A generalised fractional derivative approach to viscoelastic material properties measurement

Viscoelastic materials are largely used as a means to provide damping to structures, thus mitigating resonant vibration responses. Devices made with viscoelastic materials such as isolators, dynamic vibration neutralisers (also called dynamic vibration absorbers), sandwich panels and structural links can be designed for highly efficient vibration control. To properly devise a vibration control strategy with viscoelastic materials, two basic dynamic properties must be known: the material loss factor and the dynamic modulus of elasticity. In the past the rheological model for viscoelastic materials was based on the classical concept of derivative (with respect to time) of integer order. These constitutive equations contained too many parameters to be identified, which made it computationally impractical. In this paper a new approach to the identification of the dynamic properties of viscoelastic materials, based on the fractional derivative model, is presented. Numerical and experimental results are produced and discussed.