Flutter Boundary Identification Using Time Domain Free Vibration Methods for Bridge Deck Sections

This paper focuses on application of system identification methods i.e. Vector Autoregressive Moving-Average, and Eigensystem Realisation Algorithm methods for identifying the critical flutter velocity of bridge deck sections. These were applied on transient free vibration response of a 2D deck section, obtained using CFD software OpenFOAM. Simulation of deck aerodynamics is performed within a fluid structure interaction framework. The obtained static coefficients are compared with available literature. Frequency and damping ratios of the transient response thus obtained are estimated for various inlet wind speeds using the above system identification methods. Finally, a flutter margin for discrete-time systems, evaluated using the VARMA coefficients, is explored for the current application. Results indicate that these methods could yield a reasonable estimate of flutter velocity.