Is it possible to use FTorch in ABAQUS Fortran subroutine?

[Fengyixin-research]

I want to utilize the neural network (Pytorch) in ABAQUS Fortran subroutine, is it possible? Do I need any extra operation?
Any advice or suggestion is welcome.

[jatkinson1000]

Hi @Fengyixin-research we are not ABAQUS users, so we'll need a bit more information to try and help you with this.

How do you compile ABAQUS code?
Can you you link to external libraries when building and running ABAQUS code?
What platform, compilers etc are you working on?
What have you tried so far?

FTorch can be linked to as a Fortran library similarly to any other external library (see details below).

A quick search suggests it is possible to link to shared libraries from ABAQUS, but you may also need to compile your code as a shared library: https://abaqus-docs.mit.edu/2017/English/SIMACAEEXCRefMap/simaexc-c-makeproc.htm

I also found this article detailing how to use the external LAPACK library in ABAQUS Fortran subroutines through linking: https://www.bibekanandadatta.com/blog/2024/lapack-Intel-Fortran-Abaqus/

Do you have anyone who has expertise in ABAQUS or can you raise with them how to link to external libraries when building?

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Linking to FTorch as an external library:

FTorch can be linked to as a Fortran library similarly to any other external library.
Whilst we use CMake in the examples, the FTorch documentation explains how to do this in the traditional way with Make by linking:

FCFLAGS+=" -I<path/to/FTorch/install/location>/include/ftorch"
LDFLAGS+=" -L<path/to/FTorch/install/location>/lib -lftorch"

Details

To build a project with make or similar you need to include the FTorch's header (.h) and module (.mod) files and link the executable to the Ftorch library (e.g., .so, .dll, .dylib depending on your system) when compiling.

To compile with make use the following compiler flag for any files that use ftorch to include the module and header files:

-I<path/to/FTorch/install/location>/include/ftorch

This is often done by appending to an FCFLAGS compiler flags variable or similar:

FCFLAGS+=" -I<path/to/FTorch/install/location>/include/ftorch"

When compiling the final executable add the following linker flag:

-L<path/to/FTorch/install/location>/lib -lftorch

This is often done by appending to an LDFLAGS linker flags variable or similar:

LDFLAGS+=" -L<path/to/FTorch/install/location>/lib -lftorch"

If you have pkg-config installed, you can easily query the compiler and linker flags of FTorch rather than manually specifying them as was shown above. FTorch provides a standard pkg-config file in both the directory in which FTorch was built (e.g., </path/to/FTorch>/build) as well as the library directory in which it was installed (e.g., </path/to/FTorch/install/location>/lib/pkgconfig). For example, the following commands are equivalent to adding the manually specified flags:

FCFLAGS+=" $(pkg-config --cflags </path/to/FTorch/install/location>/lib/pkgconfig/ftorch.pc)"
LDFLAGS+=" $(pkg-config --libs </path/to/FTorch/install/location>/lib/pkgconfig/ftorch.pc)"

You can simplify these commands by adding FTorch to the PKG_CONFIG_PATH environment variable:

export PKG_CONFIG_PATH=${PKG_CONFIG_PATH}:</path/to/FTorch/install/location>/lib/pkgconfig/
FCFLAGS+=" $(pkg-config --cflags ftorch)"
LDFLAGS+=" $(pkg-config --libs ftorch)"

You may also need to add the location of the dynamic library .so files to your LD_LIBRARY_PATH environment variable unless installing in a default location:

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:<path/to/FTorch/installation>/lib

[Fengyixin-research]

Thanks for your quick reply.
I think the first link could help me to use FTorch in ABAQUS Fortran subroutine.
The second link I have used before, it is mainly dealed with math computation. Quite simple, but not suitable for neural network.
The reason for posting this question is that I have seen many researchers manually recode the neural network in ABAQUS Fortran subroutine, it might be possible for shallow neural network. But it is really huge work for deep learning neural network. Therefore, I want to use FTorch for simplification.
I will try to do some test.

[jatkinson1000]

Great.

I shared the second link not suggesting you use LAPACK, but because it discusses linking an external library into ABAQUS Fortran subroutines.

Direct linking for complex architectures is definitely the sensible approach in our opinion.

Good luck.
Please let us know how you get on and share anything that might help future users.