Dynamics and experiments of an inflatable tri-boom system

Inflatable structures have gained significant attention in aerospace engineering due to their lightweight, compact, and highly deployable design. However, their complex on-orbit dynamic behavior poses huge challenges for theoretical simulation and experimental validation. In this paper, a new integrated framework including orbital dynamic model of a rigid-flexible multibody system and micro-gravity ground experiments is proposed to study the dynamic behavior of an inflatable tri-boom system. Initially, by integrating absolute nodal coordinate formulation (ANCF) with equivalent beam theory, high computational efficiency is achieved while predictive accuracy for on-orbit behavior is maintained. To validate the dynamic model, a micro-gravity ground experimental system for the structure is established to simulate key dynamic conditions encountered in space, including micro-gravity and Coriolis force disturbances, which are achieved by air bearings and distributed eccentric rotor devices. This setup not only verifies the accuracy and reliability of the dynamic model in terms of modal characteristics and on-orbit dynamic responses, but also makes the experimental design applicable to other large spinning space structures. On this basis, taking an on-orbit inflatable tri-boom system with a baseline of 100 m as an example, the dynamic responses, attitude variation and space alignment between the sub-satellites under spinning motions are analyzed. Furthermore, the influence of the spinning angular speed and inflation pressure on the out-of-plane vibration is also investigated. The results provide fundamental advances for its optimization design and control strategies in space environments.