Time-Domain Analysis of Sandwich Shells with Passive Constrained Viscoelastic Layers

Damping e ects on THE vibration behavior of a sandwich cylindrical shell with a passive constrained viscoelastic layer are investigated in the time-domain. Equations of motion in terms of transverse modal coordinates in the frequency-domain are obtained by means of an energy method and the Lagrange equation, and they are solved by the assumed-mode method. The viscoelastic behavior is represented by the frequency complex modulus model. The equations of motion are transferred from the frequency-domain to the time-domain by the Inverse Fast Fourier Transform, (IFFT). Thickness e ects of constrained and viscoelastic layers are investigated by a transient external load response and evaluation of the damping factor and settling time.