Maria Mingallon who graduated from the AA and its currently a professor at McGill University, along with students Jheny Nieto, Sakthivel Ramaswamy and Konstantinos Karatzas, study the architectural applications of the dragonfly wing. Videos, more images and potential architectural applications included in the rest of the post.
In the words of the team “the morphology of the dragonfly wing is an optimal natural construction via a complex patterning process, developed through evolution as a response to force flows and material organization. The wing achieves efficient structural performance through a nonlinear variation of pattern, corrugations and varied material properties throughout the structure.”
Below is an excellent diagram showing how the dragonfly wing is divided into various shape areas that are designed to handle force very differently, quadrilateral, pentagonal and hexagonal.
The team explains that the seemingly random variation in the natural pattern of the wings were in fact optimized to allow rigid and flexible configurations along the span of the wings that allow for a logic based use of ambient energy for the purposes of flight.
Based on the above diagram the general geometrical conclusions arrived at by the team were as follows:
1. The patterns of the wings follow the general tensile forces exhibit on the wing
2. The various shapes carry the responsibility of determining the amount of stiffness or flexibility in that area of the wing.
For example the quadrilateral areas on the edges determine the more rigid and stiff portions of the wing while the largely compartmentalized hexagonal areas are responsible for the areas more likely to bend and sway. Furthermore, connections between the cells also determined the degree to which adjacent cells were free to bend, that was also highlighted in the research:
“Two main types of joints occur in the dragonfly wings, mobile and immobile. Some longitudinal veins are elastically joined with cross veins, whereas other longitudinal veins are firmly joined with cross veins. Scanning electron microscopy reveals a range of flexible cross-vein and main-vein junctions in the wing, which allows local deformations to occur. The occurrence of resilin, a rubber-like protein, in mobile joints enables the automatic twisting mechanism of the leading edge.”
After understanding these various characteristics of the wing that could be applied to structural design elsewhere the students began to model their findings and ran various test deforming the meshes and analyzing the responses. Below is a video demonstrating.
The interesting part of all biomimetic research are its potential applications to the field, the next excerpt is a summary from the team expressing how they feel their research can be applied to construction techniques.
“Specialization of different areas for support and deformability is nearly universal in insect wings. These properties present to us an interesting field of research on structures that could change constantly, but retain their equilibrium through a complex geometrical logic. Buildings can be envisaged as envelopes made of complex flexible foils, abstracting the geometrical logic of the dragonfly wings. The property of rigid quadrangular geometry and a more flexible polygonal geometry could be used to build a surface…the experiment was focused on deriving the different morphologies that could be obtained by passive deformation under uniformly applied loads. The distribution of constrain points within the grid follows a similar logic to that of the dragonfly wing, in which the mobile and immobile joints are distributed in order to enable corrugation in a particular direction.”
More images below from the various tests run on the model. We will also be posting about Maria’s recent thesis project with AA as well. A truly exciting proposal. stay tuned.
maria just released her book on her thesis project, check it out: Fibre Adaptive Composite Systems