一种用于焊接结构多帧满秩成像检测的超声SH导波换能器  

An ultrasonic SH-guided-wave transducer for image detection of welded structure with multi-frame and in full rank

作　　者：朱新杰 李永涛 邓明晰 姚森 ZHU Xinjie;LI Yongtao;DENG Mingxi;YAO Sen(School of Materials Science and Engineering,North Minzu University,Yinchuan,750021,China;College of Mechatronic Engineering,North Minzu University,Yinchuan,750021,China;College of Aerospace Engineering,Chongqing University,Chongqing,400044,China)

机构地区：[1]北方民族大学,材料科学与工程学院,银川750021 [2]北方民族大学,机电工程学院,银川750021 [3]重庆大学,航空航天学院,重庆400044

出　　处：《焊接学报》2023年第4期84-92,I0008,共10页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(12164001,12074050);宁夏重点研发项目(引才专项)资助项目(2021BEB04006)。

摘　　要：超声水平剪切(shear horizontal,SH)导波换能器在对焊接板结构进行缺陷检测时具有重要的应用价值.为了研制换能器以对焊接结构进行多帧满秩成像检测,运用导波半波长理论对超声SH导波的激发和换能器内部多重散射回波进行了分析.根据多重散射理论推导了匹配层介质颗粒密度与衰减的关系,确定匹配层的组分.提出3种V型斜楔结构,对平面型前楔结构换能器和非平面型前楔结构换能器内部的多重散射回波进行对比试验.结果表明,正交前楔结构换能器内部二重以上散射回波幅值减小了45%以上.对正交前楔结构换能器进行性能测试,其所激发的SH导波对焊接结构板中尺寸当量为φ12 mm的缺陷回波信号信噪比达到了14.5 dB,具有较为优异的检测能力.试验验证了理论分析的有效性,所研制的正交前楔结构超声SH导波换能器可对焊接结构板中与波长尺寸当量的缺陷进行多帧满秩成像检测.Ultrasonic transducer of shear horizontal(SH)guided wave has great application value in defect detection in welded structural plate.In order to develop the transducer that could perform multi-frame and full rank imaging detection of welded structures,the theory of half wavelength of guided waves was applied to analyze the excitation of ultrasonic SHguided waves and the multiple-order scattering inside the transducer.According to the multiple-order scattering theory,the relationship between particle density and attenuation in the matching layer is derived,and the composition of the matching layer is determined.Both the multiple-order scattering echoes inside planar and non-planar front wedge transducers were analyzed experimentally.The research results indicate that the amplitude of the double or more scattered echoes inside the orthogonal front wedge structure has decreased by more than 45%.Performance testing was carried out on the orthogonal front wedge structure of transducer,and the SH-guided waves excited by it reached a signal-to-noise ratio of 14.5 dB for the defect echo signal when a size equivalent toϕ12 mm in the welded structure was applied.This has demonstrated its superior detection capability.The effectiveness of the theoretical analysis has been verified through experiments.The SHguided-wave transducer with orthogonal front wedge structure could be used to detect equivalent defects of different sizes in welded structural plates.

关 键 词：多重散射 超声SH导波 换能器 正交前楔结构 焊接结构 

分 类 号：TG439.9[金属学及工艺—焊接]