Smoothed particle hydrodynamics simulation of granular system under cyclic compressions
Smoothed particle hydrodynamics simulation of granular system under cyclic compressions
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循环压缩下颗粒系统的平滑颗粒流体动力学模拟
DOI：
10.1016/j.powtec.2019.04.079
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发表时间：
2019
影响因子：
5.2
通讯作者：
Zhang, Yuwen
中科院分区：
文献类型：
--
作者：
Tayeb, Raihan;Mao, Yijin;Zhang, Yuwen
使用平滑粒子流体动力学 (SPH) 方法的改进版本来模拟二维无摩擦颗粒材料对各向同性循环压缩的响应，其中包括单个颗粒变形的真实本构模型。该研究揭示了平均配位数和全局压力随周期的演变。还报告了不同压缩循环的接触力的概率分布函数 (PDF)。最大压缩时的整体压力显示出填充分数低于特定值时呈下降趋势。通过绘制相对粒子迁移率并使用四点磁化率测量量化动态异质性，研究了可以引起这种应力松弛的结构重排。四点磁化率测量揭示了可以表征驱动系统动态的长度和时间尺度。使用仿射和非仿射变形的 Falk-Langer 测量研究了细观尺度结构重排。仿射和非仿射变形下降到稳定值并围绕该值振荡，这表明结构正在朝着更稳定的配置发展。局部堆积分数与非仿射平方位移之间存在负相关关系。最后，采用复杂的网络分析来更好地理解中观尺度的结构重排。从复杂网络分析获得的平均度和平均聚类系数显示在最大压缩时出现峰值，但峰值随着周期而增加。发现每个颗粒的程度与局部堆积分数正相关，与非仿射平方变形负相关。看到了三周期群体的富集，表明它是介观尺度粒子的最优选构象。
The response of two-dimensional frictionless granular material to isotropic cyclic compression is simulated using an improved version of the Smoothed Particle Hydrodynamics (SPH) method, which includes realistic constitutive model for deformation of individual grains. The study reveals the evolution of mean coordination number and global pressure over cycles. The probability distribution function (PDF) of contact forces for different compression cycles is also reported. The global pressure at maximum compression shows downward trend for packing fractions below a certain value. The structural rearrangement that can give rise to such stress relaxation is studied by mapping relative particle mobilities and quantifying dynamic heterogeneity using a four-point susceptibility measure. The four-point susceptibility measure reveals length and time scales that can characterize the dynamics of driven system. Meso-scale structural rearrangement is studied using Falk-Langer measure of affine and non-affine deformation. The affine and non-affine deformations drop to a stable value and oscillates around it, which suggest that the structure is driving towards a more stable configuration. A negative correlation is found between the local packing fraction and the non-affine squared displacement. Finally, a complex network analysis is employed to better understand the structural rearrangement at meso-scale. The average degree and average clustering coefficient obtained from the complex network analysis show peaks at maximum compressions, but the peak values increase with cycles. The degree per particle is found to be positively correlated with local packing fraction and negatively correlated with the non-affine squared deformation. An enrichment of three-cycle population is seen, suggesting it as the most preferred conformation for particles at the meso-scale.
DOI：
10.1103/physreve.97.012909
发表时间：
2018-01
期刊：
Physical review. E
影响因子：
--
作者：
VanderWerf K;Jin W;Shattuck MD;O'Hern CS
通讯作者：
O'Hern CS
剪切椭圆和圆盘的动力学：颗粒形状的影响。
影响因子：
8.6
作者：
Somayeh Farhadi;R. Behringer
通讯作者：
R. Behringer