采用向量式有限元的拉索参数振动模拟

Vector form intrinsic finite element based simulation on parametric vibration of cables

  • 摘要: 拉索的参数振动主要是由连接拉索端部的结构振动引起的,当端部振动频率与拉索的自振频率满足一定倍数关系时,拉索端部激励容易激发较大拉索参数振动。由于参数振动存在复杂的非线性振动特征,传统的解析方法难以应用于实际工程。本文发展了模拟拉索参数振动的向量式有限元方法,对斜拉索在动边界条件下的振动进行分析,对比控制方程的数值解以验证结果的准确性。并基于向量式有限元模型对端部支座轴向运动激励下产生的主共振区和主参数共振区特性进行讨论,分别研究了拉索倾角、阻尼比以及风荷载协同作用对参数振动的影响。研究结果表明向量式有限元可以有效模拟复杂工况下的拉索参数振动,有利于实际工程应用。

     

    Abstract: The parametric vibration is mainly caused by the vibration of the end supports connecting the cables. The cable is the main force component of the cable?stayed bridge. A small disturbance of the stayed cable will be motivated to oscillate with large amplitude once the natural frequency of cables meets a certain multiple relationship with that of support motion, which will cause security problems of bridges. As the complexity of nonlinear problems in the parametric vibration, the traditional analytical methods are unsuitable to be applied in engineering. Hence, the vibration analysis of the stayed cable under dynamic boundary conditions were conducted based on the Vector Form Intrinsic Finite Element method (VFIFE) in this paper and the accuracy of the results were validated by comparison with numerical solution of the governing equations. In addition, the characteristics of the main resonance regions and the main parameter resonance regions excited by axial support motion were discussed. The effects of the angle of inclination, damping ratio and the wind loads on parametric vibration were also analyzed, respectively. The results showed that the VFIFE method is enable to efficiently simulate the parametric vibration of cables under various conditions, which is benefit to engineering application.

     

/

返回文章
返回