ESTIMATION OF MODEL PARAMETERS IN NONLINEAR ENGINEERING SYSTEMS: THE CASE OF SUSPENSION BRIDGE OSCILLATIONS

Modeling of nonlinear systems occurring in engineering applications always involves a choice of parameters for both analytical work and computer simulations. These parameters lead often to interesting dynamics, like complex periodicity, chaos and crises; but not always the set of parameters yielding rich dynamics is consistent with realistic applications. As a case study of this question, we consider the dynamics of the lowest order transversal vibration mode of a suspension bridge, for which the hangers are treated as one-sided springs, under a time-periodic external forcing caused by a von Karman vortex street. We analyze in particular the multi-stability of periodic attractors and the basin of attraction structure in phase space and its dependence with the model parameters. The parameter values used in numerical simulations have been estimated taking into account structural, aerodynamical, and physical considerations.