Research On Stability Capacity Of Elastic Open Thin-walled Circular Steel Arch

Curved beams have been widely used in structure engineering because of graceful shape. Curved beams can be classified into arch and horizontally curved beams based on the plane on which load is acted. When load is acted on the curvature plane, it is named arch; when load is acted on the plane perpendicular to the curvature plane, it is named horizontally curved beams. Curved beams differ from straight beams simply because of the presence of the initial curvature. The geometrical equations of flexure, torsion and warp of curved beams are coupled, which results in complexity of theoretical analysis. Now it is lack of the all-sided and exact analysis for curved beams, which limits the application of curved beams.This dissertation focused on the nonlinear equations and stability capability of open thin-walled circular arches. On the basis of the investigation of the related home and overseas literatures, extensive researches are carried out on the subjects by theoretical and numerical analyses.Firstly, the nonlinear equations of open thin-walled curved beams are derived. Based on the basic assumptions of thin-walled members, using the exact expression of warping displacement, the stability equations of curved beams are obtained by the principle of virtual displacements. The total potential energy is given also.Secondly, a classical elastic flexural-torsional buckling tests on arch is introduced, which is simulated by shell element SHELL63 and beam element BEAM189 of commercial software ANSYS. Numerical results are consistent with test results, so elastic flexural-torsional buckling load of arches can be analysed by SHELL63 or BEAM189 elements. A fewer elements need be divided with beam element,and calculation speed is more rapid, but only when load acts on centroid of the section the arch of double symmetric section can be simulated by beam element. Succedent buckling load equations of arch under uniform compression or uniform bending can be verified by finite element method.Following theoretical investigations on buckling of thin-walled circular arch...