磁流变液高剪切率特性测试方法及装置

Testing Method and Device for Rheological Properties of Magnetorheological Fluid at High Shear Rate

为了研究磁流变液(magnetorheological fluid,简称MRF)在高剪切率应用场合的流变特性,设计了一种基于流动模式的MRF流变特性测试装置。利用平行板模型得到了MRF的性能参数关于阻尼通道的结构参数、压力梯度的解析解,并分析了流体的流态变化,为高剪切率条件下MRF流变特性的测试提供了理论依据。通过实验得到了阻尼通道中磁感应强度与励磁电流的关系,分析并排除了MRF流变特性测试的影响因素。最后,使用该装置对本研究小组配置的MRF试样进行了测试。结果表明,MRF的剪切屈服强度随活塞速度的增大而减小,设计的流变测试装置的剪切率可达到2.5×105/s,能满足高剪切率条件下MRF流变性能测试的特殊要求。

In order to research the rheological property of MRF at high shear rate,a magnetorheological fluid(MRF)rheological property testing device based on valve mode is developed.The accurate analytical expressions of MRF rheological parameters in terms of structural dimensions of testing device and pressure gradient in the damping channel are derived,and the flow State of MRF is considered,which provides the theoretical foundation for testing the rheological property of MRF at high shear rate.The relationship between magnetic indication in the annular channel and excitation electrical current is experimentally obtained.Some elements influencing testing are analyzed and eliminated.The device is used to test the rheological parameters of MRF,and the results show that the yield stress of MRF falls off significantly as the piston velocity continues to increase.The shear rates in designed device may exceed 2.5×105/s,which meets the special demands in MRF testing.