Optimization of Vibration Isolation Mounts With Internal Rotation in Response to Shock Type Inputs

The design of isolation mounts is of critical importance in the protection of structures and sensitive equipment from damage or failure. Simultaneous protection from both shock and vibration is particularly challenging because of the broadband nature of the input signal and because of the deleterious effect of damping on high-frequency isolation. Prior work by the authors has shown that chains of translating and rotating mass/spring elements can act as a “mechanical filter” for input disturbances. If designed correctly, the isolator is able to trap some of the input energy into rotational vibration, preventing it from damaging the structure. However, in finite-length chains, wave reflections can result in secondary pulses that hit the structure and can diminish the effectiveness of the isolator. In this paper, the design of dynamic isolation mounts is improved using an optimization technique. Numerical simulations are performed using a parametric model of the new mount design. The simulated annealing optimization algorithm is used to determine the optimal system parameters for a given chain length. It is shown that the optimized system is able to achieve significant performance improvements. It is also shown that dynamic mounts that allow rotational movement of internal elements outperform optimized purely translational-motion systems.