论文标题
阻塞不对称bidisperse颗粒包装中的结构过渡
Structural transitions in jammed asymmetric bidisperse granular packings
论文作者
论文摘要
我们研究了不对称的bidisperse granu \ lar包装中沿堵塞过渡的局部结构变化。包装的局部结构通过接触定向顺序,$ \ tilde {q} _ {\ ell} $进行量化,该结构量化了干扰结构中每个接触配置(大型,小型,小,大小,小,小,小,小,小,小,大,大,大,小,小,小,小,小小的,小型,大型)的贡献。 $ \ tilde {q} _ {\ ell} $的部分值是根据已知的有序晶格计算的,这些晶格由粒子的尺寸比$δ$固定。我们发现,包装在$ ϕ_j $上进行结构过渡,这表现为部分$ \ tilde {q} _ {\ ell} $。每种触点配置都以不同的方式有助于堵塞结构,以$δ$和浓度的小粒子的浓度变化,$ x _ {\ mathrm {s}} $。结果不仅表明包装在干扰时会发生结构变化,还表明bidisperse包装在单分散包装中也显示出局部的HCP和FCC结构。这表明,bidisperse系统的堵塞结构固有地赋予了局部结构秩序。这些结果与理解颗粒的排列如何确定bidispasse颗粒堆积的强度有关。
We study the local structural changes along the jamming transitions in asymmetric bidisperse granu\-lar packings. The local structure of the packing is assessed by the contact orientational order, $\tilde{Q}_{\ell}$, that quantifies the contribution of each contact configuration (Large-Large, Small-Small, Large-Small, Small-Large) in the jammed structure. The partial values of $\tilde{Q}_{\ell}$ are calculated with respect to known ordered lattices that are fixed by the size ratio, $δ$, of the particles. We find that the packing undergoes a structural transition at $ϕ_J$, manifested by a sudden jump in the partial $\tilde{Q}_{\ell}$. Each contact configuration contributes to the jammed structure in a different way, changing with $δ$ and concentration of small particles, $X_{\mathrm{S}}$. The results show not only that the packing undergoes a structural change upon jamming, but also that bidisperse packings exhibit local HCP and FCC structures also found in monodisperse packings. This suggests that the jammed structure of bidisperse systems is inherently endowed with local structural order. These results are relevant in understanding how the arrangement of particles determines the strength of bidisperse granular packings.