Study On Wind-induced Response Of Different Tall Building With Balcony

With the vigorous development of China’s economy,high-rise building structures tend to be irregular,different elevation balcony forms and the building surface to add a variety of envelope components,such as the raised balcony has significant influence on wind pressure and wind induced vibration.Wind-induced comfort of high-rise buildings has been paid more and more attention.There are different standards for comfort evaluation index in different countries.In China,the standard of vertex acceleration is used as the basis to classify occupants’ comfort.In this paper,Based on the dynamic time history analysis,the comfort of high-rise buildings is evaluated by combining the root mean square acceleration index with the code.The main works of this paper are as follows:The FLUENT 17.0 numerical calculation platform is used to establish the numerical wind tunnel with smooth and square high-rise buildings.The intake turbulent wind field is synthesized by CDRFG turbulent wind velocity generation method.The turbulent wind field generated by CDRFG meets the three-dimensional anisotropic Von-Karman spectrum better.The unsteady large eddy simulation method is used to calculate the wind pressure distribution on a smooth square building with four wind angles based on different sub-grid models,different meshes and different time steps.Considering the computational efficiency and accuracy under different working conditions,sub-grid model,mesh number and time step are selected to simulate the wind pressure distribution of tall buildings with balcony.Based on the known subgrid model and time step,the wind pressure distribution characteristics of balcony buildings in turbulent wind field are simulated.In this paper,two kinds of square high-rise buildings and cross high-rise buildings with rough bars and balconies on the wall are used to simulate the transient large eddy current at four wind angles.The influence of rough bars and balconies on the wind pressure and aerodynamic distribution of structures is analyzed quantitatively,and the influence of local shape complexity on the instantaneous vorticity distribution of structures is considered.The influence of different building shapes and surface details on the wind characteristics of structures are discussed.Based on ANSYS and ETABS modal analysis of finite element models of square and cross-shaped buildings,the accuracy of dynamic characteristics such as natural frequencies and modes of vibration of the finite element model is verified.Transient dynamic analysis and equivalent wind load static analysis are carried out by using ANSYS.The acceleration and displacement time-history responses of the structure floor under random wind load are calculated.Fitting the relationship between the peak value of acceleration and displacement and the root mean square value,the peak factor g of acceleration and displacement for different building shapes is obtained.This paper calculates the peak acceleration according to the Code for Building Structural Load of China,and puts forward the suggestion of applying the Code for Building Structural Load to the displacement calculation of wall and balcony buildings.The disadvantage of peak peak acceleration for evaluating structural comfort is proposed.The innovation of this paper is that the numerical wind tunnel simulation of highrise buildings based on CDRFG turbulent entrance generation method is used to obtain the simulation parameters suitable for ordinary high-rise residential buildings.The windinduced response of buildings with balconies on the wall is solved under random wind loads.The difference between numerical simulation and load code calculation of highrise comfort response is compared.The relationship between peak response and root mean square response of tall building with balcony is discussed,and the influence of increasing wall balcony on the dynamic response of high-rise building structure under wind load is discussed to guide practical engineering application.