Rudimentary statistical energy analysis and structural fuzzies

Structural fuzzies (Sfs) is a dynamic complex that is attached to a primary structure in order to provide a higher degree of dissipation. The dissipation is with respect to the power that is injected into the driven primary structure. It is argued that care needs to be exercised in the definition of the loss factor that is associated with this dissipation. This definition is examined and discussed; then, the role of the Sfs is analyzed in terms of a rudimentary statistical energy analysis (SEA). It is shown that the effectiveness of the dissipation is enhanced if the coupling of the Sfs to the primary structure is strong enough to approximate equipartitioning of modal energies, if the modal density in the Sfs either approximates or exceeds that in the primary structure and, finally, if the inherent loss factor in the Sfs is sufficiently higher than that in the primary structure. The definitions of strong enough coupling, modal densities, and inherent loss factors will be given. Examples of Sfs will be cited and discussed.