Capturing transient granular rheology with extended fabric tensor relations
Capturing transient granular rheology with extended fabric tensor relations
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DOI：
10.1007/s10035-019-0948-9
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发表时间：
2019-08
期刊：
影响因子：
2.4
通讯作者：
Eduardo Rojas Parra;K. Kamrin
中科院分区：
文献类型：
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作者：
Eduardo Rojas Parra;K. Kamrin
我们提出了一种改进的颗粒简单剪切过程的连续介质模型，该模型预测了有效摩擦系数和组构张量的耦合演化。具体地说，该模型给出了与准静态状态下颗粒介质的运动学和结构相关的瞬时强度。将连续介质模型的模拟结果与分子动力学模拟结果进行了比较。对织物张量的主方向模数和主方向角的比较表明，对于所分析的所有情况，都具有很好的一致性。新的织物演化模型能够捕捉到当网络被破坏时，在反转过程开始时，织物模数和有效摩擦系数的突然下降。在反转过程中，当力链从一个稳定状态移动到另一个稳定状态时，该模型还预测了织物角度的正确自旋方向。通过将摩擦系数与织物和单位剪切率张量相关联，改进了应力建模。
We present an improved continuum model for transient processes in granular simple shearing, which predicts the coupled evolution of the effective friction coefficient and fabric tensor. Specifically, the model gives the transient strength associated to the kinematics and the structure of the granular media for the quasi-static regime. The results of the continuum model were compared against molecular dynamic simulations. The comparison for the modulus and the angle of the principal directions of the fabric tensor showed a very good agreement for all the cases analyzed. The new fabric evolution model is capable of capturing the abrupt fall in the fabric modulus and in the effective friction coefficient at the beginning of reversal processes, when the network is destroyed. The model also predicts the right spin direction of the fabric angle, when the force chains move from one steady state to another, during reversal. Improvement in modeling the stress is obtained by relating the friction coefficient to the fabric and the unit shear rate tensors.