Since TH-cam is about to delete annotations, figured I'd post them here for everyone to see. Enjoy the video! 0:01 The numbers in this video are generic data taken from official sources (such as DuPont) to demonstrate trends. Your material specifics may vary significantly. Always consult your material data from your manufacturer before designing a layup! 10:14 What I more should've said was shock loading where the part is expected to not fail, as fibreglass and kevlar will do better here. Carbon is a very common material in impact attenuators because they are designed to permanently deform (fail) inwards. Carbons high stiffness allows you to use a tube like structure and be very strong in direct compression (10:19 in video) without buckling. You then use a geometry like a tapered cylinder or cone and it essentially folds in on itself, absorbing large amounts of energy as it progressively folds down. This is further helped by the thicker walls per unit weight for carbon, which means they have more bending strength on a skin basis. FIbreglass may have buckled in this scenario (on either a skin or whole structure level, not stiff enough), and kevlar is weak in compression, so carbon is the way to go. 10:31 Kevlar fuel tanks: Kevlar has very high toughness and good abrasion resistance, and fuel tanks are a component that will only ever see very high loadings in tension, so Kevlar is appropriate here. I guess for the applications I was only really thinking bodywork
what would be the best for crash structures, to soften the impulse in collisions (adequately decelerate car but in a long enough time period to reduce crash impact g-forces), while also optimizing weight and cost?
Swedish studies apparently showed that bamboo sticks of 30 mm diameter are a better used in earthquake prone regions than regular steel rebars. :) You possibly still could build a race car of bamboo.
Wow, you really understood what we non-engineers needed to understand. Thanks for the interpretation of these materials. I had tried to understand it myself in the past and it was frustrating to not be able to get a clear interpretation. I will rewatch this several times until I can regurgitate it for applications in the future.
This agrees with my experience building high performance power and sailboats. I worked with S glass, carbon, and Kevlar from about 1978 to 1998, it appears that things haven't changed much. Most of the failures I saw were compression failures, we quickly learned never to use Kevlar in compression. I think part of the problem is that it's hard to get Kevlar (basically a polyethylene, therefore "slippery") to bond to the matrix. It was always a pain in the ass to use, hated by all. I loved S glass, by far the best strength and stiffness / dollar, great in compression. With any fiber, but especially with glass you must make sure that the sizing is compatible with the resin you use. Carbon fiber, miracle shit. We built a 30' carbon fiber/epoxy/Nomex honeycomb sailboat hull and bracing (ca. 1988) that came off the mold at about 250 lbs, stiff as a brick. Two layers of 0/90 tow | Nomex honeycomb | 0/90 tow. Only issue? you could take a sharp pencil and smash it straight through the hull. We warned the purchaser not to do that...
Have done boatloads of research & hands on. Give you some tips. freemansuppy.com for their free vid library using their pattern/moldmakers gear. Look carefully at compositeenvisions.com for their 3 (yes they cost something) videos explaining how to do professional layups. Com Envisions is the best place on the continent for exotics. Things are wild out there as some can use 3D software, 3D optical/lazer scanners to do near female mold quaulity with 3D printers. Now that Stratasys patents on their Ultem 9085 (PEE plastic)have lapsed a thin honeycomb & thin film covering both sides with a laundry list of prepegs vac bagged/autoclaved cheeper than female molding processes. Look at 3dp-platform.com i like their WorkBench Series #400 with bed size at 39" on "Y"axis by 57" on "X"axis by 27&3/4" on "Z"axis(folds thru house doorways & runs 45 to 55K$ depending on extruders and enclosures). It is thoff to get all their info on TH-cam but their next model up is 112" on the "X"axis.
I'm assuming that's 2 layers of 0/90, 2 layers nomex, and 2 layers more 0/90, otherwise that's insanely thin for a boat hull. Even still, that's thin for a hull. I've done aerospace stuff and am slightly triggered you didn't do any 45. We only use kevlar for things like belly panels that get lots of abrasions or internal "hinges" Otherwise it's not a very good structural component. Never tried stabbing it with a pencil, but a (I believe) 2 ply tailboom is practically unbreakable and works as a baseball bat.
In sailplane construction, we use glass fibre extensively to handle bearing stress, where it outperforms aramid and carbon fiber. We use aramid in the crash protection zone of the canopy, where glass and carbon dust would be harmful in a crash. We use carbon fibre only where lightness and stiffness is important. Also, the stiffness you give for the raw materials is much greater than the fibre-matrix combination, with carbon fibre in an epoxy matrix having only a quarter of the stiffness of steel.
There's a bit more to it than that. Matrix materials are only as good as their design. By playing with the characteristics of the material used in junction with pattern design, part geometry and so forth you can easily rig up a design that makes one material excel over the other. This is true even in cases where the first material is better for the application on paper. For this reason you often see carbon in sailboat masts, for example, where flex to weight ratio is a key factor or even in rigid bike frames which often experience high momentary forces. This is also the idea behind enforcing carbon with kevlar. Furthermore, carbon parts also excel in the long run when you look at plastic deformation over time, due to applying bending and torsion forces to a geometry. This, in turn, lets us to look at the economics of materials science differently as well. The biggest problem with carbon fibre, however, is the lack of automation options in a production scenario... hence the price tag.
Love this video, I use both carbon and fibreglass, carbon isnt needed in my application but some customers hear carbon and theyre impressed even if fibreglass is the more suitable material...
That was a great lecture. I have not had one like that since I was in my engineering materials class at the University of Arizona 30 some years ago. You covered it masterfully.
Great video. I build R/C speedboats and these rules pretty much apply to speedboats too. Contrary to my collaegue model-builders I have always appreciated the use of GFK (fibreglass) in many areas where others chose Carbon-fibre by default.
Excellent that you defined what the words and terms mean at the start of the video, sooo many people don't know what the words actually mean and it shows in the comments even after you defined them.
Hey man great vid, I was looking for something like this. One variable you never mentioned is temperature resistance. I would love to see you going through matrices, different resins or other materials to bond the fibers!
Ah no. I would suggest that the failure mode of S glass (if you can get it) is not superior to Kevlar. Kevlar is a curious material as you note. Being a form of nylon its failure more in some respects that of metal: when loaded to saturation the micro failures along the fibres allow for energy absorption, which can be very useful. However the fibres are very tough and so the composite will not break into pieces. I think you also have the thickness aspect of CF/FG backwards. You will need a thicker FG part compared to CF as the FG needs more material for the same stiffness - with the thicker laminate becoming stiffer in part due to beam theory. There is also the tooling and resin requirements for each fibre system to consider, you can use a poly/vinylester resin for the FG, but epoxy is best for aramid/epoxy. The 200gsm textreme CF is around $30/m.
