缺陷滚动轴承应力应变的有限元分析

发布时间：2018-01-15 16:22

本文关键词：缺陷滚动轴承应力应变的有限元分析　出处：《河南科技大学》2012年硕士论文　论文类型：学位论文

【摘要】：在轴承的设计、分析过程中，轴承的承载能力、预期寿命、疲劳破坏、刚度、振动与噪声等问题都与轴承的应力分布和变形状态密切相关。因此，通过接触分析，掌握轴承接触面的应力分布和变形特点为改进设计和加工工艺，提高轴承承载能力及可靠性提供了有效的理论依据。通过模拟轴承的制造加工缺陷及点缺陷，掌握其应力应变特点对轴承寿命估计、振动与噪声和故障诊断都具有重要的意义。本文以通用有限元软件ANSYS为主要工作平台，主要研究了具有沟道点缺陷和椭圆缺陷轴承的静力学特征和点缺陷轴承的瞬态动力学非线性特征。首先，建立了最大承载钢球的有限元静力学模型，并将有限元分析结果与Hertz弹性接触理论的解析解进行了对比分析，表明有限元法的分析结果满足实际工程需要。然后，建立轴承外圈沟道的点缺陷有限元分析模型和沟道的椭圆形缺陷有限元模型，比较与理想轴承应力应变的不同。最后，构建了外圈沟道存在不同直径的点缺陷模型，研究点缺陷直径的变化对轴承应力应变及振动特性的影响。本文通过研究获得以下结论：von mises stress的峰值出现在滚动体与沟道接触表面下一定深度，为轴承的疲劳剥落提供了理论支持。桃形椭圆沟道使轴承的单点接触变为双点接触，改变了轴承内圈的载荷分布减小了变形量，而反向的椭圆沟道增加了外圈的最大应力值，沟道的形状对轴承的应力分布和变形具有重要影响。通过对不同直径的点缺陷分析得到以下结论：随着缺陷直径的增大，缺陷处的最大接触应力值不断减小，而轴承内圈和钢球的振动不断加剧，且钢球的振动强于内圈的振动。轴承转动过程中概率密度函数不断变化，这表明轴承的振动具有强烈的不确定性特征和非线性特征。本文以有限元仿真的方式形象地揭示了轴承疲劳剥落的成因及早期失效特征-点缺陷对轴承应力应变及振动造成的影响。研究表明当点缺陷直径较小时，缺陷处的等效应力巨大，经过交变载荷的作用点缺陷直径将扩大，随着缺陷直径的增加，轴承的振动与冲击增强，造成更多的点缺陷形成，导致轴承失效。
[Abstract]:In the process of bearing design and analysis, bearing capacity, life expectancy, fatigue failure, stiffness, vibration and noise are closely related to the stress distribution and deformation. Through contact analysis, the characteristics of stress distribution and deformation of bearing contact surface are improved design and processing technology. Improve bearing capacity and reliability to provide an effective theoretical basis. By simulating the manufacturing defects and point defects of bearings, grasp the characteristics of stress and strain to estimate the bearing life. Vibration, noise and fault diagnosis are of great significance. In this paper, based on the general finite element software ANSYS as the main platform, the static characteristics of the bearing with channel point defect and elliptical defect and the transient dynamic nonlinearity of the point defect bearing are studied. The finite element static model of the maximum bearing steel ball is established, and the results of finite element analysis are compared with the analytical solution of Hertz's elastic contact theory. The results show that the finite element method can meet the needs of practical engineering. Then, the point defect finite element analysis model and the elliptical defect finite element model of the outer ring of bearing are established. Finally, a point defect model with different diameters in the outer ring channel is constructed to study the effect of the point defect diameter on the stress strain and vibration characteristics of the bearing. In this paper, the following conclusions are obtained: the peak value of mises stress appears at a certain depth under the contact surface between the rolling body and the channel. It provides theoretical support for fatigue spalling of bearings. The peach-shaped elliptical groove changes the load distribution of bearing inner ring to double point contact and reduces the deformation. The reverse elliptical channel increases the maximum stress value of the outer ring. The shape of the channel has an important effect on the stress distribution and deformation of the bearing. Through the analysis of the point defects with different diameters, the following conclusions are drawn: with the increase of the diameter of the defects, the maximum contact stress at the defects decreases continuously. The vibration of bearing inner ring and steel ball is increasing, and the vibration of steel ball is stronger than that of inner ring. This shows that the bearing vibration has strong uncertainty and nonlinear characteristics. In this paper, the causes of fatigue spalling of bearings and the effect of early failure characteristics-point defects on the stress, strain and vibration of bearings are vividly revealed by means of finite element simulation. The results show that the diameter of the point defects is small. The equivalent stress at the defect is huge, and the diameter of the action point defect will be enlarged after alternating load. With the increase of the diameter of the defect, the vibration and impact of the bearing will be enhanced, resulting in more point defects and resulting in the failure of the bearing.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH133.33

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