Spatial Correlation Of Fluctuating Wind Loads And Wind-Induced Response On Rectangualr High-rise Buildings

In order to study the flow around charactertics and the mechanis of aerodynamic forces on rectangular high-rise buildings,a series of rigid model synchronous pressure tests with different side ratios were carried out in turbulent boundary layers.Taking the 2D and 3D bluff bodies with rectangular cross-sections as the research object,this dissertation attempts to give some shorteviews on the three-dimensional spatial structure of fluctuating wind loads(alongwind,acrosswind and torsional wind loads)of high-rise buildings.The three-dimensional spatial structure analysis method of turbulent boundary layers and the normalized threedimensional fluctuating wind loads coherence empirical models are proposed by introducing additional parameters and vertical spacing dimensionless correction.The simplified calculation method of three-dimensional wind-induced response for engineering application is deduced,which provides a reference for the analysis of fluctuating wind loads and windinduced response of high-rise buildings.The main research contents of present study are shown as follows:1.The homogeneous isotropic turbulence theory and the vertical uniform sheared velocity tensors model are introduced.The three-dimensional spatial structure and correlation of atmospheric boundary layers are analyzed from the perspective of theoretical derivation and experimental verification,including spectra of the three velocity components and the coherences of any combination of the velocity components at two chosen points.The lateral and vertical coherence models of the three velocity components are modified,and a simplified method to predict the correlation of arbitrary spatial points in 3D shear flow is proposed.2.The flow around and unsteady aerodynamic charactertics of two-dimensional bulff bodies with rectangular cross-section under the turbulent boundary layers and the three-dimensional vertical flow are studied.The influence of large scale turbulence,side ratio,terrain clearance and end effect on the separation flow charactertics,reattachment,the wake state and the surface pressure field are discussed.The variation of the length of the recirculation zone and the law of change along the height are given quantitatively.The probabilistic density of the fluctuating pressure on the lateral sides of rectangular models is analyzed,and the method of the extreme wind load partitioning on the lateral sides of the rectangular buildings by considering the influence of the reattachment zone is proposed.3.The three-dimensional space charactertics of the fluctuating wind loads in turbulent boundary layer flows are analyzed by the rectangular buliding rigid model pressure measurement tests.The effect of large-scale turbulence,structure feature size,ground heigh and end effect on fluctuating wind load spectrum and energy conversion are discussed in the frequency domain.The contribution ratio of each side of rectangular cross-section with different side ratios to the fluctuating torsional wind loads is given quantitatively.A normalized coherence function model of the fluctuating wind loads with high physical meaning is proposed by considering the effect of turbulence spatial structure,dimension charactertics of the rectangular buildings and non-dimensional correction of distance.4.A practical model for calculating wind induced response by considering the threedimensional spatial structure of fluctuating wind loads is proposed.The applicability of the simplified method to wind induced vibration analysis of high-rise buildings is verified by numerical examples of two buildings and a 2:1 rectangular prism pneumatic elastic model wind tunnel testing.