# Calibration using compression test to simulate indentation

Hello!!

I am doing a simulation in Abaqus of indentation in silicone (Ecoflex 00-10 from Smooth-On), but first I needed to find the material parameters. I had test data for compression and I used it to get the hyperelastic parameters for different models, using the evaluate function in Abaqus.

Later, I used the parameters of the 2nd order reduced polynomial (which was stable for all strains) to run an indentation simulation. My resultant force was 10 times bigger than my experimental results for indentation !!!(I calculate this force by adding the nodal force in the indentation area).

I verify the units and they are correct. I started to run new simulations with different diameters of indenter (to get a similiar diameter that the conic indenter used in the experimentation), this helped but my results still being 4 times bigger

Anybody can please tell me what is wrong??

I appreciate any help.

Thanks!!

The stiffness of silicone is dependent on the deformation rate, but your material model will give the same response independent or rate. That could one of the reasons for your problem.

-Jorgen

Thanks for your reply!

I did two compression test at two different strain rates and the stress/strain curve was basically the same.

I already realized why the forces were different: even if I apply talcum powder between the plate and the tissue, there was some friction during the test which makes the reaction forces be different.

Thanks again for your answer.

Elizabeth

- fourier output analysis5 years ago
- Adaptive remeshing5 years ago
- Polyurethane - Gaining Hyperelastic material constants6 years ago
- Hypereslastic and viscoelastic fitting high strain rate compression data9 years ago
- Stiffness changes with temperature under compression9 years ago

- 21 Forums
- 3,870 Topics
- 13.2 K Posts
- 9 Online
- 29.4 K Members