Analysis Of Heat Dissipation Performance And Structural Optimization Design Of The Brake Disc Of High-Speed Train

With the speed of the high-speed train increasing,its safe operation has become one of the key issues of research.The researchers have indicated that braking technology is essential to the safety of high-speed trains.The Disc brake that consisted of the brake pads and disc is the base brake.During the braking operation,there exits the severe friction between the brake pads and disc,where a great deal of heat is generated and accumulated.The high temperature of the Brake Disc is forced to cool down by the convection heat transfer occurred the surrounding air of the Brake Disc,which reduces greatly the thermal fatigue of the Brake Disc.Therefore,the research on the heat dissipation performance of the Brake Disc of the high-speed train is of great significance.This paper takes the axle-mounted Brake Disc of a high-speed train trailer as the research object to study its heat dissipation performance under emergency braking conditions.Based on the original brake disc,by changing the shape and arrangement of the heat dissipation ribs,compare the heat dissipation performance of the Brake Disc with different heat dissipation rib structures,and study the influence of the single structure parameter of the heat dissipation rib on the heat dissipation performance.To improve the heat dissipation performance of the brake disc and reduce the quality of the Brake Disc,and optimize the structural parameters of the Brake Disc based on multi-objective,it provides a reference for the design of brake discs for high-speed trains.The main research contents and conclusions of this paper are as follows:A finite element model of the Brake Disc was established,and the heat transfer process of the Brake Disc was analyzed.it is concluded that the irregularity of the airflow around the Brake Disc leads to the irregular distribution of the convective heat transfer coefficient on each surface.Except for the moments when the train stops,the maximum convection heat transfer coefficient always appears on the surface of the radiating ribs.The average convective heat transfer coefficient on the surface of a single radiating rib changes in a non-uniform period;the maximum temperature of the Brake Disc increases first and then decreases,and the average temperature gradually increases,but its variation gradient gradually decreases.The paper analyzes the heat dissipation performance of Brake Disc with different heat dissipation rib structures,The research results show that the heat dissipation performance of the Brake Disc with cylindrical heat dissipation ribs is better than that of the Brake Disc with ribshaped heat dissipation ribs,and the curvilinear distribution of the heat dissipation ribs is helpful for the heat dissipation;the maximum temperature and convective heat transfer coefficient on the surface of the cylindrical heat dissipation ribs decrease with the increase of the diameter of the cylinder.Finally,to improve the heat dissipation performance of the Brake Disc and reduce the quality of the Brake Disc as the optimization goal,and reasonably select optimized parameters,and build a response surface model to establish a functional relationship between optimization parameters and optimization goals.The optimization is carried out by the NSGA-II genetic algorithm.And the validity of the optimization results is verified by finite element analysis.Compared with that before the optimization,the maximum temperature is reduced by about2.7%,the average convective heat transfer ratio is increased by about 8.3%,in which the surface of the radiating rib is increased by about 10.4%,and the mass of the Brake Disc is reduced by about 2.3%.