Buffeting Analysis Of Railway Suspension Bridges Considering Non-uniform Wind In Mountainous Areas

With the continuous development of the society,the span of bridges is also increasing,the sensitivity of the bridge to the wind loads is more and more prominent.Due to the complexity of terrain and varied wind field,the effect of wind loads on bridges is also more evident in mountainous areas.Buffeting is one of the four main types of wind-induced vibration,although not destructive damage to the bridge structure,but it has a very important influence on the fatigue durability of the bridge structure and the driving comfort.For the buffeting response,many researchers have studied it in the past,but there is little research on the analysis of the buffeting response under the influence of the non-uniform wind in mountainous areas.This paper focuses on the introduction of the non-uniform in mountainous areas as the main research object and carries on the detailed and in-depth buffeting response analysis,the research contents are as follows:(1)The development history of long-span suspension bridges is summarized,and the new discipline developed with the development of long-span bridges,the wind engineering of bridges,are introduced,and the phenomena of wind-induced vibration of bridges and their related research methods are presented.(2)Simulating the canyon at the mountainous bridge site into the inverted trapezoid section,the model is established in CAD,and then the grid is divided in the grid division software ICEM,and the wind velocity distribution characteristics of the mountainous area are obtained by using the FLUENT software,and the curve of the wind speed along the bridge axis direction is obtained.(3)The finite element model of the whole bridge is established by ANSYS software,to calculate the dynamic characteristics of the bridge.(4)The buffeting responses are calculated by buffeting frequency domain analysis program,including buffeting displacement response,buffeting internal force response and buffeting acceleration response.The buffeting responses of whether considering the uneven distribution of wind speed along the axis of the bridge and the aerodynamic admittance function taking the 1 or the Sears function are discussed respectively,and the results are compared and analyzed.