As an engineer, I love your channel as we speaks the same language. Appreciate that you put efforts on trying to explains engineering knowledge in a laymen way for non engineers. Hope to promote your channel for education purpose or even worth to translate into other languages
I'm sincerely impressed by your explanation of the different compounds. I had always known that "traditional carbon fiber twill" had no actual value against glass but this is definitive information to back it up
Hi! I need to clear up some things! So you are saying that High modulus Carbon fibers are essentially strands of diamonds? After 2800°C heat treatment of mesophase pitch-based Carbon fibers they reach a mean interlayer distance of 0.342nm. Ideal Graphite's is about 0.335nm, so MPP-based Carbon fibers are nearly Graphite fibers! The carbon atoms in graphite are sp2 hybridized. That's why MPP-based CFs are good electrical conductors. Diamond bonds on the other hand are purely sp3 hybridized, the bonds are saturated so there are no electrons to transport any current. Diamonds are insulators. It is also important to note that the microstructure of carbon fibers both pitch- and PAN-based are not 100% understood to this day. Side note: Diamond Nanothreads can be synthesized by applying huge pressure (200000bar) to benzene and slowly reducing the pressure to let the threads grow. Also I need to ask you something about your table of material strengths. I'd be glad if I could buy materials with these strengths off the shelves lol. Where did you get the data of Kevlar + Epoxy. 3500 MPa? Look, here is some tensile strength data of epoxy prepreg laminates from Hexcel which are basically available off the shelf: E-Glass: UD: 1100 MPa Fabric: 600 MPa Aramid: UD: 1100 MPa Fabric: 500 MPa High Strength Carbon: UD: 2000 MPa Fabric: 800 MPa Intermediate Modulus Carbon: UD: 2400 MPa Fabric: 900 MPa I think it would have been smarter to compare laminate strengths than pure fiber strengths. Pure fiber strength data is a marketing tool! PAN-based IM fibers are marketed with strengths over 7000 MPa. The data is gathered from tensile testing of single filaments with huge measurement errors that are sometimes larger than the measurement value!!!
I did love the explanation of differences! Yes that 15% is more than worth it!!! If u have any idea! What that and the stiffness is worth!!! But that is if u are building an entire car. Not just repairing or replacing a panel!!!!
What we figure out now in high end racing is that stiffness is not always great. Similar to how racing tires shape up under heat and high RPM, shaping itself as a nice sideeffect to higher performance, we find now that the downpressure on a car also can have a smoother and therefore performant curve on less stiff materials. Essentially the body can push down, allow for less downforce, and therefore stable downforce when more air pressure (high speed) is applied. Therefore you can expect a comeback of carbon fiber in the racing department
Huge fan of your vids- def the best at explaining motorsport engineering on the web. I have a request- can you do one on chassis rigidity? It's generally accepted that stiffer is better, but is that really true? Is chassis flex ever a good thing? Do engineers actually tune for it?
Seconded! It's interesting how chassis rigidity is always touted as a plus, but many cars that we hold in high regard, like the Lotus Exige, or Honda's s2000 are not the most rigid. Great video as always, Kyle. Lots of information!
In top fuel dragsters flex is extremely important. I don't know any details, but the frames are so delicate looking, that I don't know how they handle the extreme horsepower and stresses. Failure in some have resulted in dramatic crashes and amazingly few injuries do to cocoon type driver pods usually made of carbon fiber.
I don't think manufacturers want flexible cars. If they did they wouldn't brag about making the car 25% stiffer from last years model every year. It may add a layer of comfort to commuter cars with cheap suspension, however on performance cars manufacturers don't want the body flexing and pulling the suspension out of alignment.
Beyond a certain point added chassis stiffness is a byproduct of other needs, usually NVH and crash worthiness. Plus OEM suspension bushes are often three-dimensional compliant, thus providing different suspension sets for different load conditions - chassis flex is far less of an issue for handling purposes than it was 15 years ago.
This is the most informative video for any novice as to the basic yet crucial to know facts about these materials. Thanks for providing such quality sound and visual content. A true materials for dummies presentation.
I think that you simply wrapped the whole thing in just 10 mins, that could have taken me like weeks and a lot of money and losts of trial and error (costy ones) .... So A really big thanks :")
Dude F chopped strand. I really don't know what it'd be good for other than plugging a fekin' hole. There's different weaves in fiberglass as well. Mat, normal weave, satin, biaxial, triaxial even.. I've seen a bunch of variations. The type of cloth and weave can determine how much epoxy the cloth absorbs. I even glassed with canvas before... Which sucked b/c I spent a lot of time trying to work the epoxy into the cloth... Luckily it was West Systems 209, so cure time is SUPER slow in a 75 degree room. Sglass can be arguably different b/c it has a twist in the weave... However I've seen E-glass (verified cheap E glass) that had a twist in the weave too. S-glass is going to be a little more whiter than E-glass (greenish), but in comparison I think it comes down to how you're laying it. I made 2 fish tanks, same exact dimensions, glassed the inside of both tanks. Went e-glass the first time for my tank, s-glass the 2nd time for the customer's tanks. Used all the same dimensions, screw spacing, same number of layers, etc. The S-glass tanks bowed on the back side (where no glass was), the E-glass tank did not. Generalizing fiberglass in a video is kinda weird. There's variations in strength between 2 different e-glass sellers with the EXACT same weave. Then to get into the epoxy strength... Cure times of hardener, temperature outside, brand, UV resistance (because fiberglass strength is different on day # 5 vs day # 2000), etc... all this comes into play too.
I actually bought a splash guard shields for my g35 (carbon fiber), on ebay a while back Well I broke the guard under my oil pan area by driving over a small branch. This was at factory height too. The small branch just kicked up and wacked the panel. I heard it crunch and knew immediately it was broken. Well it was only a long crack with a huge hole... So I peeled/cut away the loose pieces, propped it back into shape and threw a couple of satin weave fiberglass mats over it with West systems epoxy, 206 hardener... built a foil plug where the hole was... Babied it/formed it - until it got tacky. Let it cure. Fastened it on so it hinges forward for oil changes. O M F G I'm lowered now, and there was a huge rock on highway 75 (dallas) that was kicked up and broke into pieces like right in front of me (they closed that lane for a few days). A huge rock tunneled under my car, as I drove over it. It sounded horrible. Just scratched fiberglass. Dented the hell out of my exhaust. Even felt like it lifted my car a bit. Another piece still cracked a lower control arm though :( ANYWAY! They make aluminum splash guards for 200$ now... probably sticking to my glassed guard though.
Well, drones are often made of carbon fiber composites, which are probably your best bet here. The light weight and high stiffness are going to be pretty important in a drone.
Chopped strand serves to add bulk. In using glass vs say carbon, and if cost is more important than weight, use of chopped strand (or mat, it's the same thing) can add some bulk and give you a stiffer, albeit heavier laminate. Mat also serves a VERY useful purpose when using woven materials, especially heavier ones. If you try to apply several layers of woven, you have to have some cushioning between the layers, or you run the risk of delaminating under impact loads. In effect, the bumps in the woven material can sit on top of one another, resulting in half the laminate having glass against glass, while the other half is resin rich. Hit it with a strong enough impact and it will tear apart. Using a chopped strand mat gives a cushion, something to fill the space between opposing skins , allowing glass fibers to interlink between them, making delaminating MUCH less likely.
