Dynamic Modeling and Stability Analysis of a Large Rigid-Flexible Space Structure under Gravity Gradient
Zibo Luo, Jialiang Sun
Abstract：Due to the coupling effects of the attitude and orbital dynamics, the gravity gradient of a large rigid-flexible space structure may have a great influence on its stability and on-orbit operations. In this paper, the gravity gradient stability of a large rigid-flexible space structure is numerically studied under both small and large disturbances. Based on the flexible multibody dynamics and orbit dynamics, an accurate dynamic model for the large space structure is established via the combination of natural coordinate formulation (NCF) and absolute node coordinate formulation (ANCF), which is able to describe the large overall motions and large deformations of the flexible structures. Furthermore, the gravity gradient stability of the large space structure is simulated and analyzed via various numerical cases, including the influence of disturbance angle magnitudes and moments of inertia of the space structure. The results reveal that the stability behavior under large disturbances deviates from classical criteria and is significantly affected by the inertia distribution. Additionally, the relationship between the spinning stability and the gravity gradient stability is investigated for a large rigid-flexible spinning space structure. Moreover, for Earth-pointing configurations under directional constraints, the inherent static deformations are identified as a source of intrinsic instability, which can accumulate over time even in the absence of external disturbances. Furthermore, the dynamic characteristics of constrained spinning structures are examined, highlighting the role of out-of-plane deformation and constraint moments in the overall system stability.
文章链接：https://www.sciencedirect.com/science/article/pii/S1007570426008889
