Study On Aerostatic Stability Of Long-Span Suspension Bridge

As the need of the rapid development of economy, the long-span transoceanic engineering is proposed. With the span of the bridge is become longer and longer, the static and dynamic problems of the bridge structure induced by wind are more and more serious. Nowadays, while studying the behavior of bridge under wind, more attention is focused on the problems of aerodynamic stability and vibration response which have been great progress. But aerostatic problem is still researched little. According to the results of the wind tunnel model tests domestic and abroad, the critical wind speed of the aerostatic stability of long-span bridge may be less than that of the aerodynamic stability. In addition, the effects of geometric nonlinearity and the aerostatic load nonlinearity of long-span bridges under strong wind load shouldn't be neglected. The problems of the aerostatic stability of long-span and super long-span bridges, particularly the suspension bridges, are also crux. Therefore, the problems of aerostatic stability of long-span suspension bridge are detailedly and deeply studied in this thesis:1.The linear method being used to calculate the critical wind speed of aerostatic stability by national guideline is expatiated. And the briefly deduced formula is used to calculate the critical wind speed of torsional divergence.2.Based on ANSYS, the program used to calculate the critical wind speed of aerostatic stability, which can sufficiently consider the geometric nonlinearity and the aerostatic load nonlinearity, is presented.3. The results of the nonlinear finite element method are detailedly compared with that of the linear method being used by...