There's metallic fiberglass that looks neat imo, but that depends on your tastes www.easycomposites.co.uk/#!/fabric-and-reinforcement/reinforcement-fabric-samples/alufibre-silver-glass-fibre-SAMPLE.html Also, I wonder why I haven't seen exotics sports cars with colored carbon fiber, I think it looks awesome. www.easycomposites.co.uk/#!/fabric-and-reinforcement/reinforcement-fabric-samples/22-twill-210gsm-3k-1m-RED-SAMPLE.html
I love it. Nuance makes all the difference. And there are a lot of nuances in engineering. Btw kevlar is used as a backup matrial on metal pullrods and cables for crash safety, so it would hold the part attached to the vehicle and won't propel it into the spectator area.
The most important discussion is competely missing here. All these materials are useless without the bonding material - Polyesters, Vinylesters, or epoxy. Without this added into the mix, all the theory on material strength is mute! It is a combination of the bonding material plus the glass, kevlar, carbon - and foam too. Strength to weight also not discussed - where polymer resins come in and play a big part. Then there is how the parts are manufactured - lay ups are important too. starting with base coat - whether it is a gel or if there is an absence of it. Good presentation, but incomplete and therefore misleading.
A lot of people might think I'm crazy but I got really excited seeing the very technical and lecture-like video and hit subscribe immediately. Thank you for sharing your knowledge!
I don't know this channel I don't like cars, but I don't get how can someone dislike this video, it was really well done, informative and enjoyable... Well I put my thumbs up good bye!
Great video! I ( like many others I'm sure ) thought that carbon fiber was far superior than fiberglass in all areas. You do a very good job in getting correct information out to us ( less educated ) experts.
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You get sudden failure in carbon fiber, as it is brittle. Much less so with glass.
For my needs; archery bows and arrows, fishing rods, and things like that, fiberglass is all I need. For archery arrows and fishing rods, carbon fiber or a combination of carbon fiber and fiberglass also works great. Only thing I ever needed Kevlar for, was a bullet resistant vest when I managed and worked a convenience store, a liquor store, and the cover charge booth, outside a couple night clubs the company had.
Awesome video! One thing I really wanted to know was heat blocking capabilities. I'm needing to make a heat-shield and building it out of conformable material like these is really my only option.
I work on arcraft that have fiberglass panels and covers. They constantly crack and a large portion of my career has been repairing fiberglass panels. There was an experiment done when designing the new model of aircraft where they made carbon fiber panels and replaced the fiberglass panels with the carbon fiber ones. I have not once had to do a repair on those carbon fiber panels. The amt of man hours saved on this one aircraft from not having to do panel repairs is insane. Now all the new models are coming out with carbon fiber panels and I am so excited to not have to worry about fiberglassing anymore!
Great video....Alot of people only see CF as "The best", but don't realize the drawbacks (Cons if you like). That's why it shatters into a million pieces, when a fiberglass part might splinter/crack.
You deserve no only my subscription, but all my admiration as this is one of the best videos I've ever seen on youtube, from a technical perspective. Not only the information is complete regarding every aspect of each material is compared in isolation, but the combination in real use is perfectly described for practical analysis. Plus conscise and not self-oriented video. I'm definetely gona stick around you channel! :)
when i went on a williams visit they used a whole varity of wierd honeycombs and different kevlars and carbons for the crash strructure, they had a great cutaway
Well presented and digested for us genies. Lightning quick intro, to the point and abundance of knowledge condensed in 11 minutes. I truly enjoyed it. Well done mate and many thanks.
Thanks Kyle, I've been flying model RC gliders and I'm starting to repair my own crashes to save on the cost of replacement parts. The video was an excellent primer and eloquently shows the path for the current repair that I've been fussing over.
I'd like to see a second video on this.. Mostly for weave materials like Carbon/Titanium, Carbon/Kevlar, etc. and I think if they can all be epoxy resin based then why not experiment with different combinations. I'd also like to see comparisons of weave styles; plain, basket, twill, herringbone, houndstooth, satin, etc. and random fiber direction. I've always known the random direction of fibers adds strength due to there not being a weak link which is the gaps in the weaves. Also, if you have access to actual research equipment, please test weave styles and materials. On the materials, if you do experimental combinations, do different mixtures; like 75/25, 50/50, 25/75, and possibly more but I think having those three plus the two plain materials could give us a good understanding of how combining them would work out for different applications. Another experiment I'd like to see done, which is kinda out there, is putting two plates of material with a honeycomb (or other tessellation pattern) layer of the same or different material in the center; like 3d printer infill. Just because science; even if it doesn't work, at least we'll know it doesn't work.
Thanks! I actually used some S-glass (S2?) on a canoe years ago, but I admit to being influenced by the "carbon fiber is best" crowd. I experienced having carbon parts failing in testing, while the initial tests with e-glass were surprisingly durable. And weight savings was disappointing.
Holy cow - this was exactly what I was looking for. Trying to determine what material to use to repair and reinforce my whitewater composite SUP. I was looking at pricey kevlar/carbon materials, but will stick with S-Glass! Thanks for saving me a ton of money!
Thank you Kyle, it was very educating. I want to know more. I want to build small jet plane, I have no education in aeronautics, just self taught and English is my third language. You know what, from the bottom of my soul I know I will succeed. Your kind of video is giving me the knowledge I need.
Awesome video. Thanks heaps for making it understandable for people (like myself) who have very little knowledge in this field. I've had the misconception that carbon fibre is just the best for everything.
Thanks for posting this. I was going to make carbon fiber aero parts for my MR2 track car but now I see that it won't make a bit of difference except cost.
I know that the point of the video is which material is best for a given application, not which is 'the best material' overall, but I'm really impressed by S Glass.
Finally, some actual information. Thanks a million. I would love the actual facts about how a foam core can be regarded suitable as a structural element in layering of fiber glass or any of these products. As described in other videos here on TH-cam we are often told that a 30 mm layer of marine grade foam board may have to be substituted by up to 9 layers of fiber glass. The immense difference in strength and stiffness of these two materials should be apparent to anyone who ever held a piece of foam between their fingers. What I lack is the facts and figures as you presented it in this video. Please do describe this for us laymen if you will. It will be highly appreciated.
I wanted to add, the carbon-fiberglass weave/cloth (likely it was the lower grade fiberglass) offered the fiberglass in multiple colors (Blues, Yellows, Reds, Greens, etc) & provided a nice color contrast when used against the black-gray Carbon. I'm sure it too may b a good way to add some flex? or reduce brittleness? It was mainly available in woven tubes for pen-making. The fiberglass added a nice, colorful "top layer". Thx for the info & your time! I never knew there were such different grades of fiberglass! As well as (the higher grade) being "pretty good stuff!" Thx again!
Hi Kyle, great video! One thing I missed in this video was when designing a structure that will be loaded in bending (which most structuren are) the moment of inertia plays a major factor in the strength and stiffness calcations. Since carbon has a significantly lower density when designing a part for strength in certain situation carbon might still be the lightest option. Still doesn't take away from the great video and your valid conclusions at the end of your video
Thanks a lot! That one was great axample abaut all these materials. I know pretty well abaut metals and all the stiffness and other properties of those. But all those others, glass fibers and carbon fibers and especialy kevlar properties was pretty much all new to me. So, big thaks to you for this video! I appreciate it! I learned something new!
