The Effect Of Brake Disc Structure On Friction Pair Performance Of High Speed Train Brake

The friction pair is the core component of the braking system.As the speed of high-speed trains continues to increase,higher requirements are put forward for its performance.Because the friction pair exists in a high temperature environment for a long time,the influence of thermal stress is easy to lead to fatigue fracture and failure of the brake disc,and the structure of the brake disc determines the size of its heat capacity and the strength of its thermal bearing capacity,which has a great impact on the performance of the friction pair.Therefore,it is of great significance to study the influence of brake disc structure on the performance of friction pair.In this paper,finite element software ADINA was used to establish a finite element model for the friction pair composed of solid disc S1(friction radius is 125mm),ventilation disc T1(friction radius is 125mm),T2(friction radius is 140mm)and triangular friction block.The temperature field of the disc surface under different braking conditions was simulated by direct coupling method.At the same time,the experiment was carried out on the TM-I reduction brake test bed,and the comparative analysis of the experiment and simulation results showed that:(1)The peak temperature of the disc surface is greatly affected by the braking conditions:with the increase of the initial braking speed and the brake pressure,the peak temperature of the disc surface increases linearly.Under the braking conditions of 0.5MPa and 60km/h,the peak temperatures of the S1,T1 and T2 disc surfaces are 93℃,85℃ and 82℃ respectively;when the initial braking speed rises to 160km/h,the peak temperatures increase respectively To207°C,192°C and 185°C.(2)The structure of the brake disc has a great influence on the peak temperature of the disc surface: under different braking conditions,the peak temperature of the ventilated disc T1 obtained by the simulation is 11-16% lower than that of the solid disc S1.When the ventilated disc structure is the same,the friction radius is increased.The peak temperature of the T2 disk surface is 3 to 6% lower than that of T1;the peak temperature of the ventilated disk T2 obtained in the experiment is 10-21% lower than that of the solid disk S1.(3)Reduced ratio brake test Under the same working conditions,the average temperature of the ventilating disk T2 and the radial temperature gradient are smaller than those of the solid disk S1,and the temperature difference between the ventilating disk surfaces is more stable than that of the solid disk.Under the braking conditions of 0.5MPa and 160km/h,the peak temperatures of the solid disc S1 and the ventilated disc T2 are 240°C and 198°C,respectively.(4)There is a certain deviation in the temperature distribution of the disk surface obtained by simulation and experiment.Under the braking conditions of 1.0MPa and 160km/h,in the early stage of braking,the highest radial temperature points obtained by the test and simulation appear on both sides and the center of the disc respectively.As the braking progresses,the test and simulation results The consistency of the temperature distribution is getting better and better.The main reason is that the friction pair has incomplete contact and uneven pressure distribution during the test.