シーアによる阻害
Dapeng Bi1, Jie Zhang, Bulbul Chakraborty
1Martin Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02454, USA.
Nature
|December 16, 2011
まとめ
シェアストレスは,これまで考えられていたよりも低い密度で摩擦粒子を詰め込むことができ,独特の脆弱で堅固な状態を生み出します. これらの移行は,密度ではなく,力を有する粒子の量に依存します.
科学分野:
- 物理 物理学 物理学とは
- マテリアルサイエンス 材料科学
- ソフトマター物理学 ソフトマター物理学
背景:
- 泡や粒状システムなどの無秩序な材料は,変形に抵抗する,詰まった状態を形成します.
- 劉・ナゲル阻害コンセプトは,大熱系における臨界密度を示している.
- 摩擦粒子の阻害移行は,実験的に理解されていないままです.
研究 の 目的:
- シャーストレスの下での摩擦粒子の阻害を調査する.
- イソトロピック・ジャミングの臨界値以下の密度でのジャミングを調査する.
- 剪定誘発の詰まった状態の現象を特徴づける.
主な方法:
- 摩擦,円盤状の粒子の実験的研究.
- 制御された切断ストレスの適用.
- 力のネットワークと粒子の分子の分析.
主要な成果:
- シーアストレスは,同otropic jammingの臨界値以下の密度でジャミングを誘導します.
- シャー・ジャーム状態の2つのタイプが現れます:脆弱な状態と堅固な状態です.
- トランジションは,密度に関係なく,力を有する粒子の分数によって支配されます.
- シャー・ジャーム状態はアニソトロピック・ファブリックを示し,アニソトロピーは臨界密度の近くで消滅する.
結論:
- 摩擦的粒子の阻害は,臨界密度を下回るシャーストレスを通じて達成できます.
- シャー・ジャム状態は,イソトロピック・ジャム状態とは異なる特性を示します.
- 力を有する粒子の割合は,ジャム移行を制御する重要なパラメータです.
関連する概念動画
01:14Normal and Shear Force
When a beam is subjected to different loads, such as weight, pressure, or other external forces, internal forces are generated within the beam. These forces can have a significant impact on the overall stability and strength of the structure. Engineers use various methods to analyze and determine the magnitude and direction of these internal forces. One common technique used to determine internal forces in beams is the method of sections. This method involves considering an imaginary point or...
01:27Shear Diagram
In the study of beam mechanics, shear diagrams play a crucial role in understanding the distribution of shear forces along the length of a beam. Consider a beam AB that is supported at both ends and subjected to perpendicular loads.
First, a free-body diagram of the beam is drawn, representing all the external forces and internal reactions acting on the beam. One can calculate the reaction forces at each support by employing the equilibrium equations of force and moment. The vertical component...
First, a free-body diagram of the beam is drawn, representing all the external forces and internal reactions acting on the beam. One can calculate the reaction forces at each support by employing the equilibrium equations of force and moment. The vertical component...
01:18Shearing Stress
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The average shearing stress can be calculated by dividing the shear by the area of the cross-section.
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01:20Shearing Strain
The shearing strain represents a cubic element's angular change when subjected to shearing stress. This type of stress can transform a cube into an oblique parallelepiped without influencing normal strains. The cubic element experiences a significant transformation when exposed solely to shearing stress. Its shape alters from a perfect cube into a rhomboid, clearly demonstrating the effect of shearing strain. The degree of this strain is considered positive if it reduces the angle between the...
01:26Singularity Functions for Shear
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01:16Shear on the Horizontal Face of a Beam Element
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