风荷载是超高层建筑设计的主要荷载之一,对超高层建筑进行风振时程分析能更准确和直观地了解结构风振响应的特性。为了进行风振响应时程分析,必须较为准确地模拟作用在结构上的脉动风荷载。首先,本文采用基于自回归(AR)模型的线性滤波法对上海中心大厦场地的脉动风速时程进行了数值模拟,通过检验模拟脉动风速的功率谱和相干函数平方根与目标值的吻合程度,验证了基于AR模型模拟超高层建筑脉动风速时程的可行性。然后,本文考虑了上海中心大厦外形向上扭转收缩的特点,由模拟的脉动风速时程计算生成作用在结构上的脉动风荷载。
Wind load is one of the main loads in the design of super high-rise buildings, and the wind induced response of super high-rise building can be calculated more precisely and be visually displayed through time history analysis. Therefor, simulating fluctuating wind load time series is necessary for time history analysis of wind induced response. Linear filtering method based on auto-regressive model was used to simulate fluctuating wind speed time series on the site of Shanghai center tower, and the method proves to be effective through comparing the simulated values of wind speed power spectral density and magnitude squared coherence with the target values. Through the simulated fluctuating wind speed, the simulated fluctuating wind load acting on Shanghai center tower was obtained afterwards with consideration of the section shrinkage and torsion.