Passive vibration suppression of large space truss structures by viscous damping

Abstract

Viscous damping methods are commonly employed to suppress the vibration due to their simple design, low cost, and stable damping performance. However, the harsh space environment makes the normal viscous dampers suspicious to various failures. This paper proposes a novel and robust design of viscous damper to provide high damping under low-frequency vibration disturbance in space. The characterisation of the damper at low-frequency and large displacement is first investigated by numerical analysis and then validated by experiments. Based on the results of the damper, this paper presents an optimal design strategy for the damping system of large space truss structures, which is critical for space mission because there is no sufficient damping in such space structures. The design is further optimised by weighted-sum that includes the damping characteristics of dampers and elastic flexibility of space truss structures. The effect of the damping system is demonstrated by the optimal design of a 60-bay truss structure. The results show that the damping ratios of the first three modes of the truss structure can be increased by over 10% with two viscous dampers. Comparisons between the structure with and without dampers demonstrate that significant vibration suppression at low-frequency bandwidth can be achieved satisfactorily.