Determination of damping properties of an elongated plate with an integral damping coating on the base of studying complex eigenfrequencies

The structure of a perspective integral damping coating consisting of two layers of a viscoelastic material with a thin reinforcing layer between them is presented. A four-layer finite element with fourteen degrees of freedom was developed for modeling a plate with a mentioned damping coating, which allows to take into account the effect of transversal compression of the damping layers during high-frequency oscillations of the plate. The generalized problem of complex eigenvalues based on the method of iterations in a subspace to determine several lower complex forms and frequencies of free vibrations of a damped plate was solved.