Numerical investigation of rubber bearings with low shape factor under seismic excitation

This study illustrates the development of a modeling strategy for simulating the seismic response of structures mounted on elastomeric bearings with a low shape factor (LSF). These bearings can be employed to achieve a three-dimensional seismic isolation of structures, due to their low vertical and horizontal stiffness. The first part of this work investigates the mechanical behaviour of LSF bearings by means of three-dimensional Finite Element (FE) analysis in Abaqus. The FE results provide a numerical evaluation of the horizontal, vertical, and rotational stiffness of the bearings. These are used in the second part of the study to develop in SAP2000 a simplified model of a structure with LSF bearings tested experimentally on the shaking table at University of Naples Federico II. The study results show that the developed model can be effectively used to simulate the response of the isolated structure under different earthquake inputs.