磁流变阻尼器拟静力力学特性及力学模型

为研究磁流变阻尼器（MRD）在拟静态作用下的力学性能，制作了一个四线圈剪切阀式MRD，在不同电流和不同位移幅值下采用三角位移加载制度对MRD进行了拟静态试验，研究了MRD的力学性能随电流和位移幅值的变化规律，分析了阻尼力波动现象产生的原因；根据试验结果提出了一种拟静态作用下修正的力学模型，对模型参数进行了识别，对力学模型进行了验证。结果表明：所用阻尼器在拟静态试验过程中阻尼力波动现象显著，无电流时阻尼力随着位移幅值增加而略微减小，有电流时阻尼力随着位移幅值增加而稍微增大；阻尼力随电流的增大明显增大，当电流超过1.5 A时，MRD达到磁饱和状态，阻尼力增幅明显降低；提出的力学模型能够较好地描述拟静力下阻尼力随电流和位移的改变而产生的变化特性。

Quasi-static mechanical properties and mechanical model of MRD

In order to study the mechanical properties of Magnetorheological Damper (MRD) under quasi-static action, a four-coil shear valve MRD was fabricated. A quasi-static test was carried on the MRD by using the triangular displacement loading system under different currents and displacements. In the test, the variation of the mechanical properties of MRD with the changes of current and displacement was studied, and the causes of the damping force fluctuation phenomenon were analyzed. Based on the test results, a modified mechanical model under quasi-static loading was proposed, the parameters of the model were identified, and the mechanical model was verified. The results show that the damping force of MRD fluctuates remarkably during the quasi-static test process. The damping force decreases slightly with the increase of displacement amplitude when there is no current, and increases slightly with the increase of displacement amplitude when there is current. The damping force increases obviously with the increase of current, and when the current exceeds 1.5A, MRD reaches magnetic saturation and the increase of damping force decreases obviously. The mechanical model proposed in this paper can well describe the variation of damping force with the change of current and displacement under quasi-static force.