The UMAT subroutine in Abaqus serves as a solution for modeling materials that cannot be accurately represented using the standard Abaqus material library. For this project, we utilized this subroutine to study a 3D isotropic isothermal beam.
The problem, as shown in the figure, involves a 3D anisotropic isothermal beam. We analyzed it once using Abaqus's built-in material model and again using the UMAT Abaqus subroutine, comparing the stress patterns. The results matched exactly.
Additionally, we’ve made all modeling files and a training video on UMAT and related workshops available on our website for download.
There’s also a free PDF offering a comprehensive explanation of the UMAT subroutine and workshops, which we highly recommend.
In this project, we have aimed to provide everything you need to develop a UMAT code for isothermal elsticity. However, since our focus has been on analyzing material behavior, we have kept the loading setup simple. If you need to apply more complex loading or boundary conditions in your model, you may encounter certain limitations in Abaqus. To overcome these, you can use the DISP and VDISP subroutines.
To learn more about these subroutines, you can download one of our free GitHub projects from the link below, which includes a DISP subroutine code and its corresponding INP file.
https://github.com/CAEAssistant-Group/Disp-Fortran-Code-Abaqus-Subroutine