Learning Forum

[Ben_Ben]

I'm using LS-Dyna in Workbench. I want to find the area-weighted average maximum principal logarithmic strain but I can't see the option for any form of strain in the results tab of workbench.

[Armin]

Hi Ben,

Could you clarify what you mean by area-weighted average and how it is defined at element level?

Under Output Controls in "Analysis Settings", ensure that Strain is set to Yes. After running the simulation, you can find the strain components including principal strains from the Worksheet object in the Solution toolbar.

[Ben_Ben]

 

Hi Armin,

Area-weighted average max principal logarithmic strain is calculated by:

 

1. Calculate comulative strain of the elements in the region of interest.
2. Average the cumululative strain by the surface area of the elements. 

I can calculate this outside of Ansys. But I still need access to the strains at element level. 

Stain is already “Yes” under “Analysis Settings”. Don't know why it' not coming up. 

Ben

 

[Armin]

Thanks Ben.

Did you try looking for the strains under the worksheet (see the picture below)?

[Ben_Ben]

 

This is the worksheet 

 

[Armin]

Looks good. For the type indicated as "EPTO", the ones shown with 1, 2, 3 (Component column) are the principal logarithmic total strains. So just right-click on these three values, and request it to be plotted for your model.

[Ben_Ben]

Thank you so much Armin! It works!! What does component 1,2,3 mean?

[Armin]

No problem Ben.

We have three principal stresses, so these are the first, second, and third principal stresses, respectively.

[Ben_Ben]

Thanks Armin. 

Do you know a way to calculate the area my region of interest? It is 4 faces on a shell from a 3D geometry.