A FUNDAMENTAL STUDY ON ULTRASONIC NONDESTRUCTIVE EVALUATION OF BUTT WELDED JOINTS OF THICK STEEL PLATE CONTAINING PLANAR DEFECTS

Abstract

Ultrasonic testing will be applied to evaluate field welded butt joints of steel girder bridges. The detectability of planar defects such as cracks is a serious problem because cracks may do damage to structures without appropriate treatment. Characteristics of flaw echoes from planar defects were investigated by doing numerical simulations and experiments. Considering multiple paths of ultrasonic wave, synthetic aperture focusing technique was conducted to reconstruct a planar defect.