Composites Corner

[Captain Ahab Jr]

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

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

[wdfifteen]

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.

[motion]

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?

[wdfifteen]

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

[Eric Coffey]

Originally Posted by motion

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?

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!

[Eric Coffey]

Originally Posted by wdfifteen

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

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...

[stevej37]

deadspin-quote-carrot-aligned-w-bgr-2

[greglepore]

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.

[Shaun @ Tru6]

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.

[VincentVega]

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.

[Seahawk]

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.



Very interesting industry.

[1990C4S]

Originally Posted by Shaun @ Tru6

The company was sold to Bauer and moved to Canada when we started to make perfect hockey stick shafts.

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.

[Seahawk]

Originally Posted by 1990C4S

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!

[sand_man]

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

[sand_man]

[sand_man]

[intakexhaust]

Originally Posted by Shaun @ Tru6

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.

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.

[intakexhaust]

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

[Captain Ahab Jr]

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.

Originally Posted by motion

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?

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.

Originally Posted by VincentVega

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.

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.

Originally Posted by Seahawk

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.
Very interesting industry.

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

Originally Posted by 1990C4S

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.

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.

[1990C4S]

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.