HFFB Technique-based Non-stationary Wind-induced Response Boundary Estimation Of Super-tall Buildings

Conventional methods for estimating the wind-induced response of super-tall buildings are usually based on the stationary wind field assumption.That is,the reference wind speed at the building height is assumed to be a constant for a certain wind direction.Together with the wind tunnel test,this method helps estimate the structural peak wind response at this wind direction.However,the real wind speed near a building varies with time during the passage of a typhoon.In actual operation,the meteorological department predicts the upper and lower boundaries of the typhoon wind speed time-varying distribution in advance,and through the boundary analysis theory,combined with the high-frequency force balance(HFFB)wind tunnel test data,it can predict the boundary value of the structural response at each moment.Estimation of the boundary behavior of a super-tall building during the whole process of typhoon can help take necessary measures,such as start the vibration control equipment or execute evacuation plan,to deal with the typhoon disaster.In this paper,the wind-induced response boundary assessment of super-tall buildings under non-stationary wind loads is studied.The main work is as follows:(1)A structural wind-induced response boundary assessment method for super-tall buildings under non-stationary wind loads is proposed.Combining the traditional Duhamel integral method with the convex model theory,a boundary analysis theory is derived as a Duhamel-convex model theory.The Duhamel-convex model theory combined with the HFFB technique is used to obtain the boundary response of super-tall buildings under non-stationary wind loads.Taking Guangzhou East Tower(GZET)as an illustrative case to obtain the response boundary value of each moment of the building,it helps the prevention of typhoon disaster.Finally,the results obtained by the traditional Duhamel method are compared to those from the proposed method in this paper,which shows the validity of the theory and the feasibility of its application in practical engineering.(2)Combining the traditional Newmark-β method with interval theory,a new boundary analysis theory is derived as Newmark-interval theory to evaluate the wind-induced response of super-tall buildings under non-stationary wind loads.Consider the correlation between wind loads at different moments,and use the autocorrelation coefficient function to express the correlation between wind loads at different moments through the Chuleschi decomposition,the wind-induced response interval is evaluated to provide targeted prevention of windstorms and reduce unnecessary losses.Finally,the case of Guangzhou West Tower(GZWT)is used as an example to evaluate the wind-induced boundary response under non-stationary wind loads.The results are compared to those obtained by the traditional Newmark-β method to prove the validity of the theory and the practical application.feasibility.(3)Based on the Duhamel-convex model theory,a Monte Carlo boundary analysis method was used: According to the simulation method of interval process,a number of sample functions are produced.These sample functions not only satisfy the interval boundary conditions,but also satisfy the prescribed autocorrelation function.Each sample function is taken as external excitation,and the response curve of the system is obtained through deterministic dynamic analysis using the Newmark-β method or central difference method,etc.The maximum and minimum values of all response values at each moment are counted,and the upper and lower boundary values of the response at that moment are obtained.Finally,the upper and lower boundary function curves of the response with time changes are drawn,this method is applicable not only to linear systems but also to nonlinear systems.Considering the non-stationary “time-variant” characteristics of wind loads,before the typhoon comes,by predicting the approximate upper and lower boundary values of wind speed;and utilizing the HFFB wind tunnel test data,the Monte Carlo boundary analysis method can be used to evaluate the super super-tall buildings.The wind-induced response under non-stationary wind loads has important reference value for typhoon disaster prevention and control.