柔性复合材料前掠翼飞机静气动弹性分析

STATIC AEROELASTIC CHARACTERISTICS ANALYSIS OF A FLEXIBLE FORWARD-SWEPT COMPOSITE AIRCRAFT

本文作者计算分析的是柔性复合材料前掠翼概念机的静气动弹性特性。文中作者利用 NASTRAN计算了单独机翼的发散速度 ,并重点计算和分析了该机在亚音速情况下 ,飞行载荷和纵向静稳定性、操纵性导数分别随马赫数和动压变化的曲线。通过对比分析可以看出 :(1)相同高度下 ,随着马赫数的增加 ,刚体纵向静稳定性、操纵性导数和弹性纵向静稳定性、操纵性导数分别呈不同的变化趋势 ,且某些变化相差甚大 ;机翼剪力、弯矩和扭矩随翼展变化的曲线中 ,刚体部分所占的比例不断减小 ,弹性部分所占的比例不断增加 ;机翼的最大垂直挠度 (在翼尖前缘处 )和最大扭角 (在翼尖处 )略有增加。 (2 )相同马赫数下 ,随着动压的不断增加 ,刚体纵向静稳定性、操纵性导数保持不变 ,弹性纵向静稳定性、操纵性导数呈线性变化 ;机翼剪力、弯矩和扭矩随翼展变化的曲线中 ,也同样是刚体部分所占的比例不断减小 ,弹性部分所占的比例不断增加 ;机翼的最大垂直挠度 (在翼尖前缘处 )和最大扭角 (在翼尖处 )略有增加。 (3)使用复合材料剪裁技术可以适当减小机翼内洗 ,从而提高发散速度 。

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.