Design theory and method for in-plane ultimate strength of arches with web openings

As a new type structural member, the steel arch with web openings combines the features of both arches and members with web openings and has found its wide applications. A finite shell element model is employed to study the buckling behavior and ultimate strength of arches with web openings. Firstly, the elastic buckling of two-hinged I-sectional circular steel arches with web openings subject to hydrostatic load is investigated theoretically. The effect of web openings is analyzed comprehensively. For design convenience, the arches with web openings are simplified as battened members composed of two T-sections. Secondly, elasto-plastic nonlinear buckling of arches with different web opening sizes is studied to review arch failure mechanism and to obtain the ultimate strength. Then, according to the established relationship between the arch ' s stability coefficient and its normalized slenderness ratio, the formulas for the ultimate strength design of arches with web openings subject to hydrostatic load and other forms of load distribution are proposed based on the equivalent slenderness ratio.