Torsional and longitudinal vibration of suspension bridge subject to aerodynamic forces

In this paper we consider a dynamic model of suspension bridge governed by a pair of coupled partial differential equations which describe both torsio nal and longitudinal vibration of the road bed. The Vertical and torsional motions are coupled through a nonlinear operation with the nonlinearity ari sing from loss of tension in the vertical cables supporting the decks. We s tudy the impact of wind forces on the stability of motion of this system bo th in the absence and presence of viscous and structural damping. The resul ts are illustrated by numerical simulation.