ABAQUS VUMAT model Clay, Sand Hypoplasticity

[anthaivn2019]

Dear all,
I use umat from the website

https://soilmodels.com/constmodels/.

Now I want to use vumat to perform dynamic analysis. Have you ever used umat to vumat conversion for me to simulate?
I am a new user of abaqus so it is difficult to write the program.
We hope to help.

thank you many.

Hoang An

 

[FEA way]

Normally conversion between UMAT and VUMAT would require some effort. However from the same website where you’ve found your UMAT you can also download an interface between UMAT and VUMAT. Not only can it be used for any UMAT model but also requires no coding at all. The only thing that you have to do is to paste the interface code into your UMAT subroutine and it will be ready to use in Abaqus/Explicit. What’s more they reference an article „Interface enabling constitutive models coded as user materials to be employed in explicit analysis” by B. Bienen et al. containing the description of the interface and tests performed for hypoplastic sand and clay models. They even share the parameters of these models.

 

[anthaivn2019]

Dear FEA way,

I used the interface between umat and vumat of Britta Bienen but the model was not working.
Very thanks if you can help me an example using vumat complete.

Best regards

Hoang An

 

[FEA way]

What steps have you taken after downloading this interface to utilize it in the analysis ? You should paste your UMAT code under the interface code between comments indicating start and end of UMAT subroutine. If used properly it should work, they tested it as described in the article. But if it still doesn't work than maybe the problem is in the model (i.e. explicit analysis setup) not in subroutine. Were there any errors when you tried submitting the analysis with this interface ?