Feasibility of a passive isolation system with nonlinear hysteretic behaviour for the seismic protection of critical equipment

The present work discusses the feasibility of an innovative passive isolation system with nonlinear hysteretic behaviour for the seismic protection of equipment in critical facilities. The study first addresses the problem of formulating a constitutive model of the system. An optimal design methodology is then developed involving both the reduction of the equipment peak responses and the maximization of a properly defined energy performance index. The seismic effectiveness of the proposed equipment isolation system and its robustness for different seismic inputs are eventually assessed by means of numerical analyses.