大型射电天线轮轨接触力学分析

发布时间：2018-03-24 08:30

本文选题：大型天线座　切入点：轮轨　出处：《杭州电子科技大学》2013年硕士论文

【摘要】：射电天文学的发展，使射电望远镜得到了越来越广泛的应用。随着射电天线规模、重量越来越大，轮轨接触副在重载荷作用下接触变形，会影响天线轨道的水平度和天线指向精度。因此对大型射电天线轮轨系统的接触力学分析、运行仿真分析和现场测量具有一定的工程应用意义。本文首先从非赫兹接触理论入手，建立了大型射电天线轮轨非赫兹弹塑性接触力学模型。从理论上对天线轮轨的载荷、接触应力、接触变形等方面进行了全面分析，得到了天线滚轮与轨道接触区的接触应力分布，并给出了轮滚接触应力的数值解，为轮轨接触仿真分析中参数设置提供精确的指导，并为仿真模型的简化提供理论支持。其次，在理论分析的基础上，运用Msc.Patran有限元分析软件建立了天线轮轨接触力学仿真模型，分析了轮轨接触区的接触载荷分布、应力分布、应变以及变形情况。针对轨道弹塑性接触应力和变形随轮轨接触区到轨道接缝距离变化这一情况，建立了大型天线轨道接头处轮轨弹塑性接触有限元模型并进行分析计算。最后，通过对国家天文台五十米口径射电天线轮轨接触变形的现场测试，进一步验证仿真模型和非赫兹弹塑性接触理论的准确性，主要包括：提出一种天线座轨道水平度偏差测量方案，利用高精度数字全站仪测量系统对轨道面进行了现场测试，提出一种可行的轨道水平度调整方法；针对轨道接头处刚度不足，易引起射电天线指向精度下降这一问题，探索了一种现场测试方案，，对靠近轨道接头不同距离的接触情况，进行测试。通过测试，初步得到了天线轮轨低速运行时实际的接触变形量，同时也验证了仿真分析模型与测试方法的准确性。本文所建立的轮轨接触力学分析模型，有利于天线轮轨非赫兹接触问题的深入研究与现场测试，为大型轮轨式天线座架设计提供一定的参考与指导。
[Abstract]:With the development of radio astronomy, radio telescopes are more and more widely used. It will affect the flatness of antenna track and the precision of antenna pointing. Therefore, it has a certain engineering application significance for the contact mechanics analysis, running simulation analysis and field measurement of the large radio antenna wheel-rail system. Based on the theory of non-hertz contact, a non-Hertz elastoplastic contact mechanics model of large radio antenna wheel / rail is established in this paper. The load, contact stress and contact deformation of antenna wheel-rail are analyzed in theory. The contact stress distribution between the antenna roller and the track contact region is obtained, and the numerical solution of the wheel roller contact stress is given, which provides accurate guidance for the parameter setting in the wheel-rail contact simulation analysis, and provides theoretical support for the simplification of the simulation model. Secondly, on the basis of theoretical analysis, the simulation model of wheel-rail contact mechanics of antenna is established by using Msc.Patran finite element analysis software, and the contact load distribution and stress distribution in wheel-rail contact area are analyzed. The finite element model of elastic-plastic contact between track and track is established and calculated according to the change of elastic-plastic contact stress and deformation with the distance from wheel-rail contact zone to rail joint. Finally, the accuracy of the simulation model and the non-Hertz elastoplastic contact theory is further verified by field testing of the wheel / rail contact deformation of the 50-meter aperture radio antenna at the National Observatory. The main contents are as follows: a measurement scheme of track flatness deviation of antenna pedestal is put forward, the track surface is tested by high precision digital total station measuring system, and a feasible method of adjusting track flatness is put forward. Aiming at the problem that the stiffness of the rail joint is insufficient and the pointing precision of the radio antenna tends to decrease, a field test scheme is explored. The contact conditions near the rail joint at different distances are tested. The actual contact deformation of the antenna wheel-rail running at low speed is preliminarily obtained, and the accuracy of the simulation analysis model and the test method is also verified. The wheel-rail contact mechanics analysis model established in this paper is beneficial to the further research and field test of the wheel-rail non-Hertz contact problem of antenna, and provides some reference and guidance for the design of large wheel-rail antenna seat frame.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P111;TN820

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