| The railway transportation is an important part in national economic development because of its speediness, safety, economy and large transportation volume characteristics. The railway transportation, especially high-speed railway transportation of China develops rapidly in recent years. Up to 2006, China has about 135360.9 km railway line on operating, and we are also plan to build more track traffic such as railway, urban subway and light rail transport in the future. Under the guide of the new strategy “One Belt and One Road”, the new silk road economic belt connection of Eurasia with 81000 km railway network, which covers 63% of the world’s population, through 26 countries and regions, accounts for 29% of the world’s economies. It is more important to have a safely, high speed and overloaded railway transport. Wheel/rail relationship as one of the key technical problems in the process of railway operation, it has a very important research significance. With the development of high speed and heavy load railway transportation, it’s more and more important to study the friction problems of the wheel/rail contact. The traction and braking of the train must be achieved by the wheel/rail contact. Security and comfort of train operation are closely related to the wheel/rail friction pair. Friction heat is an important product of wheel/rail friction pair, its transport results determines the temperature of friction pair. The stress level, mechanical properties and microstructure of wheel/rail material are closely related to the temperature of the wheel/rail friction pair, the friction heat production area has a significant influence on the wheel/rail temperature field. It’s necessary to get accurate frictional heat and research its transmission mechanism.This paper introduced the general calculation method of friction heat production area, discussed the characteristics of wheel/rail friction heat, and then analyzed the wheel’s temperature field characteristics with a finite volume method. The results show that the thermal characteristics of wheel/rail friction and temperature field characteristics are mainly related to the wheel/rail material, the diameter and speed of wheel, the axle load, the friction coefficient and the forced convection heat transfer coefficient of the wheel surface. The results show that if we only consider the longitudinal creep, the heat flux calculate by local method is greater(about 1000 times) than average method. If we calculate the heat flux by the average method, the axle load, the traction and the speed of the train are the main factors influencing the friction heat flux, and the friction coefficient has little effect on the heat flux. The surface temperature of wheel/rail contact spots changed periodically with the wheel’s rotation, the highest and equilibrium temperature are rising slightly before reaching the periodic balance but the influence is very little. The temperature which we get from the friction heat flux calculated by the local method will increase with the increase of traction, train speed and friction coefficient, but decreases with the increase of axle load. The relationship between the axle load and temperature is the comprehensive effect of the area of the wheel/rail contact spot and heat flux, the greater the axle load is, the smaller the temperature rise. Different speed will affect the length of the temperature cycle, which is caused by the change of heat source action time. When calculating the temperature of contact spot, the temperature of considering the lateral force is much higher than only considering the longitudinal creep force, the effect of transverse force should not be neglected. |
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