大型真空调试平台的结构设计及低温特性分析

发布时间：2018-02-27 09:32

本文关键词： 调试平台低温材料温度场瞬态热分析　出处：《哈尔滨工业大学》2013年硕士论文　论文类型：学位论文

【摘要】：大型真空调试平台设备是用于航天摄影测量技术的地面调试的关键设备，随着航天摄影测量技术的发展，测绘相机的尺寸和重量越来越大，对于位置精度的要求也越来越高，这就对地面模拟仿真设备提出了更高的要求。另外，调试平台要在真空环境下正常工作还要考虑真空下材料的问题。总之，对于大型真空调试平台的研制具有十分重要的意义。首先对大型真空调试平台的总体结构进行了总体设计，得到了大型真空调试平台的初步方案。大型真空调试平台是一个四维运动的调试平台，包括俯仰运动、升降运动、水平移动和方位调整运动。本文对它的俯仰运动和升降运动做了详细的设计，计算了俯仰轴的回转精度。本文设计了卸荷系统。为了验证结构设计的合理性，本文利用有限元法对结构进行了静力学和动力学的模拟仿真分析，分析了结构在有卸荷和无卸荷时两种情况下的应力和变形。此外，还对升降平台运动过程中的应力状态进行了分析。对整机结构进行了模态分析，得到整体模型的固有频率和各阶振型。对低温条件下的材料性能变化规律进行了理论分析，确定了大型真空调试平台的材料，并对这种材料低温下的线膨胀系数进行了实验测量，然后对材料的比热容和导热系数进行了拟合，，得到了低温条件下的性能参数，为真空调试平台的热分析做了充分准备。最后应用有限元法对大型真空调试平台的加热过程进行了瞬态热分析，得到整机模型的温度场分布随时间的变化规律。然后，将不同时间节点温度场加载到模型上得到热变形和热应力随时间的变化规律，通过对比不同的加热方式的温度场分布和热应力的大小得到最优的加热方式，为温控系统的设计提供理论依据。
[Abstract]:Large-scale vacuum debugging platform equipment is the key equipment for ground debugging of aerospace photogrammetry technology. With the development of aerospace photogrammetry technology, the size and weight of surveying and mapping cameras are becoming larger and larger, and the requirements for position accuracy are becoming higher and higher. In addition, in order to work normally in vacuum environment, the material in vacuum must be considered. In short, it is very important for the development of large vacuum debugging platform. First of all, the overall structure of the large-scale vacuum debugging platform is designed, and the preliminary scheme of the large-scale vacuum debugging platform is obtained. The large-scale vacuum debugging platform is a four-dimensional debugging platform, which includes the pitch motion, the lifting motion, the moving up and down. Horizontal movement and azimuth adjustment movement. In this paper, the pitching and lifting motions are designed in detail, and the rotation accuracy of the pitching axis is calculated. In order to verify the rationality of the structural design, the unloading system is designed in this paper. In this paper, the finite element method is used to simulate and analyze the static and dynamics of the structure, and the stress and deformation of the structure under both unloaded and unloaded conditions are analyzed. The stress state of the lifting platform is also analyzed, and the modal analysis of the whole structure is carried out, and the natural frequencies and vibration modes of the whole model are obtained. Based on the theoretical analysis of the properties of the material at low temperature, the material of the large vacuum debugging platform was determined, and the linear expansion coefficient of the material at low temperature was measured experimentally. Then the specific heat capacity and thermal conductivity of the material are fitted, and the performance parameters at low temperature are obtained, which makes a good preparation for the thermal analysis of the vacuum debugging platform. Finally, the transient thermal analysis of the heating process of the large-scale vacuum debugging platform is carried out by using the finite element method, and the temperature field distribution of the whole machine model is obtained. The variation of thermal deformation and thermal stress with time is obtained by loading the temperature field of different time nodes into the model. The optimum heating mode is obtained by comparing the distribution of temperature field and the magnitude of thermal stress in different heating modes. It provides theoretical basis for the design of temperature control system.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P236;TH703

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