Benchmark structural control problem for a seismically excited highway bridge-Part II: Phase I Sample control designs

Abstract

This paper presents sample control system designs for the three-dimensional benchmark structural control problem for seismically excited highway bridge. Three types of sample control systems, namely nonlinear viscous dampers, ideal hydraulic actuators and magnetorheological fluid dampers, are designed and presented for comparison by participants in the study. For each of the three-sample control systems, a total of 16 control devices are proposed to be placed orthogonally between the deck-ends and abutments for the reduction of earthquake-induced vibrations of the highway bridge. An H2/LQG control algorithm is selected for the active case and a clipped optimal control algorithm is chosen for the semi-active case. To facilitate the controller design, an eigenmode reduction method is used to reduce the number of degrees of freedom of the initially elastic model to obtain a reduced-order model. However, the evaluation model to simulate the performance of control strategies is the full-order nonlinear finite element model. A Kalman filter is used to estimate states of the reduced-order model required for the applications of controllers for both active and semi-active cases using selected acceleration and displacement measurements. The modeling and sample control system designs presented in this paper are for illustration purposes only, and are not intended to be competitive. Participants of this benchmark study are expected to employ more competitive control designs for their own control strategies. These control strategies may be passive, active, semi-active or a combination thereof. Copyright © 2009 John Wiley & Sons, Ltd.