Wind Tunnel Test And Numerical Simulation Study On The Effect Of Rough Strip And Arc Angle On Wind Load Of High-Rise Buildings

With the increase of building height,wind loads become one of the dominant loads for structural safety and comfort design.From the perspective of design aesthetics,small scale components and corner areas are often set in the facades of modern super high-rise buildings for the fillet treatment,which makes the building shape change relative to the standard shape given in the code to a certain extent,and the effect of wind on the structure will also change accordingly.In order to consider the design characteristics of real buildings,a series of highrise building models are designed on the basis of summarizing the design characteristics of facade rough strips and rounded corners of many super high-rise building projects.The wind tunnel test of rigid model and large eddy simulation(LES)study are carried out to analyze the influence of these models on the wind load of structures.The main work includes the following aspects:(1)First,based on the CAARC standard building model,the design considers six different conditions of surface rough strips and rounded corners;Then,a series of pressure test models were made by 3D printing technology.The model is composed of the main body and angular area components with different radians or rough strips through modular splicing to realize various test conditions of different rounded corners and rough strips.Finally,a series of wind tunnel tests were carried out on the standard building model and considering different conditions of circular arc angle and rough strips.Through the wind pressure distribution on the surface of six models and the distribution of wind load body coefficient,the influence of circular arc angle and rough strips on the wind load of high-rise buildings was systematically analyzed.The results show that the rough strip can significantly reduce the fluctuating wind pressure coefficient on the crosswind side of the test model.Partial wind direction angle(45° wind direction angle in this paper)reduces the average wind pressure coefficient and fluctuating wind pressure coefficient of all test conditions.(2)Secondly,a new method for inflow turbulence generators for large eddy simulation,The Improved Narrowband Synthesis(INSRFG)method,was adopted.Standard building model and LES were carried out considering the effect of rounded corners and rough strips.Based on the numerical simulation of the turbulent wind field in the atmospheric boundary layer,the numerical simulation of the flow around the CAARC standard model was carried out firstly.The results were compared with those of wind tunnel tests at home and abroad to verify the effectiveness and reliability of the numerical modeling method presented in this study.Then the effects of different rounded corners and rough strips are simulated and compared with the results of wind tunnel tests.Through comparison,it is shown that the LES numerical model established in this study has good accuracy,and can simulate the influence of rounded corners and rough strips on wind pressure,vortex shedding and base bending moment coefficient power spectra.The numerical simulation results show that rounded corners reduce the vortex action range on both sides of the building and the wake,and increases the dimensionless frequency corresponding to the peak value of the base bending moment coefficient power spectra.The frequency corresponding to the peak value of the downwind power spectra increases from 0.101 of the right angle and 0.128 of the 5% arc angle to 0.135 of the 10% arc angle.The rough strip will increase the vortex action range on both sides of the building and the wake,and reduce the characteristic frequency of the model with circular arc angle.(3)Finally,the wind tunnel test method is adopted to study the influence of surface rough strips on wind load in a practical project.To Foshan a super-high building project as the background,the article rough set building model surface and remove rough working condition of two kinds of rigid model respectively to carry out with pacing the pressure test,through building surface wind pressure coefficient,the structure of the base overturning moment,the top peak acceleration and wind load shape coefficient,the article analysis rough structure of tall building on the impact of wind load,It provides reference for the study of similar problems.The research shows that the rough strip increases the overturning shear force and overturning moment of the base X-axis of the main tower in the test,which increases by about 4.9% and6.0% respectively in this project.The rough strip reduces the peak acceleration at the top of the tower structure in the test,which is 7.9% in this paper,and also has a certain influence on the working angle where the extreme acceleration occurs.