Warnings during simulation G3015, 3012

[richard_pears]

Interior angles greater than and less than 10

skew angle greater than 80

making simulation take a very long time to run, despite being relatively simple model with course mesh.

I have attached model with data inside if anyone wants to open and explore.

Thanks Richard

[John_Holtz]

Hi @richard_pears 

• How long does your analysis take to run? (It should be on the order of 6 seconds.)
• What version of Inventor Nastran are you using? (In the Nastran environment, click the "i About" button on the Nastran Support panel.)

I see you have the mesh convergence turned on. That should not make too much difference, but you might want to turn it off to see how just running the analysis one time works.

John

[richard_pears]

Hi John,

I have turned off the convergence and hit run.

Its taking almost 10 minutes

In Nastran 2025

Autodesk Inventor Nastran version 2025.0.0.36

Autodesk Nastran 2025 version 19.0.0.6

I have run other simulations that take much less time.

So I dont feel it is my software or PC.

[richard_pears]

In model analysis time summary it says:

4.44 seconds - total CPU time

612 seconds - Wallclock time

total warning 3940

[John_Holtz]

Interesting. The analysis ran for 612 seconds and used only 4 seconds of CPU. That doesn't sound right. 🤔

Try this so that we can isolate where the time goes:

1. At the bottom of the Model Tree, "Parameters > Edit > ELAPSEDTIME > ON"
2. Run the analysis.
3. Zip the file "beam1.ipt" and the folder "beam1".
4. Attach the zip file to the forum post.

The parameter ElapsedTime will write some time stamps to the log file which will show where the extra 600 seconds was used.

I suspect the problem is related to updating your display to show the 3900 warnings.

1. Where is the model stored? On your local hard drive? On a network drive?
2. Edit the parameters again and set WARNING=OFF.
3. Run the analysis. Is it faster now that the 3900 warnings are now shown in the Nastran Output tab?

John

[richard_pears]

hi John

please see attached beam folder zip as requested.

I turned on 'TIMEELAPSED' in parameters

I did leave convergence on in this occasion, but it does take a long time with or without convergence.

Actually I am struggling to understand the convergence information also, but perhaps I should make a separate post on that.

I turned warnings off and yes it ran in under 1 min

Thanks, Richard

[John_Holtz]

Thanks Richard.

Is the V: drive where the model is saved a network drive? Sounds like it is. Although the 3900 warnings is not a lot of data as far as memory, transmitting that information line by line is inefficient over a network. If you save your model to your local hard disk (just use "File > Save As" in Inventor), you should see that the analysis only takes a minute even when it outputs all the warnings.

Let me know if that is correct.

John

[richard_pears]

I have saved a copy onto desktop

according to the wall clock was 650 seconds when I ran from here

yes your right V: is on the server

[John_Holtz]

Hi Richard,

If I understand correctly, the analysis still took 10 minutes when the model was saved to the desktop! That is unexpected.

Let's try one more test. 

1. Make a "temp" or "junk" folder underneath the C: drive. (Hopefully you have permission to do that on your computer. It would be nice to not put this new folder under the desktop or Documents in case you computer is setup to backups or something. But if you do not have permission to put is directly under C:, then make it where ever you can.)
2. Save the attached file "run my analysis.zip" to the temp or junk folder.
3. Unzip the file. The zip contains two files: your original model "kon1e68h5.nas" and "run nastran.bat".
4. Double-click on "run nastran.bat". This runs the Nastran solver from a command prompt using the model name. (Feel free to edit the .bat file to see what the command looks like. The "pause" command at the end keeps the Command Prompt window open so that you can see if there are any errors with the syntax of my command. The end result should like like the image.)

If the runtime is 10 minutes, this indicates the delay is in the solver. If the runtime is 15 seconds (like on my laptop), this indicates the 10 minute delay is in Inventor.

Thanks.

John

[richard_pears]

Hi John,

I did as you say in the C:

and running this takes yes around 10 minutes.

see screenshot of result below

My computer is a laptop 

Thinkpad P16 G2

Intel i7 processor

(my work computer)

[John_Holtz]

That's interesting. The delay is in the processor itself and not with the Inventor interface like I thought. (Apologies to Inventor!)

Can you send us the system details?

1. Right-click on the Windows "Start" button.
2. Click "System".
3. Click the "Copy" button.
4. Paste the text into your reply and delete any sensitive information. It should look like this:

Device name	
Processor	Intel(R) Core(TM) i7-10850H CPU @ 2.70GHz   2.71 GHz
Installed RAM	32.0 GB (31.7 GB usable)
Device ID	
Product ID	
System type	64-bit operating system, x64-based processor
Pen and touch	Pen support

The main thing I'm interested in is the details on the i7 processor and whether it has P-cores (performance cores, the ones that do the heavy calculations) and E-cores (efficiency cores, the ones that do the background stuff, except they are not very efficient and do not limit themselves to the background stuff!).

John

[richard_pears]

Hi John,

Please see I have attached a snip of the information from 'system information'

it was slightly different from the instructions you sent, but maybe its a different version of windows I'm running.

I hope it has the info you are interested in:

 

[John_Holtz]

Thanks. That is the information that I wanted. Now I just need to determine what it implies for the Nastran solver!

Based on the Intel website, this processor has 8 performance cores (the ones that do the hard calculations), 12 efficiency cores (not sure what they do other than cause problems from gamers and Autodesk CFD) for a total of 28 threads total (8*2 hyperthreading + 12 = 28). Intel Core i713850HX Processor 30M Cache up to 5.30 GHz Product Specifications

John