Spatial Stress and Strain Distributions of Viscoelastic Layers in Oscillatory Shear.
Spatial Stress and Strain Distributions of Viscoelastic Layers in Oscillatory Shear.
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振荡剪切中粘弹性层的空间应力和应变分布。
DOI：
10.1016/j.matcom.2010.07.031
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发表时间：
2012
影响因子：
4.6
通讯作者：
Hill,DavidB
中科院分区：
文献类型：
--
作者：
Lindley,BrandonS;Forest,MGregory;Smith,BreannanD;Mitran,SorinM;Hill,DavidB
粘弹性材料的标准实验探针之一是测量被困在平行表面之间的层的响应，在一个边界处施加周期性应力或应变，并测量另一个。应力和应变之间的相对相位产生类似固体和类似液体的性质，分别称为储能模量和损耗模量，然后在一定范围的施加频率下捕获。很少考虑剪应力和法向应力的完整空间分布，主要是因为除了边界处之外，它们无法测量，并且这些信息在理论研究中并不被认为是特别感兴趣的。同样，应变分布在整个层传统上被忽略，除了在一个经典的协议的渡轮，阿德勒和索耶，基于快照的剪切驻波。然而，最近对暴露于振荡应力（呼吸）和应变（协调纤毛）的薄肺粘液层的调查表明，广泛的健康状况和环境或疾病攻击导致与表征经典流变仪的“表面负载”和“间隙负载”条件完全不同的条件。在这篇文章中，我们扩展了我们以前的线性和非线性模型的边界应力控制振荡应变到整个层。为了说明非直观的非均匀响应，我们表征实验条件和材料参数范围，其中最大应力迁移到通道内部。
One of the standard experimental probes of a viscoelastic material is to measure the response of a layer trapped between parallel surfaces, imposing either periodic stress or strain at one boundary and measuring the other. The relative phase between stress and strain yields solid-like and liquid-like properties, called the storage and loss moduli, respectively, which are then captured over a range of imposed frequencies. Rarely are the full spatial distributions of shear and normal stresses considered, primarily because they cannot be measured except at boundaries and the information was not deemed of particular interest in theoretical studies. Likewise, strain distributions throughout the layer were traditionally ignored except in a classical protocol of Ferry, Adler and Sawyer, based on snapshots of standing shear waves. Recent investigations of thin lung mucus layers exposed to oscillatory stress (breathing) and strain (coordinated cilia), however, suggest that the wide range of healthy conditions and environmental or disease assaults lead to conditions that are quite disparate from the “surface loading” and “gap loading” conditions that characterize classical rheometers. In this article, we extend our previous linear and nonlinear models of boundary stresses in controlled oscillatory strain to the entire layer. To illustrate non-intuitive heterogeneous responses, we characterize experimental conditions and material parameter ranges where the maximum stresses migrate into the channel interior.