Co-Cured Wing Structure Using Dry Carbon Fiber Application/Overbraiding & Resin Transfer Molding
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- čas přidán 2. 08. 2024
- Watch a demonstration of how Hawthorn Composites can create a co-cured wing structure using a combination of dry carbon fiber application & overbraiding, liquid infusion, and Smart Tools. Learn more about this application at hawthorncomposites.com/portfo...
0:00 Overview
0:32 Layup
1:39 Closing the Mold & Bagging
2:34 Infusion Process
3:20 Smart Tool Extraction & Reforming Process
3:58 The Hawthorn Advantage
Hawthorn Composites delivers high value complex composites by deploying low cost materials with liquid infusion and novel manufacturing methods. This combination significantly lowers labor and material costs while maintaining structural integrity and weight neutrality when compared to conventional prepreg and autoclave cured components.
Today we will be demonstrating the advantages of fabricating a co-cured control using braided carbon fiber sleevings and resin transfer molding of epoxy resin.
To start, we pull braided biaxial dry carbon fiber sleevings over each of the three smart tools to create the sheer webs and part of the structure of the control surface. The Smart Tools are fixtured together to prevent shifting, and then pre-shaped dry carbon fiber noodles are secured at each smart tool interface.
Next, 2 layers of quasi-isotropic carbon fiber fabric, called QISO, are laid into the mold to form the lower skin of the control surface. Veil can be attached to the outside of the fabric to assist with resin & air propagation. We then place the laid up smart tools into the mold on top of the lower skin and one layer of the upper skin fabric is pulled over top of the tools. Next multiple custom formed noodles are placed into the trailing edge of the control surface and sealed by the lower skin. Finally, the 2nd layer of the upper skin is pulled over the 1st layer and secured in place.
Now that the lay up is complete, we begin to close the mold. We place the upper half of the clamshell mold onto the lower half and secure it with bolts. Next, we attach the first set of end plates, called intermediate seal plates. Once these are secured with bolts, vacuum bags are pulled through each of the Smart Tools and sealed to the intermediate seal plates. This setup provides a vacuum & pressure barrier between the internal tool cavity and the dry carbon fiber preform. This will allow us to maintain vacuum & pressure throughout the process.
After the vacuum bags are secured, the 2nd set of end plates, called pressure plates, are attached to the mold. This will allow the internal cavity of the mold to be pressurized to 75 psi of pressure, creating a reverse auto-clave like effect inside the mold.
We are now ready to begin the infusion process. The mold is placed into an oven and plumbed for infusion. We attach two resin exit lines and one resin inlet line to the mold. We will be making the control surface using light resin transfer molding. Next, the mold and resin is preheated and resin is infused to fully wet out the carbon fiber preform. Once complete, the exit and inlet tubes are closed, allowing the pressurized Smart Tools to create a hydrostatic force to consolidate the preform and voids during cure.
After the cure is complete, we remove the mold from the oven and disassemble the end plate. Next vacuum bags are removed from each cavity and the now elastic Smart Tool is extracted with low force from the cured composite part. After extraction, each Smart Tool is placed into the pre-heated reforming mold, the upper lid of the reforming mold is secured, vacuum bags are pulled through the Smart Tools and sealed to the mold, and vacuum is pulled to reset the geometry of the Smart Tools. Once cooled, the now rigid Smart Tools are ready to begin the next production cycle.
Using the combination of techniques shown in this video; including Smart Tooling, low-cost raw materials, and resin transfer molding, enables the design and fabrication of low cost composite parts with structural integrity and weight neutrality when compared to conventional prepreg and autoclave cured components.
When comparing the Hawthorn method of manufacture to the industry standard manufacturing methods of pre-preg and autoclave cure, we commonly achieve cost savings of 20-50% over the baseline.
Hawthorn Composites utilizes dry carbon fiber, resin infusion, and novel manufacturing methods to make complex geometry composites parts that are equal in performance and quality to baseline manufacturing methods at significantly lower cost. Learn more about Hawthorn Composites at hawthorncomposites.com - Věda a technologie
What a surprisingly transparent glimpse into how complex composite structures are made. Thanks for sharing!
