Magneto-Rheological Fluid Dampers for Control of Bridges

Abstract

Magneto-rheological fluid (MRF) dampers are utilized to control vibration of a scaled, two-span bridge. In this work, the focus is on a combination of passive and semi-active damping capabilities of a bridge structure. Theoretical and experimental studies are performed to evaluate the effectiveness of MRF dampers. In addition, steel and graphite/epoxy-concrete (G/E-C) columns are utilized in the scaled bridge to increase passive structural damping. Finite element and experimental studies are conducted to assess the performance of each column. Strains in the columns are determined under different input motions and electric power input to MRF dampers. The results demonstrate that MRF dampers can significantly improve the response of the scaled model bridge. It is also shown that, although stiffer, the steel column develops much higher strains compared to those of G/E-C column.