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

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.