大范围运动柔性索网多体系统动力学理论建模与仿真

Flexible cable nets usually have some common features such as complex constitutive relation, high tension stiffness, low bending and torsion stiffness, the geometry nonlinear deformation during their motion is large and the interaction among yarns is complex, and the entanglement of yarns may occur during the motion of flexible textiles, which will bring a great challenge on their dynamics modeling and numerical simulation. The flexible textiles are considered as the reasearch object,the equivalent force models and their applicable conditions will be studied,and the parameter database of cable nets made of common materials will be established,the modeling methods of flexible cable nets dynamics and numerical algorithms are studied, the contact point searching algorithms, the switch conditions and simulation methods of impact dynamics of flexible cable nets will be developed, the entanglement mechanism of cable nets will be explored. The folding techniques of space large mesh antenna with anti-entanglement of cable nets will be obtained as the engineering. and the software of dynamics simulaiton and entanglement evaluation of flexible cable nets will be depleped. After the project would be accomplished, the knowledge on the multibody dynamics modelling and simulation for the complex system with many freedoms will be added.The project research will help to add the knowledge on the multibody dynamics modelling and simulation for the complex system, and the ability of the design,analysis and anomaly management spacecraft with large deployable mesh structure will be enhanced.

柔性索网具有材料本构关系复杂、抗拉刚度大与抗弯刚度极低等特点，其运动过程几何非线性变形大、纤维间相互作用关系复杂，甚至可能发生缠绕，这些给柔性索网动力学理论建模与仿真带来了极大挑战。本项目以大范围运动柔性索网为研究对象，研究探索柔索等效力学模型及各类柔索力学模型的适用条件，建立空间常用柔索材料等效力学模型参数库，以此为基础研究柔性索网动力学建模方法和仿真算法，开展空间大范围运动柔性索网接触点搜索、碰撞瞬时切换条件及碰撞动力学全局仿真方法，探索大变形柔性索网空间大范围运动缠绕机理，并以空间大型可展开网面天线为背景，突破其在轨展开过程防索网缠绕折叠技术。在以上研究基础上，开发基于参数化的空间大型柔性索网动力学仿真与缠绕特性评估软件。该课题研究不仅可为大自由度复杂系统动力学问题理论建模和数值仿真积累经验，而且对于提升我国带大型可展开网面结构的航天器设计、分析和故障预案处理水平均有重要价值。

本项目以大范围运动柔性索网为对象，结合带大型空间网面天线航天器设计和空间飞行器在轨维护与服务需求，深入开展了网索与织物动力学理论建模、柔性索网桁架耦合动力学建模、网索与刚体及网索间接触碰撞动力学理论建模和相应数值算法研究工作，开发了带有大型桁架的索网多体动力学软件和预张力柔性索网热致振动仿真等软件，并将索网天线展开动力学仿真与在轨测试数据进行比较，验证了建模理论和软件的正确性。研究期间，解决了基于力元的柔性绳索拓扑关系描述方法和前处理技术，有效提高了计算效率，突破了刚体、小变形弹性体和大变形柔性索网耦合动力学建模方法，实现了基于混合坐标的刚体、小变形弹性体和基于绝对坐标的大范围运动柔性索网动力学耦合动力学建模理论，并结合实际工程应用需求，提出了多时间积分步长和矩阵分割桁架索网耦合动力学求解方法，兼顾能量守恒和计算效率，通过与在轨摄影测量结果比较，进一步验证大范围运动索网动力学模型有效性。解决了基于动力阻尼的静平衡构型快速计算问题，重点分析了GEO轨道卫星热致振动对天线预张力网面精度的影响，建立天线表面精度影响因素误差链；突破了大变形柔性绳索间及其与刚体、小变形弹性体间快速接触搜索技术，建立了基于弹簧阻尼模型接触力模型。突破了带大范围运动柔性索网空间飞行器多体动力学软件设计技术，实现了计算机图形演示、轨道动力学、姿态控制与带大变形柔性索网多体动力学软件的功能集成，为我国后续带更大口径网面天线航天器总体设计和带飞网空间飞行器在轨维护与服务重大科技专项实施提供有力的分析仿真工具。