Dynamics Design Of Oversized Load Whole-spacecraft Vibration Isolation Systems

Oversized load satellite has many features，such as the big structure size，huge mass，largedeflection which lead the natural frequency to be low-ordered,compacted and the problem ofthe closed modes happen. The appearance of the closed modes brings extremely detrimentaleffects for the vibration isolation of the whole-spacecraft isolation systems.For the closed modes system, the traditional ways for designing the vibration isolator arenot satisfied by the demands of the isolation, since the kinetic parameters are not optimizedfor all the frequency in the closed modes.In this paper, the dynamics design of oversized load whole-spacecraft vibration isolationsystems is discussed.First of all, the judgment method of closed modes for the oversized load satellite is presentby formulating the analytical method in the closed modes dynamic system.In addition, based on the classical constitutive relationship model and the mechanicalproperties of the viscoelastic materials, a new constitutive function is derived for the pressclose to the actual structure. The feature changes in relations of viscoelasticdampingmaterialbetween the temperature and frequency are on show and the actual parameters are measuredby designing a new experimental equipment.Then the optimization model of the kineticsparameters for the isolation are given by theoptimaldesigntheory.And the kineticsparameters for the isolation are optimized and analyzedfor the effect of the optimization design. The isolator parameters of the closed modes dynamicsystem are modified.At last, the finite element model of the oversized load satellite and the isolation are founded.By dynamic analyzing and optimization designing for the isolator, the axial response ofmagnitude of transmissibility can fall about40%.