Modeling of wave propagation in polycrystalline ice with hierarchical density gradients

FARSHAD GHANBARI ; EDUARDO G. RODRIGUEZ; DANIEL MILLÁN; FRANCESCO SIMONETTI; ANDREA P. ARGÜELLES ; CHRISTIAN PECO

FINITE ELEMENTS IN ANALYSIS AND DESIGN

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2023 vol. 217

0168-874X

Polycrystalline solids are composed of many small grains of varying sizes and crystallographic orientations. An elastic wave that propagates through such a material experiences distortion and attenuation. While the influence on propagation in random configurations can be captured with conventional statistical descriptors, the role of second-order features such as the hierarchical gradient in material properties has not been explored. In this paper, we optimize a numerical strategy based on Finite Elements and Local Max-Entropy approximants to characterize the role of grain density gradients on ultrasonic attenuation. We focus on ice as a model for mesoscale ordered configurations due to its relevance to the emerging technology of cryoultrasonics. Our simulations in one- and two-dimensional settings indicate that second-order descriptors are required to predict attenuation in polycrystalline ice. Furthermore, we define a novel parameter, based on the standard deviation of the speed of sound gradient distribution, which shows a quadratic relationship with the ultrasonic attenuation. The model results can be understood as a phase diagram for the design of metamaterials with specific ultrasonic scattering properties.