Can I set NASTRAN real memory in FEA module?

[landy_zhu]

This is the first time I have been on this forum, I am the OSD user for a few years, here I have a question.

When I activate the FE analysis module and try to perform a pre-check in define job, it shows a low resource message. I notice this is casued by low NASTRAN memory.

Can I adjust the memory setting?

Pls see details below.

Thanks.

Resource estimations for study: /a1/RC1-7758-Rail-L.1/study1
--- OneSpace Designer Memory. ---
Estimated required memory within OneSpace Designer: 28.62 MB.
Available OneSpace Designer memory: 1663.12 MB.
--- Solver Memory ---
Warning: Solver Memory not sufficient for this analysis run:
NASTRAN real memory setting: 16.00 MB
Estimated required NASTRAN real memory: 27.85 MB
--- Disk space ---
Estimated required disk space: 386.78 MB
Available disk space: 13093.46 MB
Solver scratch directory: C:/temp
--- Mesh ---
Part: /a1/RC1-7758-Rail-L.1
Valid mesh found
Nodes: 15471

--> Resources are low <--
--> No problems found <--

[mramseyISU]

You don't need to change it to run a study, just be prepared to have an un-usable computer for a while.

[John Scheffel]

The memory allocation can be changed by the following command.

(ferrum::ferrum-set-nastran-real-mem xx)

where xx is the number of MB allocated. The default value is 16. I don't know why CoCreate hasn't increased the default, it was set back when 16MB was a lot of memory.

I'm not sure if you can set this on the fly, but you can add this command to the da_customize startup file in this path to change your default.

<install-dir>\personality\sd_customize\DesignAdvisor\da_customize

You can edit this file with NotePad or any text editor. This file is loaded when FEA is activated (DesignAdvisor was the original name for the FEA module). I know this is pretty obscure but I think it is in the documentation somewhere and this is the only way that I know to do it.

[landy_zhu]

Originally Posted by mramseyISU

You don't need to change it to run a study, just be prepared to have an un-usable computer for a while.

That's right, I can reduce the quantity of mesh to make the anlysis be more safer. I just want to block more memory for nastran.

[landy_zhu]

Originally Posted by John Scheffel

The memory allocation can be changed by the following command.

(ferrum::ferrum-set-nastran-real-mem xx)

where xx is the number of MB allocated. The default value is 16. I don't know why CoCreate hasn't increased the default, it was set back when 16MB was a lot of memory.

I'm not sure if you can set this on the fly, but you can add this command to the da_customize startup file in this path to change your default.

<install-dir>\personality\sd_customize\DesignAdvisor\da_customize

You can edit this file with NotePad or any text editor. This file is loaded when FEA is activated (DesignAdvisor was the original name for the FEA module). I know this is pretty obscure but I think it is in the documentation somewhere and this is the only way that I know to do it.

Hello John,

Thanks for the explaination, I can find a line code of real memory inforamation in customzized script file.
It looks like the memory size limit is from nastran rather than Cocreate, what you think about this?

[Wolfgang]

Originally Posted by John Scheffel

I'm not sure if you can set this on the fly, but you can add this command to the da_customize startup file in this path to change your default.

<install-dir>\personality\sd_customize\DesignAdvisor\da_customize

Even after years it is STILL NOT recommended to change files in the installation directories:

<usercustdir>\DesignAdvisor\da_customize
e.g.:
c:\Documents and Settings\MikeUser\AppData\CoCreate\CoCreate Modeling 2007\15.00\DesignAdvisor\da_customize

would be the right place. That file might not exist, so create one.

[clausb]

Originally Posted by Wolfgang

Even after years it is STILL NOT recommended to change files in the installation directories:

On Vista, most users won't even be allowed to change files there.

That said, Design Advisor configuration is a bit arcane, IMHO, and could use a few improvements.

[John Scheffel]

Originally Posted by Wolfgang

Even after years it is STILL NOT recommended to change files in the installation directories:

True. I just got lazy and didn't want to take time to explain the details for creating a user file. Although in this case the default file under the personality folder is empty so it seems pretty safe. Is there any reason it is not recommended other than the file being overwritten if you reinstall the same version?

[Wolfgang]

Originally Posted by John Scheffel

Is there any reason it is not recommended other than the file being overwritten if you reinstall the same version?

clear backup!
"Program Files" is not needed to be backup'ed every day.
%APPDATA% directory with all the user data should be in normal backup..

Clear separation of Installed Software and Customization!

The customization dir might be transferred to another machine. If you partially do the 'hack' in "Program files" you have an incomplete transferred customization.

[Mike Swartz]

One more thing.....Note that the message received is a warning, not an error.
There is a reason for this.

The setting (ferrum::ferrum-set-nastran-real-mem xx) does not really change the memory allocated to FEA, it only changes the threshold of when this message is thrown.

FEA will use all the memory it needs to get the job done (limited only by your machine or your OS) no matter where this threshold is set. You can ignore this message, or (if you never want to see this warning message again) raise the threshold to some large number.