Research Of Viscous Fluid Damping Isolator Used In Space

In order to suppress the disturbance of space optics load caused by the satellite,there is a need for optical payload isolation design. Passive vibration isolationtechnology is widely used in the aerospace field because of its high reliability andexcellent isolation effect. This paper designed a viscous fluid damper used in space,which could be sealed reliably and adapted the space environment well.First it introduced the development of the isolator at home and abroad and therelated theories, then calculated the structural parameters of the isolator according tothe demand of space optical remote sensor isolation. A spring sheet with threedirections stiffness was designed. It used finite element method to study several keyparameters which influence the spring stiffness-thickness, arc number and arc radius.The isolator damping force calculation model was created according to the relevanttheory of fluid mechanics. It also researched how the length of the orifice, the orificeradius and the viscosity of the fluid influence the damping coefficient. On the basis ofthe isolator stiffness and damping coefficient, the isolator structure design wasfinished with full consideration of the crafts, sealing, oiling and other issues.Then apply the isolator to1m diameter camera vibration isolation system andthe positioning arm isolation system. Build its finite element model to get the first sixmodal and transfer rate curve by modal analysis and frequency response analysis. Thesimulation results show that the vibration attenuation rate is more than60%when thevibration frequency is higher than20Hz.The isolator was also used in the positioning arm for optical facilities movement compensation. According to the simulation results,the system’s swing frequency can be controlled within1Hz, which can effectivelysuppress the amplitude of the optical facilities.Finally use hammer percussion method to test the isolator performance atdifferent orifice diameters, different damping fluid viscosity and differentconfigurations. In addition, modal analysis of the isolator-mass system was made toget the first three modes and compare it with the experimental results. According tothe results we can see that the error between experimental results and the finiteelement simulation results is controlled within4%. After data processing it could getthe numerical value relationship between viscosity and viscous fluid damping lossfactor, whereby we can design the expectant isolator stiffness and damping with lesstime and costs.