论文标题

软球包装的缺陷和挫败感

Defects and Frustration in the Packing of Soft Balls

论文作者

Jao, Kenneth, Promislow, Keith, Sottile, Samuel

论文摘要

这项工作引入了Hookean-Voronoi Energy,这是一种最小的柔软,可变形球的模型。这是由二嵌段和星形聚合物致密堆积产生的准周期平衡的最新研究所激发的。我们限制了平面案例,我们研究了相同的,可变形物体的平衡包装,其形状由周期性矩形的$ n $ site voronoi tessellation确定。我们得出了在Equilibria上显示的系统的降低的配方,每个站点都必须位于其相关的Voronoi区域的``Max-Center''中,并构建了一个有序的``单弦''的家族,其基数为$ O(n^2)$。我们确定系统允许常规的六边形镶嵌的尖锐条件,并确定在所有情况下,每个位置的平均能量都以单位大小的常规六角形为界。但是,对随机初始数据的梯度流量的数值研究表明,对于$ n $的适度值,系统将在低能量和较大吸引力盆地的准排序状态下平衡。对于较大的$ n $,平衡能量的分布似乎接近了$δ$功能的极限,其能量明显高于基态六边形。该极限可能是由两种机制来塑造的:中等能无序的平衡的增殖,该平衡的扩散阻断了梯度流向较低能量准排出的态态的梯度流量,并且对稳定状态的最大能量的刚性阈值。

This work introduces the Hookean-Voronoi energy, a minimal model for the packing of soft, deformable balls. This is motivated by recent studies of quasi-periodic equilibria arising from dense packings of diblock and star polymers. Restricting to the planar case, we investigate the equilibrium packings of identical, deformable objects whose shapes are determined by an $N$-site Voronoi tessellation of a periodic rectangle. We derive a reduced formulation of the system showing at equilibria each site must reside at the ``max-center'' of its associated Voronoi region and construct a family of ordered ``single-string'' minimizers whose cardinality is $O(N^2)$. We identify sharp conditions under which the system admits a regular hexagonal tessellation and establish that in all cases the average energy per site is bounded below by that of a regular hexagon of unit size. However, numerical investigation of gradient flow of random initial data, reveals that for modest values of $N$ the system preponderantly equilibrates to quasi-ordered states with low energy and large basins of attraction. For larger $N$ the distribution of equilibria energies appears to approach a $δ$-function limit, whose energy is significantly higher than the ground state hexagon. This limit is possibly shaped by two mechanisms: a proliferation of moderate-energy disordered equilibria that block access of the gradient flow to lower energy quasi-ordered states and a rigid threshold on the maximum energy of stable states.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源