Local deformation and stiffness distribution in fly wings
Local deformation and stiffness distribution in fly wings
复制标题
DOI：
10.1242/bio.038299
复制
发表时间：
2019-01-01
期刊：
影响因子：
2.4
通讯作者：
Lehmann, Fritz-Olaf
中科院分区：
文献类型：
--
作者：
Wehmann, Henja-Niniane;Heepe, Lars;Lehmann, Fritz-Olaf
昆虫翅膀的力学特性是昆虫飞行空气动力学的关键。在扑动过程中，机翼会发生巨大的变形，这取决于机翼的空间刚度分布。我们在这里展示了一个实验评估的翅膀刚度在三种苍蝇使用微力探针和成像方法的翅膀表面重建。在机翼表面的11个特征点上响应点载荷的垂直偏转表明，机翼铰链和点载荷之间的弯曲线的平均弹簧刚度在小果蝇中相差77倍，在大苍蝇中相差28倍。后一个结果表明，机翼局部变形在很大程度上取决于机翼扑动过程中机翼表面的惯性力和气动力分布。刚度随着身体质量的增加而增加，果蝇的刚度约为0.6 Nm(-1)，家蝇的刚度约为0.7 Nm(-1)，苍蝇的弯曲线刚度约为2.6 Nm(-1)，这些弯曲线从机翼底部延伸到靠近空气动力压力中心的区域。家蝇翅膀在腹侧和背侧载荷下的平均刚度具有1.4倍的各向异性，而果蝇和苍蝇则不存在各向异性。提出了两种基于曲面对称和机翼曲率的局部曲面变形计算方法。这些数据显示了载荷下的空间变形模式，并突出了叶脉如何将机翼细分为功能区。我们在活体动物翅膀上的实验结果不同于以往在分离的、干燥的翅膀上的实验，并有助于构建更真实的力学模型来测试特定机翼变形的空气动力学后果。
Mechanical properties of insect wings are essential for insect flight aerodynamics. During wing flapping, wings may undergo tremendous deformations, depending on the wings' spatial stiffness distribution. We here show an experimental evaluation of wing stiffness in three species of flies using a micro-force probe and an imaging method for wing surface reconstruction. Vertical deflection in response to point loads at 11 characteristic points on the wing surface reveals that average spring stiffness of bending lines between wing hinge and point loads varies similar to 77-fold in small fruit flies and up to similar to 28-fold in large blowflies. The latter result suggests that local wing deformation depends to a considerable degree on how inertial and aerodynamic forces are distributed on the wing surface during wing flapping. Stiffness increases with an increasing body mass, amounting to similar to 0.6 Nm(-1) in fruit flies, similar to 0.7 Nm(-1) in house flies and similar to 2.6 Nm(-1) in blowflies for bending lines, running from the wing base to areas near the center of aerodynamic pressure. Wings of house flies have a similar to 1.4-fold anisotropy in mean stiffness for ventral versus dorsal loading, while anisotropy is absent in fruit flies and blowflies. We present two numerical methods for calculation of local surface deformation based on surface symmetry and wing curvature. These data demonstrate spatial deformation patterns under load and highlight how veins subdivide wings into functional areas. Our results on wings of living animals differ from previous experiments on detached, desiccated wings and help to construct more realistic mechanical models for testing the aerodynamic consequences of specific wing deformations.