Coupled Analysis Of Temperature Fieldand Thermal Stress Of Disc Brake Based On Copper-based Friction Materials

With the rapid development of high speed train,the safety of its operation has become the primary factor affecting the development of high-speed train.Modern disc brake for high-speed train brake disc is mainly concentrated in the temperature field and stress field distribution.The current form of failure for the disc brake is mainly thermal fatigue failureand disc brakes work is a direct heat-structure coupling process.The entire brake vibration,fatigue,noise has a huge impact on it.Therefore,it is very important to analyze the temperature field and stress field of the disc brake by means of the thermo-structure direct coupling method.Based on the three-dimensional finite element model and the relevant theory of thermal-structural coupling,the friction coefficient of the disc brake and the structural steel are taken as the prototype.Based on the theory,stress field.The results show that the friction temperature is 160km/h and the thermal conductivity is 80W/(m·K),the temperature gradient of the brake is the smallest,and the equivalent stress is the smallest,the friction pair is composed of copper-based friction material and structural steel.The choice of brake discs and friction block should not be selected when the thermal conductivity of the material difference is too large,excessive pursuit of reducing the thermal conductivity of the friction plate will lead to the brake disc and friction between the excessive temperature gradient,cause serious of the thermal damage,seriously shorten the life of the brake.The brake pressure and brake initial velocity were analyzed.The temperature and stress fields were studied under the conditions of 0.6MPa and 0.8MPa respectively.the results show that the brake pressure has a significant effect on the temperature field of the brake temperature field and stress field were analyzed with braking speed of 160km/h and 300km/h.the instantaneous maximum temperature of the braking field was 160km/h,the maximum instantaneous temperature was 200.948 ?,and the three-directionequivalentstresswas2.48e5 MPa,braking speed 300km/h instantaneous temperature up to 513.78 ?,three-way equivalent stress 3.04e6 MPa,the initial brake speed is the actual conditions of the brake temperature and stress field of the greatest impact factor,with the increase of muzzle velocity,the temperature and stress field of the brake increase first and then decrease and the same temperature curve as that of the simulation result is obtained by the experiment,which verifies the correctness of the simulation result.