Mooney-Rivilin Constants Calculation

[Byoung-Chul Lee]

Hi, everyone!

I'm trying to design a EPDM rubber pad with ANSYS to reduce vibration or noise. And I'm going to do planar compression test to get a stress-strain curve.
Then If I have a experimental data, how can I calculate Mooney-Rivilin Constants?
I know how I can calcualte constants with ANSYS. But I want to make Mooney-Rivilin Constants calculation program with MS Excel or Matlab.

My question is when I have an experiment data, how can I calculate Mooney-Rivilin Constants?

Thank You.

[skacel]

First you have to derive a proper stress-strain relation and then find the constants associated with minimal distance between your experimental data and this function. This leads to optimization problem.
Instead of ANSYS, you can also try a freeware fitting utility HYPERFIT that can help you to fit the material constants for various hyperelastic models:

www.hyperfit.wz.cz

[nandish.rv]

Mooney-Rivilin Constants Calculation
to find the mooney rivlin constants curve fitting method can be used.in that it can be selected for veriable parameters, means 2-parameter model or 3,5,9 parameter models. with this it can observe that the which parameter model is suitable for the model and we can directly get the model constants.to get this we require experimental data.

[napoleonm]

Hello skacel

Have you got the hyperfit exe that run properly,, I tried to download it and dosen't works,
could you share it with me please?..

Thanks

[skacel]

Hello Napoleonm,

could you send me your PC configuration? I tried to run the HYPERFIT application on several PCs and it works. In one case however the application did not work (AMD Athlon 64 + WIN XP 32-bit), but I still do not know why. Your configuration may help me to solve that problem. Is there any system-generated error after the instalation?

Regards,
Pavel Skacel

[napoleonm]

Thanks Skacel.
now is working, it seen because I change the file name.. and run it, it did not reconized it.

now it is working..

call my attetion the 8 moths trial..

[nepolean.r]

Hi Pavel,
I dowloaded from www.hyperfit.wz.cz

But this error msg comes when I try to install it. ( filename change is not doing the trick)
"The setup files are corrupted. please obtain a new copy of the program"

following is my PC config.
Windows XP-SP3 32 bit
Intel(R) Core(TM)2 Extreme

I am working with Hyperelastic models for various simulations. Your application seems promising and I would love to try it for my thesis..

Can you kindly send me setup files to rajasenn@mail.uc.edu
(or) nepolean.r@gmail.com

thanks a lot

[skacel]

Hi Nepolean,

it is nice that (as you wrote me):
"It is working now in my original PC... I didnt do any changes but somehow it is working.."

I hope that HYPERFIT software will be helpful for you.

[nfarbod]

Hello Pavel,

I am using the Hyperfit v 1.x at to retrieve the Mooney Rivlin
constants for my Uniaxial, biaxial and planar tests on rubber. I can easily extract the
constants for each individual test, but how can I get one set of constants for all three
tests? (as in a set of C10 & C01 that takes into account all three tests). I need this to
represent my material under global loading conditions. Your reply would be very much
appreciated.

Regards,

Farbod Nassiri

[skacel]

Hello Farbod,

sorry for late reply:

you can add more data-sets into one fit of constants to take into
account more tests.

1/ Just push the "Add new data-set" button in
the left top corner of application form and load/add your data-file. Repeat this for any additional
data-set (number of data-sets is not limited). This will add other data into application for further
fitting. Do not forget to change the "Protocol" listbox for individual
data-set.
2/ Then you can arrange the sub-windows (containing the data-sets)
through menu (Window - Cascade)
3/ When you fit this arrangement now the resulting parameters take into
account all the data-sets.
4/ You can simply "activate" or "deactivate" any data set to try to fit the parameters from only a sub-set of data without the need of deleting and re-loading the data from files.

Pavel Skacel