Nov 28, 2015 | By Benedict

Researchers at Purdue University have teamed up with General Motors to develop a new kind of 3D printed, energy absorbing material. The material could have a range of applications, from earthquake engineering to safer football helmets.

For many years, 3D printing has been used to develop materials with complex internal architectures, which would be impossible to create using other manufacturing techniques. 3D printed microlattice structures, for example, provide extremely resilient yet lightweight materials, which are incredibly useful for aerospace and automotive engineering. Boeing is one of several companies to have implemented precisely engineered, 3D printed materials with complex internal structures. The airplane manufacturer has recently declared its 3D printed microlattice material to be the “world’s lightest metal”.

Purdue and GM have created a 3D printed material, similar in functionality to Boeing’s microlattice, but with a distinctive honeycomb architecture, which contributes to the material’s high capacity for energy absorption. The honeycomb pattern could theoretically be scaled to any size, giving the material a wide range of potential uses. The "phase transforming cellular materials" (PXCMs) could be used in helmet construction, to provide greater shock absorption and minimize head injuries. Another potential use would be in the walls of buildings, to dampen earthquake forces. A smaller sized 3D printed honeycomb pattern would be used in helmets and other small objects, with a larger scale version being used in buildings.

"The main advantage is that not only can it be used as an energy absorbing material, but unlike many other materials designed for this purpose the PXCMs would be reusable because there is no irreversible deformation," explained Pablo Zavattieri, an associate professor in the Lyles School of Civil Engineering and a University Faculty Scholar at Purdue.

Whilst the research suggests that the 3D printed PXCMs could be used for a variety of purposes, the scientists admit that there is still work to be done before the material could be implemented into commercial products. "The ability to realize the energy absorption offered by PXCMs at various length scales makes it possible for engineers to integrate energy absorption as a secondary function into structures that are already in use," said Nilesh D. Mankame from the Smart Materials & Structures Group at the General Motors Global Research & Development Center. "It is currently in the realm of fundamental materials research and shows a lot of promise but is not yet ready for commercial applications.”

Structures made with the 3D printed PXCMs are able to flex back and forth, like a playing card. "It has two stable positions," Zavattieri said. "I push it and it goes to the other position. If you remove the force and the card returns to the original position, the mechanism is said to be meta-stable. Then you could combine many of these building blocks and have bi-stable or meta-stable materials, which gives us the flexibility to design these materials for specific needs. For instance, you might need materials with meta-stable unit cells for head protection in helmets, but then maybe you would need materials with bi-stable unit cells for buildings to protect against earthquakes.”

The researchers are confident that the flexible material could be used in other applications and industries besides those mentioned. "The energy dissipation due to the mechanical behavior of the unit cells adds to the intrinsic energy dissipation of the base material," Mankame said. "Many emerging materials like aluminum, magnesium and fiber-reinforced composites, that play an increasingly important role in the transportation, defense and construction industries, suffer from low intrinsic energy dissipation. The energy absorption capability of structures that are made of such base materials can be increased by incorporating PXCMs into the structures.”

The honeycomb architecture of the 3D printed material could be altered to suit a variety of different uses. Researchers believe that cubes, tetrahedrons and pentagons could also be used for different kinds of energy absorption. ”The fact that we demonstrated that phase transforming cellular materials exhibit the same levels of energy dissipation as traditional metallic honeycombs opens the door to use these materials in a variety of applications ranging from passive dissipation dampers in high rise buildings, to human body protection," said doctoral candidate David Restrepo.

The researchers’ full findings can be found in their research paper “Phase transforming cellular materials”, published in September’s edition of Extreme Mechanics Letters.

 

 

Posted in 3D Printing Application

 

 

Maybe you also like:


   






Leave a comment:

Your Name:

 


Subscribe us to

3ders.org Feeds 3ders.org twitter 3ders.org facebook   

About 3Ders.org

3Ders.org provides the latest news about 3D printing technology and 3D printers. We are now four years old and have around 1.5 million unique visitors per month.

News Archive