Influence of ground motion scaling methodology and lead rubber bearing seismic isolator modelling technique on seismic response of an isolated structure

In this study, the maximum isolator displacement (MID), maximum isolator force (MIF), and maximum acceleration (MA) values that occur at the isolation level in seismically isolated structures were investigated using the nonlinear response history analyses (NRHA) by considering four different scaling methods. Both horizontal components of the ground motion records scaled with different scaling methods were applied simultaneously to the isolation unit modeled with lead rubber bearing, and bi-directional analyzes were performed. In the analyses, lead rubber bearings were modeled with two different approaches as the case deterioration due to the heating effect in the lead core is considered (Temperature Included, TI) and the case it is not considered (Boundary Analysis, LB-UB). In the analyses, four different Q/W ratios (0.75, 0.90, 0.105, and 0.120) representing the isolation unit strength, and five different Tiso (2.5s, 2.75s, 3.0s, 3.25s, and 3.5s) representing the isolation period were taken into account. As a result, while the variation in the scaling methods does not create a significant change on the maximum isolator forces, it is observed that it can cause changes up to 25% in the maximum isolator displacements and maximum acceleration values. This differentiation is negligibly affected by how the seismic isolator is modeled. © 2024 Gazi Universitesi. All rights reserved.