Experimental Verification of an MR Damper Controlled Highway Bridge

There exists a current need in our nation to address the deteriorating integrity of our infrastructure. Highway bridges in particular are continuously approaching or exceeding their design life and are increasingly being classified as structurally deficient. The service life of highway bridges can be extended through the innovative application of structural control to reduce the peak stress in the critical elements of the bridge due to heavy truck traffic. A promising class of controllable hardware, the Magneto-Rheological (MR) damper, is proposed to reduce the dynamic response of bridges and extend the service life. The inherent stability, robust performance, and low power requirements of MR dampers make them an attractive type of controllable hardware for highway bridges. In this paper the large-scale real-time experimental verification of a typical highway bridge excited by a crossing truck and controlled with MR dampers using hybrid testing at the Lehigh University Network for Earthquake Engineering Simulation (NEES) facility is described. Preliminary simulation results indicate that peak and dynamic responses can be effectively reduced to increase the fatigue life of the structure. Initial experimental tests validate the simulations and indicate the potential of using MR dampers to reduce traffic induced vibration of bridge structures.