螺栓失效对压剪复合型弹性车轮强度安全性影响

Influence of Bolt Failure on Strength Safety of Compression-shear Composite Resilient Wheel

弹性车轮螺栓用以紧固轮芯和安装环,在工作过程中承受预紧力和拉伸载荷,其应力状态对弹性车轮的运行安全至关重要。通过建立弹性车轮三维有限元模型,模拟螺栓在螺栓载荷作用下的初始受拉状态,利用接触单元和目标单元模拟各部件之间的接触状态,设置过盈量模拟轮芯与安装环之间、橡胶与轮辋之间的初始过盈接触状态。参考国际铁路联盟标准UIC 510-5和欧洲标准EN 13979-1,计算分析螺栓失效对弹性车轮整体静强度的影响。研究结果表明,螺栓未发生失效时,车轮各部件的危险系数均不超过0.61;综合分析多种工况下轮芯、安装环、螺栓和橡胶块的最大Von-Mises应力,其应力均随螺栓失效个数的增加而增大;螺栓失效后,运行工况下轮辋的最大Von-Mises应力无明显变化;当5个螺栓发生失效后,轮辋、轮芯、安装环、螺栓和橡胶块的危险系数分别为0.27,0.92,1.01,0.95,0.40。所得结论可为轨道车辆弹性车轮静强度校核提供参考。

The resilient wheel bolts are used to fasten the wheel core and the mounting ring,and are subjected to pre-tensioning and tensile loads in operation.Their stress state is critical to assess the operational safety of the resilient wheel.The three-dimensional finite element model of the resilient wheel was built by using the finite element software.The initial tension state of the bolt was simulated through applying static load,and the contact state between the components were simulated by using the contact unit and the target unit.The initial interference contact state between the wheel core and the mounting ring and between the rubber and the rim was numerically simulated by setting the interference amount.Based on UIC 510-5 and EN 13979-1 standard,the impact of bolt failure on the overall static strength of the resilient wheel was investigated.The research results showed that the risk coefficient of each wheel component did not exceed 0.61 in normal condition.The maximum Von-Mises stresses of the wheel core,mounting ring,bolt and rubber block under the considered operating conditions increased with an increase of the number of failed bolts.When five bolts failed,the risk coefficients of the rim,wheel core,mounting ring,bolt and rubber block were,respectively,0.27,0.92,1.01,0.95,0.40.In operation the failure of the discussed bolts had no significant effect on the maximum Von-Mises stresses of the wheel rim.The conclusions provided a reference for the static strength check of the resilient wheels of rail vehicles.