【作者】 文汉云；

【导师】 莫易敏；

【作者基本信息】 武汉理工大学 ， 机械设计及理论， 2007， 博士

【摘要】 铁路运输中带扣环轮对由于其结构的改变可能在静强度、疲劳强度、动力学性能、最小许用边界等诸多方面发生变化从而威胁到列车的安全运行。本文以带扣环的轮对为对象进行了理论和实验研究，主要研究结论及创新点为：（1）首次采用直接带扣环计算的方法，对本文中的各项研究内容进行了模拟、计算与分析。（2）提出了采用极限过盈量计算的方法，对本文中的各项研究内容进行了模拟、计算与分析。（3）对轨道车辆轮对装配应力研究结果表明，带扣环轮对在最大过盈量下的最大应力值为271.7MPa，扣环上的最大应力值为271.7MPa，这些应力值远小于其屈服极限420MPa，不会对轮对的强度构成威胁。扣环本身的应力值达到最大，说明扣环受到严重挤压，可见装配过程中产生的残余应力不容忽视，应尽量减小这种应力。（4）对带扣环轮对的热分析结果表明，在最小过盈量下，轮箍表面温度高达145.10℃，已超过轮箍弛缓临界值140℃，说明轮箍已接近弛缓，这是要尽量避免的。但车轮一般不会在最小过盈量下运行，所以紧急制动工况下轮箍仍不会弛缓。最高温度载荷以及最大过盈量下的热应力为236.1 MPa，比单独过盈装配时还小，说明热载荷使轮箍产生热膨胀，抵消了一部分过盈量，这种情况虽然不会对轮对强度构成威胁，但比较危险，应尽量避免。（5）首次对带扣环轮对进行了多场联合作用下的力学性能分析，并对轮对的静强度σ和疲劳安全系数σ_-1d进行了评定。对静强度评定结果表明，轮对上的最大平均应力为267MPa，远低于屈服极限420MPa；对疲劳强度评定结果表明，轮对的疲劳安全系数σ_-1d=20.65，由此可知轮对的静强度和疲劳强度均满足运行需要。（6）对加装扣环前后轮对进行模态分析的结果表明，二者前10阶固有频率最大相差12.7Hz，且它们的前10阶振幅几乎相等，振型基本一致。由于前10阶振型基本反映了车轮在运行过程中可能存在的振动情况，可知加装扣环后不会对车轮的动力学性能造成影响。而在轨缝冲击载荷作用下，扣环的存在虽对车轮动力学性能影响较大，但仍没引起质的变化。（7）使用逐次减小轮箍厚度的方法和优化两种方法，分别求得了轮箍最小理论许用边界为25mm和26.03mm，最终取26mm作为轮箍最小理论许用边界。证明了轮对加装扣环后铁道部规定的38mm许用边界仍满足运行要求。（8）首次采用虚拟工程的方法对带扣环轮对进行了疲劳寿命仿真。结果表明其疲劳寿命可达到5.05年。而且根据疲劳寿命仿真结果云图，可知轮对疲劳寿命的薄弱位置在轮箍的滚动圆处。（9）选取带扣环轮对作为试验对象，使用无线传输应力测试仪和相应的虚拟仪器采集试验数据，将所得数据与有限元计算的数据进行对比分析。通过对轮对静态情况下装配应力的测试分析，本论文计算的结果与测试结果的相对误差约为8％，说明本论文研究成果是可信的。更多还原

【Abstract】 The snap ring of wheelset influences the wheelset’s behavior in many aspects, such as the static intensity, the fatigue strength, the dynamics performance and the minimum allowable stress. This may be a threat to the train’s operation safety. This essay aims to the theory and experimental research of the train wheel which installs the snap rings. The main conclusions and the creative points are as following:(1) Takes a method of calculating with a snap rings directly to carry on imitation, calculation and analysis to the various research contents in this essay.(2) Put forward a method of calculation with the adoption extreme limit to carry on imitation, calculation and analysis to the various research contents in this essay.(3) The conclusion from the research on the assemble stress of the wheels of the Orbit vehicle shows that the maximum stress of the wheels under the maximum extreme limit when installed with snap rings is 271.7MPa. These stresses are much smaller than its yield stress, which is 420MPa. So it doesn’t threaten the intensity of the wheels. However, the stress of the snap rings reaches its maximum value, which means the snap rings are extruded seriously. We should note from this that the remaining stress produced in the assemble period can’t be neglected. We should try to reduce this stress.(4) The conclusion from the thermal analysis of the wheels installed the snap rings shows that under the minimum extreme limit, the surface temperature of the tire . is as high as 145.10℃, which has exceeded the critical temperature of the relaxation of the tire. This means that the tire has approached relaxation. In general, the wheel does not work under the minimum extreme limit, so the tire would not relax when it work under emergency brake. The thermal stress under the maximum temperature load and the maximum extreme limit is 236.1Mpa, which is smaller than that under single extreme assembling. This means that the thermal stress cause the heat expansion of the tire, and counterbalances a portion of the extreme limit. It should be avoided because it is dangerous although it would not threat the strength of the wheel.(5) For the first time to carry on mechanical capability analysis of wheel set equipped with coupling collar, and to assess the static strength, the fatigue strength. The maximum average stress in wheel set is 267MPa,.far below the bend limit 420MPa. The fatigue strength is 20.65MPa. Thus, we can know that both the static strength and the fatigue strength meet the moving demands.(6) The result of modal analysis of front wheel set and rear wheel set equipped with coupling collar indicates that, the maximum discrepancy of the first ten ranks inherence frequency is 12.7Hz, and the swing of them is almost the same as the shake model. Because the shake type of the first ten ranks reflect wheel’s oscillation might existing in the moving, we can know whether the equipped coupling collar will affect wheel’s dynamic capability or not. Under rail slot’s impulsion load, although the existing of coupling collar has serious effect on the wheel’s dynamic capability, it doesn’t result in qualitative change.(7) By optimizing the thickness of the wheel hoop, we get the minimum allowable boundary of wheel hoop, which are 25mm and 26.03mm. Theoretically, 26mm is the minimum allowable boundary. Proving that the allowed boundary 38mm set by railway department, after equipping coupling collar on wheel set, still meets moving demands.(8) Simulate the fatigue life of the wheel set equipped with circlet by means of dummy project for the first time. The result shows that its fatigue life can reach 5.05 years. Moreover, according to the fatigue life simulation result, the weakness position of the wheel set is on the roll circle of the tire.(9) Select wheelset equipped coupling collar for the test, gather the data of the test with wireless instruments, and contrast the data with the result of finite element analysis. The discrepancy between the calculation and experimental results is about 8%, which proves this paper’ s result is believable.更多还原