IHS ESDU Methods for improving damping. Part 2: layered damping treatment for structures: analysis and examples. 91013

ESDU 91013 introduces computer programs to estimate the resonant frequencies and loss factors in any mode for beam or plate structures with damping treatment applied. ESDUpac A9113 deals with free-layer treatment applied over the whole of one or both sides of a structure with any combination of simply-supported, clamped or free edges. The method of analysis and assumptions made in the theory are described in ESDU 91012. ESDUpac B9113 deals with constrained-layer treatment over the whole of one side of a structure that vibrates in modes that have a sinusoidal displacement form which implies the edge condition for a plate must be simply-supported and a beam must have pinned ends; single or multiple layers of different materials can be used. ESDUpac C9113 deals with a single constraining layer applied to a beam and does not require the condition of a sinusoidal displacement so it applies to any combination of clamped, pinned and free end supports, except pinned-free. Both constrained-layer programs assume that all damping occurs in the damping layer. The input to and output from the programs are explained and illustrated with worked examples.