DEVELOPMENT OF ANGLE BEAM TECHNIQUE OF UT FOR PLANAR DEFECT LOCATED NEAR SURFACE IN BUTT WELDED JOINTS

Abstract

Ultrasonic testing could be applied to evaluate field welded butt joints of steel girder bridges. It is, however, a difficult problem to detect planar defects like cracks. Cracks should influence on the fatigue strength of the member of structures. Hot cracks are formed in the first weld path. In case of groove weld, hot cracks are located near the surface. Numerical analyses and experiments were carried out to investigate the detectability of planar defects near the surface. Experiments on a field welded joint specimen were also conducted to investigate detection and sizing of a planar defect.