Vibration and damping analysis of a sandwich beam containing a viscoelastic constraining layer

Viscoelastic layered systems provide a simple and flexible solution for damping vibration of sheet metal panels. They also help to effectively eliminate noise from resonant structures and surfaces. This article presents an analytical formulation to predict the stiffness and damping of three layered beams with two different viscoelastic materials adjacent to each other. The complex modulus approach is used to model the elastic and shear moduli of the viscoelastic material and closed-form equations are derived for predicting system stiffness and damping. The model is derived for unsymmetrical setups using variational methods. Experiments are conducted on simply supported three-layered beams at different temperatures to validate theoretical results. Similar results are obtained from both the theoretical model and the experiments. A procedure for the optimization of structural and material parameters for maximizing the damping and minimizing the system mass for a given temperature and frequency range is also presented. © 2005 Sage Publications