J0406-3-4 Study on nondestrutive detection limit of slant part through flaw using interference method and pulse echo method

Abstract

A new method is proposed to detect a tilted planar flaw on the back surface of a plate using the interference of ultrasonic waves. Parameters for flaw evaluation are developed and examined through experimental results for artificial flaws. The existence of the flaw and its height are estimated by parameter B_h, which shows the first amplitude of the interference fringe. The effect of tilt angle of the flaw on parameter B_α, which indicates the amount of asymmetry of the interference fringe along the direction normal to the flaw, is investigated. Flaw with a tilt angle of 60 deg from the normal direction of the inspection surface having 1 mm length can be detected using the present method.