59940 - Design, Optimization and Experimental Verification of a Metal Rubber Isolator for Momentum Wheels 

The inertial actuator, such as momentum wheels, is the key mechanical component of spacecraft for attitude stability and accuracy maintenance. However, it is also the main excitation source affecting the spacecraft payload accuracy. With the increasing demands of spacecraft for precision and stability, isolating vibrations of momentum wheels must be considered.

Metal rubber (MR), also known as entangled metallic wire material, is a kind of porous functional damping material, manufactured through the process of entangling, stretching, weaving and molding of metallic wires. With its excellent mechanical properties of high damping, designable stiffness and environmental adaptability, MR is widely used in the area of aerospace and aviation for vibration isolation.

To this end, a method to design and optimize a metal rubber isolator is developed. The MR isolator consists of a squirrel-cage spring and metal rubber in parallel. A FEM model coupling the squirrel-cage spring and the simplified momentum wheel is established to assist in the design and optimization of the configuration of the spring, and the goal is to minimize the frequency bandwidth of the first six modes. The influence of the structural parameters of the spring on the frequency of the first six modes is also discussed. The MR is then designed to provide stiffness and damping. The stiffness and damping coefficients of the MR isolator are obtained by the quasi-static compressive experiments. Finally, the performance of the MR isolator is verified through both sine-sweep vibration experiments and random vibration experiments.