FLUTTER DERIVATIVES OF A THIN PLATE MODEL UNDER DIFFERENT ATTACK ANGLES

Flutter derivatives of a thin plate under different attack angles are scarcely studied. The flutter derivatives of a thin plate model with a side ratio of 40 are tested under 0°, 3°, 5° and 7° by forced vibration test in a wind tunnel. The results show that the four key flutter derivatives of the model are consistent with the ones of an ideal plate. The flutter derivatives A₂^* are negative under 0°, 3°, 5°, and the absolute values decrease with the increasing attack angles. They are positive and increase rapidly under 7° wind attack angle when the reduced wind speed is greater than 15. The changes of other flutter derivatives are not obviously under 0°, 3° and 5°, but are significant under 7° attack angle. The critical flutter speeds are obtained by calculations using flutter derivatives and tested by free vibration wind tunnel tests. The errors between the two results were less than 4.5%, which proved the validity of the flutter derivatives. The research achievements also offer parameters for flutter calculation of long span bridges with the consideration of attack angles.