Accelerated Space-Time Modeling of Quasi-Longitudinal Waves in Austenitic Weld Structures

For ultrasonic inspection of austenitic welds and cladded components mostly horizontally polarized shear waves and quasi-longitudinal (qP) waves are applied. Depending on the testing situation the one or the other wave type offers certain benefits. To eyplain experimentally ovserved phenomena and to prdeict how qP-waves might be best employed, modling of the respective wave propagation effects is useful. In this contribution, a computationally efficient modling code is presented for qP-waves propagating in ideally fiber-texutred austenitic weld material. Based on a mild anisotropy approximation given previously by Tverdokhlebov and Rose, a direct relationship between wave propagation directions and spatial coordinates has been obtained. This relationship has been applied to the Generalized Point-Source-Synthesis mehtod (GPSS) to model radiation, propagation and scattering effects. The GPSS-code thus improved is characterized by a considerable reduction of computer run-time and is there fore particularly convenient in view of a respective extension to inhomogeneous weldments.