Advanced hybrid vibration control with applications to cable -stayed bridges
The focus of this study is active vibration control with application to cable-stayed bridges. Hybrid vibration control, involving the combined use of feedforward and feedback control, is proposed for a cable-stayed bridge. The control objective is to reject all disturbances that produce unwanted motion in the bridge structure, namely seismic activity, wave loading and wind loading. A 1/150 scale model of a cable-stayed bridge is designed and fabricated from steel, aluminum, and steel wire and compared to an existing structure using modal analysis. A three-dimensional finite element model of the bridge is developed for verification purposes. The frequency range of interest for the structural active vibration control is determined using influence coefficients for each mode using analytical and experimental methods. A method for placing sensors and actuators on the structure is developed using operational vibration data within the frequency range of interest. Controllers are designed, developed and implemented on the structure using classical control techniques and adaptive control techniques for combined feedforward and feedback architecture. The control system considers multiple modes in the design as the vibration of a cable-stayed bridge is not dominated by a single mode. Implementation issues including sampling rate, anti-aliasing filters, reconstruction filters, gain stages, analog filters to control bandwidth, and other important implementation issues are discussed. Experimental results showing large reductions in vibration levels are accompanied by discussions for the active control implementation. The study is finalized with a set of conclusions and areas of work for future study. ^
Major Professors: Rahmat Shoureshi, Purdue University, Charles M. Krousgrill, Purdue University.
Engineering, Civil|Engineering, Mechanical