Prediction of the echos of diffraction resulting from the ultrasonic beam interaction with a plane flaw

The ultrasonic non-destructive testing and more particularly the characteri zation of material flaws requires a good knowledge of ultrasonic field inte raction with flaws. The aim of this work is to model the interaction of an ultrasonic beam with a plane flaw to simulate a fatigue crack in a solid in bidimensional geometry. The model takes into account all the sequences: Em ission - Propagation - Transmission through a plane interface - Interaction with the flaw Retro-propagation towards the transducer - Reception. This m odel predicts the echographic signal stemming from the diffracted field by both edges of the crack in order to have profound understanding and better interpretaion of the experimental results.