Identification of the constitutive equations for linear viscoelastic composite materials

The constitutive equations for linear viscoelastic materials are experimentally verified. The generalized Hooke´s law, which gives a frequency-dependent relationship between the stress and the strain, is modeled using a parametric transfer function model. The parameters of the proposed rational transfer function are estimated from forced vibration experiments. Instead of using the classical stepped sine excitation, a broadband excitation (Schroeder multisine) is applied under uniaxial tension conditions. It is shown that generalized Kelvin/Maxwell models are necessary to describe accurately the behavior of viscoelastic materials