Insufficient memory. Need suggestions, please.

[ptsal]

Hi all,

I have a very large model and I got this error today. It seems that my computer doesn't have enough physical memory to run the whole job.

Error: Abaqus/Standard has exited because there is insufficient memory available. A limit of 16337.00 megabytes was specified using the memory parameter. The physical memory available on the machine in use is 16337.59 megabytes. The user may need to run this analysis on a machine with more physical memory.

I dont think that I'll be able to upgrade the memory in the next days, so I was thinking if you could give me some hints on out to reduce the size of the model.

I've already started reducing the quantity of information on the history and field outputs, suppressed some instances from my model, reduced the mesh density of several other parts, but the job won't finish.

(for the record, I'm running a frequency extraction step followed by a modal dynamics)

I took a look the .dat file and the minimum required memory is around 13000 Mb, I know this is just an estimation.

If someone could give me more suggestions to reduce the memory needed I would really appreciate.

Another question related to this. Is it possible to turn round this problem using virtual memory? If yes, how does it work? how does Abaqus use it?

Hope somenoe can help me.

Thanks in advance.

 

[IceBreakerSours]

a) request specific output variables only for specific node/el sets at specific time points.
b) comment out the restart command (unless restart is needed)

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[DanStro]

Can you use substructures or submodeling?

Han primo incensus

 

[ptsal]

A large portion of the model is already made of substructures. I haven't tried submodeling because I didn't understand how that works yet, but it seems that I have to look into it to solve this limitation.

If you have any other sugestions, they would be useful.

 

[Drej]

Reducing history and field outputs will not help you - this is a RAM problem according to your post and not a disk space problem.

Considering you say the problem is insufficient memory, you will need to reduce the physical size (ie reduce the number of DOF) of the model to reduce memory usage.

If you're running a modal analysis using Lanczos then reducing the number of modes requested may help since the Lanczos solver is very memory hungry, and for a large number of modes the memory required increases rapidly.


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[IceBreakerSours]

Reducing history and field outputs will not help you - this is a RAM problem according to your post and not a disk space problem.

My experience with large models has been that if there is too much data being written in to output files, then that overwhelms my machine.

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[ptsal]

Thank you guys,

I'll try to reduce the size of my model and see if it runs again.