The role of aerodynamic forces in a mathematical model for suspension bridges

Abstract

In a fish-bone model for suspension bridges previously studied by us in [3] we introduce linear aerodynamic forces. We numerically analyze the role of these forces and we theoretically show that they do not influence the onset of torsional oscillations. This suggests a new explanation for the origin of instability in suspension bridges: it is a combined interaction between structural nonlinearity and aerodynamics and it follows a precise pattern. This gives an answer to a longstanding question about the origin of torsional instability in suspension bridges.