The 3DExperience Material Calibration App, R2026x, currently supports the following material user-subroutines:
| Abaqus User Subroutine | Description |
|---|---|
| CREEP | User-defined creep behavior. |
| UANISOHYPER_STRAIN | User-defined anisotropic hyperelasticity bases on stretches. |
| UANISOHYPER_INV | User-defined anisotropic hyperelasticity based on strain invariants. |
| UHYPER | User-defined isotropic hyperelasticity based on strain invariants. |
| UHYPER_STRETCH | User-defined isotropic hyperelasticity based on stretches. |
| UMAT | User-defined mechanical behavior. |
| UHARD | User-defined hardening. |
| UCREEPNETWORK | User-defined nonlinear viscoelastic networks. |
| UMULLINS | User-defined Mullins effect. |
In 2026x FD02 we added the capability to calibrate the UANISOHYPER_INV user subroutine. Also, these two items are now available across all user-subroutines:
- Solution Dependent variables (state variables) available for all user-subroutines.
- Custom Schemas can now be used for all user-subroutines.
In 2025x FD01 we added the capability to calibrate the UMullins user subroutine.
This post is meant to bring together other posts related to calibration of user subroutines. As of R2026x the calibration app requires the user to prepare and import a single compiled DLL file. The compilation of the user-subroutine should be performed with the same version of Abaqus that will be used in the calibration app. The app only supports UMATs and other material user-subroutines for use in Abaqus/Standard and not VUMATs. At this time the calibration app runs Abaqus/Standard but cannot run Abaqus/Explicit.
Note: You must use the filename given from the Abaqus make facility. For the old (non-uniquelibs) style, the dll will be named standardU.dll and you must not change this filename. For the newer, uniquelibs style, the filenames will depend upon the particular user-subroutines, but again, you must not modify the filename(s).
Note: A current limitation is that only one .dll file may be uploaded and used in the Material Calibration App. This single .dll file may contain multiple user-subroutines (see example below of using a UHyper + UMullins user-sub)
Here is a UMAT calibration example from 2019:
Here is a UMAT calibration example from March, 2025:
Randy Marlow's UMAT calibration (R2024x GA), Dec 22, 2023
The CREEP user-subroutine is a bit special because in the Abaqus input file (.inp) it does not support the use of data lines to pass data values into the user-sub. There is a relatively new feature in Abaqus called *Parameter Table and *Property Table that allow values to be used in any user-subroutine. These CREEP user-subroutine examples below use the *Parameter Table to pass in the material model parameters.
In the 3DExperience platform, a Custom Schema xml file is used to enhance the UI to support the Parameter and Property Tables.
This post shows the use of both UHYPER and UHYPER_STRETCH. The UHYPER_STRETCH capability is new in R2026x FD01 which will be released in early 2026.
Back to: Material Modeling and Calibration - An Overview and Curriculum
