In the search of modal parameters configuration of passive and active isolation systems, applied to moment frames

The use of seismic base isolation is a very good strategy to reduce the seismic design forces in structures, additionally, damages can be avoided and the possible collapse of the structure prevented. Passive isolation is the seismic base isolation system more frequently used. It allows to reduce the excitation force transmitted to the structure through the base. Normally this kind of system is designed to control the excitation forces for a given frequency. However, for changing magnitudes outside the design frequency, the passive system loses efficiency and can generate unwanted behaviour. The active control used in isolation systems allows to increase the roll-off at high frequencies whereas the risk of resonant behaviour is drastically reduced. In this paper, the dynamics of the base isolation system will be studied, for this it was done an analysis of sensibility parametric, that determines how the changing in the frequency or damping of an isolation elastomeric influences in the response frequency of the structure. With the values of stiffness and damping for an isolation elastomeric, are assumed that is the same values of stiffness and damping to an active base isolation system, and so be able determines the ideal gain of this type of system. These parameters will be used to obtain the reduced response of both, passive and active systems, of a given seismic signal and will be compared for 3 different types of structures