Composites Corner
 

This is the only part of the internet I look at pretty much everyday as I'm always finding out about cool stuff or learning something new about something I know nothing about.

I've been a member on here for over 7 yrs and not posted much so I thought it was about time to add something worth while to the 'Pelican knowledge pool' which is part of what makes this forum such an interesting place to visit.

I know a lot of people here dig new technology, materials and manufacturing methods needed to make all things fast and cool or just cool so I thought a thread on all things composites especially carbon fibre composites might be of interest.

Guess as I've started this thread I should contribute as often as I can and the best way I think I can do that is to share as much of my knowledge/experience learnt from over 25 years working in the super road car/world championship motorsport industries as I can give away without causing any conflict of interests with the work I've done or doing.

Don't consider myself a top world class expert but I do know enough to hopefully answer any questions, guide/advise with any carbon composite projects that a Pelican would like help with. Carbon fibre spoon anyone :cool:

I'm not sure how this thread topic will evolve but I'm hoping it will turn into an interesting read as people add links, videos, experiences, pictures, first hand knowledge etc

I collaborated on several studies of several composite materials back on the 80s. Carbon/epoxy, carbon/aluminum, etc. can't tell you much because I have been out of it so long.

I have tons of carbon fiber pieces on my various motorcycles and am always amazed at the overall positive marketing ability of this stuff. It doesn't seem very strong to me at all, and it seems to shatter, rather than deform or crack. What am I missing here?

Carbon/epoxy does shatter rather that deform in dimensions common to metals, but at much higher loads. Youngs modulus is pretty linear.

I am guessing there is a huge difference in the quality and level of engineering that goes into consumer-grade cosmetic CF parts, vs. structural and/or racing CF parts. The former might more often be lower quality, with low-cost epoxies and/or curing methods. Whereas the latter structural stuff is more likely to be well-engineered, use higher-end pre-pregs and cured in high-$$ autoclaves (ensuring proper saturation/consistency, etc.), with much better QC.
Not to mention, I am sure there is no shortage of CF garbage out there (primarily coming out of SE Asia?) that ends up on many consumer cars/bikes/etc.

I could be way off though. Hopefully, Stephen will be along shortly to school us all!

It obviously has it's place and limitations. Although I think another one of the key benefits of CF (where applicable/useful) is the ability to "tune" the modulus (and resulting end-product characteristics, harmonics, etc.) simply by altering the pattern/weave, orientation/lay-up, and epoxy type/content/saturation/etc. used. Pretty versatile stuff it would seem...

Filament wound carbon fiber parts are driving prices down in the sports world. No "layup" from sheets of fabric, the fiber (usually wet resin but can be dry) is wound with automation on to a mandrel in the shape of the part.

My first real job out of college was as the business manager for a small pultrusion company back in 1990. We did a lot of military work making parts for the Stealth bomber, arrows for Browning, tubes for Kestrel and made a huge carbon fiber main sail mast. The company was sold to Bauer and moved to Canada when we started to make perfect hockey stick shafts. Everything prior of any length had a slight curve to it. It was a fantastic experience.

Captain Ahab, i will have a need to employ your expertise and services if stars align by the end of the year.

Cool stuff

I make small parts and repairs mostly on boats with epoxy and fiberglass. Pretty simple to work with once you get the basics. Swapping carbon cloth for fiberglass then vacuum bagging ups the game. Seems wet out, keeping weight down and strength are issues no matter the material. Yeah, I know, I'm an amateur. Ultimately the engineering is what impresses me the most. Why make it exactly this thin/thick? Why the specific epoxy and then ratio? Thinking about boats or F1, the dynamic loads on such a think/light material blows me away.

Even the simple carbon fiber, or is it fibre? :) , front fender seems to weigh less than nothing. Crazy.

Very cool. I'll post below since we don't do any race stuff!

I own a composite design, tooling, manufacturing and assembly business in North Carolina: VX Aerospace. We are small (15 employees) but have a great reputation in the industry.

The other owner is the real composite guru (I am the CFO and COO). He is a member of the Standford Composites Design Workshop, numerous other orgs and has a very wide set of relationships in the industry.

We do a lot of really neat stuff in transportation, aviation (we have our FAA Part 145 for Composites) and DoD - we are making a really interesting UAS that we designed called Dash X.

