Modal Analysis and Experiments of an Inflatable Space Structure with a Moving Mass

As the inflatable space structures are widely used in large space-based observation systems, the inflatable space structures with moving mass are in urgent need of research. In this paper, a complex rigid-flexible multibody system model is used to study the dynamics of the inflatable space structures with a moving mass. Firstly, an accurate dynamic model of the inflatable space structure with a moving mass is established based on the Absolute Nodal Coordinate Formulation (ANCF) and the Natural Coordinate Formulation (NCF). Then, the dynamic equation and characteristic equation of the inflatable structure in the rotating coordinate system are derived. The eigenfrequencies and the corresponding modal shapes of the spinning inflatable structure with a moving mass are obtained. The influence of moving mass position and the spinning speed on the vibration properties of the spinning inflatable structure are studied. Finally, an experimental platform for the inflatable structure with a moving mass is built. The first-order in-plane vibration properties of the inflatable structure with a moving mass are studied, which agree well with the simulation results.