Study On The Bifurcation And Chaotic Behavior Of Disc Brake System Induced By Dry Friction

The vibration and noise in the disc brake have always been a difficult problem for people and the vibration during the braking process will not only affect the performance of the brake system but also the comfort of the occupants.By far,it's believed that the vibration and noise problem is caused by multiple factors combined,mainly the friction and structure factors.To study these phenomena,many scholars proposed different models of friction and models of brake system,but seldom has the research on double pad brake system been done.The contents of this paper are as below.(1)A transmitting belt model of double pad was established.The tangential movements alone were taken into consideration and the torsional movement of the disc brake.We chose exponential model of dry friction and performed the numerical analysis with Matlab and then studied the Hopf bifurcation characteristics of the system and the parameters that help to improve the stability of the system.After that,we studied the vibration of the model at low velocity and the effects of friction parameters and system parameters on the periodic and chaotic vibration with stick-slip.(2)The impact of the brake disc to the brake system was added on the basis of model in chapter there.A torsional model of double pad brake system was established.We studied the stability of the system and the effects of the parameters,like connecting stiffness,damping and the distribution of the mass between two pads and so on.And then we studied the effects of parameters on vibration of the pad and the bifurcation and chaos at low velocity,such as the influence of the brake pressure on the sizes of the chaotic intervals.(3)A model of a new type of disc brake with bilayer double pad was established.We studied its dynamical behavior at low velocity and compared the vibration between the upper layer and the lower layer as well as the effects of parameters on the bifurcation and chaotic behavior of the system.