Implicit /mat/law79 for Al2O3 no Idel (brick elements)

Marcin Kneć_21510

Hi. 

I would like to model quasi-static compression of foam made of Al2O3.  I tried with explicit but due to very small element size (0.2) and amount of elements - computation time is very long. I would like to try implicit. 

First I would like to create a working model for a low elements  and simple component. 

Below are the data for Al2O3 taken from the Radioss manual for /law/mat79.

For compression test I need failure. 

In the manual :

https://help.altair.com/hwsolvers/rad/topics/solvers/rad/mat_law79_john_holm_starter_r.htm#mat_law79_john_holm_starter_r__mat_law79_john_holm_starter_r_fn_zrj_t4h_vz

there is 'Idel' option mentioned. But I can not see it in my settings. 

So what can I do with failure ? There is also no /FAIL/MAXSTRAIN availabe which seems to be best and simple for this material 

Any hints about the best aproach are welcome

 

Model attached. 

MK.

 

AdrienR

Hi Marcin,

Radioss implicit module is no more developped, so this is something you need to consider.  Anyway, here is some help to resolve the issues you have reported.

Idel formulation is not supported yet in HyperMesh but can work properly with Radioss Solver.  The way to set up this feature is to directly update the 0000.rad file so that the Idel parameter you want is defined.

Figure 1: Initial 0000.rad file

Figure 2: Final 0000.rad file

Additionally, the /FAIL/MAXSTRAIN is not supported in HyperMesh yet, so you have to create the corresponding Card directly in 0000.rad file.  You can find a sample of the card you need to insert in Radioss Help at Example Chapter for every available card.  The Help page for /FAIL/MAXSTRAIN is the following:

https://help.altair.com/hwsolvers/rad/topics/solvers/rad/fail_maxstrain_starter_r.htm?zoom_highlight=%2FFAIL%2FMAXSTRAIN

 

The Card should be like the following:

Figure 3: /FAIL/MAXSTRAIN