At my university (University of Miami) They had a student project where a concrete bridge on campus was built by students, except instead of being steel-reinforced, the concrete was fiberglass reinforced.
As a victim of four self designed propellers and their fatigue failures, the last one while I was flying, here is one factor you missed, comparative fatigue life. I suppose that carbon fiber is better at this, but certainly carbon fiber is used for more than decoration. This factor is worthy of discussion. Nice vid, anyhow.
Congratulations you've done a really nice video. I agree with everything you said except that: you have not taken into consider the flammability of materials and about the cost of carbon are higher but not so much for don't use it. The fiber glass is highly flammable while the carbon and Kevlar not. Kevlar is used for coating parts subject to impact, also has the highest resistance to fire. For example, combine carbon and Kelvar on portire makes a thief-proof. Incorporating into different materials structure offers different results. For example, there are PVC that can be inserted in doors and isolate noise and give a rigidity in the event of impact. The list does not even mentioned composites made of kevlar-carbon, carbon-titanium that would make the discussion an important guide on the subject. Treating the composite materials I have to say also a very negative point since the difference of electric charges on the carbon of definitely different from other materials already present in the car which would end bad without adequate protection. If you do a more complete video I will be happy to examine it could get out of it is something really interesting that would fill many doubts of many people.
very informative video.. now I know much of the things about Kevlar ,glass fiber and carbon fiber .. all the best my friend you impressed me alot through your quality information
Great video! As a boat builder in the 70's and 80's, and 90's, mostly sailboats and sailboards, with a specialty of foils -- and a few offshore unlimited cats, I came to similar conclusions. S glass for compressive strength, carbon for stiffness to weight, and fuck no Kevlar. You illustrated the exact problem with Kevlar, it pops out of the resin in compression, such as when it's on the inside of a bend on a composite beam. I don't think it ever really bonds with the epoxy and any tiny wetting void is a potential failure point, I could never trust the stuff. Carbon has some surprising issues, too. We built a 30' sailboat, Nomex cored 0/90 carbon, the bare hull weighed 250#'s, stiffer than .... Worked great, but you could take a sharp pencil and drive it right through the hull.
All and none are the best: Carbon is the stiffest and the more resistant in tension and compression, but also the most expensive. Kevlar have the lowest density and is the most resistant in sheer strenght and abrasion but very poor in compression and needs to be dehumidified before lamination. fiberglass is average for tension compression and sheer resistance, heavier but alot more afordable for everyday use and is comming in the biggest range of technical fabrics.
The points being made here are very good, much of the carbon, glass, kevlar is still misunderstood. Here is a generalisation of the materials in point and how they react to different loads etc. There are many types of each fabric, the way they are made the directions they are laid and the numerous resins employed. In reality carbon is stupidly expensive, it's useless without epoxy resins : also stupidly expensive and what you gain might never have any effect on what you actually need it for, unless you're competing at stupid money levels. For the rest of us Glass fibres with a decent isophthalic or vinyl ester resin maybe even epoxy is the way to go. You might be surprised to learn that 90 percent of boats are built with the lowest grade orthophthalic resins, chop strand mat and woven rovings, but it works, so how much do you really need exotic materials in the end?
You can sometimes get a CF/Fiberglass mixture where the base is fiberglass and the final layer or 2 (in usually a 6-ply stack-up) is CF. That way you can save costs while giving off that sexy twill pattern.
Jeez Kyle, you absolutely knocked it out of the park with this. The trouble is, I end up with more questions than answers but I guess the takeaway from that it, what are you trying to use this material for? The only bit you left out - unless I missed it - were the differences in strength: tensile, compression and sheer. Does this matter much for racing applications? How much difference is there between the different materials? Otherwise, you best yet. Well done.
Thanks. Beginner questions. Q1: why not having a first coating in carbon(stifness) and on top of it fiber glass(for impact resistance)? Q2: "Fiber glass doesn't look good", why not a final "polishing layer" with a fiber of 160g/m² or 100g/m²?
Since TH-cam is about to delete annotations, figured I'd post them here for everyone to see. Enjoy the video!
0:01 The numbers in this video are generic data taken from official sources (such as DuPont) to demonstrate trends. Your material specifics may vary significantly. Always consult your material data from your manufacturer before designing a layup!
10:14 What I more should've said was shock loading where the part is expected to not fail, as fibreglass and kevlar will do better here. Carbon is a very common material in impact attenuators because they are designed to permanently deform (fail) inwards. Carbons high stiffness allows you to use a tube like structure and be very strong in direct compression (10:19 in video) without buckling. You then use a geometry like a tapered cylinder or cone and it essentially folds in on itself, absorbing large amounts of energy as it progressively folds down. This is further helped by the thicker walls per unit weight for carbon, which means they have more bending strength on a skin basis. FIbreglass may have buckled in this scenario (on either a skin or whole structure level, not stiff enough), and kevlar is weak in compression, so carbon is the way to go.
10:31 Kevlar fuel tanks: Kevlar has very high toughness and good abrasion resistance, and fuel tanks are a component that will only ever see very high loadings in tension, so Kevlar is appropriate here. I guess for the applications I was only really thinking bodywork
Carbon Fiber looks better too, but...What about Carbon Fiber wrapped on a Fiber Glass core? Like 50/50, 40/60, 30/70 wrap to core? just wonderin
can you please share the PDF file containing all these graphs. that would be very kind of you , Thanks
Where can I buy the fiberglass S glass And the resin?
what would be the best for crash structures, to soften the impulse in collisions (adequately decelerate car but in a long enough time period to reduce crash impact g-forces), while also optimizing weight and cost?
Hi Kyle, if you're about to make war suit in case of handling sword/spear not bullet what material you'll use?
carbon fiber vinyl is the best, instantly adding 100+ horsepower unlike any of those
Don't forget to put a toyo tires sticker because with all that horsepower provided by the carbon fiber vinyl, you will need more grip
YES!
And this is only for doorlock, if prepare the transmission you adding 10000+hp
add a vtec sticker and instant 1500 hp
@@xkobeplayz5396 what you really need is a Wu-Tang Clan sticker. will add 3500 hp
I didn't understand any of this, screw it, i'm using concrete.
I wonder if carbon fiber reinforced concrete is a thing
lmao this made my day
Swedish studies apparently showed that bamboo sticks of 30 mm diameter are a better used in earthquake prone regions than regular steel rebars. :) You possibly still could build a race car of bamboo.
lol
Make sure its hemp Crete...it will be like s glass, to e glass. Worst case scenario, smoke the bud first, and don't worry about nothing.
Wow, you really understood what we non-engineers needed to understand. Thanks for the interpretation of these materials. I had tried to understand it myself in the past and it was frustrating to not be able to get a clear interpretation. I will rewatch this several times until I can regurgitate it for applications in the future.
This agrees with my experience building high performance power and sailboats. I worked with S glass, carbon, and Kevlar from about 1978 to 1998, it appears that things haven't changed much.
Most of the failures I saw were compression failures, we quickly learned never to use Kevlar in compression. I think part of the problem is that it's hard to get Kevlar (basically a polyethylene, therefore "slippery") to bond to the matrix. It was always a pain in the ass to use, hated by all.
