Aerospace Composites: carbon fiber, glass fiber and Kevlar in aerospace applications.
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- Опубликовано: 9 окт 2020
- Sometimes choosing the wrong support material can have devastating consequences…
The Terran Space Academy is dedicated to educating you so you can avoid these mistakes and have a long and healthy career in the space industry…
This course is the first in a series on Space Engineering…
This lesson will be covering Composite Materials for Aerospace Applications…
(and where I sometimes say millimeter... I meant micrometer... I have no mu key...)
Composites are light and can be shaped into nice curves for aerodynamics, they are strong at normal temperatures, but most cannot survive temperatures above 200C, and become very brittle and weak with cryogenic temperature exposure. The most successful use of composite materials to date is the Electron Rocket by Rocket Lab, a US-New Zealand company. This is the most innovative space company flying next to SpaceX. Like SpaceX they have embraced vertical integration, designing their own cryogenic systems that allow them to have composite liquid oxygen tanks. This is a very big deal as it is extremely hard to get a fabric to contain a gas or liquid, and cryogenic temperatures usually cause composite materials to become too brittle and fail. This company has not only solved this problem but designs its own cryogenic valves. Rocket Lab also designs the avionics and control computers keeping it in control of its designs and making it less dependent on outside vendors, which may not be as dedicated to quality control as your company.
These composite rockets have proven themselves as an excellent choice for small payload deployment and composite materials are the perfect choice for the spaceplanes and suborbital capsules we covered. But as Elon Musk discovered when he tried to use composite materials for his innovative Starship design…once you get to larger volumes and colder cryogenic temperatures…and you must reenter the atmosphere from orbital or translunar velocities…these materials are a poor choice. Remember that volume increases cubed while surface area is squared. Let us look at where trying to use composite materials in the wrong application led to the shutdown of an excellent spaceship design and the wasting of hundreds of millions of dollars.
The X33 was going to be a single stage to orbit spaceship to replace the space shuttle. It was going to use an innovative linear aerospike engine that could have revolutionized rocket propulsion. Everything was going great and the ship was almost completely built when they hit a snag. Composite materials had been chosen for the fuel tanks. The funding for the ship had been predicated on this application. The engineers tried and tried to solve the problem of a large composite tank being strong enough to hold the volume necessary to get this massive ship into orbit. The engineers had to make the composite layers thick to prevent gas leakage and prevent fracturing from the very cold cryogenic fuels. Especially the liquid hydrogen. Liquid hydrogen must be kept below 20 kelvin and this extreme cold will make almost anything brittle enough to fracture. While the materials could have worked with liquid oxygen and supercooled methane or RP-1, they could not get it to work for hydrogen. The engineers went to the administrators and told them that they could easily solve the problem with aluminum alloy tanks, but it could not be done with composite tanks. The administrators told the engineers that they had to use composite tanks, or the project would be canceled…and it was. This is a very good lesson in why allowing non-scientists and non-engineers to make critical design choices for a spaceship is a very bad idea…the N1 failed because of administrative interference in design choices…and the X33 was canceled because the administrators…trying to make politicians happy instead of building the best possible ship...failed to make the necessary changes to save the X33.
aerospaceengineeringblog.com/...
www.wired.com/2016/01/how-fas...
www.rocketlabusa.com/electron/
www.virgingalactic.com/
Corrections: a few places I keep saying millimeter instead of micrometer... no mu key on my keyboard but I think the error is obvious. 10mm would be the size of a little finger. 
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My compliments on an extremely well done presentation of a complex & highly misunderstood subject. Having worked the X33 program you are so, so correct. Keep up the good work.
Thank you so much Jim! We really appreciate your saying that!
Excellent presentation. We are off and running in the race to space. Wait, we ARE in space already!
It's the new addresses we are reaching for that makes it all so amazingly exciting. Please keep up the great work!
Thank you so much!
Thank you for making a concise video explaining the beginnings of composite materials. I feel like I have a better understanding of both what they are and a glimpse into the history of were they derive from.
You are most welcome and will probably love today's lesson!
Concise and well presented video. The old Corvettes had a thin plywood form under the fiberglass.
I'd forgotten about the X-33...
That's right! The X-33 was cool but single stage to orbit will always have limited payload, until we get nuclear, or fusion, or antimatter! Love the antimatter.
Great video! I learned a lot. Thank you!
Glad you enjoyed it!
I hope you have a million subscribers soon. We have a solar system that needs exploring and your videos are an excellent introduction to the knowledge the world needs.
