Research On Dynamic Of Disc Brake System In Train Considering Surface Roughness Factor

At present,the braking method adopted by most high-speed trains in various countries in the world is disc brakes.The friction of the brake pads and the brake disc makes the train slow down and stop.In a real working environment,the train's braking system will be disturbed by factors such as wear,different braking pressures,the stiffness of different friction pairs,and the surface roughness of each brake component,which will cause the train to brake The process produces noise pollution and a series of nonlinear vibrations.Especially when the train performs emergency braking under high-speed driving,the surface roughness of the contact surface of the friction pair of the train braking system has seriously threatened the braking performance and personnel safety of the train.Therefore,it is necessary to study the dynamic behavior of the following vehicle brake systems affected by different surface roughness factors,which can provide a certain basis for the optimal design of the brake system and the selection of various component parameters.In this paper,taking full account of the specific working conditions and working environment of the train disc brake system,taking its specific basic components as the research object,first established a single degree of freedom train disc brake syst em model,by The solution of the equation and numerical simulation have successively studied the dynamic behavior of the single-degree-of-freedom disc brake system under the influence of different system parameters.Subsequently,it is considered that during braking,the relative position of the brake disc in the disc brake system of the train during the braking process will also change accordingly.Therefore,the brake disc should be considered as a mass,and a two-degree-offreedom model of the train disc brake system was established.The dynamic characteristics of different system parameters on the train braking system under the action of the Dankowicz dynamic friction model are emphasized.The main contents are as follows:For these two disc brake system models,the motion equations are first dimensionlessly processed,the roughness factor is introduced through the Dankowicz dynamic friction model,and the state equation of the system motion is written.When the system brakes,the brake pads and brake discs The friction force generated by the Dankowicz dynamic friction model is provided by the C language fourth-order variable-step Runge-Kutta algorithm programming to solve the equation of state,and then numerical simulation.Keeping the principle of single variable,successively study the effect of different system parameters on the dynamic characteristics of the braking system under the action of the Dankowicz dynamic friction model.The results show that when the braking speed of the train is large,the vibration amplitude of the braking system is large and the vibration is strong.When the braking speed becomes small,the chattering of the braking system becomes intense.When the braking pressure of the train gradually becomes larger,the amplitude of the train braking system increases significantly,and the flutter also becomes severe.With the increase of the damping coefficient,the smaller the amplitude of the brake pad,that is,increase the damping coefficient can effectively suppress flutter.When the roughness value increases,the amplitude of the brake pads and brake discs continues to increase,but the time for the system to reach a steady state is not linear.It appears that it first decreases to a certain value and continues to increase.At the same time,the train The dynamic characteristics of the brake system are also more complicated and irregular,and the chattering phenomenon is significantly enhanced.