The Study On The Structure Of The Upper-stage For Launch Vehicle

The upper-stage is an individual stage added on the base of launch vehicle, whichis of effective task adaptability. The working part of upper-stage can do slidding、orbit-transfer、effective load distribution on the earth orbit. These actions are the effectiveapproach to improve the performance and task adaptability of launch vehicle. Theupper-stage is be able to provide multi-times startup、long-time work、independentfight. It sends the satellite to the scheduled orbit through the way of the combination ofa launcher and a satellite or a launcher and muti-satellites. Besides, it is also be able tosend the satellite into the higher orbit directly. The upper-stage can not only launchmuti-satellites, but also being used for multiple independently targeted reentryvehicle(MITRV). Therefore, it is of great significance to improve the national defenceand aerospace technology of our country.Based on analysis of domestic and foreign similar technology and product statusand development trend, this article make a needs analysis. Meanwhile, according to theoverall structural strength, stiffness, interface requirements and upper stage overalllayout, it make a splitter structural design. For the purpose of reducing structural massand increasing structural frequency, and taking crafts, simulation analysis of strength,stiffness and the modal into consideration, it decided to apply carbon fiber compositesto ‘#’ beam and variable cross-section, high-span joist. Forward tapered and invertedcone used in compartment housing support is analyzed. Compartment housing supporttaking forward tapered is even by force, excellent in dynamic characteristics and light inmass compared with inverted cone. Conical structure and cylindrical structure used inCompartment housing support is analyzed. Conical structure has a higher first-orderlateral vibration frequency and lighter mass compared with cylindrical structure. Three-dimensional modeling tool, strength analysis method, engineering algorithm and FiniteElement Method are used in optimization design of compartment housing support coneangle and strengthening head structure. Structural strength and stiffness of the localsplitter is verified through two different loading methods. Structural systemperformance can meet the design requirements under the combined effect of the axialpressure, bending moment and shear force.After a full analysis and principles of experimental verification, splitter structurecan meet the overall requirements of performance index and make a technicalfoundation for further study.