传统磁流变(MR)阻尼器活塞需缠绕励磁线圈,因此阻尼通道1/2以上长度为无效长度,影响阻尼器的最大出力。针对上述问题,提出了两种磁路结构改进方案,根据改进的磁路结构,结合磁场有限元分析,完成了两种阻尼器的结构设计和磁路设计,并采用Bingham平板模型对两种阻尼器出力状况进行预估,得到了阻尼器工作状态下的力-速度曲线,并比较了其性能。结果表明:改进的磁路结构切实可行,两种阻尼器与同尺寸传统MR阻尼器相比,提高了阻尼通道的有效长度,较好地实现了全通道有效,最大出力提高一倍以上;方案-阻尼器的阻尼力可调范围较大,方案二阻尼器在最大出力、防沉降性能和故障安全性能方面更具优势。
Magnetic coils ought to be winded around pistons of the conventional MR dampers, and hence, the above half of the damping path is ineffective, which affects the performance of MR dampers. In order to overcome this disadvantage, two improved magnetic circuit structures are proposed in this paper. Based on the structures of the proposed magnetic circuits and the finite element analysis of the magnetic fields, the structures and the improved magnetic circuits of MR damper are designed. The output powers of these two dampers in states are then predicted by Bingham model, from which the force-velocity hysteresis loops are also obtained. Finally, the performances of these two dampers are compared. The results show that the proposed magnetic circuits can realize the purpose of full-length effective damping path, thus the maximum damping forces of the new dampers are at least doubled compared with traditional MR damper of the same size. The MR damper using the first improved magnetic circuit has bigger adjustable extent of the damping force, while the MR damper with the second improved magnetic circuit has the advantages of larger maximum damping force, better ability to prevent MR fluid settling and better fail-safe ability.