Static aeroelastic characteristics analysis of a flexible forward-swept composite aircraft

The static aeroelastic characteristics of a flexible forward-swept composite conceptual aircraft are calculated and analyzed by the NASTRAN software, in which the divergence speed of a wing is alone included, and the variation curves of flight-loads, longitudinal stability derivatives and longitudinal control derivatives with respect to Mach number and dynamic pressure respectively under the subsonic case are involved emphatically. By comparison and analysis, the following results can be found: (1) At the same attitude, with the increase of Mach number, for the longitudinal stability and control derivatives, the rigid one and the elastic one change in different trends respectively, and there are great differences between some variation curves; for the variation curves of the shear force, bending moment and torsional moment of the wing along the lines of span, the rigid proportion decreases while the elastic one increases; for the maximal vertical deflection of the wing (at the leading edge of the wing tip) and the maximal torsional deformation of the wing (at the wing tip), both increase a little. (2) At the same Mach number, with the increase of dynamic pressure, for the longitudinal stability and control derivatives, the rigid one remains unchanged while the elastic one changes linearly; for the variation curves of the shear force, bending moment and torsional moment of the wing along the lines of span, the variation trends of rigid and elastic proportions are the same as result (1); for the maximal vertical deflection and the maximal torsional deformation of the wing, both are the same as result (1). (3) By the use of composite tailoring, the wash-in of the wing can be reduced; therefore the divergence speed can be enhanced, and the deformation of the wing and the elastic proportion of flight-loads can be decreased.