MAT_295 (MAT_ANISOTROPIC_HYPERELASTIC) parameters

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Žiga Donik

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Feb 18, 2022, 2:21:30 AM2/18/22
to LS-DYNA2
Hi,

I would like to use MAT_295 for arterial wall modelling in LS-Dyna. I am still new to LS-Dyna, and before trying anything more specific, I want to try a simple test sample case. In Abaqus documentation, there is a test case (with all the parameters) from the Gasser-Ogden-Holzapfel 2006 paper, which I want to replicate. Can anyone please provide some guidance on the model parameters? I am attaching the keyword file for the analysis. It runs well with a Neo-Hookean model (an Ogden ISO model from MAT_295). Still, I can not figure out the other ISO and ANISO card parameters with an incompressible HGO formulation (TYPE = -3).

The parameters in LS-Dyna are different from other software which have implemented the HGO model (Abaqus, FEBio), so I am confused.

I really appreciate any help you can provide.

Žiga
HGO_LSDyna_test.k

James M. Kennedy

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Feb 18, 2022, 1:32:50 PM2/18/22
to Žiga Donik, LS-DYNA2

Dear Ziga,

 

Did you perhaps look at these presentations?

 

Nagy, A.P., Benson, D.J., Kaul, V., and Palmer, M., “Constitutive Modeling of Biological Soft

Tissues”, 15th International LS-DYNA Users Conference, Dearborn, Michigan, June, 2018.

 

https://www.dynalook.com/conferences/15th-international-ls-dyna-conference/biomedical/constitutive-modeling-of-biological-soft-tissues

 

Nagy, A.P., “MAT_295 – Constitutive Models”, Livermore Software Technology LLC,

Livermore, California, September, 2020,

 

https://ftp.lstc.com/anonymous/outgoing/support/PAPERS/mat_295_formulation_public.pdf

 

Sincerely,

James M. Kennedy

KBS2 Inc.

February 28, 2022

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Žiga Donik

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Feb 21, 2022, 4:54:35 AM2/21/22
to LS-DYNA2
Dear James,

Thank you for a swift reply. I have checked the links you have provided. I get an error when running the keyword file with the ANISO module. I am attaching the corrected keyword file and the output file if it would help. 
Also, in the first link you provided (Nagy, A.P., Benson, D.J., Kaul, V., and Palmer, M., “Constitutive Modeling of Biological Soft Tissues”, 15th International LS-DYNA Users Conference, Dearborn, Michigan, June 2018.), there is an “&” before nu in the ISO module. Is that a reference to a predefined variable in the keyword file? If so, it would be helpful to see the keyword file where it is defined. I have not found any example keyword files for *MAT_295.

Thanks again.

Žiga
petek, 18. februar 2022 ob 19:32:50 UTC+1 je oseba jmk napisala:
HGO_LSDyna_test.k
lsrun.out.txt

James M. Kennedy

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Feb 21, 2022, 12:10:26 PM2/21/22
to Žiga Donik, LS-DYNA2

Dear Ziga,

 

From the LS-DYNA User’s Manual (*PARAMETER entry):

 

http://ftp.lstc.com/anonymous/outgoing/jday/manuals/DRAFT_Vol_I.pdf

 

Remarks:

 

1. Syntax for Using Parameters. Parameters can be referenced anywhere in the

input by placing an "&" immediately preceding the parameter name. If a minus

sign “-“ is placed directly before “&”, i.e., “-&”, with no space the sign of

the numerical value will be switched.

 

2. Character Parameter. A character parameter can be included as part of a

larger string. The included character parameter should start with ‘&’ and end

with ‘^’. The ending character ‘^’ will be replaced by ‘_’ in the resultant larger

string. For example, a string definition of “&TORSO^lower arm” will result in

“P101_lower arm” if parameter “TORSO” is defined as “C” type with a value

of “P101”.

 

For example, suppose you have the following input files:

 

main.k:

*PARAMETER

R VAL1 1.0

*PARAMETER

R VAL2 2.0

*PARAMETER

R VAL3 3.0

*CONTROL_TERMINATION

&VAL1

 

I also do not have any example keyword files for *MAT_295.

