High-precision Algorithm And Comfort Analysis For Wind-induced Vibration Of Tall Buildings

In recent years,with the continuous progress of economic development,material science and computer science,more and more tall buildings have appeared around the world.The main lateral load of tall buildings is wind load,so it is of great significance to accurately calculate the wind-induced vibration response and determine the safety and comfort of the structure based on the calculation results.By combing,comparing and analyzing the calculation methods of wind-induced vibration response of tall buildings,the time-domain-based highprecision calculation method is improved;the key factors affecting the structural wind-induced vibration comfort are explained and discussed,and suggestions for improvement are put forward for the shortcomings of Chinese codes.The factors affecting the calculation accuracy of the wind-induced response of the structure in the time domain are discussed,and the high-precision calculation method based on the time domain is improved.Taking the windinduced vibration response calculation of a two-degree-of-freedom system as an example,the calculation accuracy,stability conditions and calculation efficiency of various stepwise methods are compared,and the precise integration and its improved format are determined as the optimal time-domain algorithm for windinduced vibration analysis.Taking CAARC(Commonwealth Advisory Aeronautical Research Council)tall building wind-induced vibration response calculation as an example,the influence of participating in the calculation of the number of modes and prototype sampling frequency on the calculation accuracy of wind-induced vibration response is discussed.For the displacement response,the single-order modal cumulative specific gravity coefficient of the first three modes can reach 95%.When the prototype sampling frequency changes within the normal range,the calculation error of the displacement response is within ±5%;for the acceleration response,the single-order modal cumulative specific gravity coefficient reaching 95% needs first 15 modes,and the acceleration response is very sensitive to changes in the prototype sampling frequency.If the prototype sampling frequency is too small,the acceleration calculation error can reach20%～30%.Analyzed domestic and foreign wind-induced vibration comfort codes,and put forward suggestions for improvement on the shortcomings of Chinese current comfort codes.The key factors affecting comfort are acceleration index,vibration frequency,vibration duration and vibration return period.Through the analysis of the measured data of the acceleration response of five tall buildings during typhoon,it is found that the peak factor has a large value range and the representativeness of the acceleration peak is weak.Using the wind-induced vibration response data of CAARC tall buildings to carry out extreme value statistics,it is found that the peak factor in the Chinese codes is too small,and the peak acceleration is difficult to calculate accurately.The current comfort codes in China do not consider the comfort problems caused by the resonance of the building and the human balance organs,and the vibration return period is too long,which is difficult to guarantee the daily comfort requirements of residents.Based on the above calculation and comparative analysis,a suggestion is put forward to use the acceleration root mean square value with a return period of 1 year and a duration of 10 minutes as the comfort evaluation index.