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Unsymmetric stress/strain tensors in Abaqus VUMAT?

Submitted by crazydriver on

Hi all,

 I am working on a VUMAT subroutine in Abaqus where I'd like to define unsymmetric stress and strain tensors to account for the material nonlinearity, so that they would include the following nine components: 11 22 33 12 23 31 21 32 13. However, from the Abaqus analysis manual it looks like stress and strain tensors in VUMAT are symmetric by default, so there are only 6 components: ndir+nshr.  Nevertheless, it does mention that unsymmetric tensors with ndir+2*nshr components, like F, can be included in a VUMAT. I tried to change the dimension of stressOld, stressNew, strainInc from ndir+nshr to ndir+2*shr (or 9) but it did not work. So does anybody happen to know if VUMAT has the capability to include unsymmetric stress/strain tensors?

 

Any help would be highly appreciated!

 

Jack

 

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shahram

hey

 

i have the same problem  changing the Straininc tensor while i am usiing the other constitutive equations than von_mises.

i checked and understood that the straininc tensor is the strain calculated by the Abaqus using Von_mises constitutive all the time.

 

thoughts? 

Sat, 02/01/2014 - 09:55 Permalink