Research on Shear Buckling Capacity of Steel Octagon-Web Beam

Based on the principle of lightweight and easy construction of prefabricated structures, steel octagon-web beam (SOWB) which has the similar appearance of honeycomb was proposed. SOWB with opening web has the advantages of both honeycomb beam and steel structure bridge. In order to obtain reasonable boundary conditions of the finite element (FE) model for evaluating the pure shear buckling capacity of SOWB, the FE method was used to verify the formulas of pure shear buckling coefficient of rectangular thin plate. Based on the FE method and data fitting method, the formulas of pure shear buckling coefficient for octagonal thin plate with round opening were obtained by modifying the parameters of the buckling coefficient formulas for rectangular thin plate. In order to predict the buckling capacity of SOWB, a calculation method was proposed through the strut model. In order to verify the reliability of the proposed method, a buckling analysis model of SOWB was realized by the FE software ABAQUS. The influences of two parameters, such as expansion ratio and the ratio of flange plate thickness to web thickness, on the buckling capacity of SOWB were analyzed. Furthermore, the proposed method which can be used to evaluate the buckling capacity of SOWB was improved by introducing the constraint effect coefficient of the flange.