Study of a roller seismic isolation bearing coupled with an eddy current damping system.

Resumo

In seismic protection of structures, seismic isolation systems have been implemented successfully. By
this year, Japan is probable to exceed 4500 buildings built with this technology. Seismic isolators, in addition to
decoupling the seismic excitation of the structure, provide energy dissipation capacity through different
mechanisms such as friction and yield of materials. A disadvantage of these dissipation methods is the contact
between the damping system components with seismic isolation system. This work studies an efficient energy
dissipation alternative, with the application of eddy currents in a roller seismic isolation system; it should be noted
that this alternative does not require direct contact with the isolation system components. The characterization of
the dissipation system was carried out with the use of magnets and non-ferromagnetic material, coupled to a
seismic isolator with rolling supports. Seeking to reduce the horizontal displacement of the seismic isolation
without affecting its dynamic behavior, several aspects were considered in this study, such as: rolling friction
coefficient, eddy current damping forces and the gap between the conductor and the magnetic system. According
to the study’s results, the proposed damping system is viable for use in seismic isolation.