| The rapid development of economy promotes the rapid development of railway, and vice versa. Especially in china, this phenomenon is inseparably interconnected with each other. Train needs to overcome friction, but at the same time, it also relies on friction to provide power. From the world's first railway was built, this contradiction has been existing until now. It has been attracting research workers from all over the world to devote to doing research and how to deal with the friction is a very crucial problem nowadays. The contact of wheel/rail is quite complex, although it has been studied in detail by a large number of researchers, wheel/rail tribology has been gradually developed into the bottleneck due to lack of high-temperature, high-speed auxiliary monitoring equipment, and still there are some factors which influence the wheel and rail contact's boundary conditions are not carefully considered.Firstly, this paper introduces the research status and development history of wheel/rail contact,(from dynamics to tribology), ANSYS finite element software and the related theory of wheel/rail contact are introduced into the research of wheel/contact. The finite element model of wheel/rail contact is established, the modeling process of the application software is introduced in detail, and 3D nonlinear heat conduction equation of friction between wheel and rail contact, which can save a lot of manpower and financial resources, even to reach the effect that an experiment can't be observed.Through having a study on extensive literature review, it found that a large number of researchers in the study of wheel/rail friction neglected the influence of convection coefficient and foundation stiffness on the characteristics of wheel/rail contact. The railway line across different area, the geographical conditions are complicated. Convection coefficient between wheel/rail and foundation stiffness bottom of rail vary due to changes in regional differences. Through building the finite element model of wheel/rail contact, the author has a simulation analysis about the influence of the changes of these two kinds of boundary conditions on the characteristics of wheel/rail contact. The study shows that temperature time curve in wheel/rail contact is almost the same in different convection coefficient under the speed of 1m/s and 2m/s. contact The temperature, pressure, stress and area of 0 W/(m2·K) contact area under 2m/s are bigger compared with others convection coefficient. With or without convection coefficient has a little influence on wheel/rail contact characteristics under the situation of 1m/s. Those indicate that the heat generation rate of wheel/rail in different speed is not the same and the influence of convection coefficient is also different. This is recommended that the wheel sliding speed of 1m/s, 2m/s and 5m/s even in the rolling research shouldn't be neglected the influence of convection coefficient on contact characteristics of wheel/rail. The specific problem needing a concrete analysis, it's better to use experimental convective heat transfer coefficient into study. Under different foundation stiffness, the maximum temperature of wheel/rail contact region is slightly larger in 500 MPa stiffness than other two conditions. From the overview of time curve, the effect of foundation stiffness on the temperature of the contact zone is little. The wheel/rail contact area is gradually decreases with the increase of foundation stiffness. From the first slide to the maximum in high temperature time curve, the wheel/rail contact area increase to about 2.2 times. In the process of static analysis, the equivalent stress and strain of wheel rail contact region vary less with the increase of the foundation stiffness. And at the maximum temperature time, the maximum equivalent stress is equal and temperature is accordance in three foundation stiffness.The existing of rail joints with height difference have great harm for railway driving safety, the passenger's comfort and line maintenance. Through the simulation analysis of 0.1mm, 0.3mm, 0.5mm three rail joints height, those draw conclusions that the stress and strain distribution characteristics of two track irregularity. With the increase of face the rail joints height the collision zone of maximum temperature is high. At the final sliding moment, the temperature of contact region reaches more than 1000?. No matter what's the situation of face the joints, the temperature, stress, strain have little different of contact region under different height. The reasons that the sliding speed of wheel is too slow which has a little influence to impact effect of wheel/rail. |
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