科研之友
微信
新浪微博
Facebook
分享链接
摘要
In order to accurately predict the dynamic response of a lunar lander during its landing process, a dynamics model for the lunar lander is built using the nonlinear finite element method. This method considers comprehensively various nonlinear factors but is time consuming. Aiming at solving this disadvantage, the generalized dynamic reduction (GDR) method is adopted to build an order reduced model for the center body of the lunar lander which takes into consideration the lander's local nonlinearities and a new modal truncation criterion is proposed based on the impulse response function. By means of this criterion, the acceleration of the center body can be characterized by selecting just a few normal modes with high model influence coefficient (MIC) based on GDR method, this further reduces the order of the center body. In a case study on soft landing dynamics, the order reduced center body is jointed with the nonlinear landing gear. Compared with the original non-reduced FE model, up to 75.5% computational time is saved using the modal truncation criterion while the relative peak error of acceleration is kept below 5%. From the results it can be concluded that the GDR method works excellently for enhancing the simulation efficiency of lunar landing and the proposed criterion has the advantage of solving modal-denseness systems with independence of input and output.
- 出版日期2014
- 单位北京理工大学