Bob's Kitty Hawk UAS design won an award in Paris two years ago.

http://forums.pelicanparts.com/uploa...1494339620.jpg

Very interesting industry.

Perfect as in straight? There's still a lot of work to do on sticks, I am about to get into and try to improve the end product. There are way too many sticks breaking at critical moments.

Interesting...and I know nothing about the sport other than one of my best friend's from HS owns this company:

About BASE - BASE Hockey - Custom Hockey Sticks

2 degrees of separation!

Subscribed! I don't know very much about the stuff, but I'm fascinated by it and the process. Looking to learn more...

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Neat. In 1991 or so purchased a Brent Trimble designed Kestrel CS-X atb. Also with it had a flat bar all carbon fiber, with the brand name Aerosports. Took a chance on the monocoque frame. Very impressed with its robustness and even after some hard impact crashes. They were vac bagged.

Though todays road bike frame layups are completely different, wafer thin and not kind to getting bumped.

I've been following the news of LeMond Composites for his eventual return to making CF bikes. But as of late there's drama in the newly established company in Oak Ridge, TN.

Apparently a key principal, Connie Jackson was instrumental in a new revolution of creating a lower cost and more efficient means in the carbon strands but now bumped out of a contractual agreement with the company.

The LeMond part is only for building bicycles but a much larger market for this new manufacturing process is automotive.

LeMond Composites of Oak Ridge game, world changer - News - Oakridger - Oak Ridge, TN - Oak Ridge, TN

Wow this thread has taken a mind of its own

Not had a chance to go through the replies until now as I've been crossing my fingers, legs and eyes while waiting for some FIA crash test results to be relayed back to me where I was hiding under a desk back at the office.

Motorsport composite design/engineering is no more clever than what is done in other composite industry sectors. The biggest differences are we sail closer to the wind when pushing the limits of failure and timescales, do our research and development work while making new parts not before, also every task that can be done in parallel is which means we do stuff in days that other industries would take weeks or years to do.

Shiny carbon doesn't mean you are buying quality. Thin laminates, cheap resin with no UV protection voided surface finish hidden under thick clear lacquer is the norm. I can offer a couple of simple tips when buying your next parts, ask if the resin is UV resistant, if it isn't it will degrade and fade over time. First side of carbon part to look at is not the moulded shiny side but the unmoulded side, compare the definition of the unmoulded side to the moulded side, it should be well defined without bridging of material in corners. Hold it up to the light if you can see specs. of light through the weave then they have tried to skimp on material. Also ask if it full thickness carbon fibre one trick manufacturers use is to just use carbon on the outer surfaces and bulk up the rest of thickness using black fibreglass. Ask if it is vacuum cured ie cured in a bag under vacuum this creates a much stronger part.

Vincent, great stuff, I'm jealous, something I really want to do but have never found the time for, principles behind making a part at home using dry carbon with wet lay up resin ie resin applied by brush and those made using pre-preg ie resin impregnated fabric using an autoclave are exactly the same. The only big difference are the more higher tech more accurate approach allows you to push the limits of the structure closer to the edge of failure.

On an F1 car something like a nose of rear impact structure that has to pass impact test will be designed with a safety factor of 1.1. Not uncommon to take 3-4 versions of crash structure to a crash test and keep testing until one passes. The scatter of the results being the deciding factor. Other safety critical parts such wings and wishbones will have a higher safety factor of 1.5 to allow for unforeseen track load conditions. Full stress analysis, fatigue testing and proof testing will have been carried out on these parts before they see time on a track. At the other end of the spectrum bodywork which is so lightweight the paint makes up a 3rd of the total weight will be designed from experience learnt from years of trying to stop parts from cracking.

Seahawk, I salute you for owning a business, too much responsibility for me. Please post up more cool stuff that you make.

I kow nothing about ice hockey sticks bit if budget allows I think my engineering approach to improve your sticks would be to make some prototype parts with a hollow upper handle section. Strain gauge the lower end of the handle shaft run the wires back to a small data logging module fitted inside the hollow handle section. This would record the real world stick loads as used in anger which could be used for stress analysis loads to would allow you to refine a break proof laminate.

