The non-linear viscoelastic response under interrupted shear flows is one of the interesting characteristics of entangled polymers. In particular, the stress overshoot in the resumed shear has been discussed concerning the recovery of the entanglement network in some studies. In this study, we performed multichain slip-link simulations to observe the molecular structure of an entangled polymer melt. After confirming the reasonable reproducibility of our simulation with the literature data, we analyzed the molecular characteristics following the decoupling approximation. We reasonably found that the segment orientation dominates the stress overshoot even under the resumed shear with minor contributions from the segment stretch and entanglement density. We defined the mitigation function for the recovery of the stress overshoot as a function of the rest time and compared it with the relaxation of the molecular quantities after the initial shear. As a result, we have found that the mitigation of the stress overshoot coincides with the relaxation of entanglement density.

中文翻译：

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缠结聚合物液体中断剪切响应的原始链网络模拟。

剪切流中断下的非线性粘弹性响应是缠结聚合物的有趣特征之一。特别是，在一些研究中，已经讨论了恢复剪切中的应力超调，涉及到纠缠网络的恢复。在这项研究中，我们进行了多链滑环模拟，以观察纠缠的聚合物熔体的分子结构。在用文献数据确认我们的模拟具有合理的可重复性后，我们根据去耦近似分析了分子特征。我们合理地发现，即使在恢复剪切的情况下，节段的方向仍能控制应力过冲，而节段的拉伸和纠缠密度的贡献很小。我们定义了用于恢复应力过冲的缓解函数，作为缓解时间的函数，并将其与初始剪切后分子量的松弛进行了比较。结果，我们发现应力过冲的减轻与缠结密度的松弛相吻合。