Numerical Simulation Of Wind Load Characteristics On Long-span Skirt Roof Structures

The long-span roof structure has the characteristics of light weight,high flexibility,and low damping,and its natural frequency is similar to the excellent frequency of wind,making the long-span roof structure vulnerable to damage in strong winds.Because the roof is usually located in the complex area of turbulence in the atmospheric boundary layer and the shape of most of the roofs is irregular,the wind load caused by the flow is very complicated.Especially in modern cities,the construction layout becomes more and more dense,leading to roof wind load being affected by the population.The influence of aerodynamic interference can not be ignored.Predicting the wind load distribution with the single housing condition is bound to cause greater errors.At present,China's "Load Regulations" does not specify the design value of wind load for complex roofs and the interference effect of group layout.Therefore,it is necessary to apply wind load characteristics to various types of complicated roofs,and the interference effects of surrounding buildings on wind loads.Conduct research to provide effective scientific guidance for wind research and design of roofs.This paper takes the Suzhou Taiping Finance Building as the engineering background,and takes into account its aerodynamic interference effects on its special long-span skirts with special-shaped steel roofs.Numerical simulation methods are used to study and analyze the distribution of wind loads and the interference of surrounding buildings on wind loads.The characteristics provide effective theoretical guidance and direct design basis for engineering wind resistance design.The main research content is as follows:(1)Based on wind tunnel test data of a long-span flat roof in the wind tunnel laboratory of Beijing Jiaotong University,the wind pressure distribution of the roof was simulated using the RANS method and the LES method,and the average wind pressure coefficient obtained by the wind tunnel test was obtained.Comparing with the fluctuating wind pressure coefficient,the validity of the numerical simulation method was verified.(2)Using the RANS time-average simulation method,taking into account different wind direction conditions,the distribution of mean wind pressure on the surface of the roof under simulated mono-buildings and group interference effects was simulated separately,and the roof was partitioned based on the characteristics of body type to calculate the wind-type coefficient of each partition..At the same time,some typical zones are selected to analyze the regularity of the average wind pressure coefficient as a function of the wind direction angle,and the interference law is used to quantify the change law of the local area under different wind-down disturbance effects,providing a basis for wind resistance design of this type of roof.(3)Using the current LES large eddy simulation method with higher precision,considering five typical wind directions,the average wind pressure and fluctuating wind pressure distribution on the roof surface were simulated and analyzed.At the same time,the typical wind pressure coefficient and the fluctuating wind pressure coefficient are analyzed according to the change rule of the wind direction angle in several typical zones,which provides a basis for wind resistance design and subsequent wind-induced vibration response analysis.