Best performing parameters of linear and non-linear seismic base-isolator systems obtained by the power flow analysis

In this paper the problem of finding the best performing base isolator parameters of a seismic excited structure is treated. The structural and earthquake parameters and the isolator type are considered assigned. The approach here proposed is based on the minimization of the power flow transmitted by the isolator to the structure. The power flow is a statistical measure of the power transmitted to the structure during an earthquake. The earthquake is idealized as a filtered stochastic process. This approach considers the structure–isolator–excitation system as a super-structure in which the structure, the isolator and the excitation filter are the sub-structures. It guarantees a very good global behaviour of the structure, both in terms of relative displacements and in terms of accelerations. The isolator types considered in this work are the linear, the yielding and the friction ones.