If budget doesn't allow then try using high strength carbon with a good toughened epoxy resin that still keeps it properties at lower temps. The most probably cause for a stick breaking other than poor design or manufacturing is the laminate section strength/stiffness changing over too short a distance which is a green light for break here failure.

I've got a friend who designed stick for a top Austrian ice hockey team I can ask him what is approach was if you like.

Yes,thanks. I would be interested. I think the root cause is a nick or stress riser that results from contact during play. They need a 'protective covering' to prevent the surface damage. Maybe.

They need a lot of flex to get the energy transferred to the puck, but not so much they snap. It's tricky.

Captain, how's it going? I've been meaning to speak to you, will send you a PM soon.

I had composite experience in F1/LMP1 before coming to WRC. I have to say, the requirements can be complete opposite. I'm constantly surprised by how much impact and deformation pre-preg autoclave parts can take, given the right materials.

Aside from carbon fibre, which is nice for shiny cosmetic parts in our case but not so much for impact resistance on its own (I know we tried it), we use the following materials in the mix:

Aramid - Kevlar, most people know what this is. Good for impact resistance and also quite flexy.

Zylon - when I was in uni some 10 years ago, this was the "wonder material" we were using for the tether part of the space elevator competition. Now it's rather "common" in the industry, and has a nice balance of properties between Aramid and Carbon - stiff and strong, and also good for abrasion resistance. Must be careful with UV and environmental exposure.

Rubber - Usually in sheets sub-1mm thick, laminated together with other fibres, and vulcanised in-situ when cured. It gives more flexibility, holds **** together when the matrix breaks, and acts as load distributing layer within the laminate, at least according to the FEA.

PET - again, thin sheets if placed on the exposed side of the laminate, provides excellent impact and abrasion resistance, i.e. inner wheelarch of an endurance car.

Then there are materials like Dyneema and thermoforming plastic pre-preg.

I was at JEC Paris this year, and there were quite a few companies with composite stamping process, but one that was particularly interesting used fibre + resin for the main surface and only the resin to create the stiffening rib structure on the backside. So similar to regular injection moulding, but with added fibre reinforcement where fibre can go easily. I thought it was very smart.

But sometimes composite is also used as black aluminium - simply for its formability and marginal weight reduction. That was a bit disappointing to see even at the highest level of the industry, after having learned all the important inter-laminar calculations and fibre orientation etc.

I must be a good thread killer... :(

This is how the titanium-capped composite main blades are made. I'm so very disappointed that hand lamination is still the best we can manage at the moment, albeit with laser projection and other best practices used I'm sure.

I heard recently that Audi, famous for their ULTRA lightweight approach, is already shifting focus away from the traditional CFRP for future development. There is still some ways to go before composites can be widely applied in everyday-car level. Or, we may not get there at all.

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Hi Won, all well here, hope you are still enjoying working on puddle jumper car :D WRC is an itch I need to scratch one day so I'm only jealous

Interesting fan blade, learnt a lot watching the first video thanks

Titanium and carbon go together very well and is one of the more common combinations of metallic/composite materials used together in F1 composite parts. The expansion rates of carbon and titanium are a good match and it is possible to easily bond the two materials together.

An F1 carbon floor will sometimes have the outboard front corners protected with a bonded on thin titanium machined capping piece to stop the floor wearing away to dust from the grit and dirt thrown up by the front wheel. As seen below

http://forums.pelicanparts.com/uploa...1494451587.jpg

This is exactly the same concept behind the way the fan blade has been designed and manufactured.

I've used titanium with very good results laminated into all sorts of more complicated composite structures. A gearbox casing is a good example as the titanium can be precision machined so bearings can be pressed in or where a threaded fixing holes is required. Best picture I can find showing this is a gearbox maincase from an Audi Le Mans car, they even went further and used ti for the suspension mounting lugs.

http://forums.pelicanparts.com/uploa...1494452021.jpg

Carbon is a great material to use but as with all materials it has its limitations

Probably the number one rule I try and work to when designing composite parts is to keep the carbon simple and put the complexity into the metal. Reason being the carbon plies are hand applied so are have a wider manufacturing tolerance and a finer level of detail can be machined into any metallic inserts or bonded on metallic parts without compromising the stiffness/strength.

