Shear response of granular packings compressed above jamming onset
Shear response of granular packings compressed above jamming onset
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堵塞开始时压缩颗粒填料的剪切响应
DOI：
10.1103/physreve.103.022902
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发表时间：
2021
影响因子：
2.4
通讯作者：
O'Hern, Corey S.
中科院分区：
文献类型：
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作者：
Wang, Philip;Zhang, Shiyun;Tuckman, Philip;Ouellette, Nicholas T.;Shattuck, Mark D.;O'Hern, Corey S.
我们研究了受各向同性压缩的排斥的、无摩擦的球形颗粒的堵塞填料的力学响应。先前对软粒子模型的模拟发现，在大压力下，系综平均剪切模数随着压力的增加而增加，其中排斥作用在粒子间重叠中按幂规律扩展，有两个关键贡献：(1)作为压力的函数沿几何族连续变化，其中粒子间接触网络不变；(2)压缩过程中由于接触网络的变化而产生的不连续跳跃。数值模拟表明，在近等静几何族内，堵塞填料的剪切模数的形式在很大程度上由仿射响应决定，其中GaF/GA0=(P/P0)(α−2)/(α−1)−P/P0，P0∼N−2(α−1)是特征压力，在该压力下，剪切模量值是一个常数，是粒子的数目。对于能承受较大压力的近等静几何族，这种形式的偏差是由显著的非仿射粒子运动引起的。我们进一步证明，系综平均剪切模数不是简单的两个幂定律之和，而是极限，且高于标度为的特征压力。
We investigate the mechanical response of jammed packings of repulsive, frictionless spherical particles undergoing isotropic compression. Prior simulations of the soft-particle model, where the repulsive interactions scale as a power law in the interparticle overlap with exponent, have found that the ensemble-averaged shear modulusincreases with pressureasat large pressures.has two key contributions: (1) continuous variations as a function of pressure along geometrical families, for which the interparticle contact network does not change, and (2) discontinuous jumps during compression that arise from changes in the contact network. Using numerical simulations, we show that the form of the shear modulusfor jammed packings within near-isostatic geometrical families is largely determined by the affine response, where Gaf/Ga0=(P/P0)(α−2)/(α−1)−P/P0, P0∼N−2(α−1) is the characteristic pressure at whichis a constant that sets the scale of the shear modulus, andis the number of particles. For near-isostatic geometrical families that persist to large pressures, deviations from this form are caused by significant nonaffine particle motion. We further show that the ensemble-averaged shear modulusis not simply a sum of two power laws, but, wherein thelimit and, where, above a characteristic pressure that scales as.