广州新电视塔模型测力风洞试验及风致响应研究Ⅱ:风致响应分析

摘要

基于节段模型测力试验的结果,采用随机振动响应分析中的完全二次组合法(CQC)对广州新电视塔结构进行随机风致振动响应分析,包含振型之间交叉项对响应的影响.“串联多质点系”力学模型被用来模拟电视塔结构,每层质点可考虑两个水平方向的线位移和绕竖向参考轴的转动位移.通过计算确定该电视塔不同高度上的风致振动位移响应、加速度响应、截面内力响应.计算结果表明,电视塔结构极值位移、内力随风向有相同的变化规律并且天线结构鞭梢效应对加速度的影响程度远大于位移.同时提供的等效静力风荷载考虑多个模态及模态间交叉项对响应的影响,可用于计算电视塔结构的位移及内力根方差响应.%Wind-induced responses of the Guangzhou New TV Tower structure are computed based on the wind pressures on the tower obtained from wind tunnel force balance test on the sectional model, and the Complete Quadratic Combination method ( CQC method) considering modal coupling effects is adopted. A multiple-degree-of-freedom system with lumped masses in series is used to simulate the tower structure, in which each mass may undergo lateral and rotational movements with respect to the vertical reference axis. The wind-induced displacement, acceleration, internal force responses are calculated. It is found that the peak values of displacement and internal force of the Guangzhou New TV Tower structure as a function of wind direction have the same trend, and that the whipping effects of the antenna have more influence on acceleration than on displacement. The equivalent static wind loads for computing RMS responses of displacement or internal force are provided, which can take into account of modal coupling effects.