ABAQUS EXPLICIT RESTART ANALYSIS HELP

[mechdrive1]

Hello everyone !

I'm currently running a dynamic coupled temp-disp. CEL analysis which has four steps in it with following time period- 0.03, 0.016, 0.03, 0.2 seconds. I'm facing difficulty in completion of the process, as the designated time on cluster computer is not enough for completing the analysis. It completes less than two steps. Can someone say if an CEL explicit analysis can be restarted with the option of 'and complete the step' in the 'model attributes' editor ? I want to restart the analysis by completing the previously stopped step and then continuing on to the next steps.

Any suggestions/questions are welcome.

Thanks !
Andy

 

[Dave442]

You can specify the frequency that data is written to the state file in explicit. Read Section 9.1.1 "Writing Restart Files" in the Abaqus Users Guide. Specifically, the section "Controlling the frequency of output from the restart files" should help you.

Use the following option to request results at the exact time intervals:
*RESTART, WRITE, NUMBER INTERVAL=n, TIME MARKS=YES

Use the following option to request results at the increments ending immediately after each time interval:
*RESTART, WRITE, NUMBER INTERVAL=n, TIME MARKS=NO

Also, consider including the parameter OVERLAY write over previous restart data and avoid storage issues.

 

[mechdrive1]

Dear Dave,

I've gone through the ABAQUS documentation, but my concern is with the following error- "[highlight #EF2929]parameter interval is only valid if the endstep parameter is also specified in abaqus/explicit[/highlight]". I googled this error and found just 1 or 2 answers saying that the previous running step must be terminated and continued from the next step, which I don't want to do. If my analysis stops at 0.025 sec in the first step, then I want to restart the analysis from the previous stopped increment and continue till the completion of all steps. I hope I'm putting my question clearly.

I've selected overlay without timemarks for my current settings.

Thanks.

 

[mechdrive1]

Hello,

I ran an example analysis with dynamic/explicit temp.-disp. steps for a process with two steps with 0.2 sec and 0.1 sec time period respectively. When I followed the process for restarting the analysis and created the job, it again showed the same error (as in my previous comment) when I selected "and complete this step" in the "model attributes" editor. However, when I selected "and terminate this step" the restart analysis ran without any error and from the next step.

According to ABAQUS documentation, the restart process for continuing from an previous step is good for abaqus/standard only. For abaqus/explicit, 'recovery' option has to be utilized if the analysis is stopped due to some technical reasons such as cpu usage time completion, power failure etc.

If anyone still has any advice/suggestion then please comment. Any help is appreciated.

Thanks,
Andy

 

[mechdrive1]

Hello,

I tried verifying this problem with Dassault tech support but all they could provide me is a reference to abaqus documentation and also restarting the analysis without specifying a increment/interval/step value in the model attributes editor. I don't know if 'recovery' mechanism works for abaqus/explicit, if anyone has any idea about it then please share.

 

[Dave442]

Hi Andy,

You should be able to write restart info to the state file at pre-specified intervals within each step. When the analysis is terminated on the cluster you should then be able to restart the analysis from the last completed interval? Does that not work? I'm not sure how your cluster works - does it just kill the process after a certain amount of time? I guess a poor workaround would be to set up your analysis to run each step individually. You could just run the first step, then restart for the second step, then restart for the third step .....

Maybe share your the .inp files for your example analysis and someone can help you figure it out?

Good Luck,
Dave

 

[mechdrive1]

Hi Dave,

I had specified writing the data in the 'restart requests' for one interval per step (to make the analysis run faster and save space) with 'overlay' option selected. I have the state file and other files required for restarting an analysis, what I'm not able to do is to restart the analysis from a particular point in the incompleted step and then continue for the next step. I have done as you've suggested, split the steps into smaller steps and restart each time a step is completed. Also, I'm not sure if my input file and the run file required for starting analysis on the university cluster are undergoing parallel processing. I'm uploading my .inp file and .pbs file (command file for cluster), can you please go through it and if possible tell me where I've to modify.

Thanks,
Andy

 

[mechdrive1]

here is the runfile.pbs