中碳钢轴类构件的微动磨损特性及其对疲劳寿命的影响

发布时间：2018-04-02 18:36

本文选题：中碳钢　切入点：轴类构件　出处：《兰州理工大学》2011年硕士论文

【摘要】：本文对45钢为例的中碳钢轴类构件的径向微动磨损特性进行了分析。将微动磨损工况下中碳钢轴类构件的疲劳寿命分为微动磨损阶段、裂纹萌生阶段、裂纹扩展阶段三个阶段,并对45钢轴类构件的疲劳寿命进行了估算,得出了载荷、摩擦系数对疲劳寿命的影响曲线。本文采用Hertz接触理论对轴类构件与平面的接触问题进行了解析分析,采用ANSYS数值分析方法对轴类构件与平面之间的接触状态、接触面应力和接触半径进行了分析,并与Hertz接触理论的解析结论进行比较,应用数据处理软件ORIGIN,得到了微动磨损的影响曲线。采用经验公式法对微动磨损工况下中碳钢轴类构件的疲劳寿命进行了估算,采用临近裂纹萌生尺寸、修正Neuber局部应力应变法、修正McEvily公式分别对轴类构件三阶段寿命进行了估算。对中碳钢轴类构件的径向微动磨损特性分析,得出接触面在施加载荷下粘滑交接处切向力出现最大值以及X方向应力出现零值位置,为中碳钢轴类构件接触面的裂纹萌生的危险点。随着施加载荷和摩擦系数的增大,径向微动接触副的粘着区、混合区增大,滑移区变化不大,接触应力以接触顶点为界,两侧近似椭圆形分布,接触顶点应力最大。两接触副粘着区相对滑移量几乎为零,滑移区的相对滑移量最大,为微动磨损的严重部分。对微动磨损工况下的疲劳寿命分析,得出材料特性相似的两接触副的疲劳寿命大,微动磨损阶段占疲劳总寿命的大部分,随着施加载荷和接触副的摩擦系数的增大,轴类构件的疲劳寿命降低,当施加载荷和摩擦系数较小时,对疲劳寿命的影响较大,当施加载荷和摩擦系数达到一定值时,对疲劳寿命的影响减弱。
[Abstract]:In this paper, the radial fretting wear characteristics of 45 steel shaft members are analyzed.The fatigue life of medium carbon steel shaft members under fretting wear condition is divided into three stages: fretting wear stage, crack initiation stage and crack propagation stage. The fatigue life of 45 steel shaft member is estimated and the load is obtained.The influence curve of friction coefficient on fatigue life.In this paper, Hertz contact theory is used to analyze the contact problem between axial members and plane, and ANSYS numerical analysis method is used to analyze the contact state, contact stress and contact radius between axial members and plane.Compared with the analytical results of Hertz contact theory, the influence curves of fretting wear were obtained by using the data processing software Orgine.The fatigue life of shaft members of medium carbon steel under fretting wear condition was estimated by empirical formula method. The local stress-strain method of Neuber was modified by using the size of near crack initiation.The revised McEvily formula is used to estimate the three-stage life of shaft members.Based on the analysis of radial fretting wear characteristics of medium carbon steel shaft members, the maximum tangential force and the zero position of X-direction stress are obtained at the visco-slip interface under the applied load.It is the dangerous point of crack initiation in the interface of medium carbon steel shaft member.With the increase of load and friction coefficient, the adhesion zone of radial fretting contact pair increases, the mixing zone increases, and the slip zone changes little. The contact stress is bounded by the contact point, and the contact stress is approximately elliptical on both sides, and the contact peak stress is the largest.The relative slip of the adhesion region of the two contact pairs is almost zero, and the relative slip of the slip zone is the largest, which is the serious part of fretting wear.According to the fatigue life analysis under fretting wear condition, it is concluded that the fatigue life of the two contact pairs with similar material characteristics is large, the fretting wear stage accounts for the majority of the total fatigue life, and the friction coefficient increases with the application of load and the friction coefficient of the contact pair.The fatigue life of axial members is decreased, and the fatigue life is greatly affected when the load and friction coefficient are small, and the influence on fatigue life is weakened when the applied load and friction coefficient reach a certain value.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH117.1

【引证文献】