Current Activities in Ultrasonic NDE Simulations-A German Perspective
The German activities in one of the emerging areas of ultrasonic nondestructive evaluation, the computer aided simulation of ultrasonic testing problems, are reviewed. Looking at the underlying physics, the currently challenging problems in ultrasonic NDE are caused (i) by micro- and macrostructural material characteristics like inhomogeneity and anisotropy, and (ii) by the presence of complex component and defect geometries. Both can lead to considerable problems in testing performance and/or data interpretation. Straightforward solutions like experience-based adaptations in the experimental set-up are in general insufficient, insecure and cost-intensive. The better choice is to combine practical experience and theoretical modeling. This, however, may suffer from the naturally limited overlap of the experimentalist’s and the theoretician’s point of view. Thus, coupling of NDE models with computer aided design and/or graphical user interfaces, which allows a user to perform e.g. parametric studies and to view quantitative simulated results, is of vital interest to the field of ultrasonic NDE. Recent approaches to progress in this field- performed by several groups-are reviewed, where different analytical and numerical techniques have been applied to model ultrasound generation, propagation, scattering and reception. Representative examples cover transducer modeling in homogeneous and layered media of various geometries, modeling of ultrasonic inspection of complex components as well as the simulation of austenitic weld inspection. The applied modeling codes run on PC or workstation in combination with graphical user interfaces or CAD-systems, some of them being also available as Windows95/NT-supported software packages.