Coupled flutter stability from the unsteady pressure characteristics point of view

In this study, coupled flutter stability is discussed from the unsteady pressure characteristics point of view. The roles played by each aerodynamic derivative in flutter stabilization were reviewed. Based on that, some conditions that the unsteady pressure characteristics should present, so that flutter can be stabilized, are pointed out. As a general rule, moving the peaks of the amplitude C˜p(x⁎) distribution to downstream resulted in beneficial effects, provided the phase difference ψ(x⁎)ψ(x⁎) between the maximum relative angle attack of the whole body and the maximum negative pressure at the deck surface was in the stability range  . In this sense, the peaks of C˜p(x⁎) usually presented at the leading edge of bridge decks were found to reduce the flutter onset velocity. Even though only cases that respect aerodynamic derivatives interdependence were considered, the procedures used in this study are applicable to any type of cross-section.