Wavelet Non-stationary Wind Speed Model And Measuremental Verification

With the continuous development of traffic,more and more large-span bridges need to be built,its flexibility,the characteristics of small damping followed by the impact of wind-induced effects become more prominent.The study of the wind field is based on the study of the wind effect and the most realistic means.The study of the wind speed field is a reliable parameter for the wind field simulation and the design wind load.Based on the study of the strong wind environment of a large span suspension bridge,this paper uses MATLAB as the analysis tool to study the strong wind environment of a large span suspension bridge with the non-stationary high turbulence effect of the National Natural Science Foundation of China(No.51508060)Based on the wavelet non-stationary wind speed model,the non-stationary wind speed field characteristics are analyzed.The main research contents are as follows:(1)The basic characteristics of the wind speed field and the calculation method are expounded.The difference between the traditional steady and non-stationary wind speed models in the calculation of the wind field parameters is compared,and the corresponding theoretical model is summarized.(2)Summarize the common methods of signal analysis and processing,compare their respective characteristics and applicability,and briefly explain the basic theoretical knowledge of wavelet analysis,and compare the orthogonal and biorthogonal wavelet in MATLAB language toolbox As well as the relevant formula for a brief introduction,and compared its advantages and disadvantages and the scope of application.(3)Based on the harmonic synthesis method and the non-stationary random wind field of a long span cable-stayed bridge are simulated by different constant amplitude functions,the time-varying mean of non-stationary wind speed is extracted by orthogonal or biorthogonal wavelet Contrast with the theoretical variance.The results show that dbl0 and coif5 wavelet have higher accuracy of extraction and more suitable for time-averaged extraction of non-stationary wind speed.(4)Based on the non-stationary wind speed model of a large span suspension bridge,the wind field parameters of a large span suspension bridge are compared and analyzed.The results show that the non-stationary wind speed model based on db10 and coif5 wavelet is suitable for describing the characteristics of non-stationary wind field.(5)Based on the local stationary wavelet process,the 1h non-stationary wind speed of a 3/4 span bridge deck is simulated and compared with the measured wind speed and the non-stationary wind speed of the constant amplitude cosine function based on the harmonic synthesis method The results show that the local stationary wavelet process has better adaptability to the description of nonstationary stochastic processes.Based on the wavelet non-stationary wind speed model,the measured wind field characteristics of a large span suspension bridge are analyzed,and some useful conclusions are obtained by simulating the non-stationary wind speed field by the local stationary wavelet process,which provides a reference for the study of non-stationary wind speed field characteristics value.