Numerical Analysis Of Welding Residual Stress Of Strengthening U-rib Orthotropic Steel Bridge Panel

The orthotropic steel bridge panel is composed of longitudinal stiffener, transverse stiffener and bridge deck. All three are welded into a whole work together. The weld under restricted state tend to form a two-way residual stress, which are more prone to produce welding deformation, cracks, cavities and other defects. Local deformation of the steel bridge panel subjected to traffic loading will cause outer surface deformation of longitudinal stiffener, transverse stiffener and bridge deck, and will generation of secondary bending stress concentration at the constraint. So, weldment prone to fatigue damage in severe fatigue environment. In order to extend the service life of bridge, the carrying capacity of reinforced structure and ensuring safety of structure, it is very necessary and important to study the size and distribution of welding residual stress in the structure.Fatigue damage often occurs at butt welding seams and T-type welding seams of U-ribs of the orthotropic steel bridge deck. A strengthening plate method was proposed in this paper for the purpose of improving the welding residual stress of these parts. In this paper, a finite element model of the U rib joint structure and reinforcement structure is established. This paper adopts the method of thermal-structure coupling analysis. First, temperature field was obtained by thermal analysis of structure. Then the temperature field is used as the temperature load for structure analysis. In the model, the spherical heat source distribution model is chosen as the welding heat source, and using the function of birth-death element and APDL language to realize the simulation of weld formation and heat source movement.The main research contents of this paper are as follows:(1) This paper uses ANSYS finite element software to establish the three-dimensional model, simulated the change of temperature field and stress field with time during welding process, and calculated the size and distribution of welding residual stress in welded structures;(2) In order to study the impacts of welding parameters on the welding residual stress, the calculation model is established and the calculation data are compared and analyzed;(3) By comparing the size and distribution of welding residual stress, the feasibility of the optimization scheme is obtained;(4) The influence of welding parameters on welding residual stress is analyzed in this paper, which provides data support for reasonable welding process.