Reza Shaebani M, Unger Tamás, Kertész János
Department of Theoretical Physics, Budapest University of Technology and Economy, H-1111 Budapest, Hungary.
Phys Rev E Stat Nonlin Soft Matter Phys. 2007 Sep;76(3 Pt 1):030301. doi: 10.1103/PhysRevE.76.030301. Epub 2007 Sep 17.
We study the mechanical response generated by local deformations in jammed packings of rigid disks. Based on discrete element simulations we determine the critical force of the local perturbation that is needed to break the mechanical equilibrium and examine the generated displacement field. Displacements decay as a power law of the distance from the perturbation point. The decay exponent and the critical force exhibit a nontrivial dependence on the friction: Both quantities are nonmonotonic and have a sharp maximum at the friction coefficient 0.1. We find that the mechanical response properties are closely related to the problem of force indeterminate where similar nonmonotonic behavior was observed previously. We establish a direct connection between the critical force and the ensemble of static force networks.
我们研究了刚性圆盘堵塞堆积中局部变形产生的力学响应。基于离散元模拟，我们确定了打破力学平衡所需的局部扰动的临界力，并研究了产生的位移场。位移随距扰动点距离的幂律衰减。衰减指数和临界力对摩擦力表现出非平凡的依赖性：这两个量都是非单调的，并且在摩擦系数为0.1时具有尖锐的最大值。我们发现力学响应特性与力的不确定性问题密切相关，此前在该问题中观察到了类似的非单调行为。我们建立了临界力与静力网络系综之间的直接联系。