Howdy. As someone hearing impaired, thank you for the clear narration and closed captions. Excellent instructional demonstration video.
no one will even come close when i stared building boats using these methods. holy smokes i love composites!
Ok
O yess that smell
That's brilliant molding technique. Excellent way to go finishing components.
One of the best manufacturing composites I have seen, with the right techniques and braided reinforcements
Elastic reusable inner pre-form!!! Guys, you're composite maniacs!
This is a great explaining for the making of an aircraft structure!
Great video, would love to see you guys do more.
This is truly outstanding!
Very impressive indeed!
Very nice! You can be proud of what you do.
These guys are two steps away from having custom tailored composite compliant control surfaces. -I mean they have stiffness which is the most important, but you take away the air blend between control surface and main wing while lowering weight, you got yourself a game changer in wing design.
Air bleed* through between control surface and main wing
Please continue uploading videos. 🙂
Nice work 👍
Well, next time I have a 10 billion dollar defense contract come across my table I'll keep you guys in mind.
Oh, it might be on your site but it might have been nice to see how scalable and modular this process is. I can imagine those molds and "smart tools" as well as the resin impregnation process facing increasing difficulty and variability as they scale up.
I don't know about difficulty. Can you elaborate? But issues with variability would definitely be a problem. It's not like you could easily make adjustments to such "smart tools", right? So everytime you'd need to swap the tools out for different ones, you'd need to pay quite a lot of money, as you're locked into their ecosystem of tools. But I guess the aviation industry doesn't care about costs as much as your average small business owner. Hell, even the cheapest Russian airlines don't care about any cost under 2000$ when it comes to repairing their planes.
@@diviscadilek1764 Difficulty with things like mold alignment and multi-piece molds, trying to get consistent resin flow through the entire carbon fiber piece, warping and thickness problems. "Difficulty" and "variability" have a lot of overlap, but in general there's a reason people don't use injection molding for parts that are meters long. I could see the cost going up exponentially as the size of the piece increases. For that roughly 1m square demonstration its not too bad, but for a 10 meter wing or flight control surface or even something like a monocoque chassis for a vehicle, these squishy inflatable mold pieces don't seem like they would scale well.
The solution deployed for this wing is very scalable to much larger parts, we use similar technology to make a approximately 12ft (3.7 meter) inlet duct for Kratos Valkyrie tactical UAV www.compositesworld.com/news/hawthorn-composites-awarded-structural-inlet-duct-manufacturing-contract- and we also made the wings and fuselage for the same vehicle afresearchlab.com/news/aerospace-systems-directorate-collaborates-with-partners-to-build-innovative-airframe/
@@HawthornComposites Thanks for responding. From my perspective it looked like it had a lot of the drawbacks of injection molding as far as scalability went, but if you're making 4m production parts its doable at least.
I could be wrong but I'm going to guess that it wouldn't be cost competitive with other composite manufacturing for less defense oriented project budgets like medium scale wind turbines?
Also: I miss the DoD days when people knew how to name projects. "Longbow Apache" makes sense. "Kratos Valkyrie" sounds like someone isn't even trying to pick names from the same sets of mythology.
Now that's a product demo video. So many industrial companies have been steered into product video that thing there selling perfume, not tools.
can you tell us where can we get this smart tool
Great job. What would be the max wing length using this tooling ?
Thanks
How thick is the fuselage made of prepeg composite fiber
Great video into the process. I'm curious about how many times you can reuse the smart tools...
Typically Smart Tools will last between 50 to 70 cycles
What are smart tool materials
How we made smart tool please inform me about your smart tools .
I'm very afraid to ask the final price of that piece of a wing
Is the smart tool a thermoplastic?
No, Smart Tools are not a thermoplastic, they are a form of an epoxy thermoset. Thanks Marc!
I've recently just become a carbon composite enthusiast.
I love how the word "quasi" is entering the English vocabulary. We've been using for centuries in Brazilian Portuguese.
It’s a real french word btw
Hello! Great video and channel! I did like to know if is there a way to calculate the right number of carbon foils to ensure a right strenght according to a definite weight of charge in axial direction. Any tools, excel page or something like this that could return the right value? Thank you!
We perform FEA to ensure we meet required design criteria. There are multiple software programs that enable FEA.
Catia V5.
