SHOCK AND VIBRATION ISOLATION USING DYNAMIC MOUNTS WITH INTERNAL DAMPING

Shock isolation systems are often modeled as having lumped stress and damping characteristics. However, the isolation performance may be improved if the isolation mount is allowed to have internal dynamics. Previous work has considered several different ways of disrupting the disturbance as it propagates along the length of a multi-degree-of-freedom mount. In this paper, the role of internal damping of the mount is re-examined. Furthermore, the damping model is extended to allow different levels of damping in different response regimes. Through simulation of the shock response, the findings show that the optimal level of internal damping depends on the magnitude of the input shock. For small shocks, performance is best for a relatively high level of damping, but for larger shocks, the best damping value drops to a much lower value. The effect on isolation performance of having different damping levels in different response regimes is shown to be fairly modest, and is shown to depend on the input excitation level.