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サイトウ クニヤス
Kuniyasu Saitoh
齊藤 国靖 所属 京都産業大学 理学部 物理科学科 職種 教授 |
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| 発行・発表の年月 | 2023/05 |
| 形態種別 | 研究論文 |
| 標題 | Sound characteristics of disordered granular disks: effects of contact damping |
| 執筆形態 | その他 |
| 掲載誌名 | Frontiers in Physics |
| 出版社・発行元 | Frontiers Media {SA} |
| 巻・号・頁 | 11 |
| 著者・共著者 | Kuniyasu Saitoh,Kianoosh Taghizadeh,Stefan Luding |
| 概要 | <jats:p>We investigate numerically the sound properties of disordered dense granular packings in two dimensions. Employing linear equations of motion and excluding contact changes from our simulations, we demonstrate time evolution of sinusoidal standing waves of granular disks. We varied the strength of normal and tangential viscous forces between the disks in contact to explore the dependence of sound characteristics such as dispersion relations, attenuation coefficients, and sound speeds on the contact damping. For small wave numbers, the dispersion relations and sound speeds of acoustic modes are quite insensitive to the damping. However, a small dip in the phase speed of the transverse mode decreases as the viscous force in normal direction increases. In addition, the dispersion relation of the rotational mode differs qualitatively from the theoretical prediction for granular crystals. Therefore, disordered configurations with energy dissipation play a prominent role in sound properties of granular materials. Furthermore, we report how attenuation coefficients depend on the contact damping and quantify how they differ from the prediction of lattice theory. These improved relations, based on our numerical results, can in future be compared to advanced theories and experiments.</jats:p> |
| DOI | 10.3389/fphy.2023.1192270 |
| ISSN | 2296-424X |