双线圈磁流变阻尼器动力特性实验研究

Experimental Study of Dynamic Characteristics of Double Coil Magnetorheological Damper

设计了一种双线圈磁流变阻尼器,并介绍了其工作原理。在INSTRON拉伸机上对所设计的双线圈磁流变阻尼器的动力特性进行了试验测试,分析了双线圈通同向电流、通异向电流以及固定其中一个线圈电流,改变另外一个线圈电流这3种电流加载条件下的阻尼器动力特性,同时对比分析了不同拉伸位移和不同加载频率下的阻尼力随位移及阻尼力随速度变化的关系。结果表明:该阻尼器的零磁场强度下的阻尼力值为120 N;改变加载频率和拉伸位移,发现加载频率变化对阻尼力大小影响较大;双线圈通异向电流时的阻尼力明显大于通同向电流时的阻尼力,通异向电流1.0 A时阻尼力最大能达到1.21 k N;固定一个线圈电流,改变另一个线圈的电流,总电流相等时其阻尼力基本相等,说明所设计的双线圈产生的磁场也相等,具有较好的对称性。

A double coil magnetorheological （MR） damper was designed, and its structure and working principle were intro- duced. The dynamic characteristics of the prop0seed MR damper were tested using the INSTRON stretching machine, and dynamic characteristics of the double coil magnetorheological damper were analyzed with the current applied to double coil in the test conditions including： applied currents with same direction, applied current with reverse direction, one coil＇s current fixed while another coil＇s current changed. Meanwhile, the relation of changes of damping force versus displacements and the damping force versus velocity were compared and analyzed under the different stretching displacement and loading frequency of the tested machine. The results show that the damping force equals 120 N under zero applied current of the damper. The influences of the changing frequency on the damping force are obvious while the loading frequency and the stretching displacements changed. Moreover, the damping force under the applied current with reverse direction in the double coil is bigger than that of under the applied currents with same direction, and the maximum damping force can reach 1.21 kN under the applied current with reverse direction. When one coil＇s current is fixed and another coil＇s current is changed, the damping force can keep stable if the total applied currents equal each other, which reveal that the magnetic flux density of the designed double coil is also identical, with rather good symmetry.