基于有限元法的圆柱与平板间接触疲劳分析

发布时间：2018-01-29 12:55

本文关键词： 接触疲劳有限元法接触应力应变疲劳寿命疲劳损伤　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：在现实的生产生活中,圆柱和平面之间的接触问题很常见,具有广泛的实际应用基础,例如在圆柱滚子轴承中滚子与套圈之间的接触、齿形零件之间的接触等等,这种接触方式可以有效减小摩擦力,减小旋转扭矩。但是这类接触方式会因为接触面上疲劳破坏的产生而使得这种结构的使用寿命降低,进而影响相关机械设备的正常运转,尤其是对一些高精度机械设备,直接影响其加工元器件的精度。本文依照接触力学理论知识,针对圆柱和平面之间的接触疲劳问题,运用有限元法分析对该问题进行了模拟分析,揭示了疲劳破坏的产生部位。本文首先基于圆柱与平板的接触关系,建立了数学计算几何模型,并推导了疲劳接触应力的计算表达式,绘制了各个接触主应力的曲面分布图,之后基于有限元软件构建了圆柱与平板接触有限元实体模型,并运用有限元法对圆柱与平板静摩擦接触系统在承受静压外载荷作用的情况进行模拟仿真,绘制了接触区域内圆柱与平板各自所承受的接触应力及所发生的形变分布云图,并运用模拟得到的接触应力与其理论解析值进行了相对误差的求解,得出有限元法对圆柱与平板之间的接触应力与应变进行分析能够得到比较可信、合适的分析结果。还指出运用有限元法分析接触疲劳存在一定的局限性,指出了其分析计算之所以存在误差的主要原因。针对圆柱与平板所组成的静摩擦接触系统,运用有限元法对其在周期性循环压载荷作用下在接触区域内可能发生疲劳破坏问题进行了模拟仿真,预测了在试验载荷下接触处的疲劳寿命及损伤状况等的分布,还绘制出了实验所用材料的寿命曲线与用有限元分析预测得到的寿命曲线的对照图,经过对照得出,有限元法可以比较精确地预测圆柱以及平板组成的接触系统中产生疲劳损伤的部位及疲劳寿命情况,进而能够帮助我们提高设计研发产品的效率,降低设计成本。针对圆柱与平板所组成的滑动摩擦接触系统,即给平板施以一水平运动速度v,其他条件保持不变,继续运用有限元法对其在承受静压载荷、周期性循环压载荷两种载荷下的接触疲劳问题进行了模拟仿真,并与静摩擦接触状态下的结果进行比较得到:在静摩擦接触系统中,接触区域的中心位置易产生疲劳破坏;而在滑动摩擦接触系统中,易产生疲劳破坏的部位是接触区域的导向边缘,而且在同样的外载荷作用之下,静摩擦接触系统比滑动摩擦接触系统更易发生疲劳破坏。本文所进行的相关研究以及所使用的研究分析方法、所得到的研究结果可以为圆柱、圆锥滚子轴承、火车铁轨等的接触疲劳相关问题研究可以提供一定的参考依据。
[Abstract]:In the real production and life, is a common contact problem between a cylinder and a plane, with practical application based, such as roller in cylindrical roller bearings with ring contact between the tooth parts of the contact and so on, this approach can effectively reduce the friction force, reduce the rotation torque. But this kind of contact way because the contact fatigue failure caused the reduction of the service life of the structure, thereby affecting the normal operation of mechanical equipment, especially for some high precision machinery and equipment, directly affect the machining accuracy of components. In this paper, according to the theory of contact mechanics knowledge, based on the contact fatigue problem between a cylinder and a plane, the analysis of the the problem is simulated and analyzed by using the finite element method, reveals the position of fatigue damage. Based on the contact relationship between cylinder and plate, set up mathematics The geometry model, and the calculation formula of contact fatigue stress is derived, surface mapping of each contact stress, finite element software is constructed based on cylinder and plate contact finite element model, and by using the finite element method of cylinder and plate static friction contact system is simulated under external static pressure load, draw contact with respective bearing cylinder and flat contact area of stress and deformation occurred in the distribution, and with the simulation results and theoretical analysis of the contact stress is calculated relative error, the finite element method of cylindrical and flat contact stress and strain analysis to get more reliable results, suitable. Also pointed out that the analysis of contact fatigue limitation using finite element method, pointed out the existence of error analysis and calculation The main reason of static friction contact system. According to the composition of the cylinder and plate, finite element method is applied to the simulation of the possible in the contact zone in the cyclic compressive loads of fatigue failure, distribution under test load at the contact fatigue life and damage condition of the forecast, also draw the comparison of the life curve of the material and life prediction curve obtained by finite element analysis, the control that finite element method can accurately predict the location of fatigue damage and fatigue life of contact system of cylindrical and flat panel consisting of, and can help us to improve the efficiency of product design and development, reduce the the cost of design. The sliding friction contact system for cylinder and plate, which is to impose a flat horizontal velocity V, other conditions remain unchanged, to continue to use The method of finite element under static load, the contact fatigue problem of cyclic load under two loads were simulated, and the static friction contact condition were compared with the results obtained in the static friction contact system, the center position of the contact area is easy to produce fatigue damage; while in sliding friction contact in the system, easy to produce fatigue damage is the site of the leading edge of the contact area, and under the same load, the static friction contact system than sliding friction contact system is more prone to fatigue failure. Research and analysis methods used in related research carried out in this paper, the research results can be cylindrical, tapered roller bearings, contact fatigue related problems such as the train tracks can provide some reference.

【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH123;O346.2

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