Study On Wind Load Characteristics Of Large Span Cantilever Structure

Due to the needs of modern architecture,the large-span cantilever structure is widely used in stadiums,railway stations,airports and other buildings.The large-span cantilever structure generally has the characteristics of light weight,small rigidity and small damping.Because the wind load acts on its upper and lower surfaces,it is a wind-sensitive structure.In natural disasters,wind disasters cause serious damage to large-span structures.However,the wind-resistant design of such buildings in the specification is not comprehensive enough.In this paper,the wind tunnel test of the cantilevered roof model with variable inclination is designed,and the wind pressure distribution,non-Gaussian division and wind pressure division of the cantilever roof are studied in detail.The main contents include the following:1.This paper analyzed the wind pressure distribution,pulsating wind characteristics and spectral characteristics of cantilevered roofs with different dip angles.This study shows that the change of the dip angle has a significant effect on the roof wind pressure distribution.When the negative dip angle is large,there will be a positive pressure on the upper surface.As the tilt angle changes from bottom to top,the peak of the pulsating wind pressure spectrum approaches a smoothing.2.Aerodynamic optimization measures of "breathable cantilever leading edge" are proposed.The test results show that this measure effectively reduces the average wind load on the cantilevered roof surface and can provide reference for the design according to the actual situation.3.Through the in-depth study of the kurtosis and skewness distribution of the cantilever roof,it is found that the characteristic turbulence is inextricably linked with the non-Gaussian,and the division criteria of Gaussian and non-Gaussian are given.The normal probability paper test method and the Jarque-Bera test method were used to test the division standard,and the non-Gaussian region of the cantilever roof was finally determined.By analyzing and comparing the statistics of various points of the measuring points,it is found that there is no direct correlation between the statistics.Finally,the probability distributions of the typical measuring points of cantilevered roofs are fitted by several commonly used probability density functions.It is found that the generalized extreme value distribution and the three-parameter gamma distribution can accurately represent the probability distribution of cantilevered roofs.4.This paper proposes a method of wind pressure zoning based on cluster analysis.Firstly,the optimal partition number is determined by the validity index,and then the improved GK clustering method is used for wind pressure partitioning.The results show that this method can better realize the wind pressure partition of cantilevered roof,and it is also applicable to other structures,overcoming artificial partitions with unreasonable drawbacks.