双金属复合弹性体摩擦性能研究

发布时间：2018-11-13 18:56

【摘要】：高速轮轨轴承、航空发动机轴承以及重型装甲车辆轴承等高副构件被要求在高温环境下,具有较高的稳定性、较大的承载能力以及较长的使用寿命。单一材料的使用工作性能早已不能满足现代工业中机械零件的加工使用要求。重载作用直接增加高副零件接触位置的接触压力,同时由于高温的作用,润滑介质黏度下降,致使油膜承载能力降低,接触表面润滑介质容易破坏,因此高温重载下的高副接触零件使用寿命不长,过早出现疲劳磨损破坏,这种破坏是不可逆的。本课题研究两种不同弹性模量金属材料复合组成高副弹性体,通过设计弹性体弹性模量外高内低的形式,增大构件整体接触变形能力。在相同载荷下,且双金属复合弹性体外层金属与单一材料高副构件相同材质时,双金属复合弹性体的真实接触面积更大,可有效的减小接触压强,对接触表面起到减摩抗磨的作用以及润滑介质的保护。课题研究的主要内容如下:(1)基于经典赫兹接触理论,探究3种不同弹性模量属性的金属材料对圆柱体接触性能的影响,进而提出双金属复合弹性体的设计理念以及设计方法,通过摩擦构件组成材料弹性模量外高内低的形式,提高构件接触变形能力,改善接触构件整体接触性能。(2)利用ANSYS有限元仿真软件,建立了平行圆柱接触有限元模型。通过单因素法对比分析了不同法向载荷作用下,单一材料平行圆柱体接触压力和接触变形的有限元模拟值与赫兹接触理论值,验证有限元模型建立的合理性和有限元方法分析平行圆柱接触问题的可靠性。(3)进而建立不同弹性模量双金属复合弹性平行圆柱体接触有限元模型,在相同载荷下,分析外层金属厚度和内外层金属弹性模量配比等单一因素对双金属复合弹性体接触性能的影响。对比分析单一材料高副构件与双金属复合弹性高副构件的接触性能,验证双金属复合弹性高副构件具有更好的接触性能。(4)针对平行圆柱接触分析,设计适合本文几何模型的平行圆柱接触摩擦试验机构,简述了动力部件和加载机构中主要部件的选择,并对受力构件进行强度分析。对比多组单一材料平行圆柱体摩擦磨损试验结果,验证本文设计的平行圆柱摩擦磨损机构具有较好的运行平稳性、试验的可靠性以及试验的重复性。(5)通过试验分析验证外层金属厚度对不同弹性模量双金属复合弹性体接触性能的影响。双金属复合弹性圆柱体相比单一材料平行圆柱体磨痕宽度较大,磨损量较小。说明较大的磨痕宽度不是磨损过深产生的,而是接触变形引起的。双金属复合弹性圆柱体内外层金属的弹性模量配比越高,复合弹性圆柱体接触性能越好。
[Abstract]:High-speed wheel-rail bearings, aeroengine bearings and heavy-duty armored vehicle bearings are required to have higher stability, larger bearing capacity and longer service life under high temperature. The working performance of single material can not meet the requirements of machining and application of mechanical parts in modern industry. The heavy load directly increases the contact pressure of the contact position of the high pair parts. At the same time, the viscosity of the lubricating medium decreases due to the effect of high temperature, resulting in the reduction of the oil film bearing capacity and the easy destruction of the lubricating medium on the contact surface. Therefore, the service life of high contact parts under high temperature and heavy load is not long, and fatigue wear failure occurs prematurely, which is irreversible. In this paper, two kinds of metal materials with different modulus of elasticity are studied to form high pair elastomer. By designing the form of high and low elastic modulus outside, the contact deformation ability of member is increased. Under the same load, and when the outer metal of the bimetallic composite elastomer is the same as the high pair member of a single material, the true contact area of the bimetal composite elastomer is larger, which can effectively reduce the contact pressure. It can reduce friction and wear on the contact surface and protect the lubricating medium. The main contents of the research are as follows: (1) based on the classical Hertz contact theory, the effects of three kinds of metallic materials with different elastic modulus properties on the contact properties of cylinders are investigated. Furthermore, the design concept and design method of bimetallic composite elastomer are put forward. Through the form of high elastic modulus and low internal elastic modulus of friction member, the contact deformation ability of the member is improved. (2) the finite element model of parallel cylindrical contact is established by using ANSYS finite element simulation software. The contact pressure and deformation of a single material parallel cylinder under different normal loads are compared with the Hertz contact theory by single factor method. The rationality of the finite element model and the reliability of the finite element method to analyze the parallel cylindrical contact problem are verified. (3) the contact finite element model of different elastic modulus of bimetallic composite elastic parallel cylindrical contact is established, and under the same load, The effects of the thickness of outer metal and the ratio of elastic modulus of inner and outer layers on the contact properties of bimetallic composite elastomer were analyzed. Comparing and analyzing the contact performance between single material high pair and bimetallic composite elastic high pair, it is proved that bimetallic composite elastic high pair has better contact performance. (4) for parallel cylindrical contact analysis, A parallel cylindrical contact friction test mechanism suitable for the geometric model of this paper is designed. The selection of main components in the dynamic component and the loading mechanism is briefly described, and the strength analysis of the bearing member is carried out. By comparing the friction and wear test results of parallel cylinder with single material, it is proved that the parallel cylinder friction and wear mechanism designed in this paper has a good running stability. The reliability of the test and the repeatability of the test. (5) the influence of the thickness of the outer metal on the contact properties of bimetallic composite elastomer with different elastic modulus was verified by the experimental analysis. Compared with single material, the wear scar width of bimetallic composite elastic cylinder is larger than that of single material parallel cylinder, and the wear amount is smaller. It shows that the larger abrasion width is not caused by excessive wear, but by contact deformation. The higher the ratio of elastic modulus of bimetallic composite elastic cylinder is, the better the contact property of composite elastic cylinder is.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB331

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