Search
Linear elastic -> H...

Clear all

# Linear elastic -> Hyperelastic coefficient conversion

8 Posts
5 Users
0 Likes
3,080 Views
Posts: 3
Topic starter
(@prathyush963)
New Member
Joined: 15 years ago

Hello,

I am currently working on modeling soft tissue. I got as only data the Young modulus E=2500 Pa and the poisson ration =0.499 (incompressible material).

They ask me to work with the hyperelastic model so I need to understand if the is an equivalence between hyperelastic and linear elastic coefficient. I will be working with Mooney rivlin model so I need C_10 and C_01.

Can someone help me?

Regards

David

Topic Tags
7 Replies
Posts: 3998
(@jorgen)
Member
Joined: 5 years ago

If all you know are E and nu (and you cannot perform additional tests), then you should not use a Mooney-Rivin model but a Neo-Hookean model.

The shear modulus for the NH model is E/3.

-Jorgen

Topic Tags
7 Replies
Posts: 3
Topic starter
(@prathyush963)
New Member
Joined: 15 years ago

[QUOTE=Jorgen,4850]If all you know are E and nu (and you cannot perform additional tests), then you should not use a Mooney-Rivin model but a Neo-Hookean model.

The shear modulus for the NH model is E/3.

-Jorgen

Thank you very much for this answer. Is there a paper/book where I can get this information in order to cite it?

David

Posts: 3998
(@jorgen)
Member
Joined: 5 years ago

You can site me đź™‚

It is actually easy to derive (perhaps you dont need to cite it):

âžˇ The Poissont ratio of most rubbers and soft tissues is typically close to 0.5 (that is incompressible).

âžˇ The shear modulus is given by (see most intro to solid mechanics books):
mu = E / (2 * (1 + nu))

If you insert nu=0.5 you will get mu = E/3...

-Jorgen

Posts: 1
(@Iweas6)
New Member
Joined: 14 years ago

What is the incompressibility parameter used in Neo-Hooken model ? how to derive it?

Posts: 5
(@sdebock)
Active Member
Joined: 13 years ago

Hello Dr. Jorgen

As i told you, I have hardness value for rubber and nu = 0.5(rubber is incompressible). You asked me use Neo-Hookean form. I needed two parameters C10 and D1

So I converted hardness s into E as per ref formula E = 0.0981(56+7.62336s)/0.137505(254-2.54s)

I will get Shear modulus 0 = E/2(1+nu). and from this i will calculate C10 = 0/2

D1 = 0 for incompressible in abaqus/standard,

So I will have both C10 and D1

please tell me if this approach is right....