摘要
采用大轴重货车是解决我国铁路货运能力不足的主要途径之一,然而提高轴重意味着车轮踏面所受的制动热负载将会增大,这可能导致大轴重货车车轮辐板热损伤加剧。因此,有必要通过对不同轴重车轮热应力的对比分析,揭示轴重大小对车轮辐板损伤的影响规律,为制定大轴重货车运行和制动条件提供支持。提出研究此问题的新思路,采用热弹塑性有限单元法,模拟在热处理工艺过程中车轮辐板残余应力分布状况,使得车轮存在仿真制动工况所需的初始残余应力。对重载运煤专线—大秦线全程循环制动进行模拟,计算得到车轮制动功率—时间历程,仿真在此工况下30 t重载货车车轮辐板的温度场和热应力场的分布状况。计算比较21 t、25 t和30 t轴重货车车轮在大秦线全程循环制动中热应力和制动完全结束后的残余应力的变化规律。结果表明,车轮在热处理后,车轮辐板残余应力是不可忽视的。随着轴重的增大,车轮辐板将承受更大的热应力和残余应力。
As an effective and efficient solution to enhance the capacity of the freight car transportation, the increase of axle loads may lead the wheel enduring larger heat loads and suffering more severe damage. In order to offer valuable technical supports for the operation, especially braking working condition, it is necessary and meaningful to compare the thermal stress of the wheel web plates for different axle load freight cars and reveal how the changes of the axle load affect the distribution of the temperature and stress. Basing on the thermal elasto-plastic theory, a new idea is put forward, which firstly studys the residual stress generated by the heat treatment process, and then simulates the distribution of the temperature and thermal stress for the wheels with residual strain using the time history of the heat braking power calculated from the omnidistance working conditions of the Datong-Qinhuangdao railway as a theraml load. It has been proved the residual stress generated by the heat treatment process cannot be ignored and the web plates will bear greater thermal and residual stress along with the increase of axle loads, by means of comparing the ones of the 21 t, 25 t and 30 t axle load wheel web plate.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2012年第12期133-138,共6页
Journal of Mechanical Engineering
基金
铁道部科技研究开发计划资助项目(2011J014-A)
关键词
车轮辐板
热应力
踏面制动
残余应力
热弹塑性
Wheel web plate Thermal stress Wheel tread braking Residual stress Thermal elasto-plastic
