基于频域子结构法的动量轮弹性边界微振动研究

Reaction wheel assembly (RWA) can have a structural coupling with the flexible installation interface of a satellite to cause the quantitative analysis of RWA micro-vibration being more complicated. Here, based on the frequency domain substructure method (FDSM), micro-vibration characteristics of a RWA-flexible interface coupled system were investigated. Firstly, FDSM was derived, and the interface coordinate transformation matrix was introduced to synthesize substructures under different coordinates. Secondly, the RWA model was simplified as a 12-DOF mass-spring-damper system, its equation of motion was deduced using Lagrange equation. Thirdly, the coupling system was divided into two substructures including RWA and flexible interface. Then the derived FDSM was adopted to synthesize frequency response functions (FRFs) of the two substructures to achieve the FRF matrix of the coupling system, it was used to calculate the system's dynamic responses. Finally, the numerical simulation and the multi-body dynamic one were done for the system to verify the system's dynamic responses obtained above. The results showed that FDSM is appropriate for predicting micro-vibration of the RWA-flexible interface coupled system and it has higher analysis accuracy and computation efficiency.