The calibration of a UANISOHYPER_STRAIN usersub is now available in R2026x FD02. The public cloud was upgraded to FD02 on the last Saturday in April. I tested this workflow today (May 5, 2026) using the public cloud R2026x HotFix 3.15.
The image above is to draw your attention to an Abaqus Verification manual section. In that section there is a user-subroutine file named uanisohyper_inv.f That file also contains a uanisohyper_strain subroutine that mimics the Abaqus native Fung Orthotropic model.
Starting files from Verification manual:
- uanisohyper_inv.f : extract just the uanisohyper_strain part and rename file to uanisohyper_strain.for
- uaniso_inv_fung.inp : extract the part related to using the uanisohyper_strain usersub and rename to uaniso_strain_fung.inp
The material model in that .inp file looks like this: The units are MKS.
*********************************
*material,name=uaniso_strain
*anisotropic hyperelastic, definition=user, formulation=strain, type=compressible, properties=11
0.9925, 0.0749, 0.4180, 0.0295, 0.0193, 0.0089, 5.0, 5.0
5.0, 26.95e3, 1e-8
*********************************
Run Abaqus outside the platform using those files and extract the (time, U1) response. The load is a cload.
This test data file is named test_data_U1.txt
Create the StandardU.dll file using:
Abq2026 make -library uanisohyper_strain.for
The video below shows how to set up a calibration of this user subroutine. It uses FE mode. This video was made using a development version of the Material Calibration App
The zip file below contains all the files mentioned above.
