Skin design studies for variable camber morphing airfoils
Skin design studies for variable camber morphing airfoils
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DOI：
10.1088/0964-1726/17/01/015025
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发表时间：
2008-02-01
影响因子：
4.1
通讯作者：
Anusonti-Inthra, Phuriwat
中科院分区：
文献类型：
--
作者：
Gandhi, Farhan;Anusonti-Inthra, Phuriwat
本文确定了变形机翼柔性蒙皮的理想属性。以翼型曲面变形为例进行了研究。理想的弹性蒙皮应该是高度各向异性的，具有较低的面内轴向刚度和较高的平面外弯曲刚度。降低的蒙皮轴向硬度允许以较低的驱动成本进行变形。然而，对于一些子结构和驱动设计，可能需要对蒙皮的面内轴向刚度设置一个较低的限值，以防止在气动载荷下不可接受的整体曲面变形。高的弯曲刚度防止了由于气动压力载荷引起的支架之间蒙皮截面的局部变形，并避免了蒙皮截面在压缩下的屈曲，就像翼型曲面在激励力下一样。对于曲面变形应用，弹性皮肤中的应变水平预计不会超过2%左右。如果弹性蒙皮的轴向刚度显著降低，可能需要考虑气动刚度(相对于经典翼型的结构刚度可以忽略不计)，以准确地计算载荷下的变形。研究中遵循的方法可以用于确定皮肤的规格，然后反向工程和设计符合规格的高度各向异性的复合皮肤。
This paper identifies the desirable attributes of a flexible skin of a morphing wing. The study is conducted using airfoil camber morphing as an example. The ideal flex-skin would be highly anisotropic, having a low in-plane axial stiffness but a high out-of-plane flexural stiffness. Reduced skin axial stiffness allows morphing at low actuation cost. However, for some substructure and actuation designs, a lower limit on the skin's in-plane axial stiffness may be required to prevent unacceptable global camber deformation under aerodynamic loads. High flexural stiffness prevents local deformation of skin sections between supports due to aerodynamic pressure loads, and avoids buckling of skin sections under compression as the airfoil cambers under actuation force. For the camber morphing application the strain levels in the flex-skin are not expected to exceed around 2%. If the axial stiffness of the flex-skin is reduced significantly, it may be necessary to consider aerodynamic stiffness (negligible vis-a-vis structural stiffness for classical airfoils) to accurately calculate deformation under loading. The approach followed in the study can be used to identify specifications for the skin and then reverse engineer and design highly anisotropic composite skins that meet the specifications.