Bending Deformation Characteristics And Carrying Capacity Of Steel Truss-ring Girder

The structural form of the steel truss-ring girder,a novel steel beam structure,is mainly based on the web-shaped girder and the honeycomb girder.The main feature of this structure is to replace the web of traditional girder structure with the hollow steel truss-ring,and connect the steel truss-ring with the top and bottom ring to form an overall structure.This structure can be used as the superstructure of bridges in engineering.This thesis mainly uses theoretical derivation combined with laboratory experiments and finite element analysis to study the basic mechanical properties of steel truss-ring girder.The preliminary design of the structure is also presented.The article mainly includes the following contents:(1)Based on the theory of Timoshenko beam which considering shear deformation,the element stiffness method is proposed.By theoretical analysis,the equivalent flexural stiffness and equivalent shear stiffness of the steel truss-ring girders are derived,and the deformation formula of the structure under bending load is obtained.The ABAQUS finite element software was used to verify the deformation results,and a reinforced construction method that can ignore shear deformation was proposed.(2)Through the static load test in the laboratory,the mechanical properties of steel trussring girder were studied preliminarily.The deformation characteristics and ultimate strength of the structure under static load were analyzed,and the failure modes and failure mechanisms were mastered.(3)By using ABAQUS finite element software simulating the test process of the test beam and comparing the simulation results the test results,the deformation characteristics and ultimate strength of the structure under bending load are further studied.The failure mode is explained according to the distribution of stress and strain.(4)A preliminary design of steel truss-ring highway bridge suitable for engineering practice is preliminarily designed based on theoretical derivation and experimental testing.Combining theoretical calculation with finite element simulation,it was verified according to the relevant specifications,and all indicators meet the specification requirements,indicating that the design proposal has engineering feasibility.