How much a difference do LS-DYNA versions have? R7.0 and R11.0 particularly.

Farshider

Hi all,

I once used LS-DYNA R7.0 to model an underground pipe full of water, and recently I have modeled the pipe again, using LS-DYNA R11.0. It shocked me that there is a noticeable difference in the results. I have narrowed down the reason to either CONSTRAINT_LAGRANGE_IN_SOLID or EOS_GRUNEISEN.

I would appreciate if someone can tell me why there is such a difference.

Thanks

tslavik

The notes for all LS-DYNA releases can be found here. Use those notes as a guide to track down the responsible change. Between the releases you mentioned, there have been many fixes and changes to *CONSTRAINED_LAGRANGE_IN_SOLID, and only a few changes to the EOS.

https://ftp.lstc.com/anonymous/outgoing/support/FAQ/ReleaseNotes/

Also, you should run all of the releases between R7.0.0 and R11.0.0 to further narrow it down, e.g., R8.1.0, R9.1.0, R10.1.0, etc.. Those executables can be downloaded here:

http://ftp.lstc.com/user/ls-dyna  (for SMP executables) 

http://ftp.lstc.com/user/mpp-dyna (for MPP executables) 

Also re-run with the latest release R12.0.0 since that should contain the most up-to-date changes.

tslavik

The notes for all LS-DYNA releases can be found here. Use those notes as a guide to track down the responsible change. Between the releases you mentioned, there have been many fixes and changes to *CONSTRAINED_LAGRANGE_IN_SOLID, and only a few changes to the EOS.

https://ftp.lstc.com/anonymous/outgoing/support/FAQ/ReleaseNotes/

Also, you should run all of the releases between R7.0.0 and R11.0.0 to further narrow it down, e.g., R8.1.0, R9.1.0, R10.1.0, etc.. Those executables can be downloaded here:

http://ftp.lstc.com/user/ls-dyna  (for SMP executables) 

http://ftp.lstc.com/user/mpp-dyna (for MPP executables) 

Also re-run with the latest release R12.0.0 since that should contain the most up-to-date changes.

Farshider

https://forum.ansys.com/discussion/comment/101304#Comment_101304

I guess you are right. It seems that CONSTRAINED_LAGRANGE_IN_SOLID is a tricky keyword to use, and I should be more cautious using it.

Thanks for the help.