Coupled Thermo-Mechanical Numerical Simulation Of Brake Discs For High-Speed Trains

At present, high-speed railway has already taken the predominant place of ground transportation trunk between cities of developed countries. With the beginning construction of Beijing—Shanghai Express Railway, the era of high-speed train is coming in China. The research and development of brake discs that is the key technology of train safe operation become the bottleneck for higher speed train. The materials for brake discs that is under produce and used in China can't meet the requirement for high-speed train of 300km/h, mostly depend on import. The present work was carried out based on these.The varied behavior of temperature and stress in disc was simulated in the duration of 200km/h high-speed train braking, the highly nonlinear finite element analysis software MSC.Marc was adopted to build coupled thermo-mechanical three-dimensional models, combined with the 1:1 dynamic bench test. Basing on the model of 200km/h, i t was simulated that the varied behavior of temperature and stress in disc during the course of 300km/h high-speed train braking. The influence of different mechanical properties and thermo-physics properties of brake disc materials that act on the temperatures and stresses in the course of braking was tested, and the effect of these properties on resistance performance of thermal crack in disc was analyzed. These provide important references for the selection of the new materials of brake discs. The distribution and variation law of temperature and stress at different braking period in radial and circumferential friction surface and thickness heading was analyzed. It was founded that there was different high temperature cyclical bands distributed in friction surface, and the stress in nodes of these bands was higher in circumferential direction than in the radial one. Consequently, the thermal cracks was always found in the radial direction of surface extending from the inner radius to the outer radius. A conception based on the foreign thermal spraying brake disc, surface overlaying materials that have excellent capabilities of heat resistance and antifriction on ordinary braking materials to improve the braking performance and cut the cost, that was presented. The conception was demonstrated by finite element numerical simulations.At last, summary was made and directions of the work to increase the precision of simulations was proposed. A full-scale bench test or a economical same scale reduced-scale physical simulation was needed.