I have a friend who is an engineer for SpaceX in Los Angeles. His project is the carbon fiber fairing. I was lucky enough to get a tour of the facility a couple months ago. Really fascinating... the fairing is HUGE!!

http://forums.pelicanparts.com/uploa...1494453396.jpg

Please keep the composite race car photos coming... beautiful.

I think there's some carbon in there
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It's huge! It's tremendous! It's real! I know a couple of ex-Renault F1 composite guys at SpaceX. I wonder how they work there; these guys would be used to a full lifecycle of design to race possibly in a week or even less. I imagine SpaceX would be not as risk-averse as, say commercial airplane companies, but they still need to worry about not blowing stuff up. Hmm.

Check this one out. It is a model builder's dream - the whole airframe is exactly like a built up balsa RC plane, except everything is bigger and made out of carbon fibre. Everything.

Old one:
http://forums.pelicanparts.com/uploa...1494619888.jpg

New one:
http://forums.pelicanparts.com/uploa...1494619888.jpg

Mid-build:
http://forums.pelicanparts.com/uploa...1494619888.jpg

The next America's Cup starts pretty soon. I really wish I had a chance to see the previous generation (AC72) boats flying around. Composite engineering for wind turbine blades are pretty cool, but these boats are like taking the blades AND the pylon and racing the entire thing in and out of water. It would be really fun to design the wing sales and daggerboards, purely from academic and theoretical point of view. I think Pelican's own Bill Verberg wrote about composite masts from his work, some time ago. Very cool.

Artemis Racing did a Youtube series about the build-up to this year's Cup. It has bits of interesting technical info, if anyone wants to check it out.
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Ok for your materials guys who want to make some $ ...

Pointe shoes.... are $150-300 per pair. And are good for about 8 hours of dancing and then they are only suitable for warm up and "casual" practice for another 8-12 hours of dancing.

They are made on a paper mache core... sweaty feet ruin 'em. Repeated bending and flexing ruin them. Excessive heat (over 100f or so) causes the glues to break down, and ruins 'em.

So some modern material as a core that can be fit into an exterior replaceable for less than $150-per-pop outer. Let it breath, flex and bend and twist.

Go crazy and design a scanning device and 3d print the inner cores custom. Make it so our teenagers can actually outgrow a set of shoes instead of needing a new pair every 4-6 weeks. Or after a 2 showing performance.

Still motorsport related but something a little different, I knew Alastair the 'Artist' as Alastair the 'Chief Mechanic'

He left the F1 team we worked at to pursue his dream of be an engineering sculpture/artist, great to see it is working out well for him.

Carbon artwork at its best and mixed in are real F1 components to make his sculptures that little bit special

His website is worth a look around and there is a cool video of his TV channel commission for Jenson Button's F1 leaving present
Artwork

Aero Manta
http://forums.pelicanparts.com/uploa...1496095077.jpg
In this shot I can see a wheel nut, rear wing end plates which could easily be a part I designed, hard to tell though :confused:, a hydraulic hose fitting and some other random titanium parts
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Carbon King
http://forums.pelicanparts.com/uploa...1496095077.jpg
Engineered Hammerhead Shark
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I love materials but I'm just a dumb metallurgist...

There are a few out there doing huge running sprints with composite prostheses. Seriously - how much good could a cc ballet shoe do? If not performance enhancement, could it help manage the beatings that these dancers' feet get?

It's not F1-sexy or SpaceX-sexy but still...

I'd be happy paying $500 a year for dance shoes vs. $2500. And that is without a "major part" in a production...

Do you have a design or could you send me a PM on where to look?

UAS that was my idea being build in the plant I am the minority owner of. We do great stuff...early fit checks:

Wings Spread

http://forums.pelicanparts.com/uploa...1497383617.JPG

Wings Folded

http://forums.pelicanparts.com/uploa...1497383860.JPG

If I told what it is for I I'd have to kill ya:cool:

Cool stuff! Throwing my name in as well as I spent a lot of time laying up aerospace composites for satellite applications during high school and college and designing layup tooling for a few years after that. Mostly autoclaved unidirectional carbon tubes, carbon skin/aluminum honeycomb panels, and kevlar skin/nomex core panels, all with potted fasteners. Had a quick stint doing concept car composite parts & tooling and working on the first set of solar panels that went up on the Dragon capsule trunk for SpaceX.

Would have stayed in the composites industry if there was significant automotive work in Southern California for it.