@yo yo thank you, my question now Is: what Is the best way/software to test?
@@PierfrancescoAstorino Ansys ACP
@@PierfrancescoAstorino Even with the best software available (Abaqus and Catia by Dassault Systems, or Ansys). You still wont be able to calculate anything at all.
Because you need to test the materials you will be using to build the aircraft.
Not just the carbon fabric, but each style of fabric weave, each different layup direction, and any combination with the epoxy or resin matrix you will be using.
Each test specimen must be manufactured by yourself by the same method you will make the aircraft, you cant use other peoples material properties data because they invariably use a different glue or different method or different skillset than you.
And you need to test at least 30 specimens for each test to obtain statistical data because each sample will fail at a different strength reading and you need to calculate the average and minimum values.
You need 30 axial tensile, 30 axial compression, 30 transverse compression, 30 transverse tension, and several different shear methods x 30 each.
Which means you need several hundred material specimens FOR EACH material you intent to use.
Material testing machines start around $8,000 and go up beyond 250,000, and it will take you many months to obtain the data yourself due to labor, but good news is you can hire a private testing lab for about $200 per sample so if you throw money at the problem you will have you data within a month of two and around $20,000-50,000 in costs.
Then you can use this material data to enter custom values in ANSYS or ABAQUS (after you purchase these programs for the going price of around $45,000, plus annual fees). ...Or attend an engineering school and have free access to student non-commercial versions.
You see, Composites are very complicated. (To do it right, strong, light and stiff calculated to the Nth degree).
But good news is they are actually very easy for quick assembly and rapid prototyping of UAVs and RC airplanes and even small Experimental/Homebuilt airplanes.
You don't actually need to do any complex calculations if you assume a very low strength limit of approximately 0.003-0.005 strain. As Carbon Fiber usually breaks at 0.01-0.012 strain (1% stretch) And epoxy breaks at 0.015-0.02 strain. (Strain being the percentage of its modulus of elasticity or how much is stretches). So just use around 0.003-0.005 strain (0.3%-0.5%).
Fiberglass breaks at 4.5% strain (0.045) but since epoxy breaks at around 0.015-0.02, you cant fully utilize fiberglasses strength because the epoxy disintegrates before you utilized the full fiber strength.
You can obtain your own properties by calculating using a formula called "Rule of Mixtures"
Don't forget to add 5% of air bubbles to your open wet layup calculated values. (E.g. use 35% fiber, 5% air, 60% resin) and mix their material properties in this ratio for unidirectional fiber placement. Half the fiber value for +/-90 degree woven fabrics because half the fibers are laying wrong direction and don't help in any given direction.
Here are some conservative values:
E-Glass Tensile Modulus = 10,400,000psi x 0.003 strain = 31,200psi (tensile strength).
31,200 x 0.35 (35% fiber fraction) = 10,920psi
Mix epoxy with a modulus at 500,000 x 0.003 = 1500psi x 0.60 = 900psi (60% of your 35/5/60 composite fraction)
Add together your 0.35 of fiberglass and 0.60 of epoxy is 10,920 + 900 = 11,820psi for design allowable of 0.003 strain (3000 "micro-strain")
So E-glass and epoxy in tension is valid for 11,820psi which is conservative and will certainly work for you. Next, calculate the same materials at 45% fiber fraction and 52% resin and only 3% air. You will see a significant improvement in strength allowable.
Or use whatever ratio your manufacturing technique allows: 70/29/1 etc.
Compression is about 85-90% of tension value so 11,820 x 0.88 = 10,401 psi compression allowable.
Thats at 0.003 strain (3,000 microstrain as its called).
You can typically use 0.005 as The fibers and epoxy begin to fatigue and break down above 0.006 for many glass composites.
And those numbers are for unidirectional fibers. For biaxial cloths you must half your fiber strength as its only half laid in the proper direction. (So 31,200 x 0.35 x 0.5 = 5,460). Then add 900psi from epoxy = 6,320psi tension allowable for 0/90 woven or +/-45 degree biaxial fabric. Use 6,320 x 0.88 for compression allowable.
Shear allowable is going to be around there or maybe slightly lower.
Now plug these numbers into a simple beam calculator or spreadsheet.
