Multi-objective optimization of an aircraft wing spar section

Abstract

Natural frequency is a critical parameter in wing design. The fact that the natural frequency of the wing is small causes the wing to displace more, while at the same time, it can cause resonance when the natural frequency of the wing and the natural frequency of the air are equal. Studies carried out to increase the natural frequency of the wing can increase the rigidity of the wing while increasing its mass. This study identified a multiobjective optimization problem for increasing the natural frequency of wings without increasing the wing mass. For this objective, optimization of the wing spar element was carried out. The wing crosssectional geometry parameters are taken as design variables. Minimizing the weight of the wing and maximizing the first natural frequency of the wing are defined as objective functions. A multiobjective optimization study was carried out to increase the natural frequency of the wing and reduce its mass. This research aims to design a wing spar section with optimum properties in terms of natural frequency and weight of the cross-sectional geometry of the spar element from the wing internal structure elements. To perform the optimization process, modeling the parametric geometry, calculation of the pressure distribution on the wing, stress and displacement by static analysis, and calculation of the natural frequency by the modal analysis model was constructed via the Ansys Workbench environment. A multiobjective genetic algorithm was used in the optimization study using the response surface method. As a result of the study, the wing's first natural frequency increased by 14%, and the wing mass decreased by about 5 %.