Abstract:

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.