Krishnaraj K P, Nott Prabhu R
Department of Chemical Engineering, Indian Institute of Science, Bangalore 560012, India.
Phys Rev Lett. 2020 May 15;124(19):198002. doi: 10.1103/PhysRevLett.124.198002.
Dense granular materials and other particle aggregates transmit stress in a manner that belies their microstructural disorder. A subset of the particle contact network is strikingly coherent, wherein contacts are aligned nearly linearly and transmit large forces. Important material properties are associated with these force chains, but their origin has remained a puzzle. We classify subnetworks by their linear connectivity, and show the emergence of a percolation transition at a critical linearity at which the network is sparse, coherent, and contains the force chains. The subnetwork at critical linearity closely reflects the macroscopic stress and explains distinctive features of granular mechanics.
致密颗粒材料和其他颗粒聚集体传递应力的方式与其微观结构的无序性不符。颗粒接触网络的一个子集具有显著的连贯性，其中接触几乎呈线性排列并传递大力。重要的材料特性与这些力链相关，但其起源一直是个谜。我们根据子网的线性连通性对其进行分类，并表明在临界线性度处出现渗流转变，此时网络稀疏、连贯且包含力链。临界线性度下的子网紧密反映宏观应力，并解释了颗粒力学的独特特征。
