Simplified prediction of wind-induced response and stability limit of slender long-span suspension bridges, based on modified quasi-steady theory: A case study

Time domain modeling of self-excited aerodynamic forces for cable-supported bridges: A comparative study

“…The traditional quasi-steady theory does not provide any aerodynamic torsional damping, which, for some cross sections, will result in a significant underestimation of the flutter threshold [6]. However, it is shown in [6] that modified quasi-steady theory, where curve fits providing a frequency-independent description …”

“…One of the main concerns for long-span bridges is wind-induced dynamic response, which is most commonly predicted using frequency domain methods, where the aeroelastic effects are introduced in terms of experimentally determined aerodynamic derivatives [1][2][3][4][5][6][7][8][9][10][11][12]. This approach is an extension of classical airfoil theory [13], where Theodorsen's function provides the self-excited forces that are actions generated by the motion of the cross section in the fluid flow.…”

“…An alternative to unsteady self-excited force models is to use quasi-steady theory [5,6,25,26] to quantify the self-excited forces. In the quasi-steady theory, force coefficients from static wind tunnel measurements are used to quantify the self-excited forces.…”

“…However, it is well known that the quasisteady theory may provide inaccurate results for some cross sections, in particular, since no aerodynamic torsional damping is provided. Øiseth et al [6] propose a modified quasi-steady approach, where curves providing a frequency-independent description of the self-excited forces are fitted to the experimentally determined aerodynamic derivatives in the important frequency range. This approach has also been used to develop simplified expressions for the critical flutter velocity of cable supported bridges [27].…”

“…The approach has been developed further in two recent papers [30,31]. In this paper the method suggested by Øiseth et al [6], focusing on the frequency dependency, has been further developed making it possible to model the self-excited forces accurately at all the natural frequencies of the aeroelastic system.…”