I loved S glass, by far the best strength and stiffness / dollar, great in compression. With any fiber, but especially with glass you must make sure that the sizing is compatible with the resin you use.
Carbon fiber, miracle shit. We built a 30' carbon fiber/epoxy/Nomex honeycomb sailboat hull and bracing (ca. 1988) that came off the mold at about 250 lbs, stiff as a brick. Two layers of 0/90 tow | Nomex honeycomb | 0/90 tow. Only issue? you could take a sharp pencil and smash it straight through the hull. We warned the purchaser not to do that...
Where can I learn your craft?
Have done boatloads of research & hands on. Give you some tips. freemansuppy.com for their free vid library using their pattern/moldmakers gear. Look carefully at compositeenvisions.com for their 3 (yes they cost something) videos explaining how to do professional layups. Com Envisions is the best place on the continent for exotics. Things are wild out there as some can use 3D software, 3D optical/lazer scanners to do near female mold quaulity with 3D printers. Now that Stratasys patents on their Ultem 9085 (PEE plastic)have lapsed a thin honeycomb & thin film covering both sides with a laundry list of prepegs vac bagged/autoclaved cheeper than female molding processes. Look at 3dp-platform.com i like their WorkBench Series #400 with bed size at 39" on "Y"axis by 57" on "X"axis by 27&3/4" on "Z"axis(folds thru house doorways & runs 45 to 55K$ depending on extruders and enclosures). It is thoff to get all their info on TH-cam but their next model up is 112" on the "X"axis.
I'm assuming that's 2 layers of 0/90, 2 layers nomex, and 2 layers more 0/90, otherwise that's insanely thin for a boat hull. Even still, that's thin for a hull. I've done aerospace stuff and am slightly triggered you didn't do any 45. We only use kevlar for things like belly panels that get lots of abrasions or internal "hinges" Otherwise it's not a very good structural component. Never tried stabbing it with a pencil, but a (I believe) 2 ply tailboom is practically unbreakable and works as a baseball bat.
Chimera my old man would like to pick your brain, he’s designing a high cruising speed ocean shuttle.
Can you hybrid layer? Say have Fibreglass on the outside, then carbon fibre? Would it bring any benefit to the penetration protection or performance?
I am now enlightened and ready to argue with everyone about racing materials..
Video man basically did just that.
Dont argue man, dudes will be head over heels for cf they will say cf is the best and should be use everywhere in car
In sailplane construction, we use glass fibre extensively to handle bearing stress, where it outperforms aramid and carbon fiber. We use aramid in the crash protection zone of the canopy, where glass and carbon dust would be harmful in a crash. We use carbon fibre only where lightness and stiffness is important. Also, the stiffness you give for the raw materials is much greater than the fibre-matrix combination, with carbon fibre in an epoxy matrix having only a quarter of the stiffness of steel.
Go into detail on how composite structures work from a stress point of view!
Brush up on your tensor calculus!
hahahaha... good observation.
why?
This pls
@@coyn11 oof tensors
I was a material science student, this is just like music to my ears, haha.
I'd love a resin comparison video. This video was really informative.
There's a bit more to it than that. Matrix materials are only as good as their design. By playing with the characteristics of the material used in junction with pattern design, part geometry and so forth you can easily rig up a design that makes one material excel over the other. This is true even in cases where the first material is better for the application on paper. For this reason you often see carbon in sailboat masts, for example, where flex to weight ratio is a key factor or even in rigid bike frames which often experience high momentary forces. This is also the idea behind enforcing carbon with kevlar. Furthermore, carbon parts also excel in the long run when you look at plastic deformation over time, due to applying bending and torsion forces to a geometry. This, in turn, lets us to look at the economics of materials science differently as well. The biggest problem with carbon fibre, however, is the lack of automation options in a production scenario... hence the price tag.
One of the very few threads where the comments are as enlightening as the original video. Thank you so much.
This was incredibly interesting and informative. Thanks!
cant add anything to this. i've whasted hours on articles, that were nowhere near as conclusive and well founded iRL information
Its good that you are addressing the subject concerning strength verses stiffness, that they are not the same thing.
Love this video, I use both carbon and fibreglass, carbon isnt needed in my application but some customers hear carbon and theyre impressed even if fibreglass is the more suitable material...
A fiberglass wing looks like someone vomited up a furball after licking their grannies hair. No one wants that on their high quality applications..
I had both fiberglass with carbon.. It depend where I want it on the bumper or on the wing...
its so hard trying to understand composites and I applaud your video for explaining the important differences!! I understand so much better now.
Anytime you ask if we want a video. My vote is yes.
That was a great lecture. I have not had one like that since I was in my engineering materials class at the University of Arizona 30 some years ago. You covered it masterfully.
Thumbs up. Much better than a bunch of professors lectures.
Great video. I build R/C speedboats and these rules pretty much apply to speedboats too. Contrary to my collaegue model-builders I have always appreciated the use of GFK (fibreglass) in many areas where others chose Carbon-fibre by default.
and that's why car manufacturers use carbon fiber for stiffness and fiberglass for strength for their race cars.
actually mix or layer them together.
Floor IT! Whats wrong with you commenting on your own comment
@@floorit3669 True, my amuse wing is a mix of carbon and fiber. It so easy to maintenance.
Excellent that you defined what the words and terms mean at the start of the video, sooo many people don't know what the words actually mean and it shows in the comments even after you defined them.
Hey man great vid, I was looking for something like this. One variable you never mentioned is temperature resistance. I would love to see you going through matrices, different resins or other materials to bond the fibers!
Great video! As someone who studied engineering, it's awesome to see someone talking in real terms.
Ah no. I would suggest that the failure mode of S glass (if you can get it) is not superior to Kevlar. Kevlar is a curious material as you note. Being a form of nylon its failure more in some respects that of metal: when loaded to saturation the micro failures along the fibres allow for energy absorption, which can be very useful. However the fibres are very tough and so the composite will not break into pieces.
I think you also have the thickness aspect of CF/FG backwards. You will need a thicker FG part compared to CF as the FG needs more material for the same stiffness - with the thicker laminate becoming stiffer in part due to beam theory. There is also the tooling and resin requirements for each fibre system to consider, you can use a poly/vinylester resin for the FG, but epoxy is best for aramid/epoxy.
The 200gsm textreme CF is around $30/m.
As an engineer, I love your channel as we speaks the same language. Appreciate that you put efforts on trying to explains engineering knowledge in a laymen way for non engineers. Hope to promote your channel for education purpose or even worth to translate into other languages
I'm sincerely impressed by your explanation of the different compounds. I had always known that "traditional carbon fiber twill" had no actual value against glass but this is definitive information to back it up
The most informative video comparing these popular media’s I’ve ever seen. Thank you.
Hi! I need to clear up some things!
So you are saying that High modulus Carbon fibers are essentially strands of diamonds?
