Fig 1.
(a) Main structural components of the forewing of the dragonfly S. vulgatum (Libellulid); (b) 3D geometry of the basal complex; (c, d) scanning electron microscopy images of spikes, a joint-associated spikes, and a resilin patch.
Fig 2.
3D configuration of the basal complex in the FE models of wings.
The models were inspired by (a) Coenagrionid wings, (b) Chlorocyphid wings, (c) Heterophlebia forewing, (d) Heterophlebia hindwing, (e) Aeshnid forewing, (f) Libellulid forewing, (g) Libellulid hindwing (see Wootton and Newman, 2008). (h) Schematic view of a model under ventral loading. The external force is applied to RP, and the model is fixed at the wing base.
Fig 3.
Deformation pattern of the models of the three model groups.
The wing deformation has been shown under both dorsal and ventral loadings. The removal of the basal veins from the models of Group 1 led to the significantly larger deformations in the models of Group 2. However, the corresponding models from these two groups show a relatively similar deformation pattern. The models from Group 3 (models without basal complex, but containing basal veins) experience much larger deformation than the models of Group 1. The totally different types of the deformation in the corresponding models from these groups indicate the crucial influence of the basal complex on the deformation pattern of Odonata wings.
Fig 4.
Selected snapshots of the deformation pattern of the realistic wing models (Group 1).
The different configurations of the basal complex result in the different types and magnitudes of the deformation.
Fig 5.
Localized stress in the realistic models (Group 1).
The models are subjected to 0.19 mN point force applied to RP from the ventral side. The regions with the maximum principal stress larger than 5% of the ultimate tensile strength of the wing material are marked with the red colour.