Influence of liquid sloshing on dynamics of flexible space structures

This study involved an analysis of the influence of liquid sloshing on the dynamics of flexible space structures with liquid on-board by considering the main body of a spacecraft as a rigid tank, the flexible appendages as two elastic beams, and on-board liquid as an ideal liquid. The meniscus of the free surface of the liquid due to surface tension was considered. The Lagrangians of the main body of the spacecraft (rigid tank), liquid, and two beams (flexible appendages) were used in addition to assuming symmetric motion of the system; the frequency equations of the coupled system were obtained by applying the Rayleigh-Ritz method. The influence of sloshing motion on the motions of the main body and flexible appendages of the spacecraft was investigated. The results indicated that the vibration characteristics of the coupled system were dependent on the static contact angle of the liquid, irrespective of whether the angle was larger/smaller than θ0=90°.