# Is there a default umat when no user material is declared **URL:** \ **Category:** Advanced features\ **Created:** [February 13, 2026, 2:49am UTC](https://calculix.discourse.group/t/is-there-a-default-umat-when-no-user-material-is-declared/3785 "2026-02-13T02:49:01Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![k3rrig4n](https://avatars.discourse-cdn.com/v4/letter/k/58f4c7/32.png) [@k3rrig4n](https://calculix.discourse.group/u/k3rrig4n)\ **Post date:** [February 13, 2026, 2:49am UTC](https://calculix.discourse.group/t/is-there-a-default-umat-when-no-user-material-is-declared/3785/1 "2026-02-13T02:49:01Z")
Hi. Is there a “baseline” umat that is used if no \*USER MATERIAL card is declared? I want to change the plasticity criterion there to Mises/Barlat/Hill or something else. Can you say if its possible? Maybe if you have such umat you can share it with me? ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [February 13, 2026, 6:30am UTC](https://calculix.discourse.group/t/is-there-a-default-umat-when-no-user-material-is-declared/3785/2 "2026-02-13T06:30:03Z")
[umat\_user.f](https://github.com/Dhondtguido/CalculiX/blob/master/src/umat_user.f) has only the heading/template, but you can find some built-in umats in the source code: [Code search results · GitHub](https://github.com/search?q=repo%3ADhondtguido%2FCalculiX+umat&type=code) According to Makefile, we have: - umat\_abaqus.f - umat\_abaqusnl.f - umat\_abaqusnl\_total.f - umat\_aniso\_creep.f - umat\_ciarlet\_el.f - umat\_compression\_only.f - umat\_def\_plas.f - umat\_elastic\_fiber.f - umat\_ideal\_gas.f - umat\_johnson\_cook.f - umat\_lin\_el\_corot.f - umat\_lin\_iso\_el.f - umat\_main.f - umat\_single\_crystal\_creep.f - umat\_single\_crystal.f - umat\_tension\_only.f - umat\_undo\_nlgeom\_lin\_el.f - umat\_undo\_nlgeom\_lin\_iso\_el.f Also, check the **[TFEL/MFront](https://thelfer.github.io/tfel/web/)** library as it includes Barlat plasticity, for instance. ---
**Author:** ![johanngil](https://avatars.discourse-cdn.com/v4/letter/j/779978/32.png) [@johanngil](https://calculix.discourse.group/u/johanngil)\ **Post date:** [February 16, 2026, 5:07pm UTC](https://calculix.discourse.group/t/is-there-a-default-umat-when-no-user-material-is-declared/3785/3 "2026-02-16T17:07:05Z")
One ABAQUS related baseline UMAT example to change the plasticity criterion you can find on [Github from Barlats group](https://github.com/theysy/mml_subroutine_public). You can easily adopt it for ccx: In the Fortran UMAT code comments you will find how they use the 2nd user material parameter to decide which plasticity criterion should be used during the analysis run: C PROPS(2): OPTIONS FOR YTELD FUNCTION MODEL C 1- VON\_MISES C 2- HILL 1948 C 3- YLD2000\_2D [1] C 4- YLD2004\_18P [7] Example: Your inp file controls with the 2nd value below the \*USER MATERIAL card which criterion will be used. Below example (bold highlighted value of 2.) selects the Hill criterion for the analysis: \*MATERIAL, NAME=ABAQUSNLYOON\_BARLAT \*Density 7.8e-09, \*Depvar 70, \*\* PROPS(2): OPTIONS FOR YTELD FUNCTION MODEL: \*\* 1- VON\_MISES \*\* 2- HILL 1948 \*\* 3- YLD2000\_2D [1] \*\* 4- YLD2004\_18P [7] \*User Material, constants=40 5., **2.** , 5., 2., 2., 3e-05, 197360., 0.33 7284., 1040., 0.135, 0.436, 0., 0., 0., 0. 0., 0., 177960., 57.02, 3., 3., 100., 150. 0.5, 0.9, 8., 0.788, 65., 1.22, 18., 6. 1.02736, 0.939644, 0.962783, 0.983882, 0.986196, 0.939192, 0.98523, 1.01359 Remark: I would not recommend to use above plasticity criterion option 3. (=YLD2000\_2D) as the 2D ccx element types are expanded to 3D! For any Barlat related criterion I would selection option 3 (YLD2004\_18P) with an inp model consisting of solid elements. ---
**Author:** ![k3rrig4n](https://avatars.discourse-cdn.com/v4/letter/k/58f4c7/32.png) [@k3rrig4n](https://calculix.discourse.group/u/k3rrig4n)\ **Post date:** [February 19, 2026, 2:39am UTC](https://calculix.discourse.group/t/is-there-a-default-umat-when-no-user-material-is-declared/3785/4 "2026-02-19T02:39:36Z")
Thanks for the reply’s guys. I’ll try your suggestions. ---
**Author:** ![k3rrig4n](https://avatars.discourse-cdn.com/v4/letter/k/58f4c7/32.png) [@k3rrig4n](https://calculix.discourse.group/u/k3rrig4n)\ **Post date:** [February 24, 2026, 4:44am UTC](https://calculix.discourse.group/t/is-there-a-default-umat-when-no-user-material-is-declared/3785/5 "2026-02-24T04:44:02Z")
Hello, i have a question regarding mfront. I generated some libraries but it isnt working, it just stops on 1st iteration. i tried to move it to some folders like usr/local/lib tried to export it to LD\_LIBRARY\_PATH but to no succes. Can you say how you do that? or maybe link some guide on that matter?