基于刚度软化试验建立磁流变弹性体的Bouc-Wen模型

采用自主设计的刚度软化剪切试验测试系统,对各向同性磁流变弹性体(MR E)进行剪切试验,得到不同电流、频率、位移幅值下的力-位移滞回环;采用Bouc-Wen模型对MRE的动态力学特性进行描述,基于试验数据验证模型的准确性,通过模型分析试验参数对MRE宏观性能的影响规律。结果表明:Bouc-W en模型拟合结果与试验数据吻合较好,剪切力的均方根误差都小于0.95,说明该模型可以较好地描述MRE的刚度软化和阻尼特性。当施加正向电流时,MRE的刚度随电流的增大呈线性递减,随频率的增加而增大,当电流大于0.66 A或频率大于1.0 Hz时,电流或频率对刚度的影响程度减弱;MRE的阻尼随电流的增大而减小,随频率的增大呈指数递减,当电流大于0.66 A或频率为2.0 Hz时,阻尼基本趋于定值。

Establishment of Bouc-Wen Model of Magnetorheological Elastomers with Stiffness Softening Tests

A self-designed stiffness softening shear test system was used to conduct shear test on isotropic magneto rheological elastomers(MRE),and the force-displacement hysteresis loop under different current,frequency,and displacement amplitude conditions was obtained.The dynamic mechanical characteristics of MRE was described by Bouc-Wen model,and the accuracy of the model was verified on the basis of test data.The influence law of test parameters on macroproperties of MRE was analyzed.The results show that the fitting results of Bouc-Wen model were in good agreement with the test data,and the root mean square error of shear force was less than 0.95,indicating that the model could well describe the stiffness softening and damping characteristics of MRE.When the forward current was applied,the stiffness of MRE decreased linearly with increasing current,and increased with frequency;the effect degree of current or frequency on the stiffness was weakened when the current was greater than 0.66 A or frequency was greater than 1 Hz.The damping of MRE decreased with increasing current,and decreased exponentially with increasing frequency;the damping tended to be stable when the current was greater than 0.66 A or frequency was 2.0 Hz.