Learning Forum

[Giorgos Troulliotis]

Dear all,

I am trying to run a coupled implicit electrophysiology - solid mechanics model but the solver does not seem to pass transmembrane potential values to Mat_295 when ELFORM 13 tetrahedral elements are used.

The solver does seem to work using ELFORM 10 tetrahedrals, however ELFORM 13 seems to be much more suitable to deal with (nearly) incompressible materials.

Is this an issue with my simulation setup or does the solver require ELFORM 10 elements for the coupling to occur? ( specifically talking about linear tetrahedral elements...)   

Many Thanks,

 

George

[Reno Genest]

Hello George,

I checked with the development team and I got the following reply:

"...it should be working for both ELFORM 10 and 13. ELFORM 10 and 13 is suited for compressible and nearly incompressible material models (both available in MAT_295), respectively. It should even work with ELFORM 15 and 16 even though those elements are not recommended even by their developer. Which LS-DYNA release is the customer using?"

Could you tell us  which  version of LS-DYNA you are  using?

 

Reno.

[Reno Genest]

Hello George,

Also, note that Ansys employees are not allowed to upload and download files on the Ansys Forum. If you want  to send us your model, please submit a service request on the Ansys customer portal:

support.ansys.com

 

Let me know how it goes.

 

Reno.

[Giorgos Troulliotis]

Hi Reno,

Thank you for the prompt reply.

I am using LS-DYNA 2022 R2. But I intend to switch to LS-DYNA 2023 R1.

I would be happy to share the model with you, however I will have to reduct the nodal coordinates of the mesh as this is a patient-specific model.

Should I use a specific thread number to reference this thread in the service request? 

Best Regards,

 

George

[Reno Genest]

Hello George,

You can specify the url of this forum post in the service request.

Also, note that both Ansys WB 2022R2 and 2023R1 come with LS-DYNA R13. The R14 version is now available:

https://ftp.lstc.com/user/mpp-dyna/R14.0.0/

username: user

password: computer

 

We may be able to provide you with a DEV version after you open a service request.

 

Let me know how it goes.

 

Reno.

[Giorgos Troulliotis]

Hello Reno,

I apologise for the late response. I have tested the new LS-DYNA version and it seems to resolve the issue, now both ELFORMs couple with the EP solver.

Is there an object version of LS-DYNA R14 available, as I am using a user-defined loading condition to couple the left ventricular model to a 0-D fluid circuit?

Thank you for helping me resolve the issue.

Best Regards,

 

George 

[Reno Genest]

Hello George,

I don't see the R14 in our object version directory, but it might be  somewhere else. Ansys employees are not allowed to send files on the forum and so the best is to submit an SR on the Ansys customer portal and ask about object files:

support.ansys.com

Our user defined function expert will be able  to help you.

Have a good day!

 

Reno.

[Giorgos Troulliotis]

Hi Reno,

As you previously suggested I already submitted a SR in the portal which I'll update it to ask for the R14 object version.

Thank you very much for the help.

Best Regards,

 

George 

[Reno Genest]

Hello George,

Are you in contact with a support engineer fo the SR you submitted? I don't think I saw it come in the LS-DYNA queue. What is the SR #?

 

Reno.

[Giorgos Troulliotis]

Hi Reno,

The SR number is 11300491914. The service request has been assigned to you and it says it's currently awaiting 3rd party activity.

 

George

[Reno Genest]

Hello George,

Could you open a new SR for the question about the object file for R14? We like to keep SRs to a single topic and the question will be assigned to our user defined function expert.

 

Thanks!

 

Reno.

 

[Giorgos Troulliotis]

Hi Reno, 

No problem I'll do that. Thanks again for the support.

Regards,

 

George