拉索由于质量轻、柔性大、阻尼小,在风荷载作用下,容易产生横向振动。一般情况下,想要通过安放在拉索锚座附近的被动、半主动控制装置来抑制这种振动有一定的困难。而在拉索的锚座处沿拉索轴向实施主动控制却是一种很好的方法。由于某些情况下拉索的抗弯刚度对振动频率有一定的影响,本文在考虑拉索抗弯刚度的基础上,建立了不同边界条件下拉索振动主动控制模型。本文通过线性二次型最优控制(LQR)策略对拉索振动实施了主动多模态控制仿真分析。计算结果表明,轴向主动多模态控制能够有效地抑制拉索的振动。
Cables in flexible structure are light, flexible, and low-damped and hence prone to have transverse vibration due to winds. As usual, the control of such vibration by the conventional passive or semiactive dampers that are placed near the cable anchorage is little difficult. Axial active control at the boundary, i.e., cables anchorage, is an attractive approach. Sometimes, the oscillation frequency of cables is affected by bending stiffness. Considering the bending stiffness of cables, the active vibration control model of rigid cables, under different boundary conditions, was given. Based on linear quadratic optimal control strategy, the active multi-modal vibration control of cables was simulated. The result proves that the vibration of cables can be controlled effectively by active multi-modal control strategy.