The study of elastic wave propagation in polycrystalline media and the modelling of associated scattering phenomena has gained renewed interest over the past decade, driven by advances in computational capabilities enabling Finite Element (FE) simulations on statistically representative microstructures. These approaches have made it possible to analyse complex polycrystalline materials with varying anisotropy and to compare numerical results with existing analytical models. Most studies have focused on the estimation of wavenumber evolution across frequency regimes for untextured media and coherent longitudinal waves. More recently, extending these approaches to shear waves has enabled a complete numerical characterisation of an effective isotropic medium. At the macroscopic scale, such effective properties can be directly used in numerical methods, including high-order FE or high-frequency ray-based approaches, to simulate ultrasonic testing (UT) of components whose dimensions largely exceed the characteristic grain size. However, for textured polycrystalline media, most investigations remain restricted to wave propagation along symmetry axes. The modelling and extraction of modal solutions become significantly more complex when multiple coherent wave modes coexist. In the case of fibre-textured media described by a Gaussian Orientation Distribution Function (ODF), we have recently developed an original numerical framework to address these challenges. By analysing wave propagation in different directions, an effective transversely isotropic medium is identified, whose complex-valued properties reproduce the estimated wavenumbers. This work investigates the evolution of the associated stiffness tensor components with respect to the ODF parameters and discusses potential applications for the characterisation of austenitic welds and claddings in UT simulations and imaging.
Leymarie et al. (Tue,) studied this question.