Analysis Of Wheel/Rail Rolling Contact Fatigue Of High-speed Train Wheel Under The Transient Mechanism

As the train running speed has increased from 120 km/h to 200 km/h or even higher, wheel/rail rolling contact geometry and dynamics parameters change largely, especially rail rolling contact fatigue damage problem. With the trains run faster, the cycle impact loading of the wheel/rail interaction becomes severe and makes fatigue damage of wheel/rail rolling contact happen easily.While using finite element method to solve the wheel/rail rolling contact normal and tangential problems broke through the limitations of the classical theory, which provide the conditions for the accurately measure the interaction force between the wheel/rail and then accurately calculate the wear between the wheel/rail. To study wheel/rail rolling contact fatigue, a 3D transient elastic-plastic finite element model of high-speed wheel-rail transient rolling contact was developed by using ABAQUS, which makes the model suitable for solving 3D wheelset transient rolling contact behavior in 300km/h speed.The fourth chapter says that based on kinetic parameters for the initial conditions, high speed transient rolling contact finite element model can better calculate the wheel/rail rolling contact fatigue problems, start with the CRH2 high-speed trains as the research object, a head car model was set up by using multibody dynamics software UM with driving in high speed 300 km/h on the straight track and then got different moment of contact geometry parameters of the serpentine movement condition,such as the horizontal displacement and Angle of attack. Afterwards to get the dynamic contact geometric parameters for the initial conditions, a 3D transient elastic-plastic finite element model of high-speed wheel-rail transient rolling contact was developed by using ABAQUS. Eventually, the normal force, the creep force and the contact area in the contact patch solved based on a results transfer between Abaqus/Standard and Abaqus/Explicit are obtained and then used in the fatigue model.The fifth chapter says that in order to study the rolling contact fatigue of non-circular wheels of high-speed train, the coupling model combing the harmonic abrasion wheel- track system dynamics with wheel circumference predicting fatigue model is been established. First of all, CRH2 China railways high-speed trains have been considered as the research object. High-speed train dynamics model of rail is established by using multibody dynamics software UM, make the train run in line rail at high speed of 200 km/h; three order, six order and 11 order harmonic wave abrasion and 0.1 mm, 0.3 mm depth of the most common statistical data of wheel creep rate/force are analyzed, Finally wheel creep characteristic parameters in a different order number, wave depth are considered as stability diagram, damage function of input parameters, then further study on harmonic abrasion wheel fatigue characteristics. Analysis shows that no harmonic abrasion wheel is in the elastic stability state, 1 order- 0.1 mm 0.3 mm wave depth wheel and 6, 11 order-0.1 mm wave depth wheel are in a state of ratchet effect, 6, 11 order-0.3 mm wave depth are in the plastic stability state. So the low-order and low- wave depth wheel is given priority to fatigue, high-order and big- wave depth wheel is given priority to abrasion. Regarding with the increase of the order, the increase of will promote the rapid increase of wheel creep force/rate.Then the tangential force also increases rapidly. So the rolling contact fatigue and wear of the wheels are more sensitive to the change of wave depth.