×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Material Properties of Carbon Fiber

Material Properties of Carbon Fiber

Material Properties of Carbon Fiber

(OP)
Do you guys know how can I justify that carbon fiber has isotropic / orthotropic material properties?

if it is isotropic, how can i justify
some papers suggest they are orthotropic?
is it because when it undergoes curing process, in the oven
it becomes elastic brittle (which induce to orthotropic rather than isotropic in its original mode (graphite/carbon)

many thanks
hope you could give me some lights

RE: Material Properties of Carbon Fiber

Fibers only reinforce in the direction that the long part of the fiber is aligned in anyway so it really doesn't matter if they the fiber properties are isotropic. All you need is the properties in the fiber long direction which you can find online. One compensates for the fact the the reinforcement is only in one direction by aligning in the fibers, or layers of fibers in different directions to create reinforcement in those other directions too.

There are reasons why a carbon fiber would have anisotropic properties. For example, many are made from PAN fibers (polyacrylonitrile) which contain highly aligned polymer chains from the spinning process. These would then carbonize to give aligned graphitic sheets.

Chris DeArmitt - PhD FRSC

Materials Consulting & Training
www.phantomplastics.com

RE: Material Properties of Carbon Fiber

Right, that makes it anisotropic in shape but not necessarily in properties.

Chris DeArmitt - PhD FRSC

Materials Consulting & Training
www.phantomplastics.com

RE: Material Properties of Carbon Fiber

Correct. That's exactly what I said in my first post here smile

Chris DeArmitt - PhD FRSC

Materials Consulting & Training
www.phantomplastics.com

RE: Material Properties of Carbon Fiber

(OP)
I have a bit of understanding now, especially when you said the geometry have influence on material properties
so it seems vendor of carbon fibre as general couldn't give generic material properties for all direction then

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources