Wind-Induced Bridge Response Analysis Based On Stochastic Pseudo Excitation Method

Recently, as the large complex high-rise structures and long-span bridges keep arising, wind load is becoming one of the major control loads on structures design and wind-induced response obviously is affecting the safety of bridge structure and riding comfort. So, structural dynamic response under wind load becomes the urgent issue of long-span bridges. Due to restrictions of production restrain conditions, the structure parameters exist inevitably randomness which causes fluctuation of wind-induced response and may also become a dominant factor. it is a new method to study the wind-induced response of structures from view point of probability theory.In order to solve the randomness of structure parameters, in this paper, a new method of analysis is based on pseudo-excitation method, named stochastic pseudo excitation method. The main contents of the present dissertation are as follows:(1) In this paper, making a summary of the existing theory at home and abroad and introducing briefly the pseudo-excitation method, a new method of analysis is based on pseudo-excitation method, named stochastic pseudo excitation method.(2) The combination of response surface method and Monte Carlo method is applied to study wind-induced response. This provid a simple and effective method for the following calculation analysis. Meanwhile the self-adaptive Gauss integral technology is introduced into pseudo-excitation algorithm. The calculation results show that the method can make a further improvement for the computational efficiency of random vibration. When the coefficients of variation is bigger, The combination of response surface method and Monte Carlo method do not meet requirements of engineering accuracy. but the improved response surface method can effectively solve this problem.(3) Analysing the linear oscillator excited by stationary filtered white noise verifies the correctness and efficiency of the stochastic pseudo excitation method. And the linear oscillator excited by stationary filtered white noise is impacted by the randomness of structure parameters.(4) With Davenport’s power spectrum, the combination of response surface method and Monte Carlo method based on stochastic pseudo excitation method is applied to study the concrete density, elastic modulus, damping ratio, the wind load and the wind action with different attack angle impacting the wind-induced response of the tower.(5) With Davenport’s quasi-steady buffeting force model, the combination of response surface method and Monte Carlo method based on stochastic pseudo excitation method is applied to study the different wind speed and wind action with different attack angle impacting the wind-induced response of the long-span suspension bridge.