Finite element modeling and stress analysis for static bending test of rail welded joint

The static bending test of rail welded joint is an important way to evaluate the welding process and joint quality. Based on the structural features of static bending test system,the contact finite element model including two contact pairs for the static bending test of rail welded joint was established. The influences of parameters of contact pairs,including element size,contact stiffness and so on,on the calculation time and result accuracy were analyzed,and the appropriate element size,contact pair parameters for FE model were determined by optimizing se-lection. Moreover,the applicability of the FE model for stress analysis was confirmed by comparing the calculated results with the experimental results presented in related literature. After that,according to the standard concerning the static bending test of rail joint welded by flash butt welding,the simulating computation of the stress distribution was conducted for both rail head being pressed（forward bending） and rail head in tension（reverse bending） respectively by using the established contact FE model,and the stress distribution characteristics as well as the value and location of the maximum von Mises stress was discovered accordingly. Through analysis on the computational results,the control requirements was put forward on the strength and residual stress of rail joint welded by narrow gap arc welding. These conclusions can offer valuable reference for the subsequent process modification,joint quality control and performance improvement of rail narrow gap arc welding.