Parameter optimization of the KDamper concept in seismic isolation of bridges using harmony search algorithm

Abstract

In this paper a novel design methodology for seismic isolation of bridges is presented employing the KDamper passive system and the Harmony Search (HS) optimization algorithm. The implementation of the KDamper concept to the absorption of seismic excitation of bridge structures requires the solution of a linear dynamic problem during which the basic parameters of KDamper design must be predefined. As this selection appears to be a quite complex procedure, the need for an optimization process is of paramount importance. In our work, an emerging metaheuristic algorithm, the Harmony Search algorithm, which has been successfully applied to several engineering problems, is employed to obtain optimum design parameters for a typical bridge structure under seismic excitation. The optimal solution is obtained for a set of 5 earthquake excitation records using as objective function the Root Mean Square of the displacement ratio. Comparative results of the dynamic response between the initial and the isolated structure are presented to verify the effectiveness, validity and reliability of the proposed design method.