铁路轴承试验机主轴疲劳强度有限元分析

Fatigue Strength Analysis of Main Shaft in a Railway Bearing Tester by Finite Element Method

某型号铁路轴承试验机接连发生3根主轴断裂事故,为了分析主轴断裂原因,建立了主轴有限元分析模型,计算出了主轴静应力分布情况。在有限元静力学分析基础上,根据给定的载荷,用"轴不动、载荷旋转"来模拟实际的"轴旋转、载荷不变"情况,采用专业疲劳分析软件Fe-Safe计算了主轴的疲劳强度。计算结果表明,主轴疲劳强度安全系数小于1,存在发生断裂的可能性。对原主轴结构进行改进设计,按照同样的流程对新主轴进行有限元静力学分析和疲劳分析,计算所得疲劳强度安全系数为1.3,满足了疲劳强度要求。

The failure breaking accident of three main shafts in a railway bearing tester is occurred continuously.The finite element model of the main shaft is built and the static stress distribution is gained in order to find the reason of main shaft fracture.The work condition of shaft rotating and force fixing is simulated with shaft fixing and force rotating according to the preset load.The fatigue strength based on the static stress is calculated by professional software FE-SAFE.It is indicated that the fatigue fracture is possibly occurred because the fatigue strength safety coefficient of the main shaft is less than 1.The statics analysis and fatigue analysis of improved main shaft is executed complying with the same flow process as above mentioned.The result presents that the fatigue strength safety coefficient of the improved main shaft is 1.3 and is acceptable.