论文标题
冲击引起的密集摩擦悬浮液的硬化
Impact-induced hardening in dense frictional suspensions
论文作者
论文摘要
我们在数值上研究了撞击引起的密集悬浮液的硬化。我们采用了晶格玻尔兹曼方法，并对撞击下的密集悬浮液进行了模拟，这些悬浮液与悬架表面之间的悬浮颗粒之间的接触结合在一起。我们对稠密悬浮液的自由落体影响器的模拟再现了实验结果，在撞击后不久，在高速撞击和高体积分数下进行摩擦颗粒进行反弹，然后随后下沉。我们发现，悬浮液的剪切应力不受冲击的影响，这清楚地区分了影响引起的硬化与不连续的剪切增厚。取而代之的是，我们发现存在与动态堵塞区域相对应的正常应力值的局部区域的存在。我们的模拟表明，悬浮颗粒之间的摩擦相互作用对于撞击引起的硬化以维持动态阻塞区域很重要。此外，持续的同源性分析成功阐明了力链的拓扑结构。
We numerically study the impact-induced hardening in dense suspensions. We employ the lattice Boltzmann method and perform simulations of dense suspensions under impacts, which incorporate the contact between suspended particles with the free surface of the suspension. Our simulation for a free-falling impactor on a dense suspension reproduces experimental results, where rebound takes place for frictional particles at high-speed impact and high volume fraction shortly after the impact before subsequently sinking. We found that the shear stress of the suspension is not affected by the impact, which clearly distinguishes the impact-induced hardening from the discontinuous shear thickening. Instead, we found the existence of a localized region with distinctively high value of normal stress corresponding to the dynamically jammed region. Our simulation indicates that the frictional interaction between suspended particles is important for the impact-induced hardening to maintain the dynamically jammed region. Furthermore, persistent homology analysis successfully elucidates the topological structure of force chains.
