SCIENCE. Researchers French and singaporeans are working on the development of materials based in the surprising properties : instead of fine-tune when pulled, they increase, on the contrary, their volume. This character would be particularly interesting in structural applications, in order to combine lightness and resistance to shocks. Details.
Exit structures, honeycomb, place the materials based inspired of flowers. But flowers elastic. Researchers from the CNRS and Cnam have developed, in collaboration with the national university of Singapore, a new design material “auxétique” in which the network takes on an aspect of flowers with six petals are flexible and deformable.
- An insulating coating to the silica aerogel to an ITE proposed
Material classic vs auxétique © Blinking Spirit – Wikimedia CC
In other words, the material behaves in a manner opposite to conventional materials. When it stretches, instead of becoming more thin and see its diameter is reduced (like a rubber hose), a thread of this type will see its volume increase. A property could have numerous structural applications, particularly in the construction, in transport or in the manufacture of adjustable filters. But generally, these materials are structured to present a low resistance in time, with fatigue noted at the level of microstructures with sharp corners, sources of cracks.
A tapestry of flowers geometric
The geometry developed by the scientists, thanks to a mathematical method using original, is based on the use of regular shapes smooth distributed in a triangular network. They state : “In response to a pull, the petals of the structure unfold, leading to an expansion in both senses of the plan“. A behavior which would be the same in all directions when the network is subjected to a force in the plan. The floral pattern could therefore help in the design of objects made of metal or polymer, which would be both lightweight and shock-resistant.
- The standard plastics could be recycled into high-performance materials
- Aerogel-starch, an insulating bio-sourced full of promises
The work was published August 15 in the journal Computer Methods in Applied Mechanics & Engineering under the title : “Isogeometric shape optimization of smoothered petal auxetic structures via computational periodic homogenization”.