磁流变阻尼器对斜拉索半主动控制的最优参数

Optimal Marker of MR Damper for Stay-Cable with Semi-Active Vibration Control

采用基于位移和速度方向的半主动控制算法,以全索全时段振动响应的均方根(RMS)评价磁流变(MR)阻尼器对斜拉索的减振效果,研究了MR阻尼器的最优型号与阻尼器安装位置、斜拉索基频(张力、索长、质量)、激励荷载(类型、频率、幅值)等各种因素的关系,为MR阻尼器合理选型提供了优化设计的方法。最优型号主要是与斜拉索基频和MR阻尼器安装位置有关。在引起索基频变化的因素中,索质量对最优型号影响最大;而索长对最优型号影响不大。对于索质量较大、张力较大、MR阻尼器安装位置较低、外界激励较大、频谱特征多变、低频为主时需要较强的MR阻尼器。

A stay cable incorporated with MR dampers exhibits pronounced nonlinearity. The dynamic response performances of a cable with MR dampers are explored in detail using Spencer photometric model. The primary measure of damper performance considered is the Root Mean Square (RMS) cable deflection integrated along the length of the cable and the whole time. The relationship of the optimal marker of MR dampers, mounting postion, voltage applied, the first frequency of cables (tensile force, length and mass perunit length), excited loads (type, frequency and amount) were studied. The semi-active control strategy of cable vibration was provided based on the direction of both displacement and velocity. It is shown that MR dampers marker is the key point to effect control of cable vibration. Vibration mitigation of cable using the optimal MR damper marker can be got the best optimum. Among the factors of changing frequency, cable mass influenced MR dampers marker more higher than cable tension does. Cable length has little influence on MR dampers marker. To some larger cable mass, larger cable tension, lower site of dampers, larger excited loads, more complex frequency spectrum and low frequency, the stronger MR damper is need.