Flutter performance and aerodynamic mechanism of plate with central stabilizer at large angles of attack

Abstract

To analyze the effects of a central stabilizer on the flutter performance at large angles of attack, this study takes the ideal plate as a section of a bridge deck. The aerodynamic characteristics of stationary cross sections are examined using computational fluid dynamics simulations, and the flutter derivatives are extracted by forced vibration. The critical flutter speed of a target bridge is then calculated, and the aerodynamic mechanism of the central stabilizer is discussed from the work done by aerodynamic forces’ perspective. The results show that use of a central stabilizer with lower heights favors flutter stability at smaller angles of attack by improving the participation level of heaving motion, but the stability of the systematic heaving motion will decrease if the stabilizer is too high, leading to galloping. At larger angles of attack, where the movement of a big vortex causes the occurrence of torsional flutter, the stabilizer can hinder the movement of the vortex if they are on the same side, and the critical flutter speed increases with the increase in stabilizer height.