Study On Some Basic Problems Of Friction Collision

The study of the friction and collision have a long history, each has formed a relatively complete theoretical basis and research methods. However, the comprehensive problem, friction collision, still has not got a complete and reasonable theoretical solution. This problem is discussed from three aspects in this dissertation.1. With "Kane’s puzzle" as the breakthrough point, in this article, a rigid sphere with an elastic half-space oblique collision with friction occurs, the kinematic equations is established according to calculating the contact force and deformation. The article discussed the motion law during the friction collision, analyzed the cause of friction collisions making objects mechanical energy increases, and pointed out that Whittaker’s assumption is only applicable to a kinetic friction state, and the direction of the frictional force is constant. In the study of collision with friction, the directional change of the friction as well as the possibility of occurrence of the static friction must be considered.2. Using the fractal model to simulate the surface. The analysis results show that two of object surface’s sliding friction calculated by the fractal model and the positive pressure, the amplitude of the model, the fractal dimension and the real contact area are related. It is demonstrated when the W-M function method is used to generate the model, its fractal dimension and that of the simulated target is similar. And the statistics of the model is controled by selecting the appropriate variable values.Through the application of elastoplastic theory analysis of a single micro convex body’s stress and deformation, calculate a specific model’s contact force and real contact area by means of programming, the obtained results show that the control parameters can effectively make the force status of model and the simulation object consistent.3. Solving the problem of the oblique impact for two elastic balls, as well as the movement state of the ball with bonding force, the friction collision problem is discussed for the multibody systems. Using multibody system model as example, the movement process is analzed, and the feasibility and effectiveness of the method inductived in the second chapter is verified.