Influence of grain morphology on ultrasonic wave attenuation in polycrystalline media with statistically equiaxed grains

0486790 - ÚJF 2019 RIV US eng J - Journal Article
Ryzy, M. - Grabec, Tomáš - Sedlák, Petr - Veres, I. A.
Influence of grain morphology on ultrasonic wave attenuation in polycrystalline media with statistically equiaxed grains.
Journal of the Acoustical Society of America. Roč. 143, č. 1 (2018), s. 219-229. ISSN 0001-4966. E-ISSN 1520-8524
R&D Projects: GA ČR GB14-36566G; GA MŠMT EF16_013/0001794
Institutional support: RVO:61389005 ; RVO:61388998
Keywords : scattering * finite element method * polycrystals' grain
OECD category: Condensed matter physics (including formerly solid state physics, supercond.); Applied mechanics (UT-L)
Impact factor: 1.819, year: 2018

The influence of a polycrystals' grain structure on elastic wave scattering is studied with analytical and numerical methods in a broad frequency range. A semi-analytical attenuation model, based on an established scattering theory, is presented. This technique accurately accounts for the grain morphology without prior assumptions on grain statistics. This is achieved by incorporating a samples' exact spatial two-point correlation function into the theory. The approach is verified by using a finite element method (FEM) to simulate P-wave propagation in 3D Voronoi crystals with equal mean grain diameter, but different grain shape uniformity. Aluminum and Inconel serve as representatives for weak and strong scattering cubic class materials for simulations and analytical calculations. It was found that the shape of the grains has a strong influence on the attenuation curve progression in the Rayleigh-stochastic transition region, which was attributed to mode conversion scattering. Comparisons between simulations and theory show excellent agreement for both materials. This demonstrates the need for accurately taking the microstructure of heterogeneous materials into account, to get precise analytical predictions for their scattering behaviour. It also demonstrates the impressive accuracy and flexibility of the scattering theory which was used.
Permanent Link: http://hdl.handle.net/11104/0281517