Transverse Properties of Carbon Fiber

[Shmisa]

Carbon fibers used as the reinforcing phase in composite materials have properties in the longitudinal E11f and transverse E22f, for example. I became interested in how mechanical testing is conducted for both the matrix and reinforcing phases. I was able to find the ASTM D3379 standard for determining the properties in the longitudinal direction, but I can't find anything about how the E22f properties are determined.

Can anyone help me figure this out? I would be very grateful!

 

[SWComposites]

E22 for a bare fiber is almost never tested. And don't know why anyone would need that property.

 

[Shmisa]

E22 for a bare fiber is almost never tested. And don't know why anyone would need that property.

Thank you for your reply!
I don't quite understand where carbon fiber manufacturers get these values for E22f. Are these derived using some chemical methods, or do they also conduct mechanical testing? Sometimes it's necessary to know E22f to use it in micromechanical models.

 

[SWComposites]

I don't know where they get the values.
And I've never found micromechanics models to be of any use in real industrial applications of composites, so don't care.
But can't imaging E2f values having much effect on overall macro scale properties.

 

[Shmisa]

I don't know where they get the values.
And I've never found micromechanics models to be of any use in real industrial applications of composites, so don't care.
But can't imaging E2f values having much effect on overall macro scale properties.

Hmm, I get it. That's interesting. Thank you!

 

[Compositepro]

The 90 degree (or radial properties) of carbon filaments are important, but only in how it affects the properties of the composite (fiber and resin together). Mechanical testing of unidirectional composite material can be done in the zero and 90 degree direction, and then fiber properties are calculated. This testing is usually for academic purposes.
For real world applications testing is done on cross-plied laminates using actual fiber orientations (0/90. Quasi, etc.).