Once you use "Rule of Mixtures" to calculate and test a few items you get a feel for it, you can stick to calculating major loads and then just use common sense for skin thickness. (Most carbon wing skins on slow UAVs and sailplanes is 2-3 layers of 5-6oz carbon cloth with about 5-10mm of foam sandwiched in between). Larger RC airplanes only need one layer of 5oz or 2x layers of 2oz, and smaller planes need 2oz-3oz cloth.
Now get yourself some epoxy & reinforcement fabric, rovings or carbon Tow ordered and start doing it.
I highly recommend searching for:
"Rutan Long EZ build"
Its a great construction process that doesn't require molds or tooling except for scissors paint brush and hand saw.
Why so *EXPENSIVE* ??😉 Love RTM.
Это очень короткая часть крыла, а как соединяются все части крыла в одну деталь?
any solution for beter stick? i mean wich can be used in high temperature like aluminium or stainles still. The problem of this is the low temperature accepted by resin. The galvanic problem i see alredy solved but we need better catalist to stick carbonfiber. Ceramics are good at high temperature and we know are working like this polymer resin.
Those machined aluminum dies look very expensive. Is this technique primarily intended for mass production use to keep the per unit savings in the 20-50% range shown? Further more, how large can you scale this construction technique?
Yes, this is for serial production and the only limit from a scale perspective is access to a large enough oven.
I was wondering that same thing. I dont know much about the other manufacturing process they mentioned. I do have a hard time believing that's anywhere near as economical as advertised. Not only is there a huge multi part mold but those specific vac bags and liners are part specific too. That means those also have to be manufactured. So there is another huge mold that is part specific.
@yo yo I think the target consumer is manufacturers and fabricators. Not really an individual.
@@marshallwages5035 price out an autoclave recently?
How about one big enough for a wing?
How about several dozen of them so you can make more than one wing per week?
It costs literally tens of millions of dollars for pre-preg/autoclave.
This process is not VBO (Vacuum bag only) it also applies significant pressure from the inside of the part which gives it an autoclave level quality without an expensive autoclave.
@@TheJustinJ nope and never said i did. Nor did i say im an expert in manufacturing. I would be more than happy to admit im wrong if you wanna do the work to prove it. I love how people like to atate their opinions or ask a question in a way that doesnt give any real information or fact. Yet they act like thats what it is.
What are this smart tools made of?
Our smart tools are made of proprietary fabric and a shape memory polymer resin that is actually a epoxy thermoset. You can learn more about it here: czcams.com/users/SmartTooling
I thought the advantage of prepreg is the lack of air bubbles because of the very short path out of the material. I wonder if one could impregnate the sheets and directly afterwards lay up wet sheets in those smart tools. In a cold room.
In this technique the resin is drawn into the carbon under vacuum inside an oven. The chances of air bubbles is small. This technique also does not require use of an autoclave oven. Boeing uses a sort of similar process in Australia making 787 parts with good success after a slow start.
@@bradster1708 now I wonder how resin behaves when I send it through a heated nozzle ( 3d printer, or due to friction ) into vacuum. Does it evaporate? Below some pressure a lot of materials are either solid or gaseous. Chemical Vapor Deposition. Then as the pressure due to the resin itself rises, the new resin going through the nozzle stays liquid.
Because the polymer tools can apply pressure both during infusion and cure, any air is driven out of the curing composite.
This solution deploys automated carbon fiber sleevings and isotropic broad good to eliminate most of the labor that would be associated with applying carbon fiber prepreg.
You could just use prepreg and not do an infusion and it there would be less steps. Also consolidation in the transitions from web to skin could be controlled a bit more maybe.
The smart tool is the secret. 150+psi will be magic. Ive made silicone intensifier parts where the layup looks like trash but, the final part is impeccable.
Prepregs may have some issues but, seems much more reliable than sucking/blowing hot resin into a super heavy tank of a mold inside a 200+C oven. 😅😅😅
I want to machine your tooling
Hello Hawthorn Composites, I would love to work with you in the automatization of production of tis product. Why not, right?
This is a representative part that could be a control surface on a business jet or wing on a small UAV. In regards to automation, Smart Tooling (czcams.com/users/SmartTooling) is compatible with robotic handling, automated fabric placement methods, automated mold opening/closing, and automated infusion.
