Learning Forum

[gmarinpaulon]

Hello,

I am applying a UMAT to ELEFORM3 elements (Truss elements) in different PARTS to run my simulations. Although the application of the UMAT works fine for one of the PARTS, I am getting a message saying that the "default UMAT 42 is being used", which I believe that means that my material model is not being correctly applied to the elements that I desire.

It is important to notice that the UMAT work fine in my local computer (Windows), but I get this error when I run my UMAT in a cluster Linux machine.

Also, I am dynamically linking my shared objects by changing the PATH variable.

Please, could someone explain why is this happening?

Thank you very much.

[Pedram Samadian]

Hi,

 

Thank you for the detailed description. It apears that LS-DYNA is not able to correctly load or call your user material at runtime and, therefore, falls back to the internal default UMAT. Given that the UMAT works correctly on your local Windows machine but fails on the Linux cluster, this strongly points to a dynamic linking rather than a problem with the UMAT formulation or the truss elements themselves. 

 

Has your UMAT been compiled with the same compiler, precision, and MPI settings as the LS-DYNA executable? Have you tried the static linking of the UMAT into the LS-DYNA executable on your Linux system? If static linking is feasible in your setup, I recommend you give it a try.

 

Please let me know if you have any questions.

 

Thanks,

Pedram

[gmarinpaulon]

Hello Pedram, thank you very much for your prompt response.

Yes, we have tried with all same configurations for the shared options, and yet, same issue. In addition, we have tried to use the *MODULE_LOAD and *MODULE_USE cards, but we got the error message that we should have an executable capable of using these (see below). Should I run my model with the new cards with a different executable?

 *** Error 30426 (INI+426)
     *MODULE_LOAD is defined to load user subroutines from a dynamic
     library, which is not supported by this executable.
     A MODULE-enabled executable is required for this feature.

 *** Error 11076 (KEY+1076)
     in *MODULE_USE :
     MODULE ID M_LIB is not found.

 *** Error 10133 (KEY+133)
     keyword input phase failed with: 2 errors

Moving towards the static link, we tried this option this morning. After compiling the codes successfully and getting an executable, we found ourselves with the following error message:

*** Error 10420 (KEY+420)
     Geometry file *CONSTRAINED_BEAM_IN_SOLID
     requested by *INTERFACE_ENSIGHT
     can not be opened

The constrained elements (which are some of the tbeams) worked fine with standard LS-DYNA, but with our compiled version, we face this error.

Please, would you have an idea why this is happening?

Thanks!

[Pedram Samadian]

Hi,

No problem. Thanks for the details. Regarding dynamic linking, please make sure you're using a right executable. The proper executable has a "sharelib" word in its name.

Regarding static linking, what LS-DYNA UMAT package version are you using? Please try the latest version.

Please let me know if you have any questions.

 

Thanks,

Pedram

[gmarinpaulon]

Hello,

Sorry, but my understanding is that I was supposed to run the dynamic link with the standard ls-dyna executable and point it to my shared object. As the dynamic link compilation does not give me an executable, but only the shared object, should I be installing another ls dyna?

We have tried the versions 15.0.0, 16.0.0, 16.1.0, and 16.1.1 (latest) and still got the same problem.

Thanks!

[Pedram Samadian]

Hi,

No worries. You shouldn't use general LS-DYNA executables for dynamic linking. You need to use the sharelib version of the LS-DYNA UMAT package. Please see an example below:

Thanks,

Pedram

 

[gmarinpaulon]

Hello Pedram,

I understand that we need to use the extractors to get the objects version, but the extration using this shell script (files listed below) and the compilation (make) of the files does not result in a lsdyna that I can use to run my model. The result is a Shared Object. So I am not sure what you meant by using the "right executable"

Thanks!

[Pedram Samadian]

Hi,

Thanks for the detail. I can see you already generated the shared library file (.so), so you now need to call it using *MODULE_LOAD in the input deck and run the model using the corresponding sharelib executable. To clarify it, see the example below:

UMAT object file package for dynamic linking:

Corresponding LS-DYNA executable:

As can be seen, both have files have the word "sharelib" in their names.

I hope this is clear now. Please let me know if you have any questions.

Thanks,

Pedram

 

[gmarinpaulon]

 

Hello Pedram,

Thank you for your clarification. Gladly, my stubborn head was finally able to understand what you meant earlier and we managed to get the following warning: 

*** Warning 21509 (STR+1509)
     Usermat shared library file ./libmppdyna_d_R16.0-619-gd222963e2f_avx512_ifort190_openmpi.so
     does not correspond to this build.
     This may lead to erroneous results.

Please, can you clarify if this is something I should be worried, or is it just to tell that I am importing from a different place and to be careful.

Thanks!

 

[Pedram Samadian]

Hi,

Perfect. Regarding the warning message, are you sure your sharelib umat package is consistent with your LS-DYNA sharelib executable?

Thanks,

Pedram

[Pedram Samadian]

Please also make sure to provide the full directory path for the generated .so file in MODULE_LOAD. If there is a concern with the 80 character limitation of the file name there, you can give the directory using *LOAD_PATH.

[gmarinpaulon]

Hello Pedram,

Gladly you are right about the versions of the umat and sharelib. No more warnings given.

However, we are having the following error:

 *** Error 10420 (KEY+420)
 UMAT42 Logic Reached - ID:              82198095  Type:tbeam
     Geometry file *CONSTRAINED_BEAM_IN_SOLID
 UMAT42 Logic Reached - ID:              82178185  Type:tbeam
 UMAT42 Logic Reached - ID:              82451099  Type:tbeam
     requested by *INTERFACE_ENSIGHT
 UMAT42 Logic Reached - ID:              82104615  Type:tbeam
     can not be opened
 UMAT42 Logic Reached - ID:              82076107  Type:tbeam

Our tbeams are the elements receiving the UMAT42 and are also constrained in solid. Is it something we are missing in our material definition?

Thanks!

[gmarinpaulon]

Hello Pedram,

Although the UMAT is now fixed, the model that contains it still shows the "*** Error 10420 (KEY+420) Geometry file *CONSTRAINED_BEAM_IN_SOLID requested by *INTERFACE_ENSIGHT can not be opened". Given that we do not have anything defined about ENSIGHT and the error still appears even after removing *CONSTRAINED_BEAM_IN_SOLID boundary, I was wondering if you would have any suggestion about this. 

Thanks!

Best,

Gustavo

[Pedram Samadian]

Hi Gustavo,

Thanks for the update. It's great that the UMAT is now working. Regarding the mentioned error, you may need to provide us with the code through the Ansys support system for our further investigations. However, let me chech with the developer if he knows what is causing this error and then get back to you.

Thanks,

Pedram

[Pedram Samadian]

By the way, do you have the same issue with the other element formulations like 1 or 2?

[Pedram Samadian]

Hi Gustavo,

Based on the developer's initial review, this issue seems not to be directly related to the UMAT itself. His current hypothesis is that the same error may also occur with a standard material model (for example, *MAT_001), which would suggest the root cause lies elsewhere in the model or setup rather than in the UMAT implementation.

To narrow this down, please try the following:

1) Replace the UMAT with *MAT_001 (or another simple built-in material)

2) Use a simplified version of the input deck, if possible, that still reproduces the error

If the issue can be reproduced this way, there is a need to inspect where in the code the error is being triggered.

Thanks,

Pedram