# Superelastic Materials

**URL:** <https://calculix.discourse.group/t/superelastic-materials/2326>\
**Category:** Uncategorized\
**Created:** [July 3, 2024, 6:26pm UTC](https://calculix.discourse.group/t/superelastic-materials/2326 "2024-07-03T18:26:03Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![lastsolidbender](https://avatars.discourse-cdn.com/v4/letter/l/f0a364/32.png) [@lastsolidbender](https://calculix.discourse.group/u/lastsolidbender)\
**Post date:** [July 3, 2024, 6:26pm UTC](https://calculix.discourse.group/t/superelastic-materials/2326/1 "2024-07-03T18:26:03Z")

</div>

HI everyone, so t am trying to model a superelastic material but I dont know how to model it in CalculiX and need your help. I was advised to use ABAQUS on another forum and while I managed to understand how to do it their, I’m afraid I need to use calculix for this and don’t know how to add a material model in it.  
TLDR

1. Need help to model superelastic material on CalculiX
2. How do I add a new material model in CalculiX. and how do I recompile it?

---

<div class="post-metadata">

**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:** [July 3, 2024, 6:36pm UTC](https://calculix.discourse.group/t/superelastic-materials/2326/2 "2024-07-03T18:36:35Z")

</div>

Since this material model is not available in CalculiX, you will need to get familiar with umat.f subroutine. There is some description in the documentafion but you can also find many examples here (mostly for geotechnical materials). Research papers should help too. Abaqus implementation is based on the work of Auricchio and Taylor (1996, 1997).

---

<div class="post-metadata">

**Author:** ![lastsolidbender](https://avatars.discourse-cdn.com/v4/letter/l/f0a364/32.png) [@lastsolidbender](https://calculix.discourse.group/u/lastsolidbender)\
**Post date:** [July 4, 2024, 7:54am UTC](https://calculix.discourse.group/t/superelastic-materials/2326/3 "2024-07-04T07:54:12Z")

</div>

Hi thank you, lets say I am able to simulate what i want to in ABAQUS, then how do I run the same analysis in CalculiX?

Like do I create an inp, and make sure calculix supports all the cards and I dont use methods that CalculiX doesn’t support and run it in then in CalculiX?

---

<div class="post-metadata">

**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:** [July 4, 2024, 7:58am UTC](https://calculix.discourse.group/t/superelastic-materials/2326/4 "2024-07-04T07:58:15Z")

</div>

> [@lastsolidbender](#):
>
> Like do I create an inp, and make sure calculix supports all the cards and I dont use methods that CalculiX doesn’t support and run it in then in CalculiX?

Yes, following this: [A Guide to Modifying Abaqus Input Files for Use in CalculiX](https://calculix.discourse.group/t/a-guide-to-modifying-abaqus-input-files-for-use-in-calculix/1430)

But you will have to exclude the `*SUPERELASTIC` keyword as unsupported in CalculiX too.

---

<div class="post-metadata">

**Author:** ![xyont](https://yyz2.discourse-cdn.com/free1/user_avatar/calculix.discourse.group/xyont/32/3553_2.png) [@xyont](https://calculix.discourse.group/u/xyont)\
**Post date:** [July 4, 2024, 9:09pm UTC](https://calculix.discourse.group/t/superelastic-materials/2326/5 "2024-07-04T21:09:02Z")

</div>

is material models have similarity with rubber like? there are many models in CalculiX

---

<div class="post-metadata">

**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:** [July 5, 2024, 7:28am UTC](https://calculix.discourse.group/t/superelastic-materials/2326/6 "2024-07-05T07:28:57Z")

</div>

Not really. It’s isotropic linear elasticity, just with the dependency of the properties on the stage of the austenite ↔ martensite phase transformation. It’s utilized to model shape-memory alloys such as Nitinol used e.g. for stents.

---

<div class="post-metadata">

**Author:** ![lastsolidbender](https://avatars.discourse-cdn.com/v4/letter/l/f0a364/32.png) [@lastsolidbender](https://calculix.discourse.group/u/lastsolidbender)\
**Post date:** [July 9, 2024, 4:06pm UTC](https://calculix.discourse.group/t/superelastic-materials/2326/7 "2024-07-09T16:06:45Z")

</div>

hi, I just wanted to come back to the point where you said superelastic is not accepted by Calculix, but I don’t know what should I put in its place, can you help me with that?

---

<div class="post-metadata">

**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:** [July 9, 2024, 5:23pm UTC](https://calculix.discourse.group/t/superelastic-materials/2326/8 "2024-07-09T17:23:43Z")

</div>

If you aren’t going to implement it as a subroutine then you are basically left with regular linear elasticity with temperature dependence.
