Defect detection in brazed weldment with lattice structure using acoustic shadow technique

Brazed weldment with lattice structure has been widely used in aerospace industry. The non-destructive testing is often difficult because of the poor inspection accessibility. The present paper illustrates how the plane-like defect lack of brazing can be detected rapidly in this kind of structure by using ultrasonic Lamb wave. Experimental weldments are prepared and weld defect are tested using S₂ mode Lamb wave. Acoustic shadow technique is employed based on Lamb wave testing method. The character of the tested D-scan image and A-scan signal is studied. The experimental results show that acoustic shadow based Lamb wave testing method is effective in detecting through-wall lack of brazing. Meanwhile, the D-scan tested data can be rapidly collected and easily interpreted compared with pulse echo based Lamb wave testing method. Copyright: