TLB型复杂焊接结构超声SH导波成像检测

Ultrasonic SH guided waves imaging and test on complicated TLB welded structure

通过光弹试验分析超声水平剪切(shear horizontal,SH)导波具有优异传播性能,构建了超声导波成像检测系统,基于合成孔径聚焦对超声SH导波用于TLB型式复杂焊接结构成像检测进行了重点研究.结果表明,基于合成孔径聚焦的超声SH导波成像用于TLB型式复杂焊接结构构件检测是可行的,检测图像能够表征板材中区域特征,对焊缝有较好的定位功能,但在焊缝之后会形成长约100 mm的固有散射盲区.文中为进一步提高TLB型式复杂焊接结构超声导波成像检测应用水平提供了基础.

The T-joint welding,the lap welding and the butt welding constitute an important and complicated industrial structure named TLB type welded structure,where imaging and testing of ultrasonic guided waves has an important influence.The testing and imaging experiment system of ultrasonic SH-guided wave for TLB type welded structure was developed.It can be known from the dynamic photoelastic experiments that ultrasonic SH(shear horizontal) guided waves technology is more suitable for testing and imaging TLB type welded structure.The imaging principle of ultrasonic guided waves in plate was discussed,and the imaging and testing of SH guided waves in TLB type welded structure was researched.The experiment results shows that it is possible for SH guided waves to image and test TLB type welded structure,which may characterize the welded structure in the testing area,and its image has the positioning function for the testing regional features.Nevertheless,in imaging there may be a weld scattering blind area,about 100 mm behind the weld,which is the inherent ultrasonic scattering properties of the weld.The topic proposed provides the basis for further researching and improving imaging and testing of SH guided waves in complicated TLB type welded structure.