Question about material model in svFSI

[Aditya Bantwal]

Hello,

The material model described in Gasser et al (2006) states that the collagen fibers do not support any compression and would buckle. Therefore, the anisotropic part of the HGO model only contributes to the strain energy if the strain in the direction of a_0_i is positive.

strain.png (109.39 KiB) Viewed 123 times

https://royalsocietypublishing.org/doi/ ... .2005.0073


I was wondering if the HGO model in svFSI handles this behavior, for example I have read in some places that a Heaviside-type function is used to turn off the effect of fibers during compression (https://polymerfem.com/holzapfel-gasser-ogden-model/). I couldn't gauge much by the code here: https://github.com/SimVascular/svFSI/bl ... ATMODELS.f


Thanks,
Aditya

[David Parker]

Hi Aditya,

There is a GitHub Issue https://github.com/SimVascular/svFSI/issues/55 that seems to address decoupling.

And there is code here https://github.com/SimVascular/svFSI/bl ... ELS.f#L363 that implements this for the HO material model.

Cheers,
Dave

[Aditya Bantwal]

Hi Dave,

If I'm not mistaken, this appears to be implemented only for the HO model, and not for the HGO model.

Thanks,
Aditya

[David Parker]

Hi Aditya,

Yes, sorry, wrong spelling.

The HGO material model documentation does references the Gasser paper but you will need to look at the implementation details (there are two) to really understand what it does, run some tests, etc.

Dave