一种用于焊接结构超声成像检测的SH导波换能器  

An ultrasonic SH-guided-wave transducer for ultrasonic imaging and testing of plate with welded structure

作　　者：朱新杰[1] 陈以方[1] 韩赞东[1] 都东[1] 

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

出　　处：《焊接学报》2013年第2期17-21,114,共5页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(60871101)

摘　　要：板中水平剪切导波可用于焊接结构板材远距离成像检测,超声SH导波换能器的性能对较大尺度焊接结构板材超声导波成像检测至关重要.对板中SH导波进行了动力学分析,并结合半波长条件设计了合理的斜楔角度、压电晶片频率及尺寸等导波换能器的重要参数,通过加前背衬、取消后背衬、楔块前沿设置锯齿槽等措施,简化了换能器的工艺结构,减小了换能器内部回波干扰,提高了检测灵敏度.结果表明,设计研发的SH导波换能器激发的导波有较强的检测能力,可用于对较为复杂的T形—对焊焊接结构板材进行成像检测,能够有效表征焊接结构板材中与导波波长尺寸量级相当的缺陷,其性能指标达到了较大尺度焊接结构板材成像检测的要求.为开展较大尺度焊接结构超声导波成像检测奠定了基础.The SH(shear horizontal) guided waves can be used to test and image in long distance for the larger-sized plate in welded structure.The performance of ultrasonic SH-guided-waves transducer is essential to imaging and testing larger-sized plate in welded structure.The dynamic analysis of SH guided wave in plate and half-wave propagation conditions was carried out.The reasonable wedge angle,the frequency,size of the piezoelectric wafer for SH-guided-waves transducer and other important parameters were designed.The steps such as adding the front lining,removing the back lining,setting the jagged slot on front wedge and so on,have reduced the internal echo interference in SH-guided-waves transducer,which improves the testing sensitivity and simplifies the transducer structure.The results shows that the developed SH-guided-waves transducer has the better testing ability and can be used in imaging and testing complex T-butt type welded structure.The image can characterize the defects,whose size is close to the guided wave length in the welded structure.The proposed research provides the foundation for the imaging and testing of larger-sized plate with welded structure.

关 键 词：超声 SH导波换能器 焊接结构 

分 类 号：TB552[理学—物理]