考虑非线性变形的航天器柔性附件建模方法

针对航天器的柔性附件,将其简化为常见的大范围运动空间柔性梁结构。根据柔性体的非线性变形原理,考虑了弯曲和扭转的非线性因素的影响,在柔性梁的三个变形方向上均考虑了变形的二次耦合项。利用有限元方法进行离散并用Lagrange方程建立了非线性变形模式下的动力学方程,包含了较为完全的刚度矩阵和各种耦合项。对一大范围运动的空间梁进行了仿真计算,表明在运动速度较大并且基座具有大范围运动时,一次耦合模型与本文模型有一定差异,且初始变形对两种模型也会产生影响。

Dynamic Modeling for Flexible Spacecraft Appendages with Nonlinear Deformation

A simplified flexible spatial beam simulating spacecraft appedages with overall motions is investigated.Considering the geometrically nonlinear effect resulting from curved and twisted deformations,the coupled terms of deformations in the longitudinal,lateral and transversal directions are taken into account.3D-finite element shape functions of a beam element are adopted for deriving the coupled dynamical formulas.where the complete expressions of stiffness matrix and all couplied terms are included.The simulated results of a flexible special beam fixed on a rigid base illustrate that the model differs from one-order coupled dynamical model as the velocity of rigid base and the initial deformation increase.