Influence of Boundary Scattering on Imaging and Inspection of Ultrasonic Shear Horizontal-guided Waves

Abstract

The ultrasonic shear horizontal(SH) guided waves are suitable and important for the imaging and inspection and the structure health monitoring(SHM) of the in-service industrial plate.Based on the synthetic aperture focusing method,the imaging and inspection with boundary scattering of ultrasonic SH-guided waves are developed.Based on the analysis of the ultrasonic array signals,the influence of boundary scattering on the imaging and inspection is mainly studied.The research results show that while applying synthesize aperture focusing into imaging and inspection of ultrasonic SH-guided waves for large-size plate inspection,the hyperbolic array feature of the imaging array signals is weaken by ultrasound boundary scattering,and the defect signals are weakened while scattering noise become larger,which decreases the image definition and easily leads to defect uninspected.Ultrasound boundary scattering may cause "dual peaks" or "multi-peaks" for the same defect that transform the hyperbolic array feature,which can result in imaging aberration and easily lead to wrong inspection.The proposed research provides important foundation for improving ultrasonic guided waves imaging quality and SHM of the in-service large-size industrial plate.