不同脉动风相干函数对高层建筑风振响应的影响

Wind-induced response of high-rise buildings analyzed by different coherence functions of gust

首先介绍了3种较为常见的脉动风相干函数表达形式，然后基于随机振动理论在频域内推导了高层结构风振响应的无量纲化解析式，在此基础上对采用不同脉动风相干函数所得到的高层结构风振响应分析结果进行了比较。结果表明，不同脉动风相干函数对结构风振响应分析结果的影响主要体现在共振响应部分，采用不考虑频率项的相干函数所得到的风振响应分析结果要偏大60％左右。最后，对中国荷载规范给出的脉动影响系数v计算提出了应乘以0．6～0．7折减系数的建议。

Coherence function is an important parameter for describing the spatial-temporal correlation property of gust in wind engineering field. Based on the on site measurement and statistical analysis results, several expressions of coherence function have been put forward, which can be divided into two categories, considering the frequency effect or without considering the frequency effect. The precision of different coherence functions has been focused in the past, but the influence of different coherence functions on the wind-induced vibration analysis results has not been studied in details. In fact, it is more important to decide which expression should be adopted. In this paper, three common expression8 of coherence function were introduced firstly, and the non-dimensional analytical solution of wind-induced vibration of hlgh-rise structures was derived by random vibration theory in frequency domain. Then, the influence of frequency component on the wind-induced vibration analysis results was emphasized. The results indicated that resonant response is the dominative factor on the influence. Approximate 60%0 magnification would he induced by using the coherence function without frequency component, which is adopted by Chinese Loading Code. Finally, a reduction factor of 0.6~0.7 was given for calculating the fluctuation influence coefficient in Chinese Loading Code.