基于有限振动信号的某移动天线有限元风荷载动力反应分析

Finite element dynamic response analysis under wind loads for antenna of China mobile based on limited vibration signals

提出了一种现场实测的有限振动信号与结构有限元模型模拟分析相结合的方法来获得结构(天线)在实际风荷载作用下的动力反应,即首先测试结构在脉动风荷载作用下的有限振动信号,如:加速度时程和频谱曲线,然后通过结构运动方程模拟出脉动风荷载时程并施加到结构有限元模型中,通过有限元计算求出模拟风荷载与实际风荷载之间的修正系数k,最后把修正后的风荷载时程再次施加到有限元模型中进而得出结构在实际脉动风荷载作用下的内力。通过比较,有限元分析结果与试验结果吻合较好,为结构在脉动风荷载作用下的全过程反应分析提供了一种简便方法。

A new method to perform the finite element analysis based on limited vibration signals measured on the spot was presented.The limited vibration signals of dynamic responses of structures（antennae of China Mobile） were measured under impulsive wind loads,such as the signals of acceleration time histories and their frequency spectrua.Meanwhile,the time histories of impulsive wind loads were simulated through the equation of motion of the structures,which were then applied to the finite element model.It the light of this finite element analysis,the correction factor k between simulated wind loads and practical wind loads was obtained,and the revised wind loads was applied again to the model.The internal forces of structure were thus gained under the closer approximation of practical impulsive wind loads.It is shown that the finite element analysis can get the results in accordance with those of experiments,which provides an easy method for total process analysis of structures under impulsive wind loads.