Biomechanical behaviors of dragonfly wing: relationship between configuration and deformation

Abstract

In this paper, the natural structures of a dragonfly wing, including the corrugation of the chordwise cross-section, the sandwich microstructure veins, and the junctions between the vein and the membrane, have been investigated with experimental observations, and the morphological parameters of these structural features are measured. The experimental result indicates that the corrugated angle among the longitudinal veins ranges from 80 • to 150 • , and the sandwiched microstructure vein mainly consists of chitin and protein layers. Meanwhile, different finite element models, which include models I and I * for the planar forewings, models II and II * for the corrugated forewings, and a submodel with solid veins and membranes, are created to investigate the effects of these structural features on the natural frequency/modal, the dynamical behaviors of the flapping flight, and the deformation mechanism of the forewings. The numerical results indicate that the corrugated forewing has a more reasonable natural frequency/modal, and the first order up-down flapping frequency of the corrugated wing is closer to the experimental result (about 27.00 Hz), which is significantly larger than that of the planar forewing (10.94 Hz). For the dynamical responses, the corrugated forewing has a larger torsional angle than the planar forewing, but a lower flapping angle. In addition, the sandwich microstructure veins can induce larger amplitudes of torsion deformation, because of the decreasing stiffness of the whole forewing. For the submodel of the forewing, the average stress of the chitin layer is much larger than that of the protein layer in the longitudinal veins. These simulative methods assist us to explain the flapping flight mechanism of the dragonfly and to design a micro aerial vehicle by automatically adjusting the corrugated behavior of the wing.

Investigation of span-chordwise bending anisotropy of honeybee forewings

“…Micro-CT ( Jongerius and Lentink, 2010 ) was used to create three-dimensional (3D) high-resolution rendering of the cross-sectional corrugation on the chordwise profile of the forewing, and to aid understanding of the influence of cross-sectional corrugations on the spanwise bending of the forewing. Then, by combining the honeybee forewing venation and previous studies ( Combes and Daniel, 2003 ; Rajabi and Darvizeh, 2013 ; Ren et al, 2012 ; Chen et al, 2013 ; Kesel et al, 1998 ) on the wing venation, it was found that the leading edge vein was another factor influencing the span-chordwise anisotropy. In summary, even though the span-chordwise anisotropy of insect wings was previously reported, we submit that the published information is incomplete and there is a need, based on our present work, to integrate all the possible factors to explain and discuss this feature as comprehensively as possible.…”

Effects of multiple vein microjoints on the mechanical behaviour of dragonfly wings: numerical modelling

“…Taking into account that the spikes on the hill side of vein joints are usually larger than those on the valley side [ 17 ], they were modelled to have different dimensions (hill-sided spikes are about two times larger than those located on the valley side). The corrugation angle, in all models, was chosen to be about 150° [ 24 ].…”

“…There are several studies available in the literature that employed finite-element (FE) method to numerically model dragonfly wings as a whole. However, given the structural complexities of insect wings, many of the previously developed models contain inevitable huge oversimplifications [ 23 , 24 ]. Therefore, in our opinion, comparative studies on individual wing components may serve as a much more useful approach to understand the role of each single component in the functionality of insect wings.…”

Antifatigue properties of dragonfly Pantala flavescens wings

“…When the loads applied on the wing, the veins near the trailing edge area are more likely to be fractured under the long time of cyclic load. Before the appearance of cracks, the 3D truss‐like structure and surface morphology of the dragonfly wings reduce inertia moment and the stress at the wing tip, which is helpful for the flexible deformation of wings during flight (Combes and Daniel, ; Ren et al, ). The characteristics of structure and morphology can effectively reduce the generation of cracks, which play an important role in improving the antifatigue properties.…”

“…Dragonfly wings possess great stability and high load‐bearing capacity during flapping flight, glide, and hover, despite the fact that the wings are thin and light, accounting for 1–2% of the total body weight (Okamoto et al, ; Song et al, ; Zeng et al, ). The special hierarchical structure of the dragonfly wings remarkably improved the torsional deformation of dragonfly wing (Chen et al, 2008; Combes and Daniel, ; Ren et al, ), therefore, the flights of dragonfly wing with longitudinal veins are efficient and intelligent, and benefic for its biomechanical behavior (Chen et al, ; Park and Choi, ; Sun and Bhushan, ; Sun et al, ).…”