减增大,信号散射噪声增强,进而使成像清晰度降低,易导致漏检;同时边界散射会造成同一缺陷信号产生'双峰'或'多峰',成像信号'双曲线'阵列特征紊乱,使成像发生畸变,会导致误检。这将为进一步改进工业在役大尺度板材超声导波成像质量与提高结构健康监测水平提供重要基础。The ultrasonic shear horizontal（SH） guided waves are suitable and important for the imaging and inspection and the structure health monitoring（SHM） of the in-service industrial plate.Based on the synthetic aperture focusing method,the imaging and inspection with boundary scattering of ultrasonic SH-guided waves are developed.Based on the analysis of the ultrasonic array signals,the influence of boundary scattering on the imaging and inspection is mainly studied.The research results show that while applying synthesize aperture focusing into imaging and inspection of ultrasonic SH-guided waves for large-size plate inspection,the hyperbolic array feature of the imaging array signals is weaken by ultrasound boundary scattering,and the defect signals are weakened while scattering noise become larger,which decreases the image definition and easily leads to defect uninspected.Ultrasound boundary scattering may cause ＂dual peaks＂ or ＂multi-peaks＂ for the same defect that transform the hyperbolic array feature,which can result in imaging aberration and easily lead to wrong inspection.The proposed research provides important foundation for improving ultrasonic guided waves imaging quality and SHM of the in-service large-size industrial plate.

关 键 词：超声 水平剪切导波 成像 检测 边界散射 

分 类 号：TB553[理学—物理]