Hello,

I am looking for relations/formula that can provide me the required fiber tension for working carbon fiber material in filament winding machine.
 
A preliminary study reveals that the determination of the required tension for a particular fiber depends on the part diameter,pattern to be wound and material of the fiber and tension determination is done experimentally.

What range of tension should i set my filament winding machine on? what governs its determination and can it be found by calculations?

Please cite references .

regards,

One of the factors is fiber slippage at the end of the pipe, when the direction of the fiber is being changed. If the tension isn't high enough the fiber will not stay in place due to lack of friction.

Which filament winder do you have? Professional one, own construction, X-Winder? Which software do you use?

thank you for your reply brainfort.

i am actually looking to reach these values theoretically before actually going down to the machine..

regards,

Brainfort,

It is a professional,built for special purpose filament winding machine..

i just need to know the fiber tension for setting up the winding process for carbon fiber.how to have it in quantitative terms.10 kN.ok..why? why not 14 kN.

regards,

I don't know of any formulas, maybe the manufacturers of such machines can help you out.
A lot of that is probably trial and error. I do know that fiber tensioning is used to change the vibrational frequencies of wound drive shafts, but this is a very specialized case.

Fiber tensioners used in professional winders are very complicated and expensive since they often do not simply apply some amount of tension but actually control it and keep it in a desired range. Try to find a manufacturer for such machinery and see if you can get more information and the tensions used from their documentation, spec sheets etc.

> 10 kN.ok..why?

Well at least for simple small diameter tubing the tension is 1 or 2 orders of magnitude lower

thank you for that insight .

Assuming you are using the shrink tapes then your initial tension is not so critical as long as it seems smooth and firm on the carbon.




Then the cooking and shrink will determine the final tension or pressure applied.




I have seen a machine where the tension was simply controlled by friction with the tension of the axle/bolt holding the tape. Adjust as you go by eye.




Trial and error, practice etc etc. Having your own understanding of your process is often best.




Edit, fibre tension not tape tension. Doh!

There are a bunch of scientific papers out there which deal with fiber prestressing, for example

Dvorak G. J. and Prochazka P. (1996). Thick-walled Composite Cylinders with Optimal Fiber Prestress. Composites Part B, 27B, 643–649
http://www.sciencedirect.com/science/article/pii/S1359836896000017

and this one:

http://link.springer.com/chapter/10.1007%2F0-306-46935-9_16

Maybe you are lucky and can download them for free somewhere.

Most papers dealing with optimised winding strategies (e.g. for buckling strength, end dome design for pressure vessels etc.) seem to totally disregard fiber tensioning.