Kurita Rei, Tamura Yuto, Tani Marie
Department of Physics, Tokyo Metropolitan University, 1-1 Minamioosawa, Hachiouji-shi, Tokyo, 192-0397, Japan.
Department of Physics, Kyoto University, Kitashirakawa-Oiwake-Cho, Sakyo-ku, Kyoto, 606-8502, Japan.
Sci Rep. 2024 Apr 17;14(1):8888. doi: 10.1038/s41598-024-59498-2.
Amorphous materials, such as granular substances, glasses, emulsions, foams, and cells, play significant roles in various aspects of daily life, serving as building materials, plastics, food products, and agricultural items. Understanding the mechanical response of these materials to external forces is crucial for comprehending their deformation, toughness, and stiffness. Despite the recognition of the formation of force networks within amorphous materials, the mechanisms behind their formation and their impact on macroscopic physical properties remain elusive. In this study, we employ a coarse-grained particle model to investigate the mechanical response, wherein local physical properties are integrated into the softness of the particles. Our findings reveal the emergence of a chain-like force distribution, which correlates with the planar distribution of softness and heterogeneous density variations. Additionally, we observe that the amorphous material undergoes softening due to the heterogeneous distribution of softness, a phenomenon explicable through a simple theoretical framework. Moreover, we demonstrate that the ambiguity regarding the size ratio of the blob to the force network can be adjusted by the amplitude of planar fluctuations in softness, underscoring the robustness of the coarse-grained particle model.
无定形材料，如颗粒物质、玻璃、乳液、泡沫和细胞，在日常生活的各个方面都发挥着重要作用，可用作建筑材料、塑料、食品和农产品。了解这些材料对外力的力学响应对于理解它们的变形、韧性和刚度至关重要。尽管人们认识到无定形材料中力网络的形成，但其形成机制及其对宏观物理性质的影响仍然难以捉摸。在本研究中，我们采用粗粒化粒子模型来研究力学响应，其中局部物理性质被整合到粒子的柔软度中。我们的研究结果揭示了链状力分布的出现，这与柔软度的平面分布和非均匀密度变化相关。此外，我们观察到无定形材料由于柔软度的非均匀分布而发生软化，这一现象可以通过一个简单的理论框架来解释。此外，我们证明了关于团块与力网络尺寸比的模糊性可以通过柔软度平面波动的幅度来调整，这突出了粗粒化粒子模型的稳健性。