 

Sincerely,

James M. Kennedy

KBS2 Inc.

February 21, 2022

James M. Kennedy

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Feb 21, 2022, 1:47:06 PM2/21/22
to Žiga Donik, LS-DYNA2

Dear Ziga,

 

Perhaps this presentation might be of some interest:

 

Nolan, D.R., Gower, A.L., Destrade, M., Ogden, R.W., and McGarry, P., “A Robust Anisotropic

Hyperelastic Formulation for the Modelling of Soft Tissue”, Journal of the Mechanical Behavior of

Biomedical Materials, Vol. 39, pp. 48-60, November, 2014.

 

https://arxiv.org/pdf/2009.08754.pdf

 

Sincerely,

James M. Kennedy

KBS2 Inc.

February 21, 2022

 

From: James M. Kennedy [mailto:j...@kbs2.com]
Sent: Friday, February 18, 2022 12:33 PM
To: 'Žiga Donik' <ziga....@gmail.com>; 'LS-DYNA2' <ls-d...@googlegroups.com>
Subject: RE: [LS-DYNA2] MAT_295 (MAT_ANISOTROPIC_HYPERELASTIC) parameters

 

Dear Ziga,

 

Did you perhaps look at these presentations?

 

Nagy, A.P., Benson, D.J., Kaul, V., and Palmer, M., “Constitutive Modeling of Biological Soft

Tissues”, 15th International LS-DYNA Users Conference, Dearborn, Michigan, June, 2018.

 

https://www.dynalook.com/conferences/15th-international-ls-dyna-conference/biomedical/constitutive-modeling-of-biological-soft-tissues

 

Nagy, A.P., “MAT_295 – Constitutive Models”, Livermore Software Technology LLC,

Livermore, California, September, 2020,

 

https://ftp.lstc.com/anonymous/outgoing/support/PAPERS/mat_295_formulation_public.pdf

 

Sincerely,

James M. Kennedy

KBS2 Inc.

February 18, 2022

 

From: ls-d...@googlegroups.com [mailto:ls-d...@googlegroups.com] On Behalf Of Žiga Donik
Sent: Friday, February 18, 2022 1:22 AM
To: LS-DYNA2 <ls-d...@googlegroups.com>
Subject: [LS-DYNA2] MAT_295 (MAT_ANISOTROPIC_HYPERELASTIC) parameters

 

Hi,

--

James M. Kennedy

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Feb 21, 2022, 2:04:43 PM2/21/22
to Žiga Donik, LS-DYNA2

Dear Ziga,

 

Have you tried using R13? Some updates are given in the following Release Notes.

 

Release Notes for R13.0.0 September 8, 2021

 

50. For *MAT_295 / *MAT_ANISOTROPIC_HYPERELASTIC, improved initial effective moduli computation used for both stable time step estimates as well as hourglass control.

 

51. For the ACTIVE module of *MAT_295 / *MAT_ANISOTROPIC_HYPERELASTIC:

• Made the default of the active stress scaling factor unity.

• Enabled activation/deactivation for all active models used in conjunction with electrophysiology coupling.

• Included an activation threshold on the calcium concentration for active models 1-3 for electrophysiology coupling.

• Increased number of history variables

 

33. For *MAT_295 / *MAT_ANISOTROPIC_HYPERELASTIC:

• Fixed a bug which let the simulation run even if negative determinants were reported in the stress update routine in MPP.

• For the ANISO module, fixed a bug for fiber models other than the Holzapfel-Gasser-Ogden; the compression tension switch is now uniformly based on the total fiber stretch.

• For the ANISO module, fixed a bug when using fiber stress vs stretch relations defined by a curve.

• Fixed a bug in the keyword reader of the ACTIVE module

 

Sincerely,

James M. Kennedy

KBS2 Inc.

February 21, 2022

 

From: ls-d...@googlegroups.com [mailto:ls-d...@googlegroups.com] On Behalf Of Žiga Donik


Sent: Monday, February 21, 2022 3:55 AM
To: LS-DYNA2 <ls-d...@googlegroups.com>

Subject: Re: [LS-DYNA2] MAT_295 (MAT_ANISOTROPIC_HYPERELASTIC) parameters

 

Dear James,

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