Launch Vehicle Dynamic Modeling and Mode Shape Slope Prediction Technology
- Paper number
IAC-11,C2,3,13,x10455
- Author
Dr. Zhongwen Pan, Beijing Institute of Astronautical Systems Engineering, China
- Coauthor
Prof. Yufeng Xing, China
- Year
2011
- Abstract
With the increase of structure dimension, circumferential differences at assembly position of sensitive components (e.g. rate gyroscope) have been more and more significant. Based on traditional equivalent beam model, only whole modal information of launch vehicle could be obtained, and effects of partial shape and corresponding slope couldn’t be reflected with the model. Therefore, whole launch vehicle dynamic characteristic experiment has been always an important way to obtain the partial shape and the slope. However, the experiment needs huge outlays for hardware manufacture and test, and would make important effects on development progress. Hence, how to improve the accuracy of partial shape slope prediction at assembly position of sensitive components becomes a significant subject in system design of launch vehicle. Detailed modeling method for partial configuration has been proposed based on equivalent beam model to predict partial shape and corresponding slope at the assembly position of rate gyroscope, which is concerned in design of attitude control system. With the proposed method, researches on subjects such as circumferential distribution pattern of partial shape and slope at rate gyroscope assembly position as well as effect of stiffness change near the hatch on the shape and slope have been carried out. By building three-dimension finite element model of typical segments in launch vehicle, carrying out dynamic characteristic analysis of a whole launch vehicle and relevant validation test, we get conclusions as below: 1) Obtained partial shape and corresponding slope are correct and could meet requirements of engineering design; 2) In the same section, circumferential difference is small in mode shape but large in mode shape slope; 3) Circumferential discontinuity of stiffness, which is induced by the hatch, has significant effect on mode shape slope. Hence, attitude sensitive components (e. g. rate gyroscope) are not recommended to locate at the position of hatch.
- Abstract document
- Manuscript document
(absent)