Can somebody help me establish the material properties of fiberglass 1

[bludog]

I am doing an FEA analysis with Pro/Engineer Mechanica of a linkage arm that is made out of fiberglass (Generic E-glass/epoxy Unidirectional Prepreg). When assigning the material of the part in Pro Engineer, I need to input the following:

E1, E2, E3, G12, G13, G23, Nu21, Nu31, and Nu32.

Can somebody please help me with what values to use. The fiber will run along the X (1) direction. The Y (2) direction will be transverse to the fiber. The thru material direction will than be the Z (3) direction.

I have found data that provides the following about Generic E-glass/epoxy Unidirectional Prepreg:

E1 = 39 GPA, E2 = 8.6 GPA, G12 = 3.8 GPA, Nu12 = .28

However, I just don’t know if I am correctly converting the rest of the values (E3, G13, G23, Nu21, Nu31, and Nu32) from these values.

Thanks,
Justin

 

[SWComposites]

As a rough estimate for uni tape:

nu21 = (E2/E1)*nu12
E3 = E2
G13 = G12
G23 = 0.67*G12
nu31 = nu21
nu32 = 0.45

 

[bludog]

Thanks SWComposites for quick response and good answer.

Just out of curiosity, where did you get nu32 = .45 ?

Also, how did you know that G23 = .67*G12?

I have read your previous posts and had seen you answer G23=.67*G12 before. Is that just something proven from experience in the field?

Finally, do you feel the values I had posted above:
E1 = 39 GPA, E2 = 8.6 GPA, G12 = 3.8 GPA, Nu12 = .28
are a good estimation values for "Generic E-glass/epoxy Unidirectional Prepreg"?

Thanks again,
Justin

 

[SWComposites]

Your values for uni f/g tape properties are reasonable.

There is some f/g data in Mil-Handbook-17 Volume 2; a copy can be purchased from ASTM,

http://www.astm.org.

There is also f/g data in various textbooks and online in vendor data sheets. Check the Cytec, Hexcel, ACG, Nelcote, etc websites.

My thru-thickness estimates are based on some carbon fiber/epoxy data in Mil-Handbook-17 and some proprietary data.

Steve