Structural design and modal behaviors analysis of a new swept baffled inflatable wing

Inflatable wing has significant application value in the design of loitering munitions because of its advantages such as lightweight and foldability. However, due to the flexible characteristics, aeroelastic behaviors of inflatable wings such as flutter are nonnegligible in flight. By designing a certain angle between the inflatable beam and the wing span, the structural dynamic and even the aeroelastic performance of the inflatable wing can be effectively improved. Based on the analysis of the mechanical and geometric characteristics of the inflatable structure, a new inflatable wing with sweep arranged inflatable beams is proposed, and the main design variables and methods are analyzed. For purpose of investigating the aeroelastic performance of the swept baffled inflatable wing, the modal behaviors by considering the wet mode are studied. In consideration of the deficiencies of the traditional wet modal analysis method, by introducing the influence on the additional stiffness of flow field, an added mass-stiffness method is proposed in this paper, and the advantages are verified by ground vibration experiments. On this basis, the effects of baffles sweep angle, pressure, and boundary conditions on the modal parameters and aeroelastic performance of inflatable wing are analyzed. The results show that the aeroelastic performance of the inflatable wing can be designed by changing the baffles sweep angle, which is enlightened for the aeroelastic tailoring design on inflatable wings.