Dynamic aeroelastic instability of structurally damped cantilevered plates subjected to subsonic airflow

In this paper, the subsonic single mode flutter of an elastic rectangular plate in the presence of structural damping is investigated. Two dimensional equations of motion for the plate are obtained using classic theory of plates with the assumed mode method. The subsonic potential flow theory is used to evaluate the aerodynamic load. Furthermore, following the eigen-frequency solution, the natural frequencies and damping ratios of the structural system are obtained. In addition, the aeroelastic flutter stability margins are calculated, and the effects of structural damping ratio and mass ratio are studied. Then, natural frequencies of the plate are validated with the classic theory of plates presented by Soedel. The numerical results indicate that, the aeroelastic flutter boundaries can be greatly improved by increasing the structural damping ratio whereas the corresponding flutter frequencies do not change significantly. The results also represent the fact that for standard materials with typical structural damping levels, single mode flutter instability is unavoidable.

کلیدواژه ها:

single mode flutter ، negative aerodynamic damping ، structural damping ، subsonic ، aeroelastic instability.