In-Plane Failure and Strength of Pin-Ended Circular Steel Arches Considering Coupled Local and Global Buckling.

Little research has been reported that investigates the effects of plate local buckling and postbuckling on the in-plane behavior and strength of steel arches, and hitherto there has been no corresponding design guidance available. This paper presents a numerical investigation of the structural behavior of steel arches, and proposes a strength design method against their in-plane failure by considering plate local elastic-plastic buckling and postbuckling coupled with global elastic-plastic buckling. The failure modes of pin-ended steel circular arches having a box section under a uniformly distributed radial load are analyzed by using a large deformation elastic-plastic finite-element formulation. It is found that plate local buckling significantly influences the in-plane failure mode and strength of a steel arch. The arch may fail owing to local elastic-plastic buckling of its plates, global elastic-plastic buckling of the arch, or coupled local and global elastic-plastic buckling. The failure mode is found to depend on a number of factors such as the height-to-thickness ratio of the plate components, the aspect ratio of the cross section, the rise-to-span ratio, and the slenderness of the arch, as well as the yield stress of the steel. It is also found that the most important factors that influence the strength of the arch are the normalized global slenderness of the arch and the normalized height-to-thickness ratio of the plate components of the cross section. A strength reduction coefficient for estimating the in-plane strength of arches is developed based on these two most significant parameters, and a corresponding strength design method is proposed. [ABSTRACT FROM AUTHOR]