节点文献
机车车轮多轴疲劳强度分析
Multiaxial Fatigue Strength Analysis of the Locomotive Wheel
【作者】 刘东;
【导师】 张开林;
【作者基本信息】 西南交通大学 , 车辆工程, 2015, 硕士
【摘要】 轮对是机车车辆走行部的重要部件之一,在机车车辆运行过程中,车轮不仅要承受巨大的机械载荷,在采用踏面制动等制动方式的情况下,还要承受制动产生的热载荷,负载十分复杂,工作环境较为恶劣。为保证车辆安全运行,有必要对车轮疲劳强度进行深入研究。由于车轮辐板孔区域受力复杂,本论文参考Sines准则、Crossland准则、DangVan准则三种多轴疲劳准则对车轮疲劳强度进行计算,研究各准则的计算特点。同时,本文还通过对机械载荷与热机耦合载荷作用下的车轮进行强度对比分析,研究了热载荷对车轮强度的影响因素。论文研究得到的主要结论结论如下:通过热力学研究表明,车轮在制动过程中踏面温度及热应力先急剧上升后缓慢下降;热量主要集聚在踏面与闸瓦的接触面,轮辋部分由于热传递的作用温度及热应力上升,辐板与轮芯温度及热应力没有显著变化;制动发生后第20s,车轮产生最高温度,且所受等效热应力最大。通过静强度分析对比研究表明,车轮的辐板孔、轮心与轴配合区、辐板与轮毂的过渡区是较为危险的区域,在曲线运行工况下出现最大Von mises等效应力值,说明车辆在通过曲线路线时最危险,道岔运行工况次之。在热机耦合作用下,车轮辐板上多点主应力值出现负值,即产生较大压应力。通过疲劳强度分析对比研究表明,选用Sines准则评定车轮得到的安全系数最小,选用Dang van准则计算的安全系数最大。因此在对带有辐板孔的车轮进行多轴疲劳强度分析时,采用Sines准则计算偏于安全。因Sines准则关注的是各节点静水应力的平均值,所以其算得的各关键节点安全系数值普遍较小,可能会使得计算结果过于保守,造成过估结果。因受制动热应力的影响,在进行多轴疲劳评判时,车轮上各点的等效应力值略有增大,但幅度很小,在工程应用中,为简便计算可以不考虑热应力对车轮疲劳强度造成的影响。
【Abstract】 Wheelset is one of the important parts of locomotive vehicle bogie. When locomotive vehicle runs, the wheel should not only bear the huge mechanical load, and also brake thermal load in the way of tread brake and other brake. The load is very complex and working environment is relatively bad. In order to guarantee the safe operation of the vehicle, it is necessary to conduct the thorough research to the wheel fatigue strength.This paper refers to rule of Sines, rule of Crossland and rule of Dang Van (three multiaxial fatigue criteria) of wheel fatigue strength calculation, study the calculation of standard features. At the same time, this paper studies the influence factors of thermal load strength of the wheel, through to the mechanical load and thermal-mechanical coupling load under the action of wheels strength comparison analysis.The main conclusions of research are as follows:The thermodynamic analysis shows that wheel tread in the process of braking temperature after a sharp rise in slow decline. Heat contact surface mainly gathered in the tread and brake shoe, rim part due to the effect of heat transfer temperature rise, radial plate and the wheel core temperature did not change. Wheel produces the highest temperature, equivalent thermal stress and suffered most when brakes after 20 s.Static strength analysis shows that the wheel disk hole, wheel heart which cooperate with shaft and wheel disk which is hub transition zone are the most dangerous areas. The maximum Von mises equivalent stress values occurs in curve operating conditions, shows the most dangerous route is curve operating conditions, switch operation takes the second place. Under the thermal-mechanical coupling effect, wheel disk principal stress value is negative, namely the larger compressive stress.Fatigue strength analysis shows that safety factor choosing Sines criterion to assess is the minimum, rule of Crossland takes the second place, and Dang van criterion calculation of safety factor is the largest. So on wheel disk with a hole in the wheel of multiaxial fatigue strength check, by means of the criterion of Sines calculation should be safe. By Sines safety factor choosing Sines criterion to assess is the minimum, rule of Crossland takes the second place, criterion is the key node values is generally small, due to the rule of Sines focuses on the mean value of each node hydrostatic stress may make the calculation result is too conservative, contributes to appraise the result. Because of the effect of brake thermal stress, when carries on the multiaxial fatigue evaluation, increase the equivalent stress value at every point on wheels, but is very small, in engineering applications, for the simple calculation can not consider the effects of heat stress on wheel fatigue strength.
- 【网络出版投稿人】 西南交通大学 【网络出版年期】2016年 01期
- 【分类号】U260.331.1
- 【被引频次】11
- 【下载频次】480