Numerical Study on Aerostatic Instability Modes of the Double‐Main‐Span Suspension Bridge

Abstract

In order to investigate the aerostatic instability mode and underlying failure mechanism of the new suspension bridge with double main spans, a corresponding program based on aerostatic load increment and two-iteration scheme was developed with considering the effects of aerostatic and geometric nonlinearity. Three double-main-span suspension bridges were taken as a case study to analyze the full range of aerostatic instability with different initial attack angles. Results show that there are two aerostatic instability modes for the double-main-span suspension bridge, one of which is the bilateral antisymmetric instability mode and the other is the single-span instability mode. The critical aerostatic velocity corresponds to the instability mode that occurs first, which is dependent on structural dynamic properties and initial attack angles. In addition, mechanism of the two aerostatic instability modes was discussed in detail.