Research On The Influence Of Wind Field Parameters Based On CAARC Standard Model Wind Tunnel Test

With the rapid development of economy and technology,more and more people are flocking to developed cities.With the gradual increase of the living population,the shortage of land resources and the fierce business competition,the development of modern high-rise buildings has been accelerated.Because of its high height and flexibility,high-rise buildings are very sensitive to wind load.In order to ensure the wind resistance safety of super high-rise buildings,wind tunnel test is usually needed.Wind tunnel test is the main method of structural wind resistance research at present.However,the research shows that it is impossible to strictly meet the similarity of all single value conditions and the equivalence of similarity criteria in the wind tunnel test design.Therefore,it is necessary to make a choice according to the importance of the influence of various test parameters on the structure,so that the test error will be introduced.Therefore,it is necessary to study the parameters of wind tunnel test,discuss the influence of similar parameters such as geometric scale and wind speed scale,and wind field parameters such as average wind speed profile,turbulence intensity and turbulence integral scale on wind tunnel test results,and determine the main control parameters of structural wind load and wind-induced response characteristics.In order to study the influence of wind tunnel test parameters on the wind load characteristics of the structure,the wind tunnel pressure test and force test are carried out based on CAARC standard model of high-rise building.The main work is as follows:1.In order to ensure the rationality of the average wind speed profile,turbulence intensity profile and pulse wind speed power spectrum,the wind field characteristics of the wind tunnel simulation are compared with the existing specifications.2.In this paper,the CAARC standard model is studied by synchronous pressure test of rigid model,and the test results are compared with the existing literature results to verify the correctness of the wind tunnel test method and the credibility of the test data in this paper.Then,the influence rules of wind field parameters such as incoming wind speed,geometric scale ratio and ground roughness on the wind load characteristics of high-rise buildings are analyzed.It is found that the incoming wind speed does not affect the results;when the wind field parameters under different scale ratios are consistent,that is,the average wind speed profile and turbulence profile are the same,the turbulence integral scale ha s the same size relationship with the model scale,and the results of 1:200 and 1:300 scale ratios are consistent;while the ground roughness has a greater impact on the results3.In this paper,the high frequency balance force measurement test is carried out for CAARC standard model,and the test results are compared with the existing literature and pressure measurement test results to verify the accuracy of the test results in this paper.Then,the influence of wind field parameters such as incoming wind speed,geometric scale ratio and ground roughness on the overall force coefficient and displacement response of high-rise buildings is analyzed.It is found that the influence of the wind speed and the surface roughness on the results is the same as that of the pressure test;when different scale ratios are used for the test,the relationship between the wind field parameters(turbulence integral scale)and the model scale is difficult to be consistent,which will have a greater impact on the fluctuating effect of the structure along the wind direction.