Learning Forum

[gcongdon]

I am running a large LS-DYNA model using R13.1 DP MPP executable. The model is of a masonry building represented primarily by inelastic solid elements connected with TIEBREAK (Option 7/Dycoss) contacts to represent the cracking/sliding in the mortar joints between bricks. Unfortunately the computational cluster I am using has a runtime limit significantly below the time which will be required for my model to run to completion. As such, I am attempting to run a series of sequential simple restart analysis models. I have had a variety of issues with the model, but have finally hit one regarding contact failure that I am unable to solve. Specifically, for the first analysis, all behavior in the model is as expected, though some cleanup/minor debugging is likely still needed. However, immediately after restarting the analysis, it appears that most (all?) of my contacts where the segment normal is not aligned with global Z are breaking when the model restarts.

Does anyone have any suggestions on how I can eliminate this erroneous restart behavior???

I have an image of just the masonry parts before and after the restart with magnified displacements shown below. In addition, I also have included the commandline syntax that I am using for the restart as well as the input data of my keyword file. The execution syntax works correctly for non-restart models and LS-DYNA runs to a normal termination condition with the syntax shown below. Unfortunately, the NOFULL command seems to be essential as the model will 'hang' after writing the d3full01 file and will neither terminate nor will it write the d3dump01.* files.

Execution Syntax:

mpiexec $EBROOTANSYS/v231/ansys/bin/linx64/lsdyna_dp_mpp.e memory=256M memory2=256M i=restart01.key r=d3dump01 o=main.otf g=main.ptf f=main.thf

Keyword (restart01.key):

$# LS-DYNA Keyword file created by LS-PrePost(R) 2024/R2(4.11.8)-25Jul2024
$# Created on Oct-28-2024 (00:39:25)
*KEYWORD
*TITLE
$#                                                                         title
NIST URM SPECIMEN I
*PARAMETER
$#   prmr1      val1     prmr2      val2     prmr3      val3     prmr4      val4
$R TERMNATE10.5
R TERMNATE3.0
*CONTROL_MPP_IO_NOFULL
*CONTROL_TERMINATION
$#  endtim    endcyc     dtmin    endeng    endmas     nosol
&termnate          0       0.0       0.0  1.0000E8         0
*END

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