Modeling and Optimization of Octostrut Vibration Isolation Platform by FRF-Based Substructuring Method

Abstract

This paper addresses dynamic modeling and performs optimization of a passive multistrut vibration isolation platform (VIP) in vibration isolation for an assembly of control moment gyroscopes (CMGs). Each strut of the VIP is composed of a metal rod and a three-parameter isolator in series. First, the frequency response function (FRF)–based substructuring method was developed to establish the dynamic model of a whole satellite system. This method can take into account the influence of the flexibility of the satellite bus and the CMG assembly as well as the gyroscopic effects of CMGs. Then, an optimization model was developed, and the FRF-based sensitivity analysis was employed to optimize the characteristic parameters of a strut under two objective functions. Finally, a numerical model was developed to verify the validity and effectiveness of the proposed method. The dynamic characteristics of an octostrut VIP were analyzed. The isolation performance was greatly enhanced after optimization. This study shows that the method is an effective and efficient tool that can be used in the design phase of VIPs.