Parametric Model Method and Deployment Simulation of Inflatable Antenna Structures

ABSTRACT: In this paper, we develop a parametric model method and simulate the deployment mechanism of inflatable antenna structures. Different folded methods are developed for the primary members of inflatable antenna structures, which include inflatable tubes, an inflatable torus, a reflector etc. The unstressed configuration and the folded configuration of these members are modeled parametrically using the developed folded methods. A simulation software is developed for the deployment mechanism of inflatable structures by the improved spring-mass system. The driving forces in the deployment process, i.e. the gas pressure and the moment of the fold hinges, are analyzed for each member. During the development process, self-contact or collision with the membrane occurs. A rule for identifying self-contact elements is applied, and a penalty function method is developed to solve this challenging problem. Finally, the equation of motion is solved using finite difference method. The developed simulation software is validated by simulating a cylindrical inflatable tube that is folded in half, and the simulation agrees well with the experiment. The deployment mechanism of the antenna model similar to that for the Inflatable Antenna Experiment (IAE) is modeled, analyzed and estimated. The deployed configurations and the dynamic parameters of each node are obtained. The numerical simulation results show that the simulation software for the deployment mechanism can correctly predict the deployment process of inflatable antenna structures.

摘要：本文提出一种参数化建模方法，对充气天线结构（inflatable antenna structures）的展开机制开展仿真研究。针对充气天线结构的核心构件，包括充气直管、充气环形构件、反射面等，设计了多种折叠方式。基于所提出的折叠方法，对各构件的无应力构型与折叠构型进行参数化建模。基于改进弹簧-质点系统，开发了一款面向充气结构展开机制的仿真软件。针对各构件，分析了展开过程中的驱动力，即气体压力与折叠铰链的力矩。展开过程中会出现构件自接触或与膜材碰撞的问题，本文采用自接触单元识别规则，并提出罚函数法以解决该棘手问题。最终通过有限差分法求解运动方程。通过对半折叠圆柱充气直管的仿真验证了所开发仿真软件的有效性，仿真结果与实验数据吻合良好。针对类似于充气天线实验（Inflatable Antenna Experiment, IAE）所用天线模型的展开机制，开展建模、分析与参数预估，获取了展开构型与各节点的动力学参数。数值仿真结果表明，所开发的充气结构展开机制仿真软件可准确预测充气天线结构的展开过程。