Finite Element Analysis Of Stress In Rail Welding Joint

Continuously-welded rail(CWR) has replaced bolted rail joints as the preferred method of joining rails in track all over the world.The CRW efficiently reduces the level of impact forces between wheel and rail at rail joints and extends the service life of the wheel and rail with respect to bolted rail.However,with the increment of train speed,the phenomenon of rail weld defect(RWD)shows a tendency to be severe.The RWD leads to the higher operating costs and represents one of the main rists for safety of railway operation.Therefore,from the practical and cognitive points of view,studies on rail welding joint are very important. andgain enormous economic benefit and social benefit.In this thesis,based on the orbital mechanics and finite element method , the mechanic properties of rail welding joint are investigated through the numerical simulation. the main work could be described as follows:1. ANSYS, the finite element software,is adopted to establish an elasto-plastic finite element model of the rail welding joint .Analyses were made with this model.the distribution of elastic-plastic stress in rail weld was displayed.and the results compared with the elastic model.The results could be referenced to further understand the mechanism of the damage on the rail-head .2. The simulation results and theoretical calculation results were compared. at last, the model is checked.3. The influences of material characteristics including Young's modulus and Poisson's ratio are analyzed in the dissertation. The analyses show that Young's modulus and Poisson's radio influences greatly maximum shear stress and have less effect on the maximum equivalent stress. and yield strength can affect on the distribution of elastic–plastic stress in rail weld. 4. Research is mainly done on the influence of fastener parameters, such as the lateral stiffness, the stiffness of rail pad, which can affect on the elastic–plastic stress distribution of the rail weld.5. Finally, based on the thesis, the potential directions to attack these hard tasts in the future are presented.