FINITE-ELEMENT FORMULATIONS FOR FRICTION PENDULUM SEISMIC ISOLATION BEARINGS

In this paper, an advanced analytical model and finite element formula tions including local bending moment effects for the Friction Pendulum System (FPS) are presented. Some important findings in these investig ations reveal that local bending moments which result from the movemen ts of the isolator, should be accounted for in the engineering design. The results presented in this paper show that if the effects of local bending moments are excluded from design considerations, it may endan ger structures during earthquakes. The new formulations considering lo cal effects provide an effective tool to simulate the behaviour of FPS -isolated structures subjected to earthquake loadings. The proposed fo rmulations can be applied directly for both two- and three-dimensional analyses without any further assumption. It is easy to implement the proposed techniques in existing finite element programs. The results o btained from the numerical analyses suggest that the local bending mom ent effects are of significant importance, and should be taken into ac count to assure the safety of isolated structures during earthquakes.