  In this paper we present a theoretical and experimental study aimed at
characterizing the hysteretic properties of viscoelastic materials. In the last
decades viscoelastic materials have become a reference for new technological
applications, which require lightweight, deformable but ultratough structures.
The need to have a complete and precise knowledge of their mechanical
properties, hence, is of utmost importance. The presented study is focused on
the dynamics of a viscoelastic beam, which is both experimentally investigated
and theoretically characterized by means of an accurate analytical model. In
this way it is possible to fit the experimental curves to determine the complex
modulus. Our proposed approach enables the optimal fitting of the viscoelastic
modulus of the material by using the appropriate number of relaxation times, on
the basis of the frequency range considered. Moreover, by varying the length of
the beams, the frequency range of interest can be changed/enlarged. Our results
are tested against those obtained with a well established and reliable
technique as compared with experimental results from the Dynamic Mechanical
Analysis (DMA), thus definitively establishing the feasibility, accuracy and
reliability of the presented technique.