After 2800°C heat treatment of mesophase pitch-based Carbon fibers they reach a mean interlayer distance of 0.342nm. Ideal Graphite's is about 0.335nm, so MPP-based Carbon fibers are nearly Graphite fibers! The carbon atoms in graphite are sp2 hybridized. That's why MPP-based CFs are good electrical conductors. Diamond bonds on the other hand are purely sp3 hybridized, the bonds are saturated so there are no electrons to transport any current. Diamonds are insulators. It is also important to note that the microstructure of carbon fibers both pitch- and PAN-based are not 100% understood to this day.
Side note: Diamond Nanothreads can be synthesized by applying huge pressure (200000bar) to benzene and slowly reducing the pressure to let the threads grow.
Also I need to ask you something about your table of material strengths. I'd be glad if I could buy materials with these strengths off the shelves lol. Where did you get the data of Kevlar + Epoxy. 3500 MPa?
Look, here is some tensile strength data of epoxy prepreg laminates from Hexcel which are basically available off the shelf:
E-Glass:
UD: 1100 MPa
Fabric: 600 MPa
Aramid:
UD: 1100 MPa
Fabric: 500 MPa
High Strength Carbon:
UD: 2000 MPa
Fabric: 800 MPa
Intermediate Modulus Carbon:
UD: 2400 MPa
Fabric: 900 MPa
I think it would have been smarter to compare laminate strengths than pure fiber strengths. Pure fiber strength data is a marketing tool! PAN-based IM fibers are marketed with strengths over 7000 MPa. The data is gathered from tensile testing of single filaments with huge measurement errors that are sometimes larger than the measurement value!!!
IEleMenTIx way to Go. Good observatórios.
IEleMenTIx Agreed. And laminate strength/modulus should always be tested using your own samples. I wouldn't trust MatWeb to save my life.
Yes, except that carbon fiber is more expensive than diamonds. ;}
TL:DR?
I did love the explanation of differences! Yes that 15% is more than worth it!!! If u have any idea! What that and the stiffness is worth!!! But that is if u are building an entire car. Not just repairing or replacing a panel!!!!
10:06 You gotta be aware of those cons -
People will think you're cheap, well duh!
Thank you for taking the time to post. FG seems to have the best flexibility and strength retention plus cost efficiency.
Good summary, but I think you should have added aloooooominum, titanium and unobtanium to your comparison too.
And plutonium
Vibranium
Adamantium
What we figure out now in high end racing is that stiffness is not always great. Similar to how racing tires shape up under heat and high RPM, shaping itself as a nice sideeffect to higher performance, we find now that the downpressure on a car also can have a smoother and therefore performant curve on less stiff materials. Essentially the body can push down, allow for less downforce, and therefore stable downforce when more air pressure (high speed) is applied. Therefore you can expect a comeback of carbon fiber in the racing department
I just watched a bar graph power point presentation in my real life. There's a first for everything.
I've been studying Mechanics of Materials lately because I failed it and I have to re-take it, this video is very much related haha
Huge fan of your vids- def the best at explaining motorsport engineering on the web. I have a request- can you do one on chassis rigidity? It's generally accepted that stiffer is better, but is that really true? Is chassis flex ever a good thing? Do engineers actually tune for it?
Seconded! It's interesting how chassis rigidity is always touted as a plus, but many cars that we hold in high regard, like the Lotus Exige, or Honda's s2000 are not the most rigid. Great video as always, Kyle. Lots of information!
In top fuel dragsters flex is extremely important. I don't know any details, but the frames are so delicate looking, that I don't know how they handle the extreme horsepower and stresses. Failure in some have resulted in dramatic crashes and amazingly few injuries do to cocoon type driver pods usually made of carbon fiber.
tmactmacy no
Never
You never want energy to be going into moving or flexing the chassis
I don't think manufacturers want flexible cars.
If they did they wouldn't brag about making the car 25% stiffer from last years model every year.
It may add a layer of comfort to commuter cars with cheap suspension, however on performance cars manufacturers don't want the body flexing and pulling the suspension out of alignment.
Beyond a certain point added chassis stiffness is a byproduct of other needs, usually NVH and crash worthiness. Plus OEM suspension bushes are often three-dimensional compliant, thus providing different suspension sets for different load conditions - chassis flex is far less of an issue for handling purposes than it was 15 years ago.
Thank you. This video was the most helpful and straightforward video I’ve seen on carbon fiber and fiberglass.
9:25 I like that you're not made of fibreglass.
This is the most informative video for any novice as to the basic yet crucial to know facts about these materials. Thanks for providing such quality sound and visual content. A true materials for dummies presentation.
You can always combine them
Rentta into one single material?
Carbon-kevlar composite.
you can do one layer of carbon with layers of glass to save one money
Is this viable? Do these composites work well together? I would love to see this.
FOUND MY ANS: th-cam.com/video/j7bQYEt_qtU/w-d-xo.html
I think that you simply wrapped the whole thing in just 10 mins, that could have taken me like weeks and a lot of money and losts of trial and error (costy ones) .... So A really big thanks :")
Dude F chopped strand. I really don't know what it'd be good for other than plugging a fekin' hole.
There's different weaves in fiberglass as well. Mat, normal weave, satin, biaxial, triaxial even.. I've seen a bunch of variations. The type of cloth and weave can determine how much epoxy the cloth absorbs.
I even glassed with canvas before... Which sucked b/c I spent a lot of time trying to work the epoxy into the cloth... Luckily it was West Systems 209, so cure time is SUPER slow in a 75 degree room.
Sglass can be arguably different b/c it has a twist in the weave... However I've seen E-glass (verified cheap E glass) that had a twist in the weave too.
S-glass is going to be a little more whiter than E-glass (greenish), but in comparison I think it comes down to how you're laying it. I made 2 fish tanks, same exact dimensions, glassed the inside of both tanks. Went e-glass the first time for my tank, s-glass the 2nd time for the customer's tanks. Used all the same dimensions, screw spacing, same number of layers, etc.
The S-glass tanks bowed on the back side (where no glass was), the E-glass tank did not.
Generalizing fiberglass in a video is kinda weird. There's variations in strength between 2 different e-glass sellers with the EXACT same weave.
Then to get into the epoxy strength... Cure times of hardener, temperature outside, brand, UV resistance (because fiberglass strength is different on day # 5 vs day # 2000), etc... all this comes into play too.
I actually bought a splash guard shields for my g35 (carbon fiber), on ebay a while back Well I broke the guard under my oil pan area by driving over a small branch. This was at factory height too. The small branch just kicked up and wacked the panel. I heard it crunch and knew immediately it was broken.
Well it was only a long crack with a huge hole... So I peeled/cut away the loose pieces, propped it back into shape and threw a couple of satin weave fiberglass mats over it with West systems epoxy, 206 hardener... built a foil plug where the hole was...
Babied it/formed it - until it got tacky. Let it cure. Fastened it on so it hinges forward for oil changes.
O M F G
I'm lowered now, and there was a huge rock on highway 75 (dallas) that was kicked up and broke into pieces like right in front of me (they closed that lane for a few days).
A huge rock tunneled under my car, as I drove over it. It sounded horrible.
Just scratched fiberglass.
Dented the hell out of my exhaust. Even felt like it lifted my car a bit.
Another piece still cracked a lower control arm though :(
ANYWAY! They make aluminum splash guards for 200$ now... probably sticking to my glassed guard though.
