Imaging-based optimisation method for quantitative ultrasonic testing of anisotropic inhomogeneous austenitic welded joints with determination and utilisation of their elastic properties

A new testing technique based on sampling phased arrays has been developed at Fraunhofer Institut. It permits the detection and quantitative analysis of defects in acoustically anisotropic and/or inhomogeneous materials amongst others. This testing technique relies on an expansion of the principle of synthetic aperture focussing (SAFT) with due consideration to material anisotropy and inhomogeneity (inverse phase adaptation). Since the characteristics of material anisotropy are generally not known, an additional algorithm for automatic determination the material's elastic properties was developed. The new testing technique permits quantitative ultrasonic testing of austenitic weld seams and dissimilar metal weld seams in a single scan with two and three-dimensional location-related representation of test results and reliable data on the size, type and location of defects.