Curve fitting - metal rubber parts

[made123]

Hi all,

i am a new member and i hope someone can help me.
Is it also possible to do curve fitting on the basis of characteristic curves of metal-rubber parts?

Thank you very much for any help you can give me.

best regards

Christian

[Jorgen]

Can you explain what you mean by: "characteristic curves of metal-rubber parts"?

- Jorgen

[made123]

Hello Jorgen,

i mean the force-deflection graph of the metal-rubber-part. I'm working with marc for simulation of metal-rubber parts by using the implemented curve-fitting procedure for material-models (Mooney-rivlin or YEOH) with uni- and biaxial stress-strain-curves. Can i make a 'reverse method' by using the force-deflection graph of a 'real' component to get the constants for a material?

:confused:

thanks in advance

christian

[Jorgen]

Ooh, I think I understand what your trying to do. Yes, you can use real force-displacement data to calibrate a material model. I have used that reverse approach a few times and it works just fine!

- Jorgen

[made123]

Hello Jorgen,

i'm relieved to hear that, but i don't have any idea how to start, maybe you can give me an advice (technical literature..)?

thanks in advance

Christian

[Jorgen]

Unfortunately I don't have a good reference for that :(

The approach is as follows:

1/ create a FE simulation of your experimental test
2/ select an initial guess of the material parameters
3/ simulate the experimental test
4/ evaluate how close the FE predictions are compared to the experimental data
5/ adjust the material parameters using some minimization algorithm. I often use the fminsearch function in Matlab.
6/ goto 3

- Jorgen

[made123]

Hello Jorgen,

thanks for the tip - i will try my best.

regards
Christian