Research On The Influence Of Initial Residual Stress On Railway Rolling Contact Stress

Along with the railway in our country to develop in the direction of high speed overloaded,rail use conditions become more deteriorating, occurred more wear and fatigue, service life is also shorter. Therefore, the study of wheel rail contact problem of rail is very important.At present, the study of wheel rail rolling contact mainly focused on relatively simple straight rail wheel rail rolling contact, the main method is using finite element method simulation, most model is straight rail and single wheel. Besides, the constraint on rail is not fully considered.In order to increase calculation efficiency,simplify the model. Taking into full account sleeper,spacer,ballast bed and rail fastening, using a spring element which has the same equivalent stiffness as the constraint to replace them. Three-d of wheel-rail rolling contact model has been build. The process of wheel rolling on the rail repeatedly has come true. Observe and analyze the shear stress in rail on cross-section and longitudinal section. Choose horizontal contours on rail tread and the symmetrical center line of rail cross-section as two paths which can map the equivalent stress of node. Analyze and compare the variation of stress in two conditions when import the initial residual stress or ignore the initial residual stress. Take advantage of ANSYS/LS-DYNA which is a kind of software about explicit dynamic FEM to analyze the Three-d of wheel-rail rolling contact model. The equivalent stress curve of node in horizontal contours on rail tread and the symmetrical center line of rail cross-section were gained after wheels rolling many times on rail. With the purpose of forecast the life of rail, the anatomy of equivalent stress is necessary. The contact part of rail with wheel is stable under the straight track. The distribution of stress first increased and then decrease from the outboard of rail tread to the inboard of rail bread.The increase of stress become gently along with the increase of rolling times, The maximum equivalent stress in rail is below the rail surface.