Another breakthrough for space travel, as 3D printing has allowed for the creation of lattice structures which could one day be used to help absorb vibrations spacecraft withstand whilst travelling. The structure can also help take more weight, applications could also include use in propellers, turbine rotors and rockets.
Researches created a structure with a lattice spacing of 3.5mm, out of plastic, which was 3D modelled and printed on a 3D printer. Steel cubes were embedded inside the lattice, which acted as resonators. The group was led by Chiara Daraio, a professor of mechanics and materials.
“Instead of the vibrations travelling through the whole structure, they are trapped by the steel cubes and the inner plastic grid rods, so the other end of the structure does not move,” explained Kathryn Matlack, a postdoctoral researcher in the group.
Most vibration absorbent materials are usually soft, such as various types of foams, so it’s interesting to know the ETH research team was able come up with a structure that is rigid, but does the same job. One particular feature of this alternative method means it is able manage weight well, unlike other softer materials that absorb vibrations.
“The structure can be designed to absorb vibrations with oscillations of a few hundred to a few tens of thousand times per second”, explained professor Daraio. “This includes vibrations in the audible range. In engineering practice, these are the most undesirable, as they cause environmental noise pollution and reduce the energy efficiency of machines and vehicles.” Another comparison to other materials shows that the lattice structure the ETH team came up with is able to absorb a bigger range of different vibrations, including faster vibrations, but especially slower vibrations.
Plastic isn’t the only material this structure can be printed in either, other materials such as lightweight metals and be used. Any lightweight material could work, so long as it was in a lattice structure, and could have the resonators with a larger mass density embedded inside of the lattice. Everything to do with the structure would need to be aligned perfectly for the vibrations the structure would have to absorb.
The absorbers are pretty much ready to be used within applications, but they’re limited somewhat by 3D printing technology itself, the researchers say. This is because 3D printing technology is still aimed mainly at small-scale production. Another problem with this method so far is that the parts that are printed, aren’t quite at the level of quality of parts created using traditional methods. It’s all a matter of waiting for 3D printing technology to be more viable option for industrial use, though thankfully the wait shouldn’t be very long at all. Once ready, the team are sure that their absorbers could go far with a wide range of successful applications.