Thank you so much Kenny!
I hope you can do a video on calculating orbits, understanding orbits, rendezvous, and docking orbits in greater detail.
That is an excellent idea. I will put it on the list :-)
Nice video. Looking forward to learning more and applying it to my next awesome career in Space robotics.
A very awesome choice of career :-) huge potential.
Great Intro, thanks a lot.
Glad you like it!
This is top notch,good job
Thank you!
When you were stating the thickness of fiberglass, aramid, carbon fiber.....perhaps you were stating some specific application thickness of multiple plies? With the possible exception of glass mat a single layer is only a fraction of a mm thick. The specific thickness depends on the weight per square yard (or sq. meter) of the fabric. For example it might be 3.0 oz., 5.0 oz. or 7.0 oz., fabric. Obviously the 7.0 oz. is thicker than the 3.0 oz. For example 3 oz. E-glass is 0.0046" (0.11684 mm) thick, whereas 7.5 oz E-glass is 0.0107" (0.27178 mm) thick. Even super heavy duty 40.0 oz. E-glass cloth is only 0.98044 mm thick. It takes multiple plies of material to get a product a few mm thick......
I’m pretty sure there was supposed to be a point in there :-) thank you for catching it. 0.10mm
@@terranspaceacademy I was about to comment that I have never seen 8mm diameter carbon filaments! 😳 pesky metric system eh? 🤣
This is a great intro video to composites very well done. 👏
Thank you very much!
Great informative video. Easy to understand and well presented. Thank u.
Wow great video
Thank you very much
Informative 👋👋👍
Thank you 👍
Funny you mention Virgin Galactic, I just got hired there for a composite tech position and was brushing up on my skills and came across this.
Congratulations Ethan! We hope it helped. Please stay in touch and let us know how things go! Spaceship 3 is beautiful and we did a lesson on long term VG prospects... let us know what you think.
@@terranspaceacademy Hey thanks! Today is day numero uno, your video definitely helped. I will definitely stay in touch and let you know how thing go in as much detail as I am allowed to provide. Just hope my carbon skills are up to snuff!
Mate, sorry to point it out but you got the units of fiber thickness wrong :/ "8mm thick"... i think it was supposed to be micrometers, microns or something?
I did indeed... I had abbreviated with just mm instead of mu-m and read it as millimeters instead of micrometers. I write and edit these but when I'm reading them to narrate I don't think too hard about what I'm saying or it can make the speech halting. Totally blew past that one. That would be a rope I'm sure :-)
I'm thumbs up number 50 😁🤘🏾🎉🎊🎉🎊🎉🎊🎉🎊🎉🎊🎉🎊🎉🎊🎉🎊🎊
Thank you very very much
Basalt fibre, cost benefits ?
Basalt?
See "High Performance Composites" periodical
ok
See Xcor Lynx cryogen valve patent
thanks
They should of used metal hydride for hydrogen tanks
metal hydride? Isn't that a little explosive? Like AlH2 etc...
Pretty sure fibreglass doesn't have 300 GPa strength otherwise we'd be taking elevators directly to space.
I'll pull an Erkle... "Did I say that?"
I think you made a mistake in the temperature that Carbon fibers can resist, you said it is 200 degrees centigrade but the correct information is about 3000 degrees.
In oxygen? I don't think that's accurate but I'll double check...
It looks like most are limited to around 100C which was my assumption, but specialized carbon fiber reinforced carbon matrix composite can tolerate temperatures above 2000℃. Thanks!
8mm? That's as big as a pencil. Are you sure you didn't slip a decimal point or two?
I did indeed... that would make a cable. I didn't have a micrometer symbol after I researched and wrote the script so it was just "mm"... my bad.
3:55 every "millimeters" should be "micrometers" (microns)...
Indeed. I remember that. Ropes instead of threads I guess :-)
As usual, bureaucrats and politicians screwing things up. Good presentation. Perhaps Elon Musk could run for president?!!! NO WAY! 😁
Sadly like Schwarzenegger he was born outside the United States :-)
@@terranspaceacademy Ironically he would do a much better job than the current occupier of the White House in my humble opinion. Then again...who wouldn't?
6:50 What curvature?
The earth is flat!
Yes of course!
Joking I hope :-) You are joking right? With all the reality denialism going on I'm never sure...
@@terranspaceacademy yes it was a joke =)))
By the way, I appreciate your work, well composed videos!
Thank you so much!!