SIMULATION OF DISORIENTED FLAWS IN A TOFD TECHNIQUE CONFIGURATION USING GTD APPROACH

The TOFD (Time of Flight Diffraction) Technique is commonly used to detect and to characterize embedded disoriented flaws using their edge diffraction echoes. We present a TOFD simulation module which includes GTD coefficients allowing to predict diffraction echoes from embedded planar flaws. Other dedicated development have been added in the CIVA software platform to simulate lateral surface waves, backwall echoes and shadowing effects from flaws. Experimental validations have been performed on various specimen containing rectangular and CAD contour planar flaws with different possible disorientations (tilt, vertical misorientation, skew) and show an overall good agreement between simulation and measure.