Dude you're like the rainman of fiberglass.
Chris Foster wow! 👍
... Which material would be best for building a micro/mini drone frame?
Well, drones are often made of carbon fiber composites, which are probably your best bet here.
The light weight and high stiffness are going to be pretty important in a drone.
Chopped strand serves to add bulk. In using glass vs say carbon, and if cost is more important than weight, use of chopped strand (or mat, it's the same thing) can add some bulk and give you a stiffer, albeit heavier laminate. Mat also serves a VERY useful purpose when using woven materials, especially heavier ones. If you try to apply several layers of woven, you have to have some cushioning between the layers, or you run the risk of delaminating under impact loads. In effect, the bumps in the woven material can sit on top of one another, resulting in half the laminate having glass against glass, while the other half is resin rich. Hit it with a strong enough impact and it will tear apart. Using a chopped strand mat gives a cushion, something to fill the space between opposing skins , allowing glass fibers to interlink between them, making delaminating MUCH less likely.
Read my textbook and then watched this. Was a really well written summary of composites
that beion said, carbon fibre looks 10x cooler than fibreglass.
There's metallic fiberglass that looks neat imo, but that depends on your tastes www.easycomposites.co.uk/#!/fabric-and-reinforcement/reinforcement-fabric-samples/alufibre-silver-glass-fibre-SAMPLE.html
Also, I wonder why I haven't seen exotics sports cars with colored carbon fiber, I think it looks awesome. www.easycomposites.co.uk/#!/fabric-and-reinforcement/reinforcement-fabric-samples/22-twill-210gsm-3k-1m-RED-SAMPLE.html
I love it. Nuance makes all the difference. And there are a lot of nuances in engineering.
Btw kevlar is used as a backup matrial on metal pullrods and cables for crash safety, so it would hold the part attached to the vehicle and won't propel it into the spectator area.
The most important discussion is competely missing here. All these materials are useless without the bonding material - Polyesters, Vinylesters, or epoxy. Without this added into the mix, all the theory on material strength is mute! It is a combination of the bonding material plus the glass, kevlar, carbon - and foam too. Strength to weight also not discussed - where polymer resins come in and play a big part. Then there is how the parts are manufactured - lay ups are important too. starting with base coat - whether it is a gel or if there is an absence of it. Good presentation, but incomplete and therefore misleading.
A lot of people might think I'm crazy but I got really excited seeing the very technical and lecture-like video and hit subscribe immediately. Thank you for sharing your knowledge!
carbon carbon
sounds like a made up material
but its not
If you have a weak, stiff material on the outside, and a strong but flexible material on the inside, you can get a pretty decent composite.
Sounded like he said rice car engineering
Australian niggas
I don't know this channel I don't like cars, but I don't get how can someone dislike this video, it was really well done, informative and enjoyable...
Well I put my thumbs up
good bye!
Cool, I am now educated to a university level as well. 😅
Great video!
I ( like many others I'm sure ) thought that carbon fiber was far superior than fiberglass in all areas.
You do a very good job in getting correct information out to us ( less educated ) experts.
You get sudden failure in carbon fiber, as it is brittle. Much less so with glass.
False, black bear is best!
Black bear, beets, battle star Galacktica
For my needs; archery bows and arrows, fishing rods, and things like that, fiberglass is all I need. For archery arrows and fishing rods, carbon fiber or a combination of carbon fiber and fiberglass also works great.
Only thing I ever needed Kevlar for, was a bullet resistant vest when I managed and worked a convenience store, a liquor store, and the cover charge booth, outside a couple night clubs the company had.
Seems kind of hard for critics to argue with material manufacturers technical data! well done Kyle!
Nice, it's been a while since I last read anything technical regarding composite materials. This video helped clearing up a lot of things. Thumbs up!
This has been the most illuminating explaination on choosing composites that I have seen... . Thank you thank you thank you thank you
Awesome video! One thing I really wanted to know was heat blocking capabilities. I'm needing to make a heat-shield and building it out of conformable material like these is really my only option.
I work on arcraft that have fiberglass panels and covers. They constantly crack and a large portion of my career has been repairing fiberglass panels. There was an experiment done when designing the new model of aircraft where they made carbon fiber panels and replaced the fiberglass panels with the carbon fiber ones. I have not once had to do a repair on those carbon fiber panels. The amt of man hours saved on this one aircraft from not having to do panel repairs is insane. Now all the new models are coming out with carbon fiber panels and I am so excited to not have to worry about fiberglassing anymore!
Great video....Alot of people only see CF as "The best", but don't realize the drawbacks (Cons if you like). That's why it shatters into a million pieces, when a fiberglass part might splinter/crack.
You deserve no only my subscription, but all my admiration as this is one of the best videos I've ever seen on youtube, from a technical perspective.
Not only the information is complete regarding every aspect of each material is compared in isolation, but the combination in real use is perfectly described for practical analysis. Plus conscise and not self-oriented video. I'm definetely gona stick around you channel! :)
This is so informative and objective, I find the fact - that you can't like this content more than once - very disturbing.
when i went on a williams visit they used a whole varity of wierd honeycombs and different kevlars and carbons for the crash strructure, they had a great cutaway
Well presented and digested for us genies. Lightning quick intro, to the point and abundance of knowledge condensed in 11 minutes. I truly enjoyed it. Well done mate and many thanks.
Thanks Kyle, I've been flying model RC gliders and I'm starting to repair my own crashes to save on the cost of replacement parts. The video was an excellent primer and eloquently shows the path for the current repair that I've been fussing over.
I'd like to see a second video on this.. Mostly for weave materials like Carbon/Titanium, Carbon/Kevlar, etc. and I think if they can all be epoxy resin based then why not experiment with different combinations. I'd also like to see comparisons of weave styles; plain, basket, twill, herringbone, houndstooth, satin, etc. and random fiber direction. I've always known the random direction of fibers adds strength due to there not being a weak link which is the gaps in the weaves.
Also, if you have access to actual research equipment, please test weave styles and materials. On the materials, if you do experimental combinations, do different mixtures; like 75/25, 50/50, 25/75, and possibly more but I think having those three plus the two plain materials could give us a good understanding of how combining them would work out for different applications.
Another experiment I'd like to see done, which is kinda out there, is putting two plates of material with a honeycomb (or other tessellation pattern) layer of the same or different material in the center; like 3d printer infill. Just because science; even if it doesn't work, at least we'll know it doesn't work.
Thanks! I actually used some S-glass (S2?) on a canoe years ago, but I admit to being influenced by the "carbon fiber is best" crowd. I experienced having carbon parts failing in testing, while the initial tests with e-glass were surprisingly durable. And weight savings was disappointing.
Holy cow - this was exactly what I was looking for. Trying to determine what material to use to repair and reinforce my whitewater composite SUP. I was looking at pricey kevlar/carbon materials, but will stick with S-Glass! Thanks for saving me a ton of money!
This has popped up in my recommended 45 times in the last week
Thank you Kyle, it was very educating. I want to know more. I want to build small jet plane, I have no education in aeronautics, just self taught and English is my third language. You know what, from the bottom of my soul I know I will succeed. Your kind of video is giving me the knowledge I need.
