Research On Non-Stationary Buffeting Response Of Long-Span Suspension Bridge Based On Measured Data

With the increasing span of the modern suspension bridge,the structure of the bridge is getting more and more gentle,the sensitivity of the large span suspension bridge under the natural wind will be more prominent,accompanied by experts and scholars on the(wind)wind speed Smooth characteristics of the problem in-depth study,in the natural wind under the bridge structure of the security problem has become a widely concerned topic.At the same time,the numerical simulation of the flow around the object is also becoming more and more mature.The numerical simulation method of computational fluid dynamics is an important and effective method in the field of wind engineering research.The aerodynamic stability of long-span flexible bridges under wind non-stationary excitation will be an important subject.This paper relies on the National Natural Science Foundation of China(Youth Science Fund Project)"mountainous large span suspension bridge non-stationary high turbulence effect study".With the help of SHMS health monitoring system of a large span suspension bridge,the aerodynamic stability and vibration characteristics of the main beam structure of the suspension bridge under natural wind are studied.The fine buffeting analysis of the bridge is very important in the field of wind resistance research.The key role.This paper mainly carried out the following aspects:(1)By simplifying the wind field,based on the harmonic synthesis method,the non-stationary random wind speed field simulation method is studied based on the harmonic synthesis method and the different modulation function overlay.The timevarying trend term of non-stationary wind speed is extracted by orthogonal or biorthogonal wavelet.The results show that the trend items of dbl0 and coif5 wavelet are highly accurate and are more suitable for time-averaged extraction of non-stationary wind speed.(2)The finite element model of the suspension bridge is built by the general software ANSYS,and the dynamic characteristics of the suspension bridge are analyzed.(3)Through the CFD software Fluent simulation,calculate the aerodynamic parameters of the large span suspension bridge,to facilitate the subsequent analysis;(4)Using the simulated non-stationary pulsating wind to add it to the ANSYS model,the buffeting time history analysis is carried out.The results show that the mean square value of the displacement response of the main girder of the suspension bridge under non-stationary excitation is basically larger than that under the stationary excitation In response to the mean square value,and the calculation of the buffeting response of the suspension bridge is affected by the complex factors,the theoretical analysis results are relatively larger than the measured values.Therefore,how to analyze the wind vibration response of the structure more accurately has yet to be studied more finely.