Simulations reveal the secret to strengthening carbon fiber | Hacker News Reader

Simulations reveal the secret to strengthening carbon fiber

ornl.gov

35 pointsgmays15 comments

Describing the issues behind the cost prohibition of material science experiments and discovery, then handwaving it by just saying we can use supercomputing is incredibly ignorant of how inaccessible and coat prohibitive supercomputers are. Not to mention, even if your supercomputer has an idea you still need a lab that can confirm the idea.

They spend a lot of text describing the fact that it wouldn’t be possible without Frontier, so I think they are aware of the cost. The whole ecosystem of little, easy to apply for compute credit grants, and then larger grants (like the one they mention applying for at the end) is part of the solution to that problem. It doesn’t seem like ignorance, but rather a choice to emphasize in the writing that they are part of the solution.

Yes supercomputer time is scarce and expensive.

Physical laboratory time, materials, and workers are also scarce and expensive. And physical lab tests can consume a lot of calendar time.

So, even with the constraints and costs, using the supercomputer to run 1,000 or 10,000 tests and then physical lab tests on only the few most promising results can still less costly in both funds and especially calendar time than the costs and time to run a similar number of physical lab tests to produce the results.

It is literally a balancing of the scarcity and costs of each mode of getting to the results, and those experts in the field, with their own labs, are making the claim that this is the way their research should proceed. Do you have actual information and specific knowledge that in fact proves them wrong (b/c that comment seems a lot more hand-wavey vs theirs)?

Only if the simulations are usefully predictive.

A lot of the physical lab tests end up showing effects we did not know exist, which is why they are interesting - simulations are historically terrible at predicting things we don’t know can exist.

See the pharma adventures in simulating potential drugs in the 90’s-early 2000’s. A lot of heat a noise for little actual effect.

>>Only if the simulations are usefully predictive.

Of course; if you cannot make your simulations produce realistic output you are either wasting your time or are clearly not yet done building your simulations.

>> A lot of the physical lab tests end up showing effects we did not know exist, which is why they are interesting - simulations are historically terrible at predicting things we don’t know can exist.

Of course, there are the lab surprises, discovery of penicillin an early famous one. I'm absolutely not saying supercomputing simulation should replace lab work — In my own shop I do lab testing well beyond where most would go to simulation, precisely because there's no substitute for seeing the physical side-effects. But when someone randomly claims the team publishing very useful work is somehow wrong to use simulation, I think the real researchers in their lab & at their terminals know better than that post.

I guess my point was less if the simulations produce realistic output, and more if they can be used to discover or model novel - but real - phenomena.

The closer we get to ‘the truth’ (if such a thing exists!), the more likely this is of course. Ideally we’d have simulations that we could even discover novel physics behaviors in that match real life!

Practically, most are simplified to the point that we can match behavior we already well understand, and maybe a few things can validate we don’t - which can help explore some of the gaps we haven’t been able to touch in the labs.

it’s not likely we’ll discover new principles that way though. But I’m guessing I’m just preaching to the choir, eh?

Yup, seems exactly right. And I think we might be nearly to the stage you're identifying, where there is enough fidelity in the models to discover new things. I sort of recall reading at least some of that happening in some fields of math?

> Not to mention, even if your supercomputer has an idea you still need a lab that can confirm the idea.

I think this is the critical aspect. You don't need to own a supercomputer to run simulations in supercomputers. Sometimes you don't even need supercomputers at all. It might be a challenge but it's not prohibitive.

What's clearly a blocker is the verification & validation work to assess if a specific model actually works. You need to run experimental tests to check if your module is any good, and you need to run experimental tests to check if the output of your computational models correlate with reality. That costs both time and money.

Supercomputers are becoming more accessible. There's a large gap between research and real-world use, such numerical models need to be thoroughly tested for robustness before they can be deployed.

And according to experience, such studies are usually conducted simultaneously with Laboratory experiments, or already have Lab results they can compare with. If not, such study acts as a new source of synthetic MD data which can be picked up by the experimental folks.

I do agree that people who write such blogs tends to sell these ideas or studies as finished products which they are far from. The product of such studies are usually a paper or in other cases a patent. An idea others can build upon, like lego bricks.

The durability and uniformity of carbon fiber makes it an attractive alternative material for mass-production of high-quality musical instruments. The difficulty is getting it to vibrate enough to sound like wood. Meanwhile, the prices of tropical hardwood instruments are becoming solidly prohibitive. The improvement described in this article, making carbon fiber thinner, lighter and stronger, may be significant in that market.

Carbon Fiber is the new Asbestos. Ask anyone who works with the stuff, and I wisened up after I used to print with Carbon Fiber PLA, one day I looked at my hands under a microscope and was horrified to see microscopic little carbon fibers embedded all over my hands. Washing my hands just spread them around. They were embedded deep in my hands, all over work surfaces and probably floating in the air. Horrifying!

I haven't heard of carbon fiber itself causing much cancer. There's a little chatter about carbon nanotubes potentially causing cancer but that's more of a "this looks sus" thing than a "this def causes cancer" thing. I'm sure you could use CF with cancerous plastics or whatever but that seems like a stretch.

But then I realized people screech about asbestos far in excess of the actual risk it poses, and here someone is screeching about CF. So it kind of is like asbestos in that way.

Task failed successfully I guess.

I am not sure that's an entirely fair comparison, there's plenty of data on how dangerous asbestos is (if it's disturbed - lots of it is hanging around in walls etc. and not causing trouble... yet...) CF is less well-studied, though of course we have lots of carbon compounds in our bodies, unlike scratchy silicates, which might suggest it should cause us less harm. But it'd be good to have the research to confirm that.

Isn't this true for regular old fiberglass as well?

We often see people working with those materials wear protective equipment (full coveralls, breathing / eye protection).

Very interesting, thanks for sharing your experience. But maybe this is the case for carbon fiber based filaments only (i.e. this is likely <1% of carbon-fiber as the use-case of 3D printing carbon fiber based hybrid plastic filaments is a new thing), and that most real-world carbon fiber is in the form of flat sheets whereby I doubt there are strands coming out.

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