Using instrumental inertia in controlled stress rheometry
Using instrumental inertia in controlled stress rheometry
复制标题
在受控应力流变测量中使用仪器惯性
DOI：
10.1007/s003970050110
复制
发表时间：
1998
期刊：
影响因子：
2.3
通讯作者：
D. Quemada
中科院分区：
文献类型：
--
作者：
C. Baravian;D. Quemada
摘要本文描述了一种新的方法来表征复杂流体在小变形和大变形下的非线性行为。对于蠕变测量，我们使用仪器惯性和材料弹性之间的耦合来跟踪iota卡拉胶溶液在屈服应力上下的流变行为。结果表明，这种耦合选择性地激发了弛豫谱的一个特定频率。采用解析计算方法量化了屈服应力附近的非线性行为。在最初几秒钟内观察到的“自由”振荡使我们能够选择最合适的力学模型。与实验结果的对比表明，即使在屈服应力以上，线性模型仍能独立可靠地反映力学模型中各元素的变化情况。通过对受控应力流变学中自由振荡和强迫振荡的比较，从实验和理论上说明了使用自由振荡是有利的。
Abstract We describe a new method for characterizing the non-linear behavior of complex fluids at both small and large deformations. For creep measurements, we use the coupling between the instrumental inertia and the material‘s elasticity to follow the rheological behavior of a solution of iota carrageenan both above and below the yield stress. It is shown that this coupling selectively excites one particular frequency of the relaxation spectrum. An analytical calculation is used to quantify the non-linear behavior near the yield stress. The “free“ oscillations observed during the first few seconds allow us to choose the most appropriate mechanical model. Comparison with experiment shows that even above the yield stress, a linear model can still give independently reliable information about the changes in each element of the mechanical model. A comparison of free and forced oscillations in controlled stress rheometry shows both experimentally and theoretically the conditions under which the use of free oscillations is advantageous.