Viscoelastic materials characterisation using the seismic response

This paper presents an investigation on viscoelastic materials characterisation using the response of cantilever beams to a seismic excitation. The basis of the procedure to determine the storage modulus and the loss factor of the viscoelastic materials is taken from the ASTM E 756 – 04 norm, which specifies that the resonance peaks of the frequency response functions must be considered to characterise the storage modulus, and then the half-power bandwidth method is required to obtain the loss factor. The cantilever beam specimens are tested in free layer damping configuration, that represents the simplest of the surface viscoelastic treatments and that is largely employed in industrial applications. This work has three objectives: (i) to study the effect of replacing the excitation force by a seismic base motion, (ii) to analyse the influence of the variables of the system on the accuracy of the results and (iii) to investigate on the curve-fitting of the experimental results to different viscoelastic material models.