登陆台风场非平稳风时频特性及其对线弹性结构风振响应特性影响研究

Fine analysis of non-stationary winds in typhoon field induced structural vibration is the trend and challenge of wind resistant design in typhoon-prone regions. In traditional wind induced vibration analysis, the wind flow is assumed to be a stationary and ergodic random process with Gaussian distribution. However, field measured typhoon winds show strong non-stationarity. In this study, with coherent structure which is essential to introduces non-stationarity of typhoon wind field as a breakthrough point, time-frequency characteristics, spatial correlation of the non-stationary typhoon winds were investigated and also the characteristics of wind-induced structural vibrations on linear elastic structures. Firstly, the coherent structures in typhoon winds will be extracted by the surrogate method, and its time-frequency characteristics will be analyzed based on wavelet coefficient spectrum. Secondly, time varying characteristics and energy spectrum of non-stationary winds in typhoons are analyzed, and a numerical simulation method is proposed to modeling the non-stationary winds. Thirdly, the influence of non-stationary winds on wind characteristics in typhoons are studied. Fourthly, the temporal and spatial correlation were investigated in typhoon wind fields based on multiple-point synchronous measurements. Finally, non-stationary winds induced vibration features of linear elastic structure are investigated in time domain based on FLUENT-ANSYS platform and structural healthy monitoring of a typical super tall building in Shenzhen; then a frequency domain analysis method is proposed for non-stationary wind induced vibration analysis, and it is validated and revised based on wind tunnel test. The objects of this research project will provide important guidance and reference for the wind resistant design of infrastructures in typhoon-prone regions.

台风场非平稳风作用下结构风振响应精细化分析即是台风影响区结构抗风设计发展的必然趋势也是面临的重大挑战。传统结构风振分析假定来流风为平稳高斯各态遍历随机过程，实测台风却展现出强非平稳性。本项目以相干结构这一诱发风场非平稳性的流场运动为出发点，研究台风场非平稳风时频特性、空间相关特性，以及其对线弹性结构风振响应影响特性。首先利用替代数据法和小波系数谱方法等对台风场相干结构进行辨识提取与时频特征分析；之后对台风场非平稳风的时变特性和能谱特征进行研究，并提出模拟重构方法；接下来对非平稳风对台风场湍流特性的影响以及风场时空相关特性展开分析；最后基于FLUENT-ANSYS分析平台和高层建筑健康监测技术，在时域对非平稳风作用下线弹性结构风振响应特性进行分析，提出频域非平稳风振分析方法并利用风洞实验进行修正。本项目的研究成果将为台风影响区各类工程结构抗风设计提供重要理论参考与应用指导。

抵御和减轻台风灾害是我国东南沿海台风影响区各类工程结构基础设施面临的主要挑战。传统结构风振分析假定来流风为平稳、高斯、各态遍历的随机过程，然而实测登陆台风过程的风速数据却展现出较强地非平稳特性和非高斯特性。因此，开展台风场非平稳风作用下的结构风振响应精细化分析是台风影响区结构抗风设计发展的重要趋势。本项目从湍流相干结构入手，对台风场非平稳风的时频特性、湍流参数统计特性、空间相关特性以及其对线弹性结构风振响应影响特性展开了系统地研究。通过向本项目的研究，取得如下几条重要结论：（1）湍流相干结构是台风场风速具有非平稳性和非高斯性的根源，台风场脉动风速的相干结构呈现出大尺度与小尺度结构交替出现的多尺度分布特征，非平稳样本在相干结构提取之后基本能转变为平稳样本，概率密度分布接近于高斯分布；（2）本研究提出的数据驱动型自回归模型与广义自回归条件异方差模型相结合的AR-GARCH模型可以准确的模拟重构台风场非平稳风的时间历程；（3）本研究提出的融合周期图谱和递归量化分析的归一化局部递归率标准差NLRRSD指标可准确地量化实测台风场非平稳风速样本的非平稳度；（4）本研究提出的考虑下垫面粗糙度长度、大气稳定度参数、偏航角和湍流积分尺度等因素影响的顺风向和横风向的相干函数模型可较为准确地刻画台风场风速的空间相关特性；（5）台风场风速剖面作用下高层建筑所受的风荷载大于常态风作用下高层建筑所受的风荷载均值，台风剖面下的结构表面风压场的本征模态差异较小，模态能量占比差别较大；台风剖面作用下结构的顺风向响应较常态风作用下呈增大趋势，而横风向响应则呈现出被抑制趋势。本项目的研究成果将为台风影响区各类工程结构抗风设计提供重要理论参考与应用指导。