论文标题
用于剪切固定悬浮液的本构模型：用超跨横向振荡的稳定剪切的预测
Constitutive model for shear-thickening suspensions: Predictions for steady shear with superposed transverse oscillations
论文作者
论文摘要
我们最近开发了一个用于致密的，剪切厚的颗粒悬浮液的张力组成模型，该模型将无关的微观结构演化与应力依赖性堵塞阈值结合在一起。尽管它定量地估计结构各向异性[J.莱特牧师。 {\ bf 123}（21），214504（2019）]。在这里，我们使用该模型来预测超跨横向振荡对增厚状态稳定剪切流量的固定效应[N.该模型成功地重现了振荡介导的粘度下降。我们将应力和微结构张量的时间依赖性组件与离散元件模拟进行比较。尽管该模型正确地捕获了主要的定性行为，但通常过度预测了稳定剪切中的微结构各向异性，并且在振动剪切中预测的粒子接触数量不足。它也没有完全捕获微结构的横向分量与剪切速率振荡之间的相角变化，因为后者的幅度增加。这些差异暗示了该模型将来改进的途径。
We recently developed a tensorial constitutive model for dense, shear-thickening particle suspensions that combines rate-independent microstructural evolution with a stress-dependent jamming threshold. This gives a good qualitative account for reversing flows, although it quantitatively over-estimates structural anisotropy [J.~J.~J.~Gillissen {\em et al.}, Phys. Rev. Lett. {\bf 123} (21), 214504 (2019)]. Here we use the model to predict the unjamming effect of superposed transverse oscillations on a steady shear flow in the thickened regime [N.~Y.~C.~Lin {\em et al.}, Proc.~Nat.~Acad.~Sci.~USA {\bf 113}, 10774 (2016)]. The model successfully reproduces the oscillation-mediated viscosity drop observed experimentally. We compare the time-dependent components of the stress and microstructure tensors to discrete-element simulations. Although the model correctly captures the main qualitative behaviour, it generally over-predicts the microstructural anisotropy in steady shear, and it under-predicts the number of particle contacts in oscillating shear. It also does not fully capture the correct variation in phase angle between the transverse component of the microstructure and the shear rate oscillations, as the amplitude of the latter is increased. These discrepancies suggest avenues for future improvements to the model.
