Frequency-dependent acoustic energy focusing in hexagonal ceramic micro-scaffolds

0517863 - ÚT 2021 RIV NL eng J - Journal Article
Grabec, T. - Koller, M. - Sedlák, Petr - Kruisová, Alena - Román-Manso, B. - Belmonte, C. - Miranzo, P. - Seiner, Hanuš
Frequency-dependent acoustic energy focusing in hexagonal ceramic micro-scaffolds.
Wave Motion. Roč. 92, January (2020), č. článku 102417. ISSN 0165-2125. E-ISSN 1878-433X
R&D Projects: GA ČR(CZ) GA17-01618S
Institutional support: RVO:61388998
Keywords : robocast scaffold * phononic crystal * acoustic energy focusing * Bloch analysis
OECD category: Acoustics
Impact factor: 2.020, year: 2020
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S0165212519300149

Acoustic properties of an additive-manufactured SiC scaffold with hexagonal symmetry fabricated by the robocasting method are studied both numerically and experimentally. The numerical analysis is based on the finite element method (FEM) using Bloch boundary conditions. The calculations show both angular and frequency dispersion of the acoustic waves with wavelengths comparable to the spacing between the rods, i.e., on a millimeter scale, indicating interesting acoustic properties in the MHz range. The dispersion character leads to focusing of the energy propagation into the directions of the rods of the hexagonal structure. This is illustrated by modal-based calculations of the propagation of longitudinal and out-of-plane shear wave packets with a dominant wavelength. The experimental analysis consists of two steps, the measurement of the resonant spectrum and shear wave propagation character. The measured resonant spectrum is in good agreement with the one calculated using numerically obtained low-frequency properties of the structure, also showing the quality of the overall manufactured structure. The time-domain measurement shows significant changes in the energy propagation between low and high frequencies, as predicted by FEM calculations.
Permanent Link: http://hdl.handle.net/11104/0310388