Evaluating the Effect of Support Rotation on the Buckling Modes and Critical Displacement of Elastomeric Base Isolators

Abstract

Base isolation is one of the ways to stabilize structures against earthquake. In general, two types of system for isolate are used: laminated rubber bearing and lead rubber bearing. In this paper, the laminated rubber bearing is used. These isolators are made of bonded steel and rubber sheets with vulcanization. One of the most important factors for their design is stability because they can cause damage to the upper structures due to instability. For stability check the buckling load calculated based on the theory relation and compared with the finite element method. The support rotation causes a significant reduction in the buckling load and critical displacement of the isolators. In this research, the buckling load of square and circular isolator is calculated and shows that the buckling load of square isolator is higher than the circular ones and also rotation decreases the critical displacement.