Premium
Hybrid isolation systems for equipment protection
Author(s) -
Inaudi José A.,
Kelly James M.
Publication year - 1993
Publication title -
earthquake engineering and structural dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.218
H-Index - 127
eISSN - 1096-9845
pISSN - 0098-8847
DOI - 10.1002/eqe.4290220403
Subject(s) - engineering , substructure , actuator , isolation (microbiology) , acceleration , structural system , reduction (mathematics) , transmissibility (structural dynamics) , structural engineering , component (thermodynamics) , vibration isolation , control theory (sociology) , computer science , vibration , mathematics , control (management) , physics , geometry , microbiology and biotechnology , electrical engineering , classical mechanics , quantum mechanics , artificial intelligence , biology , thermodynamics
Abstract This paper presents a formulation for earthquake resistant design of optimum hybrid isolation systems for sensitive equipment protection. The hybrid system under consideration consists of laminated rubber bearings, viscodampers and a set of actuators which, grounded on the main structural system, deliver forces on the basement of the isolated substructure mounted on the main structural system. An integrated design procedure for the passive and active components of the isolation system is developed aiming at acceleration reduction under random excitation. Linear models are used for the isolated structure, the main structural system and the isolation system. Fractional derivative Maxwell elements are used to model the mechanical behaviour of the viscodampers. The active component of the isolation system applies forces proportional to the absolute velocity of the isolated piece of equipment. Constraints in the deformation capacity of the isolators as well as constraints in the capacity of the actuators are considered for the design of an optimal hybrid isolation system. Simple numerical examples are developed herein to illustrate the design procedure. The superiority of hybrid systems over passive systems in reducing acceleration response is demonstrated.