The Ultimate Behavior of the Circular Hollow Section Arch Rib for Steel Arch Deck Bridges

In recent years, steel arch bridges has gained an established application in the medium span bridges owing to the excellence in the structural stability and the beauty of the arch structure. The circular tube arch rib used in the arch bridges often, has high local and flexural-torsional buckling strength. Therefore, since the buckling modes and deformed shapes under the lateral load are different in many cases, elastic membrane and out-of-plane buckling analysis can not suffice for the estimation of the stability for arch structures but the elasto-plastic buckling behavior and ultimate strength of the steel arch rib should be investigated further. The numerical research on the ultimate behavior and the failure mode of circular arch ribs for deck bridges is presented in this paper. Elastic buckling analyses, geometrical nonlinear and material nonlinear analyses have been carried out to investigate the buckling strength, buckling modes, post-buckling strength, ultimate strength and failure modes of arch ribs. The effects of main factors such as boundary condition, yielding stress of the material, load cases, lateral supports, slenderness ratio of arch rib and included angle into the ultimate strength of arch ribs have been studied.