3D real-time and in situ characterisation of fibre kinematics in dilute non-Newtonian fibre suspensions during confined and lubricated compression flow
3D real-time and in situ characterisation of fibre kinematics in dilute non-Newtonian fibre suspensions during confined and lubricated compression flow
复制标题
在受限和润滑压缩流期间稀非牛顿纤维悬浮液中纤维运动学的 3D 实时和原位表征
DOI：
10.1016/j.compscitech.2016.09.004
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发表时间：
2016
影响因子：
9.1
通讯作者：
M. Terrien
中科院分区：
文献类型：
--
作者：
T. Laurencin;Laurent Orgéas;P. Dumont;S. R. Roscoat;P. Laure;S. Corre;Luisa Silva;R. Mokso;M. Terrien
短纤维增强聚合物复合材料的物理和机械性能取决于聚合物基体中纤维的几何形状、含量、分布和取向。这些微结构特征主要是在成形阶段，即，当复合材料通常在模具中流动并表现为非牛顿纤维悬浮液时。它们的流动诱导微观结构仍然不能很好地预测目前的流变模型。为了更好地理解它们，非牛顿稀纤维悬浮液的制备和进行润滑压缩实验，使用安装在同步加速器X射线显微摄影机的微流变仪。这些实验首次实现了悬浮液中纤维平移和旋转的快速原位3D成像。纤维运动与Jeffery模型的预测进行了比较。尽管使用非牛顿悬浮流体和受限流动条件，即，在压缩压板之间的间隙与纤维长度的数量级相同的情况下，我们表明，如果纤维离压缩压板足够远（大约在其直径的一到两倍的距离处），则Jeffery的预测是令人满意的。另外，实验的平均取向率高于Jeffery的预测。
The physical and mechanical properties of short fibre-reinforced polymer composites depend on the geometry, content, distribution and orientation of fibres within the polymer matrix. These microstructure features are mainly induced during the forming stage,i.e., when composites usually flow in moulds and behave as non-Newtonian fibre suspensions. Their flow-induced microstructures still cannot be well predicted by current rheological models. To better understand them, non-Newtonian dilute fibre suspensions were prepared and subjected to lubricated compression experiments using a micro-rheometer mounted in a synchrotron X-ray microtomograph. These experiments enabled, for the first time, fast andin situ3D imaging of the translation and rotation of fibres in the suspending fluid. Fibre motions were compared with the prediction of the Jeffery's model. Despite the use of a non-Newtonian suspending fluid and confined flow conditions,i.e., with a gap between compression platens of the same order of magnitude than the fibre length, we showed that Jeffery's prediction was satisfactory if the fibres were sufficiently far from the compression platens (approximately at a distance of once to twice their diameter). Otherwise, the experimental average orientation rates were higher than the Jeffery's prediction.