基于AR模型模拟超高层建筑的脉动风速时程

Simulation of fluctuating wind speed time series of super-tall buildings based on AR model

风荷载是超高层建筑设计的主要荷载之一,而且通过风振时域分析可以更全面地了解超高层建筑风振响应特性,更直观地反映超高层建筑风致振动控制的有效性。因此,本文使用线性滤波法即白噪声滤波法(white noise filtration method,WNFM)中的自回归(auto-regressive,AR)模型模拟超高层建筑的风速时程。首先,考虑超高层建筑风速时程的时间和空间相关性,导出了四阶AR模型的参数表达式。接着,基于AR模型模拟了一幢高度为200 m超高层建筑的风速时程。最后,通过比较模拟风速功率谱、模拟自相关函数和互相关函数与目标风速功率谱、目标自相关函数和互相关函数的吻合程度,验证基于AR模型模拟超高层建筑风速时程的可行性。

Wind loading is one of the main loads in the design of super-tall buildings. Likewise, we may gain an insight into the dynamic characteristics of vibrations of super-tall buildings under wind loads via the time history analysis. The effectiveness of wind vibration control of super-tall buildings can be intuitively displayed in the time domain. Therefore, the main objective of the present paper is to simulate the fluctuating wind velocity time series of super-tall buildings with resorting to the auto-regressive （AR） model in the white noise filtration method （WN- FM）. Firstly, considering both the time and space correlativity of the wind speed time series of super-tall buildings, the parametric expressions of the AR model have been derived with four orders. Subsequently, the simulation of the wind velocity time histories of a super-tall building with 200 m height has been carried out on the basis of the AR model. Eventually, through comparing the simulated values of wind speed spectral density, auto-correlation and cross-correlation functions with the corresponding targets, the flexibility is then corroborated for simulating the fluctuating wind speed time series of super-tall buildings by using the AR model.