【作者】 王立国；

【导师】 王本利；

【作者基本信息】 哈尔滨工业大学 ， 飞行器设计， 2006， 硕士

【摘要】 空间展开桁架结构属于多体动力学研究范畴,本文利用Lagrange乘子法建立多体动力学方程,通过ADAMS和I-DEAS建立空间展开桁架的多体动力学仿真模型,进行仿真计算。首先,对一带有铰接间隙的空间展开桁架利用ADAMS进行建模仿真。通过对有无铰接间隙的刚性空间展开桁架模型的计算结果比较,说明铰接间隙的存在对于桁架展开过程的影响及这一过程对卫星的姿态角速度的影响,同时比较了有无铰接间隙时铰接处在展开过程中接触力的变化。其次,对一空间展开桁架建立了多柔体动力学模型并进行仿真计算。利用I-DEAS对桁架单元的模态进行计算,生成模态中性文件,然后将其输入到ADAMS/FLEX里与卫星组成柔性空间展开桁架结构模型,进行展开桁架的多柔体动力学仿真计算。文中给出了展开前后的动力学固有特性;对展开过程中分别为刚性桁架和柔性桁架两种情况进行了仿真计算,对比了两种情况的桁架展开过程中卫星姿态角及姿态角速度的变化;比较了柔性桁架不同展开速度对卫星姿态角及姿态角速度的影响;分析了柔性桁架展开过程对卫星非展开方向的姿态角度及角速度的影响及原因;对柔性桁架展开过程中及展开锁定后的卫星姿态角速度的变化曲线进行快速傅立叶变换,得到柔性桁架展开过程即展开锁定后卫星姿态角速度的频幅特性曲线。最后,对空间展开柔性桁架进行运动稳定性进行分析。根据无扰运动的稳定性定义,通过对卫星在不同初始姿态角速度下及受到力矩脉冲作用下展开时卫星的姿态角速度的影响的比较,说明在这两种初始扰动下桁架的展开运动的稳定性情况;对不同驱动角速度下桁架展开的仿真结果比较得到该桁架的失稳条件。更多还原

【Abstract】 A spatial deployable truss structure was studied by the ways of multibody dynamics. The equation of multi body dynamics was set up with the Lagrange multiplier method and the dynamics simulation models of deployable truss structures were built by ADAMS and I-DEAS.Firstly, a rigid spatial deployable truss system with joint clearance was simulated with ADAMS. By comparing the ideal joint and clearance joint for the deployment process of a spatial deployable truss structure in multibody dynamics, it is found that the existence of the joint clearance makes the movement discontinuous, and also found the attitude angle degree and angle velocity of the spacecraft are affected in the deployment for the joint clearance. The contact forces in the joint increase as the same reason.Secondly, a flexible spatial deployable truss system was simulated in the combination of ADAMS and I-DEAS software. The modal neural files (MNF) derived from I-DEAS modal solution were imported into the ADAMS/FLEX. Then the flexible multi body dynamics simulations of the deployable truss system were carried on when the truss is assembled with a spacecraft. The dynamics characteristics of the truss in the moment of folded state and completely deployed state were listed.The rigid and flexible trusses were simulated respectively. The dependences of the attitude angle degree and angle velocity of the spacecraft on the rigid and flexible situation in the deployment process and drive velocities loaded on the joints were derived. The frequency-amplitude characteristic curves were gained from the attitude angle velocity curves of the deployment of the flexible truss and locked flexible truss after deployment through the Fast Fourier Transition (FFT) method.Finally, the motion stability of the flexible deployable truss mentioned before was analyzed. According to the definition of motion stability, the simulation results under the conditions of different initial attitude angle velocities and pulse torque function indicate that the deployment motion of flexible truss under these initial distortions was steady. The drive angle velocity of deployment更多还原