calculate materials properties from finite element method

[anusharm]

Hi,

I have stress-strain curve (from compression test experiments) of a composite structure. Is there any method by which I can predict the materials properties of this composite structure using finite element analysis. Kind of back calculation.

Thanks

 

[rb1957]

I'm not sure what you have ...
a) a stress/strain curve of the material, or
b) a load/deflection curve of the structure (made from this material) ?

If b), and if the material is reasonably homogeneous, then I guess you could build a FEM of the structure, give it some property and adjust until you get the deflections you measured. Mind you, I'd expect more than one solution (for E and G) would work so I don't think it'll tell you something definitive.

another day in paradise, or is paradise one day closer ?

 

[anusharm]

Hi,

Thanks for the quick reply. My case is b. However the problem is that the structure material is hyperelastic and it is difficult to guess the properties.

 

[structSU10]

One thing to be cautious of is that finite elements tend to be stiffer (essentially a higher apparent I) than they would be by normal analysis. This will throw off your result a little bit, by maybe a few percent.

 

[Stanum]

https://www.sharcnet.ca/Software/Ansys/fluent/14.0/help/ans_mat/Hlp_G_STRmcfhyp.html

try out this one. It seams like your problem, but it is for stress-strain curves.

 

[rb1957]

did your structure deflect in a hyper-elastic manner when you loaded it ?

whatever, give it some properties and see what happens; though like I said I'd expect there are several solutions that'll give the response you measured.

another day in paradise, or is paradise one day closer ?