So do the smart tools operate on some form of witchcraft or is it just your more run-of-the-mill magic?
We'll leave that to your discretion ;) watch more magic at czcams.com/users/SmartTooling
No ribs? The wing skin must be very thick resulting in very heavy wing. But still very interesting.
Check out how Mike Patey installed ribs to his wing slats: czcams.com/video/WhLTUCTdYYk/video.html
The shear webs provide the stiffeners for the structure.
We're going to start manufacturing in USA. I'll contact we have a meeting 🤝
Damn, you have much more money in tooling than you would have had hand laying that part over cut foam...
I imagine such methods aren't precise enough for aviation, so you need a mold wither way.
What we have found is that if you a making more than 6 parts, a Smart Tooling solution will be less expensive than using machined foam, because precision machined foam is so expensive
@@HawthornComposites 3D printed dissolvable foam. Much more geometry could be added to lighten and strengthen the parts
Multiple machined molds has to be really expensive for a 3ft part? Multiple molds and a massive oven for one full length single wing...that has to be insane expensive.??
These molds are 10k €
If your making a production UAV wing or business jet/UAV control surface and want good compaction during cure, you will need a mold to make washout cores or multi-piece metal mandrels and silicone bladders that you pull over the cores/mandrels. You will also need a cure mold. This solution generates lower labor cost and higher quality with similar or lower capital costs for molds/mandrels.
@@HawthornComposites wasn't knocking ya, just in awe of the efforts ect..
@@HawthornComposites Can't disagree with this statement. It's well written. May I ask, what is your vacuum pressure in the oven??
@@keronGR You want as much vacuum as possible with any CF manufacturing.
Mein gott muss das sein
I wish all these equipment were under 300 dollars 😪
Thank Sir 👍😊, God Heavenly Father Jesus Christ Joseph and Mary Blessings United States of America today
Low cost Carbon Fiber an oxymoronic Nicety for the rich
Good lookin' part, but seems way too labour-intensive.
this guy sounds like bojack horseman from bojack.
Perhaps carbon skimming isn't the best... yall make wings for my car?
Just 1 clip??...(!!!)
Subscribe for more in 2022!
Am I the only one, who thinks it is too much manual work for cost savings in mass profuction?! They even use manual keys, not akku or pneumo!
Why to put parts in a huge oven when you could directly apply heaters on or In the Alu-forms together with thermal sensors for an accurate temperature control?! Isolate them outside and one could save, I bet, >90% of electicity costs compare to that huge inefficient oven.. And time of course, because to put the thing in the oven, attach vaccum there again. hoses and so on.. again manually... Then detouch. And wait till whole oven will cool down.. each time!
Instead of a simple automated press they bolt and unbolt things together.. manually each time. With manual tools. Same for re-shaping of forms.. With the press big enough one could produce one wing at a time, not just 1m part of it.
Extremely unoptimised procedure.. year 2021.. Sure, one can use it for private Jets or small series, when price is originally set high. But any startup which will really want to mass produce same staff, will jump forward just by optimised procedure, not even because of another technology..
I can see that, but t's done that way for higher quality. The higher the quality the less chance for failure. And the FAA doesn't care about what you have to pay to get a part that won't fail.
I hope the efficency of manufacturing gets improved upon. This looks promising. It would be nice to have affordable carbon fibre products.
We agree that a lot of this process could be automated, but this is a self-funded demonstration so we're not going to fund all the automation. You can check out another case study where we did use a self-heated out of oven/out of autoclave mold smarttooling.com/portfolio/co-cured-i-beam-using-bladder-smart-tools/
'low cost"
Apparently, it costs less than the traditional way of manufacturing carbon fibre composites
We did achieve a 67% reduction in labor hours in producing the inlet duct for the Kratos Valkyrie tactical UAV using a similar solution www.compositesworld.com/news/hawthorn-composites-awarded-structural-inlet-duct-manufacturing-contract-
Looks overly complicated
If you want to shake up the world and be a household name for a world first...message me. I've rough crunched the numbers, the flight time would be 7min max at best, but the power to weight would equal a F22 Raptor.
Do not try this at home!
LOL, this is NOT low cost or efficient. There are much better ways.
which are the better ways? using prepreg