VISCOELASTIC BEAM DYNAMICS: THEORETICAL ANALYSIS ON DAMPING MECHANISMS

Viscoelastic materials are widely utilized in different engineering areas, however it is still not so easy to properly assess their mechanical properties, in terms of viscoelastic - frequency dependent modulus. Standard experimental procedures are utilized in this direction (e.g. DMA - Dynamic mechanical analysis), but such techniques still present some complexities, and this is why possible alternative approaches would be desirable. For example, the experimental investigation of a viscoelastic beam dynamics would be challenging, especially for the intrinsic simplicity of this kind of test. In this direction, a deep understanding of damping mechanisms in viscoelastic beams results to be a quite important task to better predict their dynamics. With the aim to elucidate damping properties in such structures, in this paper an analytical study of the transversal vibrations of a viscoelastic beam is presented. By means of a dimensional analysis, some key parameters are presented, which depend on the material properties and the beam geometry. In this way, by properly tuning such disclosed parameters, e.g. the dimensionless beam length once the material is chosen, it is possible to enhance or suppress some resonant peaks, one at a time or more simultaneously. This is a remarkable possibility to efficiently control damping in these structures, and the results presented in this paper may help in elucidating experimental procedures for the characterization of viscoelastic materials.