MODEL REDUCTION FOR FINITE ELEMENT ANALYSIS OFBASE ISOLATED BRIDGES UNDER SEISMIC LOADS

A model reduction method for the finite element analysis of base isolated bridges under seismicloads is developed. The lead rubber bearing (LRB) is used as the base isolation system. It isdemonstrated that model condensation of a base isolated bridge can be performed in the same manneras in ordinary (fixed-base) structures. However, for extraction of the seismic performance of baseisolated bridges, nonlinear behaviour of the base isolation system is introduced as a virtual force. Inorder to verify the accuracy of the present method, an example is solved. The results confirm theaccuracy of the proposed condensation method for base isolated bridges.

Keywords:

Base Isolated Structures , Model Reduction , Finite Element Analysis , Seismic Loads