轮毂突悬量对轮轴过盈配合结构微动疲劳强度的影响研究

Influence of Overhang on Fretting Fatigue Strength of Press-Fitted Wheel-Axle

基于ABAQUS建立轮轴过盈配合结构有限元模型,分析摩擦剪切应力、滑移幅值、配合面张开区宽度和过渡圆弧最大主应力等参数随轮毂突悬量的变化,进而研究突悬量对轮轴过盈配合结构疲劳强度的影响规律。结果表明:轮轴配合面的摩擦剪切应力随突悬量的增加而增大,过盈配合部位接触边缘的滑移幅值随突悬量的增加而减小。随着突悬量的变化,过盈配合部位张开区宽度的变化趋势与微动疲劳强度的变化趋势呈负相关,即突悬量增加,则张开区宽度减小,微动疲劳强度增加;当突悬量超过某一个临界值,张开区宽度和微动疲劳强度均趋于稳定。过渡圆弧的最大主应力随突悬量的增加而增加,这增加了轴身发生疲劳失效的风险,并可能导致车轴疲劳失效位置由过盈配合部位转移至轴身。因此,随着突悬量的变化,过盈配合部位微动疲劳强度和轴身疲劳强度存在竞争关系,选取一个合理的突悬量对延长车轴的使用寿命具有重要意义。

In this paper,finite element models of wheel-axle were established by using ABAQUS.The evolution of friction shear stress,slip range,width of open zone,and the maximum principal stress of transition with overhang was analyzed.Then,the influence of overhang on the fatigue strength was investigated.The results showed that with the increase in overhang,the friction shear stress increased while the slip amplitude at the contact edge decreased.The evolution of width of opening zone was negatively correlated with that of fretting fatigue strength when the overhang increased.With an increase in overhang,the width of opening zone decreased while the fretting fatigue strength increased.When the overhang exceeded a critical value,the width of opening zone and fretting fatigue strength nearly remained unchanged.The maximum principal stress of the transition increased with an increase in overhang,which increased the risk of axle fatigue failure,and the failure site may shift from press-fitted part to axle body.Therefore,there was a competitive relationship between fretting fatigue strength of press-fitted part and fatigue strength of axle body when the overhang varied.In order to prolong the life of axle,it was important to select a reasonable overhang.