Shock isolation through the use of nonlinear energy sinks

We consider shock isolation designs based on the use of nonlinear energy sinks (NESs). These are a priori determined points of a system where unwanted disturbances are transmitted ("pumped") and then eliminated by passive or active means. The underlying dynamic phenomenon that causes nonlinear energy to pump into a sink is resonance capture on a 1:1 resonance manifold of the dynamics. In this work, essentially nonlinear stiffness elements are used to couple the NES with the primary system in order to achieve robust energy pumping, in a sufficiently fast timescale. "Fast" energy pumping at the early stage of the motion is important in order to achieve the shock isolation objectives. The proposed shock isolation design is practical and realizable. Its modular form enables the alteration of the global dynamics of a system by attaching a number of local NESs. The proposed design has the additional interesting feature of dual mode shock isolation, e.g., the capacity to significantly reduce the level of unwanted disturbances initiated at different points of the system.