Stick-slip Vibration And Experimental Study Of Automobile Brake System

With the development of automobile industry,the self-excited stick-slip vibration of automobile braking is gradually recognized and studied.Many scholars have established various models to simulate this phenomenon.However,the effect of tire vibration on brake friction is not considered and the simulation is seldom verified.The main contents of this thesis are as follows:(1)A simplified model of disc brake is established.The comprehensive braking system of the two coupling mechanics model including the simplified model of disc brake and the dynamic tire Lugre model that considering the influence of tire tangential vibration is establish then.The influence of parameters on the chaotic motions of the system is analyzed.The results show that the adjustment of some tire parameters can change the vibration state of the braking system,and some brake parameters also affect the chaotic vibration state of the braking system..(2)Based on the mechanics model of the comprehensive braking system,different function forms of friction model are applied and the influence of the friction model parameter on the braking system bifurcation is studied,the results show that the functional form of the braking system movement form is less affected,while some parameters may change the chaotic motion range of the braking system.(3)The braking friction vibration test is designed,speed and braking pressure and friction coefficient as variable parameters are in consideration.Disc brake vibration data is collected and processed.The above analysis results are validated.It is found that under the same speed increasing of brake pressure can make the system bifurcate into the chaos movement.Systems will perform chaotic phenomenon when brake pressure is constant.