Perpustakaan Digital ITB

Due to their operational condition, military aircrafts such as fighter fly in a high-speed condition while carrying armaments that cause the possibilities of structural failure due to aeroelastic problems including flutter. Armaments instalment affects the inertial of aircraft wing structure that cause the change of dynamic aeroelasticity characteristics. Structural dynamics and aeroelasticity analyses are conducted to study the effect of armament placement on the wing to the aeroelastic characteristics of the aircraft wing. The armament is placed at the tip of the wing and will be modelled as concentrated mass and beam element to compare the results. Structural dynamics analyses conducted using finite elements method to obtain the dynamic characteristics of aircraft wing, such as natural frequencies and mode shapes. These dynamics characteristics then used for aeroelastic analyses. Doublet-lattice method and piston theory are used to model the unsteady aerodynamics. DLM is used for subsonic regime flutter analyses while piston theory is used for supersonic regime. The transonic regime is not included in this research due to the non-linearity in aeroelastic problem. The flutter solution is obtained using p-k method. The results show that the placement of armament affects the flutter speed. The shifting of armament’s CG to the trailing edge increases the instability of the aircraft wing. It also shows that the armament model also affects the flutter results. The inertial of the beam element affects the flutter characteristics, unlike the concentrated mass model.