Research Information System
ÇANKAYA INTERNATIONAL CONGRESS ON SCIENTIFIC RESEARCH, Ankara, Turkey, 10 - 12 April 2023, pp.1217-1228, (Full Text)
In this study, the flutter speed is investigated depending on the lamination angle of the composite material which is preferred in aircraft wings because of the high strength-weight ratio. The flutter speed is a key factor for aircraft parts and it must be desired in the design stage. In the present aviation industry, CFRP (Carbon Fiber Reinforced Polymer) composites are mostly preferred. In this study, the UD (Unidirectional) CFRP is implemented in the analysis. Laying up angles, one of the important design parameters for composite structures directly affects the strength and weight of the structure. Besides, that affects the behaviour of the structure in the static state as well as its behaviour in the dynamic state. Aircraft or UAV wings have bending and twisting responses due to flight loads. It is not possible to make a completely rigid wing with today's technology. Instead, it is an approach applied in the aviation industry to study flight under certain or pre-calculated deformation of the wing. Lamination is an important parameter by which this amount of deformation can be adjusted or the stiffness in this deformation direction can be controlled. In this study, flutter analysis was performed for the wing structure modelled at different angles and the flutter speed of the wing was investigated in different modes. The lamination also affects the behaviour in different modes, changing the dynamic behaviour of the structure, and the behaviour of the structure in different modes during design can be examined with numerical analysis methods. In this analysis, the wing design, lamination, and finite element model (FEA) are carried out using MSC Patran. MSC FlightLoad was used for the dynamic instability, that is flutter analysis, which is one of the aeroelastic phenomena. The Mach-Frequency couple was created and included in the analysis for the atmospheric parameters in the flight condition and the unstable aerodynamic model. In order to investigate the effect of different lamination structures on flutter velocity, the aerodynamic model was kept constant in the numerical study. Today, there are different numerical methods to examine the flutter speed. The analysis was solved with the pk – method, which is a method that has been validated by many studies at subsonic speeds. This method gives the damping graph of the structure at a certain sound speed and a certain Mach range. With the help of this output, the flutter speed of the structure can be determined. The aerodynamic and aeroelastic model prepared for the analysis was kept constant and the lamination was created for five different degrees as 0,30,45,60,90. Different input files were created and the solution was realized with the MSC Nastran solver. Since the bending and torsional stiffness of the structure differ according to the lamination angle, the flutter speed results in different modes were examined.