Carbon Fibre

[Danny McGee]

Howdie folks.

Am currently designing some stuff and was wondering if anyone knew which type of carbon fibre it is that our model cars used. Im trying to use COSMOS to see the forces etc and want to have a realistic material.

The options that i have are;
Zoltec Panex 33
Hexcel AS4C
Thornel Mat VMA
Thornel VBC-20 Carbon Cloth

Thanks in advanced

[glypo]

None of the above. With the exception of AS4 those all sound pretty obscure. I'm not even sure if the others are PAN sourced fibres?

Cheaper RC stuff tends to be made of T300 which has a modulus around 230 GPa and strength of around 3.5 MPa. The better quality stuff found on race models is T700. It has roughly the same modulus as T300, but has a much higher UTS, around 5.3 MPa.

AS4 is common in general use, but I am not sure about in RC use.I think it will likely be found in Japanese models. The Txxx materials are American developed and the AS4 is Japanese developed if I remember correctly. AS4 actually has the highest modulus, albeit just marginally better then T700 at around 240 GPa. Very stiff stuffer. The modulus is placed between T300 and T700 at 4 MPa.

So basically, you want T700 ideally for good stuff, but if that's not an option AS4 will be fine. For the matrix it will be thermoset and almost certainly epoxy. To get good results also make sure you select a multi-directional (quasi-isotropic) layup, if you have to specify the typical layup for MD sheet is 0/±45/90. Hope that helps, be as accurate as you can inputting data as it gives you best results.

I've not used comsos for FEA before as I don't use solid works. However in other FEA software I have used, setting up composites can take a while as you also need to input that you are using sheet material, and also specify the correct plane the sheets are in. Otherwise it can assume mad stuff and give crazy results.

good luck

[jimmy]

I was gonna say the same as Glypo

[Scouser]

I was just going to give him a link to Fibre-Lyte!!

[RogerM]

Glypo ..... great info ..... who do I talk to about melting my work's copy of Solidworks .. LOL

Seriously though ... good shout.

Danny, if you look around the net you'll find an info set for T700 0-45-90 in the format that COSMOS needs ..... just enjoy the painful experience of trying to import a new material to the lists.

[jimmy]

man, I'm gonna stick to placing objects in UnrealEd if 'proper' CAD is this complex. I've no idea what anyone just said apart from scouser.

[elvo]

Originally Posted by jimmy

man, I'm gonna stick to placing objects in UnrealEd if 'proper' CAD is this complex. I've no idea what anyone just said apart from scouser.

Don't worry. SolidWorks can be as simple as sketching objects and sticking them together a bit.

Anything that has 'COSMOS' in it, or uses abbreviations, is advanced stuff.

[glypo]

Yup anyone can use CAD, and in fact many do. But to design stuff well, you still need a good engineering sense or knowledge. What we're talking about isn't specifically CAD though, but more CAE (computer aided engineering), more specifically about FEA in this case (finite element analysis) which is used to simulate load on the designed component, to find any areas of high stress. The packages aren't 100% accurate, and it depends how well you mesh the component, but they aren't too far off, and are very useful. Anyway as has been said it's a little more technical then just using CAD blindly to design stuff, so don't let it put you off!

As for T700 and other materials, I have stacks of material data here, if you want to do a manual input I can happily supply the figures. However it could be hard to set-up a MD layup so if you can simply import a T700 MD data as suggested by Roger, I would it would be ideal and should give you better results then using the AS4

[Danny McGee]

Any ideas where i can get that data from? Also not really looked at it to much but how do i add it

i guess the idea of designing something appeals to me as i've just finished off my motorsports engineering degree and although i'm more interested in aerodynmanic performace i thought i would give myself a little challange until i go on my travels. At the mo i've got the front and rear tower completed. some rear wishbones (with pick up points) so that i can analyse the geometry etc. Its actually quite good fun , all with the help of my trusty Milliken & Milliken book