Experimental Study of Diffraction of Elastic Waves on Crack Model

Abstract

Small-opening slots have been used to simulate cracks in butt welds. The influence of the orientation of the slot ribs on their detectability with pulse echo and diffraction methods of ultrasonic testing has been studied. It is shown that the processes occurring during the scattering of elastic waves on cracks should be modeled by a three-dimensional problem. However, theoretical analytical and numerical studies in this area most often concern two-dimensional problems of diffraction of elastic waves, where the target edge under study is located on the acoustic axis of the ultrasound source and/or receiver and is oriented perpendicular to the incident beam. The article presents experimental results illustrating the influence of the orientation of the edge (rib) in three-dimensional problems on the received signals both when using diffraction schemes of the TOFD type, and in classical ultrasonic testing by the pulse echo method according to the “tandem” scheme and with the transducers turned according to the “duet” scheme.