磁流变液剪切屈服应力模型的理论分析与实验

剪切屈服应力是评价磁流变液流变性能的最重要参数,建立全面、准确的磁流变液剪切屈服应力模型对于反映磁流变液的流变学本质及磁流变液的工程应用都具有重要意义。在分析磁流变液微观结构的基础上,采用电磁力学与流体动力学相结合的方法,建立了磁流变液的剪切屈服应力模型,并在自行研制的磁流变液剪切屈服应力测试装置上对自制的磁流变液进行了实验测试,验证了模型的正确性。

A Micro-mechanic-hydrodynamic Model for Yield Stress of Magnetorheological Fluids

A new micro-mechanic-hydrodynamic model(MMH-Model) to predict the yield stress of magnetorheological fluids has been developed. The storage modulus of a MR fluid with a three-dimensional chain structure model and the apparent viscosity of a MR fluid using the balance between the magnetic torque and hydrodynamic torque are determined.The magnetic interaction between the particles and the wall,as well as the static coefficient of friction,are considered.The predictions of the model are compared to preliminary experimental data obtained in a controlled stress plate-plate rheometer and other theoretical predictions.It is found that the model gives almost the correct yield stress for the MRFs in the magnetic fields lower than the saturation field,but underestimates the experimental results obtained in the magnetic fields higher than the saturation field.