Finite element modeling of single and multi-spherical friction pendulum bearings

Abstract

Base isolation is a modern strategy to decrease the effects of earthquakes on buildings of high significance. The general principle is that the structure is decoupled from the horizontal components of the earthquake ground motion by interposing a layer with low lateral stiffness between the structure and the foundation. One of the major devices to apply seismic isolation is Friction Pendulum Systems, which use the characteristics of a pendulum to lengthen the natural period of the isolated structure. These systems consist of an upper and a lower spherical plate with sliding surface applied with special coating, and an articulated slider. The aim of this paper is to simulate Friction Pendulum Isolation Systems, using the finite element method. All models are constructed using full three dimensional continuum modeling in ABAQUS software. Particularly, this study includes single, and multi-spherical Friction Pendulum Bearings simulation. Dynamic time history analyses are performed and results in terms of hysteretic loops are presented. The analyses results of the proposed models are verified with the analytical solution of the friction pendulums response and with those obtained by analyses in other commercial software which contains Friction Pendulum Bearing model.