中文摘要：

针对制动热应力问题,运用有限元直接耦合法,对车轮热接触工况进行了模拟,采用耦合方程同时求解温度场和位移场,研究了纯机械载荷工况和热接触耦合工况下轮轨应力分布与变化规律,分析了车轮及钢轨表层材料和次表层材料的变形、温度与应力之间的关系。分析结果表明：由于热应力的影响,车轮表面以下0～1 mm的表层区域等效应力最大值增大了18%,且车轮等效应力较大区域由表面以下1～4 mm处的次表层区域变动至车轮表面以下0～3 mm处。

英文摘要：

Aiming at the thermal stress caused by brake,a thermo-contact coupling calculation method was used to simulate the process of wheel/rail thermal contact based on finite element method.The temperature field and displacement field were synchronously solved by using coupling equations.The distributing and varying rules of the stresses for wheel and rail were studied under pure mechanical load condition and thermo-contact coupling condition.The relation among the displacements,temperatures and stresses of wheel＇s and rail＇s surfaces and second surfaces were analyzed.Analysis result shows that affected by the thermal stress,the maximum equivalent stress of wheel＇s surface rises by 18%,and the area with high stress varies from 1-4 mm to 0-3 mm below the surface.1 tab,10 figs,11 refs.