COMPLEX EIGENFREQUENCIES AND DAMPING PROPERTIES OF AN ELONGATED PLATE WITH AN INTEGRAL DAMPING COATING

This paper considers the classical methods of surface damping of bending vibrations of thin-walled structures and a promising integral version of a damping coating consisting of two layers of a material with pronounced viscoelastic properties separated by a thin reinforcing layer of a high modulus material. A finite element with 14 degrees of freedom for modeling an elongated plate with the specified damping coating has been developed with consideration of the transverse compression of damping layers under high-frequency vibrations of the plate. The generalized problem of complex eigenvalues in the lower part of the spectrum of complex modes and frequencies of free vibrations of a damped plate is solved by the subspace iteration method taking into account the frequency dependence of the dynamic elastic moduli of the material. The damping properties of the plate are determined from the imaginary parts of the complex eigenfrequencies and the relative energy dissipation at resonance.