Element deletion using subroutine: help with element status output

[Aislingoh]

Hi all,

I am running an explicit simulation with vuanisohyper subroutine. I've included a simple failure criterion using element deletion which seems to work well.

My problem is that I can't seem to get abaqus to change the element status from 1 to 0 for deleted elements. stateNew(k,1) is the calculated stress, stateNew(k,2) is my damage flag which equals zero when the failure criterion is reached. In the material definition in the .inp i have

*DEPVAR, delete=2
2
1,USVM,"User stressVM"
2, damage, "damage flag"

and in the subroutine I have

c Failure criterion
c
if(stateNew(k,1).gt.failurestress) then
field(k,2)=0.0
end if
c
stateNew(k,2)=field(k,2)

Can anybody spot my mistake?

Aisling

 

[akabarten]

Hi,

Can You post your inputdeck and the subroutine.
I can take a look for them.

Regards,
Bartosz

 

[Aislingoh]

Sure, I left out the geometry in the .inp file and i pasted the subroutine in at the bottom of the input because i think you can only upload one file at a time here.

Thanks,

Aisling

 

[akabarten]

Hi,

Thank you for the files. I see your model use submodel option.
I need also global model to run the analysis.

Regards,
Bartosz

 

[Aislingoh]

opps, I didn't know you were going to try run it.... in that case you'll need the full model.

If you have any general comments either, please, don't hold back!

 

[Aislingoh]

here's the submodel in it's entirety. It's rather big. I'm spoilt with access to a cluster...

 

[MechIrl]

Had a very quick look through your subroutines. You seem to have all the obvious things covered, e.g. often people leave out the STATUS variable request and so it seems elements aren't being removed.

Do the values of statenew(k,1) and statenew(k,2) come out as expected as the analysis progresses? How about the STATUS variable, does its value change at all? As a further check I would print the value of statenew(k,2) at the end of the 'vuanisohyper_inv' subroutine to make sure it is being passed in correctly from vusdfld.

 

[Aislingoh]

Ok, I see the global model never uploaded. here it is.

 

[Aislingoh]

This is an updated version of the subroutine.

 

[Aislingoh]

Wait. the answer has just come to me.

At the beginning of the simulation all element status =1.
As the simulation progresses the failure criterion of some elements are met, setting status=0.
These elements are deleted from view immediately, so I never see any elements with status=0.

So it was working all along. and now that I look closely I can see the element erosion taking place, D'OH!