Semi-active control of three-dimensional vibrations of an inclined sag cable with magnetorheological dampers
Semi-active control of three-dimensional vibrations of an inclined sag cable with magnetorheological dampers
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DOI：
10.1016/j.jsv.2005.10.028
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发表时间：
2006-09
影响因子：
4.7
通讯作者：
Qiang Zhou;S. Nielsen;W. Qu
中科院分区：
文献类型：
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作者：
Qiang Zhou;S. Nielsen;W. Qu
本文利用有限差分法（FDM）研究了带有离散磁流变（MR）阻尼器的倾斜下垂索的三维半主动振动控制。采用修正的达尔模型来描述磁流变阻尼器的动态特性。首先建立了缆索阻尼器系统的非线性运动方程，该方程考虑了面内和面外运动之间的耦合，也考虑了支撑点的位移。磁流变阻尼器可以近似认为是一个可变摩擦阻尼器，因此提出了一种基于调制均质摩擦算法的半主动控制策略。以典型的短电缆为例，通过与单模态响应的粘性阻尼器进行比较，数值验证了最优控制磁流变阻尼器的减振能力。分析表明，如果满足最优调谐粘性阻尼器的设计条件，磁流变阻尼器和粘性阻尼器的性能相当；然而，如果拉索的响应由多种模态主导，磁流变阻尼器与粘性阻尼器相比可以取得更好的减振效果。特别是，如果支撑点运动的幅度小于阈值，磁流变阻尼器可以防止由支撑点运动引起的次谐波激励的发生，因此，与粘性阻尼器相比，磁流变阻尼器实现了显着的减振。此外，还检验了测量噪声对控制效果的影响以及所提出的半主动控制规则的鲁棒性。
Three-dimensional semi-active vibration control of an inclined sag cable with discrete magnetorheological (MR) dampers is investigated in this paper using the finite difference method (FDM). A modified Dahl model is used to describe the dynamic property of MR damper. The nonlinear equations of motion of cable–dampers system are first established, which accounts for coupling between in-plane and out-of-plane motions, and also for the displacement of the support points. A MR damper can be considered as a variable friction damper approximately, so a semi-active control strategy based on the modulated homogeneous friction algorithm is proposed. Taking a typical short cable as an example, the vibration reduction ability with optimally controlled MR dampers is verified numerically by comparison with the viscous damper tuned to a single mode response. The analysis show that, if the conditions are fulfilled at which the optimal tuned viscous damper is designed, the MR damper and the viscous damper are performing equally well; however, if the response of the cable is dominated by several modes, the MR damper can achieve better vibration reduction effect compared with viscous damper. Especially, if the amplitude of the support point motion less than a threshold value, MR damper can prevent subharmonic excitation caused by support point motion from taking place, consequently, MR damper achieves significant vibration reduction compared to viscous damper. In addition, the influence of measurement noise on control effect and the robustness of the proposed semi-active control rule are also examined.