【摘要】 以斜拉索为研究对象,忽略索桥之间的耦合作用,研究支座简谐运动下,磁流变阻尼器对拉索参数振动的智能半主动控制。首先建立斜拉索-阻尼器系统的三维运动方程,并采用有限差分法进行离散化。针对磁流变阻尼器的力学特点,提出简单适用的基于平衡逻辑算法的半主动控制策略,该控制策略的实现仅需测量阻尼器的位移和速度反应。重点考察支座简谐运动频率与拉索面内基本频率之比为2,1,2/3和1/2这4种工况。仿真分析表明,采用半主动控制策略,大多数情况下磁流变阻尼器能显著地降低拉索的面外位移,可以认为磁流变阻尼器能有效避免拉索平面外参数振动的发生;另一方面,仅在少数情况下磁流变阻尼器才对拉索的面内振动产生明显的减振效果。此外,提出的控制算法会导致拉索振动的混沌性。更多还原

【Abstract】 Intelligent control of stayed cables with MR dampers under simple harmonic support motions is studied, without considering cable-bridge interaction. The three-dimensional motion equation of the cable-damper system is established and then discretized by using the finite difference method. According to the dynamic characteristics of the MR dampers, a semi-active control strategy based on the balance logical algorithm is proposed, the implementation of which requires the measured displacement and velocity response of the dampers. Four cases are analyzed when the ratios of the frequency of the support motion to the first in-plane frequency of the cable are 2, 1, 2/3 and 1/2, respectively. Numerical analysis indicates that in most cases the MR dampers can effectively mitigate the out-of-plane parametric vibration of the cable, while only in special cases can the in-plane vibration of the cable be suppressed. In addition, chaotic behaviour of the cable vibration may be introduced due to the proposed nonlinear control rule.更多还原