Nonlinear aerostatic stability analysis of new suspension bridges with multiple main spans

In order to solve the aerostatic stability problem of long-span bridges more effectively, an upper limit of the external iteration number is set optimally to improve the incremental double iteration method, and an optimum iteration method is brought forward. For new suspension bridges with multiple main spans, the assumption of the spatial uniformity of wind speed is invalid due to their long decks and high towers. Taking into account the spatial non-uniformity of wind speed, a program corresponding to the optimum iteration method is developed and used to analyze the full-range aerostatic stability of the Maanshan Bridge, which is a long-span suspension bridge with double main spans in China, and the effect of wind speed spatial non-uniformity on the aerostatic stability of the bridge is investigated analytically. The result shows that the lowest critical wind speed of aerostatic instability is gained when the distribution of wind speed is non-uniform and the spatial non-uniformity of wind speed has a considerable effect on the aerostatic stability of suspension bridges with multiple main spans. The optimum iteration method is compared with the method without improvement in analysis, and the result indicates that the accuracy and efficiency of the optimum iteration method are much better, so the validity and advancement of the optimum iteration method are proved.