【作者】 张伟；

【导师】 黄继雄；

【作者基本信息】 武汉理工大学 ， 机械设计及理论， 2005， 硕士

【摘要】 为了防止内燃机车轮箍弛缓造成的机车脱轨事故,郑州铁路局机务处提出了给组装式机车轮对轮箍加装扣环的方案。机车轮对轮箍加装扣环后的运行实践证明,该方案可有效地防止因轮箍弛缓而造成的机车脱轨等重大事故,但轮箍加装扣环后由于结构发生了变化,存在以下几个方面的问题:轮辋与轮箍的配合面变短,轮辋受力中心外移导致轮辋弯曲变形;扣环槽部不可避免会有应力集中;轮箍的踏面和轮缘在使用过程中会发生磨损;恢复踏面和轮缘的线型时,需要对车轮进行车削修整,导致轮箍与轮缘变薄。因此,就加装扣环车轮在结构上的变化而引起车轮强度的变化进行分析与研究,在为机车轮对的结构设计提供理论依据,保证铁路机车安全运行等方面具有十分重要的意义。 本文以大型通用有限元分析软件ANSYS为分析工具,在装配应力、直线及曲线三种工况载荷下分别对加装扣环车轮及未加装扣环车轮进行了静力分析,并对计算结果进行了对比,确定了扣环槽对车轮结构的影响。此外,还对计算结果从静强度和疲劳强度两方面进行了评价。结果表明扣环槽对车轮局部的静强度产生一定影响,但这些影响主要是由于扣环槽的应力集中和轮箍轮辋配合面变窄引起的,对整个车轮的应力分布并没有多大影响,而且从应力数值上看,影响也很小的。 同时,对加装扣环车轮进行了模态分析,提取了前十阶固有频率和振动型态,与未加装扣环车轮的前十阶固有频率和振动型态进行对比,并在此基础上针对机车过过轨缝受到冲击的垂向动力学响应进行了分析,进一步确定扣环槽对车轮动力学性能的影响。结果表明无论是节点位移,节点力及节点应力均滞后于垂向动载荷的变化,扣环槽的存在对车轮动力学性能的影响较对静力学性能的影响要大一些,但并没有引起质的变化。 最后,针对铁道部提出的轮箍踏面禁用厚度,用穷举的方法对三组不同厚度(38mm,30mm,25mm)的踏面车轮在最恶劣工况载荷下进行分析计算,结果表明踏面厚度的变化并没有影响车轮整体的应力分布,而是将应力最大值由新轮的辐板弯曲处转移到轮箍上,仅从静强度和疲劳强度两方面考虑,加装扣环车轮在踏面厚度为30mm时运行是安全的。因此可以断言,轮箍加装扣环后铁道部原来规定的踏面与轮缘的禁用限度能够保障机车的安全运行。更多还原

【Abstract】 For the purpose of preventing against relaxation of train wheels, Zhengzhou railway station brought forward the project of equipping coupling collar on train wheels, which could prevent against the serious accident after putting on practice. However, there are some problems that inevitably exist. First, the assemble face becomes narrower. Second, stress concentration is inevitably. Third, tread and wheel rim will be abraded. Forth, tread and wheel rim will become thinner after cutting and repairing. Therefore, it is very important to research on the project, which will provide theoretic evidence for the run security.Using the large general finite element analysis software ANS YS as analytic tool, and taking the geometric structure and boundary condition into consideration, the train wheel equipped with coupling collar and the wheel unequipped were analyzed and compared in static in three differ rent operating load. The result shows that equipping coupling collar only influence the local part of the wheel, the change of stress can also ignorant.The modal analysis was made for the wheels that equipped coupling collar and not, on the basis of which the transient dynamic analysis also was made when crossing the rail gap. The result show that no matter what the node displacement, node force and node stress, which all delayed compared to the change of vertical load, and the influence on dynamic capability made by coupling collar was more remarkable.At last, aimed at tread’s forbidden thickness brought by railway department, three types of wheels in different tread thickness were analyzed in bad operating load, which will provide theoretic evidence in searching the security boundary. The result shows the change of treads’ thickness made no effort on the wheel’s stress distribution, just convert the stress maximum to tire. In addition, with the thickness becoming thinner to 25mm, stress maximum reach to 429MPa, which is beyond the yield limit.更多还原