Numerical Simulation Of Mean Wind Load On Low-rise Flat Roof With Different Shapes

The frequent occurrence of wind disasters in the southeastern coastal areas of China has led to many destructions of low-rise buildings and significant loss of life and property.Study of roof wind load characteristics for low-rise flat roof buildings located along the southeast coast,using numerical simulation technology,is helpful to understand the influence of building shape parameters on the wind load distribution characteristics.This paper allows to find out the building shape parameters that are optimum for wind resistance design,to provide guidelines for the wind resistance design of low-rise buildings in that area.Numerical simulation technology is used to carry out relevant research work in this paper.Firstly,six turbulence models are selected to simulate the wind load on the Silsoe Cube model,and results are compared with field measurements and wind tunnel test data to verify the feasibility of numerical simulation of wind load on low-rise buildings.Then,fifty-six different building models are selected to study the wind load characteristics of low-rise flat roof buildings by setting different wind direction angles,length to width ratios,height to width ratios,cornice lengths and parapet heights.The variation characteristics of the mean wind pressure coefficient of the roof in association with different shape parameters are analyzed,and recommended values of the shape coefficients of the low-rise flat roof in relation with different length to width ratios is given.Finally,based on the shape parameters,a shape coefficient adjustment formula and adjustment coefficients are obtained.The research shows that the mean wind pressure coefficients of a low-rise flat roof increases with the increase of the length to width ratio and the height to width ratio.The distribution of wind pressures on a roof can be effectively reduced by the presence of cornices and parapets.The mean wind pressure coefficient of a flat roof can be effectively reduced by having cornices,but the change of cornice length has no obvious effect on the mean wind pressure coefficient.The mean wind pressure coefficient of a flat roof can also be reduced by having parapets,especially reducing the negative pressures near the leading edge of the roof.