Reliability of indicial functions in bridge deck aeroelasticity

Self-excited forces in bridge aeroelasticity are modeled in time domain by means of indicialfunctions (IF). These functions are characterized by sets of parameters, identified from measured aeroelasticderivatives (AD), which are their frequency-domain counterpart. Indicial functions are strongly dependent onoriginal data, on approximation used, and on numerical procedures set up to identify them. Therefore, an in-vestigation on estimated functions is recommended. In this paper, a Monte Carlo approach is adopted to ob-tain distributions of critical flutter velocities and frequencies for a sample cross-section. The results of classi-cal flutter analyses and simulations performed through indicial functions are compared. A satisfactory level ofreliability is demonstrated. This suggests a confident use of indicial functions for full bridge simulations, in-cluding unsteady load contributions and allowing structural nonlinearities to be taken into account.