Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in
  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Abaqus VUMAT doesn't given identical results for orthotropic linear elastic material 1

Status
Not open for further replies.
tyzhang

tyzhang

Civil/Environmental
Dec 29, 2021
14
Dear Community,

Hi! I am trying to verify Abaqus VUMAT with simple examples so I wrote a VUMAT for orthotropic material and compare the result with Abaqus built-in material model (Elastic -> Engineering constants). The material constants are given in 1.png and 2.png. All other settings from part to mesh is identical. The stress distribution of built-in material model is in 3.png and the stress distribution of VUMAT is in 4.png. The discrepancy is not ignorable. The VUMAT code is also attached as a .txt file.

Is there anything that I miss in my code? I will appreciate your help. Thanks!
1_ckva1x.png

2_varcde.png
3_v8oasp.png
4_cq7gsr.png


The Fortran code is based on code from which is a VUMAT for continuum damage model for composite material, written in a nice and readable style.
 
Replies continue below

Recommended for you

Sort by date Sort by votes
That’s a simplified version of VUMAT subroutine composite_cdm.for available on Rutger Kok’s github repository, right ? He mentions there that the code may not work properly for multi-element models. I guess that it relates to the CDM part but it would be better to start from single element tests anyway. Also, there is a chance that you accidentally removed some part of the code that should stay there.
 
Upvote 0 Downvote
Yes! I have added reference to his repo and thx for mentioning that. Actually, I have already done one element test for my code for orthotropic elastic material. The results had discrepancy too but it's negligible so I didn't pay attention on it. Although Rutger mentions that his VUMAT may not work for multi-elements case, I believe that he is referring to the damage model part. The code should work fine during elastic stage, when no damage happens. Besides, the VUMAT in this thread just implements elastic material.

By the way, I believe there is one place in Rutger's code that doesn't work as it should do. I will contact him about the issue and maybe some update is needed.

Another question about VUMAT: do we have to implement inertia forces? I have viewed several VUMAT code but none of them considers that.

Thanks again for your comment.

 
Upvote 0 Downvote
No, that’s on the side of the element formulation (VUEL subroutine if user-defined elements are used).
 
Upvote 0 Downvote
Got it. Indeed it doesn't make sense to incorporate that in VUMAT since it defines constitutive relation.
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

H
  • Question
B31 VUMAT
Replies
2
Views
399
hswwh
H
M
  • Question
3D HASHIN VUMAT
Replies
1
Views
1K
FEA way
FEA way
M
  • Question
Material model for plain weave in ABAQUS
Replies
4
Views
1K
Materials Freak
M
SKSA
  • Locked
  • Question
ABAQUS VUMAT Writing on Modified Mohr-Coulomb
Replies
1
Views
162
FEA way
FEA way
arif1729
  • Locked
  • Question
ABAQUS VUMAT subroutine
Replies
1
Views
125
FEA way
FEA way

Part and Inventory Search

Sponsor

Back
Top Bottom