各向同性磁活性弹性体的磁感应形变及其与磁流变效应的关系
Magnetically induced deformation of isotropic magneto-active elastomers and its relation to the magnetorheological effect
AI总结：
该研究通过实验与理论结合，探究各向同性磁活性弹性体磁感应形变与磁流变效应的关联，调整统一平均场模型揭示微观结构演化对形变、模量及磁化的影响，实现隐藏材料属性的定量获取。
摘要：
各向同性磁活性弹性体（Magneto-Active Elastomers, MAEs）能否同时产生巨大的磁感应形变并表现出显著的磁流变效应？在这项结合实验与理论的研究中，我们揭示了MAEs的宏观形变与施加磁场引发的颗粒重构过程之间的关联。为此，我们研究了不同长径比和颗粒填充量的MAE圆柱在均匀磁场中的行为，通过光学相机获取圆柱的轴向形变数据。我们对既往研究中提出的统一平均场模型进行了调整，用以描述初始各向同性圆柱向横观各向同性圆柱的转变。这种力学转变由颗粒重排为沿磁场方向排列的致密柱状结构所引发，且被认为会产生显著的磁流变效应。然而，我们的模型预测，沿磁场方向评估时弹性模量的增幅不到3倍。该预测基于对所研究MAEs的剪切模量及柱状结构的细致分析。较弱的磁流变效应解释了沿磁场方向测得的显著轴向形变；而较强的磁流变效应会因模量提升数个数量级而阻碍轴向形变。不仅模量和宏观形变受微观结构演化的影响，颗粒的磁化强度也会受其影响——当颗粒重排为致密柱状结构时，磁化强度会升高。通过这项研究，我们表明统一平均场模型可定量获取具有不同形状和演化微观结构的MAE样品中隐藏的材料属性，如磁化强度和刚度。
英文摘要：
Can isotropic Magneto-Active Elastomers (MAEs) undergo giant magnetically induced deformations and exhibit huge magnetorheological effects simultaneously? In this experimental and theoretical study, we reveal how the macroscopic deformation of MAEs relates to the process of particle restructuring caused by application of a magnetic field. For this purpose, MAE cylinders with different aspect ratios and particle loadings are studied in uniform magnetic fields. The axial deformations of the cylinders are acquired using an optical camera. A unified mean-field model proposed in previous studies is adapted to describe the transition of initially isotropic cylinders into transversely isotropic ones. This mechanical transition is caused by the rearrangement of particles into dense columnar structures aligned with the field and is believed to result in a huge magnetorheological effect. Our model however predicts less than three-fold increase in elastic moduli when evaluated along the field direction. This prediction is based on a careful examination of the shear moduli of studied MAEs and the columnar structures. A weak magnetorheological effect explains significant axial deformations measured in the field direction. A strong magnetorheological effect would hinder axial deformations due to an increase in modulus by several orders of magnitude. Not only are the moduli and macroscopic deformations influenced by microstructure evolution, but so is the magnetization of particles, which increases as they rearrange into dense columns. With this study, we show that the unified mean-field model provides quantitative access to hidden material properties such as magnetization and stiffness in MAE samples with different shapes and evolving microstructures.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
