Abstract: The multi-body contact model of wheel and rail is established with the technology of multilayer and multi-branch structure. The method of parameter variation principle and the mathematical quadratic programming is applied to solve the contact force. The distribution of wheel-rail contact force is computed under different contact angle and lateral load, and it is analyzed that the contact angle and lateral load effect on the longitudinal friction(traction) and adhesion coefficient. The results show as follows: The friction force direction in the wheel-rail contact is obvious different between the stick and the creep area, and in the stick area the angle between the friction direction and rails longitudinal is smaller, while in the creep area the angle is bigger. When the contact angle is smaller, the adhesion coefficient decreases with the lateral load increasing, and when the contact angle is bigger, the adhesion coefficient first decreases and then decreases with the lateral load increasing. The adhesion coefficient decreases with the lateral load increasing on the straight rail, and the adhesion coefficient can be improved by selecting proper lateral load on the curve rail.

Key words: Adhesion coefficient, Contact angle, Finite element method, Wheel-rail adhesion, Dynamics, Gantry Hybrid Machine Tools, Kinematics, Principle of Virtual Work, Singularity