Numerical Simulation Of Wheel-rail Rolling Contact Based On The Vector Form Analysis

Wheel-rail rolling contact has always been a serious problem in wheel-rail relationship, as it involving contact and continuous body large rotation. Although there are many methods, most of them have difficulty in inertia effect and real dynamic process. With the increase of train speed and axle load, the interaction between wheel and rail shows a tendency increase. Therefore exact investigation for wheel-rail rolling contact is very important from the theoretical and practical points of view.Supported by the Natural Science Foundation Committee of China (Nos. U1134202), the National Basic Research Program of China (No.2011CB711103) and the National Science and Technology Support Program of China (No.2009BAG12A01-B04), this thesis carries out an intensive research regarding the simulation and analysis of wheel-rail contact based on a new numerical mechanics method-vector form analysis, especially for wheel-rail rolling contact under inertia force.The main research work in this thesis is as follows:(1) Vector form analysis theory and formulations of2D triangle element is introduced, difference is analyzed between vector form analysis and finite element method. It is found that vector form analysis is able to be investigated continuous body large rotation under inertia force, which provide theoretical basis for wheel-rail rolling contact.(2) As there has not been confirmed in contact by vector form analysis quantitatively, static wheel-rail contact is simulated. The numerical results(wheel-rail normal contact pressure distributions contact patch size、max wheel-rail normal contact pressure、wheel-rail Von-Mises stress) of vector form analysis、Hertzian contact theory and the finite element software Ansys are compared, which show that vector form analysis is accurate in wheel-rail contact. (3) Based on presented controlling velocity method, this thesis investigates wheel-rail rolling contact under inertia force. Conclusions can be drawn from the numerical results as follows. In the same axle load, compared with static wheel-rail contact, when wheel rolls, max wheel-rail normal contact pressure increase, and wheel-rail normal contact pressure distribution shows a asymmetric phenomenon, the normal contact pressure becomes larger in the leading area of contact surface. With an increasing velocity, max wheel-rail normal contact pressure increases gradually, and the phenomenon of the larger normal contact pressure in the leading area is serious. In the same wheel velocity, with an increasing axle load, contact patch size、max wheel-rail normal contact pressure increase gradually.