Learning Forum

[VisMadhavan]

Can you please let me know if there is a way to export unit vectors along the eigen directions or scaled vectors representing the total principal stresses?  I also would like to know if there is a way to output eigen vectors of plastic strain rate.  We are using Mat-18, Johnson-Cook.

 

The real goal is to create streamlines of these eigen vectors. We used to obtain them from ABAQUS/CAE and had to then sort neighboring vectors to make this meaningful.  However, looking at the vectors in LS-PREPOST they seem to already be sorted, at least in the region of most interest to use.  Is there a way in LS-PREPOST to directly create streamlines of these vector fields?  I ask because I am not familiar with the fluids post-processing and believe this should be easily doable.

 

Or should we look into LS-Taurus (is it even available, or work?) or some other software?

 

Thanks,

Vis

 

[Alex R.]

 

 

Hello, 

I will consult the LS-PrePost developer. Could you please confirm the material model used. MAT_18 is *MAT_POWER_LAW_PLASTICITY, *MAT_015 is *MAT_JOHNSON_COOK.

Thanks, 
Alex 

 

 

[Alex R.]

Hello, 

The principal stresses can be output for shell elements in the option "Output Principal direction" is checked under Configuration Setting>Display>General. LSPP would dump the principal direction to lspost.msg file.

I am not sure if LS-DYNA has ever written the plastic strain rate to d3plot files. I didn’t see an option to plot eigen vectors of plastic strain in LSPP. Can you plot the quantity?

Regarding streamline options for models that were solved with ICFD/EM/CESE solvers. When it comes to a set of generic models (like structure, ALE, etc), LSPP has a feature called Streamline (Post-Trace) which only works on the velocity quantity.

The task that you are trying to do is quite unusual, I cannot give you any direction which software might give you the capabilities that you need.

Thank you,
Alex

[VisMadhavan]

Alex,

Thank you very much for your very helpful response.  It is deeply appreciated.  We were able to get the principal stress vectors exported at element centroids and processed to get what we needed. 

Best regards,
Vis