齿轮疲劳寿命及齿根裂纹仿真分析

发布时间：2018-07-10 05:42

本文选题：齿轮 + 疲劳寿命　；参考：《重庆大学》2011年硕士论文

【摘要】：齿轮传动具有效率高、结构紧凑、工作可靠和传动比稳定等特点,广泛应用于机械传动领域。在齿轮所有失效形式中,疲劳断齿所占比例最大,其次是表面接触疲劳,因此疲劳破坏是齿轮失效的最主要形式之一。开展齿轮疲劳寿命及齿根裂纹仿真方法研究,对提高齿轮的可靠性和使用寿命具有重要的理论意义和工程应用价值。本课题来源于国家科技支撑计划项目。综合运用机械疲劳分析理论、断裂力学理论以及有限元法和边界元法,对齿轮的疲劳寿命问题进行数值仿真分析。本文的主要研究工作如下: ①对风电机组各工况实测输入转矩的随机载荷历程进行雨流循环计数,得到载荷循环数、均值与幅值的关系,并将其合成为转矩总载荷谱。 ②在ANSYS中建立增速箱输出级斜齿轮副的三维接触有限元模型,计算静载荷下斜齿轮副的应力应变;在FE-SAFE软件中,考虑材料的S-N曲线和应变-寿命曲线,采用名义应力法和局部应力应变法计算了斜齿轮副的疲劳寿命,并研究了载荷、表面粗糙度、残余应力以及轮齿修形对斜齿轮副疲劳寿命的影响规律。 ③采用三维断裂分析软件FRANC3D,对含半椭圆形初始裂纹的直齿轮模型进行边界元分析,计算齿根裂纹前缘的应力强度因子,并研究了载荷、裂纹大小和裂纹形状对齿根初始裂纹应力强度因子的影响规律。 ④利用FRANC3D的边界元裂纹自动扩展功能,模拟了齿根和齿面裂纹的扩展轨迹,分析了齿根裂纹扩展过程中的裂纹张开位移和应力强度因子,并对齿根裂纹扩展寿命进行估算。
[Abstract]:Gear transmission is widely used in the field of mechanical transmission because of its high efficiency, compact structure, reliable operation and stable transmission ratio. Among all the failure modes of gears, fatigue tooth breakage is the largest, followed by surface contact fatigue, so fatigue failure is one of the most important forms of gear failure. The research on the simulation method of gear fatigue life and tooth root crack has important theoretical significance and engineering application value in improving the reliability and service life of gear. This topic comes from national science and technology support plan project. The fatigue life of gears is simulated by using mechanical fatigue analysis theory, fracture mechanics theory, finite element method and boundary element method. The main research work of this paper is as follows: 1 the random load history of the measured input torque of wind turbine is counted by the rain flow cycle, and the relationship between the load cycle number, the mean value and the amplitude is obtained. It is composed as the total torque load spectrum. 2 the three-dimensional contact finite element model of the output helical gear pair of the speed box is established in ANSYS to calculate the stress and strain of the helical gear pair under static load, and in the software FE-SAFE, the stress and strain of the helical gear pair are calculated under static load. Considering the S-N curve and the strain-life curve of the material, the fatigue life of the helical gear pair is calculated by using the nominal stress method and the local stress-strain method, and the load and surface roughness are studied. The influence of residual stress and gear tooth modification on the fatigue life of helical gear pair is analyzed by using the 3D fracture analysis software FRANC3D. the model of spur gear with half-ellipse initial crack is analyzed by boundary element method. The stress intensity factor of tooth root crack front is calculated, and the influence of load, crack size and crack shape on the stress intensity factor of tooth root initial crack is studied. The propagation trajectories of tooth root and tooth surface cracks are simulated and the crack opening displacement and stress intensity factor during tooth root crack propagation are analyzed and the crack propagation life of tooth root is estimated.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH132.41

【引证文献】