Research On The Local Stability Property Of Webs In I-Section Steel Arch Structure

I-section steel arch structures have been applied widely in kinds of structures all over the world because of their advantages of beautiful shape, good mechanical behavior and simple manufacturing process and so on. However, little country' design codes give the design items of steel arch structure about stability. The specialized design provisions of steel arch structure have not been offered by the current design codes in China and the studies on local stability behavior of web plates in steel arch structure are almost blank. Based on the existing theory of local stability behavior of web plates in I-girders, finite element method was used to analyze the elastic buckling and ultimate strength of web plates in I-section steel arch structures under uniformly distributed radial load as well as bending.First of all, the elastic buckling behavior of arched plates with different boundary conditions and subjected to uniformly distributed radial load was analyzed with the finite element method. The conditions included all four edges being simply supported and two opposite edges being simply supported and fixed. Based on the form of the formula of elastic buckling coefficients of rectangular plates and numerical results, the fitting formulae were obtained to determine elastic buckling coefficients of the forementioned arched plates. Then, an eigenvalue buckling analysis was carried out on webs in I-section steel arch structure under uniformly distributed radial load with ANSYS. A parameter correlating the ratio of the torsional stiffness of flange and the flexural stiffness of the web was introduced to measure the restriction from the flange to the web. A fitting formula was obtained to determine elastic buckling coefficients of the webs in I-section steel arch structure subjected to uniformly distributed radial load.Secondly, the elastic buckling behavior of arched plates under bending, with all four edges being simply supported and two opposite edges being simply supported and fixed, was also analyzed with ANSYS. The fitting formulae were proposed to determine elastic buckling coefficients of the forementioned arched plates through data fitting on the basis of many numerical results. Then, an eigenvalue buckling analysis was conducted on webs in I-section steel arch structure under bending. A fitting formula of elastic buckling coefficients of webs in I-section steel arch structure considering the restriction from the flange to the web was gained through data fitting.At last, the studies about plastic buckling behavior of webs in I-section steel arch structure with regard to initial geometric imperfection and residual stress under uniformly distributed radial load as well as bending, were analyzed respectively. The analysis of the influence on the ultimate strength acted by different parameters was discussed, such as aspect ratio of arched webs, center angles, thickness of webs, flange width and thickness. On the base of the forementioned researches, the advices on the design of I-section steel arch structure were proposed.