EVOLUTIONARY MODEL OF VISCOELASTIC DAMPERS FOR STRUCTURAL APPLICATIONS

The effects of temperature on the energy dissipation of viscoelastic d ampers for seismic mitigation of structures are investigated. To simul ate the damper behavior, an evolutionary model is proposed to describe the dependence of the mechanical properties of the damper on the defo rmation frequency and the temperature increase due to dissipation. The rmorheologically simple materials are considered and the influence of the deformation frequency on the storage and loss moduli is modeled us ing fractional derivative operators. The effect of material temperatur e on the force-deformation relation is modeled using the concept of ev olutionary transfer function, and the proposed model is implemented us ing a step-by-step technique in the frequency domain. The predictions of the proposed model in the case of sinusoidal and seismic deformatio ns show good agreement with experimental results. Finally, the respons e spectra of single-degree-of-freedom structures with added viscoelast ic dampers and subjected to seismic excitation are computed using the proposed evolutionary model; the results obtained show that the therma l effect due to energy dissipation is not always negligible.