铁路车轴过盈配合面微动损伤分析及有限元仿真

Damage Analysis and Finite Element Simulation of Fretting Wear on Press-Fitted Surface of Railway Axle

基于全尺寸铁路车轴疲劳试验,观察并分析了微动区损伤形貌及损伤机理.基于测量的磨损轮廓建立有限元模型,计算分析了微动磨损对过盈配合面微动参量及轴向应力的影响.结果表明:轮座近加载侧存在1个宽度约为20 mm的微动损伤区,根据形貌特征可以分为3个区域.仿真得到的微动滑移区宽度与损伤区宽度基本一致,张开区宽度略小于磨损区.未磨损时,接触压应力、摩擦剪应力及轴向应力峰值均出现在接触最边缘;在微动磨损作用下,接触压应力、摩擦剪应力、轴向应力峰值出现在磨损-未磨损边界,且轴向应力数值在磨损区由负变正.磨屑的存在为接触面提供承载平台,在一定程度上抑制应力集中向内部转移.

The fatigue test was conducted for the full-scale railway axle,and the fretting damage on the press-fitted surface was analyzed.The finite element model was then established to investigate the influence of fretting wear on the fretting parameters and axial stress.The results show that the total width of the fretting damage area was about 20 mm.According to the characteristics of surface appearance,it can be divided into three areas.The width of the damage zone was almost the same as the width of the fretting zone,and the width of the opening zone was slightly smaller than that of the wear zone.The peak values of the contact pressure,the frictional shear stress and the axial stress appeared at the contact edge for the axle without wear.With the occurrence of fretting wear,the peak values of the contact pressure,axial stress and frictional shear stress appeared at the worn-unworn boundary.At the same time,the value of the axial stress changed from negative to positive in the wear zone.The wear debris provided a bearing platform for the contact surface and inhibits the stress concentration moving from the external to the inside of fretting area.