Shock-dissipating fractal cubes could forge high-tech armor:
Tiny, 3-D printed cubes of plastic, with intricate fractal voids built into them, have proven to be effective at dissipating shockwaves, potentially leading to new types of lightweight armor and structural materials effective against explosions and impacts.
"The goal of the work is to manipulate the wave interactions resulting from a shockwave," said Dana Dattelbaum, a scientist at Los Alamos National Laboratory and lead author on a paper to appear in the journal AIP Advances. "The guiding principles for how to do so have not been well defined, certainly less so compared to mechanical deformation of additively manufactured materials. We're defining those principles, due to advanced, mesoscale manufacturing and design."
Shockwave dispersing materials that take advantage of voids have been developed in the past, but they typically involved random distributions discovered through trial and error. Others have used layers to reverberate shock and release waves. Precisely controlling the location of holes in a material allows the researchers to design, model and test structures that perform as designed, in a reproducible way.
The researchers tested their fractal structures by firing an impactor into them at approximately 670 miles per hour. The structured cubes dissipated the shocks five times better than solid cubes of the same material.
(Score: 4, Informative) by c0lo on Thursday July 09 2020, @10:18AM (2 children)
670 miles per hour is about 300m/s. Which is subsonic in air, even more so in solid media.
No info about the weight of the impactor, no info about the thickness or the materials they used for their "fractal cubes", not even a DOI!!! (which is currently TBD even at the source [lanl.gov])
Apologies for being totally unimpressed, based on the provided info I don't have reasons to be otherwise.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: -1, Flamebait) by Anonymous Coward on Thursday July 09 2020, @10:47AM
In other words,
Or, not.
Very informative article, for those in need of High-tech Armour, like criminals and racist cops. STEM, again? Science, Thievery, Evasion, and Munitions.
(Score: 2) by Rupert Pupnick on Thursday July 09 2020, @01:37PM
Well, it's phys.org...
(Score: 2) by Phoenix666 on Thursday July 09 2020, @01:12PM (5 children)
Dispersing the shockwaves from the projectile is key to armoring against higher calibers. I saw a video recently of an experimental bulletproof vest rated to stop a 50-cal bullet; the vest prevented the bullet from penetrating, but the shockwave still would have snapped the wearer's spine and probably killed him from internal bleeding from ruptured organs.
Washington DC delenda est.
(Score: 2) by Runaway1956 on Thursday July 09 2020, @02:55PM (4 children)
Was that a .50 M2 machine gun (Ma Deuce) or was it a .50 muzzle loader? Your description sounds more like the former, and I don't think there is going to be a human portable armor that will deflect that round for a long, long time. The Twelfth of Never, maybe.
(Score: 2) by Phoenix666 on Thursday July 09 2020, @03:45PM (1 child)
The former. This [youtube.com] is the guy I watched. The vest stopped the round, but seemingly at the cost of mulching the target's bones and organs.
On the bright side, there was another guy testing the idea of taking cover behind normal-sized trees and the ballistics gel dummy was quite safe there. It took a decent number of 50 cal rounds before he could pound/blast through the trunk and get the target.
Washington DC delenda est.
(Score: 2) by Runaway1956 on Friday July 10 2020, @12:37AM
Yeah, oww! The thing about a Ma Deuce, you have hundreds, or even thousands, of those projectiles flying around. Take two or more of them, and set them up to catch your targets in a crossfire. They'll tear even most armored vehicles to shreds, given a few minutes. Put AP rounds in them, and it won't take minutes, but seconds.
(Score: 0) by Anonymous Coward on Thursday July 09 2020, @08:12PM (1 child)
.50-140-600 Sharps? I just love how "high-caliber" is confused with "high-power". High caliber is just large bore. Power is mass x velocity times the Constant of the target holding still.
(Score: 0) by Anonymous Coward on Friday July 10 2020, @12:01AM
17.5kJ
(Score: 1) by nostyle on Thursday July 09 2020, @05:43PM
Just last night, I dreamed I was accidentally firing a railgun into the wall, and projectile failed to shatter under the launch stresses, thereby making a rather neat hole. As far as I remember, when the projectile velocity exceeds the speed of sound in the target, it causes melting/evaporation at the point of impact. I don't guess fractal design would make much difference there.