The combined influence of fibre orientation evolution and fibre concentration migration on rheological properties was considered in this study. Simple shear flow was imposed on centre-gated injection moulded PA6-33GF samples in a cone-plate geometry with a cone angle of 0.105 rad and a truncation height of 0.8 mm. Evolution of fibre orientation and fibre concentration distributions were imaged from sheared samples using X-ray computed tomography (X-CT). It was determined experimentally that the shell-core fibre orientation and fibre concentration distributions evolved towards a steady-state distribution. The orientation and concentration evolution was modelled using the Reduced Strain Closure (RSC) and Suspension Balance Model (SBM), respectively, and showed a reasonable fit. Numerical predictions for transient viscosity were obtained using constitutive equations for fibre-composite suspensions by including predicted results from the RSC and SBM models. Viscosity predictions from four different empirical models were compared with experimental data. The predictions from the Evans Model showed the best fit when comparing absolute viscosity values. Examination of the transient rheological response predicted by the empirical models revealed that they all had a lower overshoot magnitude and displayed a quicker decay of the overshoot when compared with the experimental results.

中文翻译：

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包含纤维取向和浓度演变的纤维填充复合材料的瞬态粘度

本研究考虑了纤维取向演变和纤维浓度迁移对流变特性的综合影响。简单的剪切流施加在锥板几何形状的中心浇注注塑 PA6-33GF 样品上，锥角为 0.105 弧度，截断高度为 0.8 毫米。使用 X 射线计算机断层扫描 (X-CT) 从剪切样品中对纤维取向和纤维浓度分布的演变进行成像。通过实验确定壳芯纤维取向和纤维浓度分布向稳态分布发展。方向和浓度演变分别使用减少应变闭合 (RSC) 和悬浮平衡模型 (SBM) 建模，并显示出合理的拟合。通过包括来自 RSC 和 SBM 模型的预测结果，使用纤维复合悬浮液的本构方程获得了瞬态粘度的数值预测。来自四种不同经验模型的粘度预测与实验数据进行了比较。在比较绝对粘度值时，埃文斯模型的预测显示出最佳拟合。对经验模型预测的瞬态流变响应的检查表明，与实验结果相比，它们都具有较低的过冲幅度，并且显示出较快的过冲衰减。在比较绝对粘度值时，埃文斯模型的预测显示出最佳拟合。对经验模型预测的瞬态流变响应的检查表明，与实验结果相比，它们都具有较低的过冲幅度，并且显示出较快的过冲衰减。在比较绝对粘度值时，埃文斯模型的预测显示出最佳拟合。对经验模型预测的瞬态流变响应的检查表明，与实验结果相比，它们都具有较低的过冲幅度，并且显示出较快的过冲衰减。