How to find out Young's Modulus E22

[Rameel]

Hi,
I am new to abaqus.I want to know that how can i find E22.
I have a unit cell of fiber reinforced composite and model is a cube and i applied displacement boundary conditions in u2 direction. I want to find Young,s modulus E22 for that i need to find sum of forces on all nodes on unit cell.
One way can be to generate field data report for NForce and dispalcement and then manually find out the E22. But i think its not the correct way, would you please guide me how i can find E22 directly from abaqus CAE.

Thanks

 

[Composites_FEA_Guru]

Hi Rameel,

The method you are describing is perfectly acceptable, although it may be a little tedious. I assume you have fiber and matrix material data and are trying to characterize a composite lamina. If that is the case, I suggest using Helius:MatSim, a free online material simulator (

http://www.firehole.com/products/matsim/)

to check your work. MatSim takes fiber and matrix material inputs (plus a fiber volume fraction) and calculates the resultant lamina properties (moduli, Poisson ratios, CTEs, and densities).

Hope this helps,
-CM

 

[ESPcomposites]

What is the objective of this? Homework, research, or other? It does not seem like an engineering solution since we usually test it at the lamina level. The next reasonable option would be to use one of several textbook solutions which are usually semi-empirically based.

There are other variables beyond the idealization you are proposing in FEM unit cell which make does not make it suitable for a typical engineering approach.



Brian

http://www.espcomposites.com

 

[Composites_FEA_Guru]

Hi Brian,

Could you expand on the textbook solutions you mention? I am familiar with the rule-of-mixtures type equations back from my days in school but cannot recall anything that was semi-empirical.

Also, can you fill us in on these "variables" that affect an ideal solution?

Thanks for the info!
-CM

 

[ESPcomposites]

Have you looked at "Halpin-Tsai" equations?

http://csrl.ucsd.edu/courses/SE253A/files/lectures/3_Halpin-TsaiEqns.pdf

Most composite textbooks have some discussion about it. The rule of mixtures works well for E1 (but the physical behavior is quite different).

The other things to consider are porosity, assumptions about the array type (square vs. hex), and the fact that the actual array won't be either. I suppose a FEM may be indicative of E22 (provided you are knowledgeable about the input parameters), but there are better ways to go about the problem.

Brian

http://www.espcomposites.com