【摘要】 为了量化辨识深沟球轴承局部缺陷,提出正反问题相结合的评估方法.正问题建模时采用"先独立,后集成"的策略,结合有限元法与多自由度振动理论,考虑外圈结构弹性变形、滚动体-内圈动态接触关系,建立深沟球轴承柔性多体接触动力学分析模型.应用非线性Hertz理论描述接触力,通过轮廓变化对表面损伤进行有效模拟.为了表征轴承-轴承座传递路径的作用,将轴承座同时计入有限元模型,并对相关参数进行修正使得该模型具有精确的损伤预测能力.将反问题计算转化为空间距离的比较,以实测信号特征量作为输入,进而测出损伤位置和尺寸.为了减小相对误差,提出损伤区间的概念,用区间代码表征损伤程度.实验数据验证表明,该方法能够高效量化轴承损伤,具有良好的预测精度.更多还原

【Abstract】 A novel evaluation method combining backward inference with forward inference was proposed to quantitatively evaluate fault degree of deep groove ball bearings with localized defects.The separation-integration strategy was used for modeling the forward infrence.A detailed multi-body dynamic contact model was developed with the assumptions that rolling elements-inner race had multi-DOF and outer race was deformable in radial direction,which was modeled with finite elements(FE).In this model the nonlinear stiffness was obtained by the application of Hertzian elastic contact deformation theory and the localized defects were modeled through surface profile changes.In order to study the influence of the transmission path,the bearing housing was taken into account in bearing model.The backward inference was translated into comparison of geometric distance,and the defects location and size can be determined by inputting the measured features.In order to reduce the relative error,a concept of damage range was introduced to characterize the fault degree by utilizing range code.Finally,the effectiveness and accuracy of the proposed method in quantitative evaluation was verified..更多还原