Development, Implementation and Verification of Dynamic Analysis Models for Multi-Spherical Sliding Bearings

Keywords: Dynamic analyses. Models. Friction pendulum bearings. Multi-spherical sliding bearings. Hysteresis. Seismic isolation systems. Shaking table tests. Seismic performance.

Abstract: This report describes the formulation, implementation and validation of multi-spherical sliding bearing models proposed for response history analysis of double and triple Friction Pendulum (FP) bearings. These bearings exhibit hysteretic behavior that is more complex than current seismic isolation devices. Since double FP bearings behave like two single concave FP bearings connected in series, the proposed model considers a series arrangement of single FP elements. Additionally, it is shown that a series arrangement can be used to capture the behavior of triple FP bearings provided that the model parameters are appropriately modified. The proposed models can be implemented in currently available structural analysis programs such as SAP2000 and 3D-BASIS. The FP bearing models presented in this report are verified by comparing the results obtained from shake table testing of a quarter-scale six-story building model to those predicted by response history analysis. Good agreement is observed even in cases of extreme response, which attest to the robustness and validity of the proposed models.