Mathematical Problems in Engineering
Volume 4 (1998), Issue 1, Pages 73-98

Stability of suspension bridge I: Aerodynamic and structural damping

N. U. Ahmed and H. Harbi

Department of Electrical Engineering and Department of Mathematics, University of Ottawa, 161 Louis Pasteur st., P.O. Box 450, Stn. A, Ottawa K1N 6N5, Ontario, Canada

Received 28 July 1997; Revised 14 November 1997

Copyright © 1998 N. U. Ahmed and H. Harbi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In this paper we consider a few dynamic models of suspension bridge described by partial differential equations with linear and nonlinear couplings. We study analytically the stability properties of these models and the relative effectiveness of aerodynamic and structural damping. Increasing aerodynamic or structural damping indefinitely does not necessarily increase the decay rate indefinitely. In view of possible disastrous effects of high wind, structural damping is preferable to aerodynamic (viscous) damping. These results are illustrated by numerical simulation.