【摘要】 首先,试验测试了不同速度和电流变化下,大吨位磁流变液阻尼器的响应时间;然后,对激励电流变化时阻尼器的磁场变化进行了有限元模拟,基于阻尼器间隙内磁流变液剪切屈服强度的变化考察了阻尼器的响应时间,并与试验数据做了比较。最后,研究了涡流和阻尼器电磁回路中电流响应时间对阻尼力响应时间的影响。结果表明,可以用有限元模拟得到的间隙内磁流变液的平均有效剪切屈服强度的时程曲线来研究磁流变液阻尼器的响应时间;电磁响应时间是阻尼力响应时间的决定因素,减小阻尼器中的涡流是缩短磁流变液阻尼器响应时间的重要途径;电流下降时涡流对阻尼器磁路的影响要大于电流上升的情况;无论是上升还是下降,电流初值越小,涡流对阻尼器磁路的影响越大,阻尼力响应时间也越长。研究还表明,缩短电流的响应时间,会带来更大的涡流,并不一定能缩短阻尼力的响应时间。更多还原

【Abstract】 The response time of a large-scale magnetorheological fluid damper (MRF damper) under different velocities and currents was tested. Then, the change of dynamic magnetic field inducted by changing electric current was simulated by finite element analysis (FEA). Based on the variation of shear yield strength of MR fluid at gap between cylinder and piston, the response time of MRF damper was calculated. The tested and calculated response time were compared. The effects of eddy current and electric current response time on the damper’s response were investigated. The results show that, using the history curve of average effective shear yield strength of MR fluid at gap, calculated by FEA, is effective to study the response time of MRF damper. The results also show that, electromagnetic response time is the most important factor which influences the response time of MRF dampers, and reducing eddy current is the key measure to reduce response time of MRF damper. Moreover, the influence of eddy current is much stronger on condition of current decreasing than that on condition of current increasing. With the same skip of current, whether current is increasing or decreasing, the smaller the initial current is, the greater the eddy current affects the damper’s magnetic circuit and the longer the damping force response time is. Shortening response time of electric current may induce higher eddy current, and does not always reduce response time of damping force.更多还原