Bending behavior of steel ring-web beam

Steel Bridge has been regarded as one of the most popular choices in engineering. Many bridges with large-span and attractive appearance emerge unceasingly due to the use of steel. A new structure of steel ring-web beam (SRWB) was presented, which has the similar appearance with castellated steel beam. SRWB whose top and bottom slabs are connected to circular steel rings by welding or bolting uses circular steel rings to form the web. First, the structure stress characteristics of SRWB were studied. To derive the equivalent flexural stiffness and equivalent shear stiffness for SRWB, the unit stiffness method based on the theory of Timoshenko Beam was proposed. Furthermore, the deflection formula of SRWB was derived, which was validated by finite element analysis (FEA) method. The detailed design of SRWB was completed for studying bending behavior of the structure through two scale model tests. The failure mode of the first specimen under four-point loading, reflecting the inadequacy of the design, was the local instability on the edge of top slab. The failure mode of the second specimen under three-point loading was due to the local buckling of the top slab. The loading and deformation progress of the structure were obtained through two bending tests. The yield loads, strains and test phenomena were also captured through two bending tests. The FEA models of two specimens whose results are compared with the tests were realized. The stress distribution of FEA models were analyzed in order to provide reference for further improvement of design. It can be concluded that SRWB with the rational design has good bending performance.