Swinburne researchers are turning origami shaped two dimensional (2D) materials into useful three dimensional (3D) ‘metamaterials’ that could replace aluminium foam use in train manufacture.
Metamaterials are materials that combine composition and shape to produce properties different to the material alone. A prime example are foams, which become lighter than the base material, but have a relatively robust honeycomb structure.
Aluminium foam is commonly found at the core of the panels on trains, which are known as sandwich panels because they are essentially two thin tough sheets of material bordering a foam core. These are essential to the lightweight strength needed to make trains cost effective to run. But if a train were to hit something, the material properties of these panels make them quite brittle.
Professor Guoxing Lu from Swinburne’s Department of Mechanical Engineering and Product Design Engineering is working on a project with the Rail Manufacturing Cooperative Research Centre to find a better metamaterial to strengthen the core of sandwich panels.
Lu’s unique inspiration are the Miura-origami shapes used in very light and strong space ‘deployables’, such as satellite solar panels that must fold up during transport and unfold in space.
The folds are named after inventor, Japanese astrophysicist Koryo Miura, who worked on designs for folding a single flat surface, such as a sheet of paper, into a smaller robust shape.
Lu is working with aluminium, one of the materials of choice in the transport industry for its low cost and light weight. His latest analytical and numerical simulations of Miura-origami aluminium 2D folded structures, welded into a 3D shaped materials, has shown better energy absorption than conventional honeycomb structures at low to moderate load intensities.
This work is being done in collaboration with Professor Zhong You from Oxford University, Professor Dora Karagiozova from the Bulgaria Academy of Science, and Professor Yan Chen from Tianjin University, China.
Such origami metamaterials, said Lu, could be fabricated by stamping, lasering or 3D printing thin metal sheets (as pictured) or carbon-based composite materials, which could then be weld together to form 3D materials.