动车组制动盘热仿真方法适用性研究

Applicability Research on Thermal Simulation Methods for EMU Brake Discs

基于目前制动盘有限元热仿真普遍采用的能量折算法、热机耦合法、热机-磨损耦合法及流固耦合传热法,研究不同动车组制动闸片压力工况下制动盘温升规律,并将仿真结果与台架试验结果进行对比,对不同热仿真方法进行适用性分析。结果表明:在17.5 kN的制动闸片压力工况下,4种热仿真方法得到的盘面温升规律基本一致,最高温差小于10%,台架试验所得的制动盘温度场分布结果与能量折算法、热机耦合法及流固耦合传热法所得的比较相近,其中能量折算法计算效率最高,可用于制动盘材料的温升极限研究;当制动闸片压力增为22.5 kN时,4种热仿真方法中热机-磨损耦合法较其他3种方法的最高温差较大,台架试验与热机-磨损耦合法的制动盘温度场分布比较接近;由于摩擦副的接触摩擦力随制动闸片力的增大而增加,导致制动盘摩擦面快速升温,材料发生热膨胀变形,热机-磨损耦合法更能反映接触影响下的微观热现象,因此应选用热机-磨损耦合法研究制动盘热生成与热分布规律。

Based on the present widely used finite element methods on thermal simulation for brake discs,including the energy conversion method, the thermo-mechanical coupling method, the thermo-mechanical-wear coupling method and the fluid-solid coupled heat transfer method, the laws of temperature rise under the conditions of different brake pad pressures were studied. And the simulation results were compared with the bench test results to carry out the applicability analysis of different thermal simulation methods. The results show that: under the condition of the brake pad pressure of 17. 5 kN during EMU operation, the laws of discsurface temperature rise obtained by the four thermal simulation methods are basically consistent and the maximum differences in temperature are less than 10%. The distribution results of the brake disc temperature field obtained by the bench test are similar to those by the energy conversion method, the thermo-mechanical coupling method and the fluid-solid coupled heat transfer method. Among the above mentioned methods, the calculation efficiency of the energy conversion method is the highest and the method can be used in the study on temperature rise limit of brake disc materials. When the brake pad pressure is raised to 22. 5 kN, compared with the other three finite element thermal simulation methods, the thermo-mechanical-wear coupling method has a large difference in the maximum temperature of the disc surface. The temperature field distributions of the brake disc in the bench test and the thermo-mechanical-wear coupling method are relatively close to each other. For the contact friction of the friction pair increasing with the rise in brake pad pressure, it leads to the rapid temperature rise of the friction surface of the brake disc;and thermal expansion friction occurs in the material.The thermo-mechanical-wear coupling method can reflect the micro-thermal phenomena of contact surfaces.Therefore, the thermo-mechanical-wear coupling method should be used to study the laws of heat generation and heat distribution of the brake disc.