Awesome video. Thanks heaps for making it understandable for people (like myself) who have very little knowledge in this field. I've had the misconception that carbon fibre is just the best for everything.
Interesting stuff. It all boils down to find the balance between weight, stiffness and strength for the particular purpose.
Thanks for posting this. I was going to make carbon fiber aero parts for my MR2 track car but now I see that it won't make a bit of difference except cost.
I know that the point of the video is which material is best for a given application, not which is 'the best material' overall, but I'm really impressed by S Glass.
Finally, some actual information. Thanks a million.
I would love the actual facts about how a foam core can be regarded suitable as a structural element in layering of fiber glass or any of these products.
As described in other videos here on TH-cam we are often told that a 30 mm layer of marine grade foam board may have to be substituted by up to 9 layers of fiber glass.
The immense difference in strength and stiffness of these two materials should be apparent to anyone who ever held a piece of foam between their fingers.
What I lack is the facts and figures as you presented it in this video.
Please do describe this for us laymen if you will. It will be highly appreciated.
I wanted to add, the carbon-fiberglass weave/cloth (likely it was the lower grade fiberglass) offered the fiberglass in multiple colors (Blues, Yellows, Reds, Greens, etc) & provided a nice color contrast when used against the black-gray Carbon. I'm sure it too may b a good way to add some flex? or reduce brittleness? It was mainly available in woven tubes for pen-making. The fiberglass added a nice, colorful "top layer". Thx for the info & your time! I never knew there were such different grades of fiberglass! As well as (the higher grade) being "pretty good stuff!" Thx again!
This was so helpful u just saved me from doing some very expensive misstakes.
Hi Kyle, great video! One thing I missed in this video was when designing a structure that will be loaded in bending (which most structuren are) the moment of inertia plays a major factor in the strength and stiffness calcations. Since carbon has a significantly lower density when designing a part for strength in certain situation carbon might still be the lightest option. Still doesn't take away from the great video and your valid conclusions at the end of your video
Thanks a lot! That one was great axample abaut all these materials. I know pretty well abaut metals and all the stiffness and other properties of those. But all those others, glass fibers and carbon fibers and especialy kevlar properties was pretty much all new to me. So, big thaks to you for this video! I appreciate it! I learned something new!
really appreciate the info, you literally just saved me a lot of green backs, thanks.
At my university (University of Miami) They had a student project where a concrete bridge on campus was built by students, except instead of being steel-reinforced, the concrete was fiberglass reinforced.
This is a great video! Really helpful for understanding the basics without getting bogged down in hyper technicalities.
As a victim of four self designed propellers and their fatigue failures, the last one while I was flying, here is one factor you missed, comparative fatigue life. I suppose that carbon fiber is better at this, but certainly carbon fiber is used for more than decoration. This factor is worthy of discussion. Nice vid, anyhow.
Congratulations you've done a really nice video.
I agree with everything you said except that: you have not taken into consider the flammability of materials and about the cost of carbon are higher but not so much for don't use it.
The fiber glass is highly flammable while the carbon and Kevlar not.
Kevlar is used for coating parts subject to impact, also has the highest resistance to fire.
For example, combine carbon and Kelvar on portire makes a thief-proof.
Incorporating into different materials structure offers different results.
For example, there are PVC that can be inserted in doors and isolate noise and give a rigidity in the event of impact.
The list does not even mentioned composites made of kevlar-carbon, carbon-titanium that would make the discussion an important guide on the subject.
Treating the composite materials I have to say also a very negative point since the difference of electric charges on the carbon of definitely different from other materials already present in the car which would end bad without adequate protection.
If you do a more complete video I will be happy to examine it could get out of it is something really interesting that would fill many doubts of many people.
very informative video.. now I know much of the things about Kevlar ,glass fiber and carbon fiber ..
all the best my friend you impressed me alot through your quality information
Great video!
As a boat builder in the 70's and 80's, and 90's, mostly sailboats and sailboards, with a specialty of foils -- and a few offshore unlimited cats, I came to similar conclusions. S glass for compressive strength, carbon for stiffness to weight, and fuck no Kevlar. You illustrated the exact problem with Kevlar, it pops out of the resin in compression, such as when it's on the inside of a bend on a composite beam. I don't think it ever really bonds with the epoxy and any tiny wetting void is a potential failure point, I could never trust the stuff.
Carbon has some surprising issues, too. We built a 30' sailboat, Nomex cored 0/90 carbon, the bare hull weighed 250#'s, stiffer than .... Worked great, but you could take a sharp pencil and drive it right through the hull.
One of the best videos on youtube. top 1% for sure.
Freaking awesome! Backed up with solid numbers and specs, no BS, no whoo whoo, good stuff!
I make giant airplane model and fiberglas vs carbon is my "today" problem. Your video really helped me, thank you. It's simple and very usefull !!!
Excellent video. I'm building a boat for a round-the-world cruise. This video has really made me reconsider what materials I'll be using where.
All and none are the best: Carbon is the stiffest and the more resistant in tension and compression, but also the most expensive. Kevlar have the lowest density and is the most resistant in sheer strenght and abrasion but very poor in compression and needs to be dehumidified before lamination. fiberglass is average for tension compression and sheer resistance, heavier but alot more afordable for everyday use and is comming in the biggest range of technical fabrics.
This is one of your best videos man. Your channel in general has very good content.
I'm looking forward to see your video about stress
The points being made here are very good, much of the carbon, glass, kevlar is still misunderstood. Here is a generalisation of the materials in point and how they react to different loads etc. There are many types of each fabric, the way they are made the directions they are laid and the numerous resins employed. In reality carbon is stupidly expensive, it's useless without epoxy resins : also stupidly expensive and what you gain might never have any effect on what you actually need it for, unless you're competing at stupid money levels. For the rest of us Glass fibres with a decent isophthalic or vinyl ester resin maybe even epoxy is the way to go. You might be surprised to learn that 90 percent of boats are built with the lowest grade orthophthalic resins, chop strand mat and woven rovings, but it works, so how much do you really need exotic materials in the end?
You can sometimes get a CF/Fiberglass mixture where the base is fiberglass and the final layer or 2 (in usually a 6-ply stack-up) is CF. That way you can save costs while giving off that sexy twill pattern.
You should nerver do that... bc fiberglass flex alot more then cf so the cf will crack/break
WOw, now it takes a month to understand that all. I need to see this again !! Thanks !
Jeez Kyle, you absolutely knocked it out of the park with this. The trouble is, I end up with more questions than answers but I guess the takeaway from that it, what are you trying to use this material for? The only bit you left out - unless I missed it - were the differences in strength: tensile, compression and sheer. Does this matter much for racing applications? How much difference is there between the different materials?
Otherwise, you best yet. Well done.
This was super educational I really appreciate it I hope you can get a sponsor for you videos
Thanks. Beginner questions. Q1: why not having a first coating in carbon(stifness) and on top of it fiber glass(for impact resistance)?
Q2: "Fiber glass doesn't look good", why not a final "polishing layer" with a fiber of 160g/m² or 100g/m²?