Seismic behavior of LRB and FPS type isolators considering torsional effects

This study aims to investigate seismic behavior of lead-core rubber elastomeric bearing (LRB) and curved surface friction pendulum slider (FPS) base isolated models considering torsional irregularity for typical reinforced concrete buildings. Nonlinear structural members was considered in analysis models. Total 1408 different nonlinear time history analyses 3-dimensional 3, 5, 7 9-story were performed 11 spectrum compatible ground motion record pairs. The results indicate that when the rigidity center isolator system is not coincided with mass superstructure, highest coefficients calculated. Lead-core type isolators are more sensitive effects compared isolators. Torsional coefficient values 20% eccentricity 47% higher than without terms averages. obtained significant scatter exists displacement individual records all Using limited number may lead inaccurate predictions demands.