Research On The Nonlinear Aerostatics Stability Of Long Span Concrete-filled Steel Tube Arch Bridges

In recent years,Concrete-filled steel tube arch bridge as a kind of novel structure has been developed rapidly in our country.Under the vertical load,the arch rib will bear a large axial stress and bending moment.Concrete filled steel tube is very reasonable in arch bridge for the interaction of both steel tube and concrete.the interaction makes it has advantages of high bearing capacity,good plasticity,low cost and convenient construction.With structure is becoming lighter,longer,the stability problem of concrete-filled steel tube arch bridge in construction stage and operation stages gradually revealed.At present,most scholars didn't consider nonlinear calm wind load when analyzing the stability of concrete filled steel tube arch bridge.In most case,the combined action of arches and bridge has been ignored.At the same time,most of the studies didn't consider the influence of material nonlinearity.Using finite element analysis software,this paper focuses on the research of extreme wind speed for long-span concrete-filled steel tube arch bridge,structural buckling deformation curve and the the stability factors affecting.Based on wind tunnel experiment and CFD numerical simulation,this paper simulated the Caiyuanba Changjiang River Bridge to validate the results.The main research contents are as follows:1)Did a general overview of the development on concrete filled steel tube structure,research status and wind resistance theory.2)Did a general overview of the nonlinear analysis methods on geometric nonlinearity,material nonlinearity and static wind load.3)Did a general overview of mechanism analysis on static instability problem solving considering geometric nonlinearity,material nonlinearity and static wind load nonlinearity.4)By APDL language,did a real bridge simulation of the Caiyuanba Changjiang River Bridge to analyze the whole process of the bridge instability.5)Researched the stability influence of the initial wind attack angle,rise-span ratio,number and form of cross arm and the wind load form.