Structure Design Andanalysis Of Low Temperature Characteristics Of Large Vacuum Testing Platform

Large vacuum testing platform is the key equipment for ground testing spacephotogrammetry technology, with the development of space photogrammetrytechnology, and the size and weight of mapping camera is large, the position accuracyrequirements are increasingly high, the ground simulation equipment has put forwardhigher requirements. In addition, testing platform to work in normal vacuum materialissues to consider. In a word, has very important significance for the development oflarge vacuum testing platform.Firstly, the overall design of the overall structure of large vacuum testing platform,a preliminary scheme of large-scale vacuum testing platform to get. Large vacuumtesting platform is a four-dimensional motion platform, including the pitching motion,the lifting movement, horizontal movement and position adjustment movement. In thispaper, the pitching motion and the lifting movement on it to do a detailed design,calculation of the rotary accuracy of pitch axis. This paper designs the unloading system.In order to verify the structural design, the finite element method for structuralsimulation analysis of statics and dynamics analysis of the structure, the unloading andwithout unloading under two conditions of stress and deformation. In addition, themovement of the lifting platform process, analyzes the stress state. For the wholestructure of the modal analysis, the natural frequency of the whole model and thevibration mode was.On the material performance changes under low temperature conditions wasanalyzed, the large vacuum testing platform material was determined, and the materialunder low temperature linear expansion coefficient were measured experimentally, andthen the fitting of the materials of the specific heat capacity and thermal conductivity,performance parameters of low temperature conditions are obtained, made full for thethermal analysis of vacuum testing platform.Finally, the application of finite element method for the transient thermal analysisof the temperature control system of heating process of large vacuum testing platform,get the model of the temperature field distribution changes with time. Then, thedifferent time the node temperature field is loaded into the model to get the thermaldeformation and stress variation with time, the temperature distribution and thermalheating way comparison of different stress get the size of heating mode optimization,and provide a theoretical basis for the adjustment of the temperature control system.