Restart analysis with *Extreme element value

[RBureau]

Hi all,

I am trying to simulate a classical tensile test on a sheet specimen in abaqus explicit, but I want to stop the simulation after PEEQ exceeds a given value (say 0.1). I use the statements:

[pre]
*Step, name=Step-1
*Dynamic, explicit
,100
[... bulk viscosity, mass scaling, boundary conditions...]

*Extreme Value, halt=yes
*Extreme Element Value, elset=tensile.ALL, max

PEEQ, 0.1
**
*Output, field, variable=PRESELECT
*Output, history, variable=PRESELECT
**
*Restart, write, number interval=1, time marks=NO
*End Step[/pre]

(The elset tensile.ALL contains all elements in the simulation)

So far, so good. Now, I want to continue the simulation until PEEQ exceeds another value (say 0.2). I therefore included a restart statement as shown in the code above, and I wrote a new input file as follows:

[pre]
*Restart, read, step=1, interval=1, end step
*Step
*Dynamic, explicit
,100
*Extreme Value, halt=yes
*Extreme Element Value, elset=tensile.ALL, max

PEEQ, 0.2
*End Step[/pre]

And... It does not work. I have tried a few variations of the restart code above, and I keep getting the dreaded doomsday message: Abaqus/Analysis exited with errors. The .dat file says:

[tt] READING RESTART DATA GENERATED ON RELEASE 6.21-1 DATE 31-mars-202 TIME 09:31:29
*Step, name=Step-2

***ERROR: UNIDENTIFIED OR INVALID OUTPUT REQUEST 73
***NOTE: DUE TO AN INPUT ERROR THE ANALYSIS PRE-PROCESSOR HAS BEEN UNABLE TO
INTERPRET SOME DATA. SUBSEQUENT ERRORS MAY BE CAUSED BY THIS OMISSION
*Step, name=Step-2
*dynamic, explicit
*extremevalue, halt=YES
*extremeelementvalue, elset=ASSEMBLY_TENSILE_ALL, max
*endstep
*Step, name=Step-2
*dynamic, explicit
*endstep
[/tt]

Does anyone have an idea, or better yet, a solution to that problem?

I use Abaqus 2021.

Thanks in advance!

 

[FEA way]

Maybe try running a multistep analysis instead of using restart. The *Extreme value card should still work there.

If it doesn’t help, try with this keyword instead:

*Filter, operator=max, limit=…, halt=step

 

[RBureau]

Thanks for the advice, I'll try something like that also. I just noticed that my .res file is only 260 Ko big, and that the results of step 1 are not transported to the new job. I suspect Abaqus does not save the restart information correctly, hence the error. I'll try to fix that first.

 

[RBureau]

Alright, after multiple trials, I have the solution: I removed the *Restart, write card from the first job and all came together. As restart files are automatically written by ABAQUS Explicit, it feels like using a *Restart, write explicitly in the first job makes for a double usage??

The weird thing is that the *Restart, write card does not throw any error when used without the *Extreme Value card, but the conjunction of the two makes ABAQUS growl.

 

[FEA way]

That's right, in Abaqus/CAE the interval for restart data writing can't be set to 0. But from the point of view of the input file, the following line is automatically added:

*Restart, write, number interval=1, time marks=NO

So your input file had just the default restart request, nothing more.