Finite Element Analysis Of Brake Noise On CRH5

Nowadays more and more People tend to take high-speed train,but when the vehicle brakes,it often induces some noise which can cause passengers dysphoric,and sometimes they even doubt the safety of the vehicle.In addition,the brake noise will reduce the service life of parts of brake system.Therefore,it is of great significance to do the research of brake noise on high-speed train,and it will greatly promote the development of high-speed railway in our country.In this paper,based on finite element theory,brake noise of high-speed train CHR5 is analyzed.The complex eigenvalue analysis and transient analysis are used respectively.The real part of eigenvalue is used to represent the possibility of brake noise in Complex eigenvalue analysis.Bigger the real part is,more easily it is to induce brake noise.If the vibration is discrete in time history,the system will be unstable in transient analysis.Through the analysis,we can draw the following conclusions:(1)Friction coefficient has much influence on brake noise.With the friction coefficient increasing,it is more easily to induce brake noise.(2)With the elastic modulus of backboard increasing,it is more likely to induce brake noise,while with the elastic modulus of brake pad increasing,the stability of the system is better.With the elastic modulus of brake disc,backboard and brake pad increasing,the real part of main mode(around 7800 Hz)varies like a parabola.If they are set reasonably,the noise at 7800 Hz can be suppressed effectively.The elastic modulus of brake pad has more influence on brake noise than the backboard.(3)Transient analysis shows that the amplitude of normal vibrate of every point on brake pad is different,but the main frequency is same;With the friction coefficient increase,the amplitude of normal displacement and normal acceleration of the brake pad increases gradually in time history,and the system is more and more unstable;There is always a vibration around 8000Hz in the system,and with friction coefficient increasing,the vibration becomes more intense,so it is more easily to induce noise.(4)The structure of pad and backboard has much influence on brake noise.When the backboard is 3mm,the stability of the system is better;The stability of the system with hexagonal,round,or triangle pads is better than that with sector pads;The stability of the system with hexagonal,round or triangle pads whose thickness is 18mm.is better than that with other thickness;When the pad is hexagonal with thickness of 18mm.there is no unstable modes at 1000Hz-8000Hz.