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

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 SHguidedwaves 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.