topic FEA module extremely slow in Inventor Forum

FEA module extremely slow

bshbsh — Mon, 06 Feb 2023 11:00:19 GMT

Hi,

I am really pissed by Inventor's built-in FEA module's "performance". Not the calculations but the UI. Like, after the calculation is done, I just want to turn on the indicator for the location of the maximum value - it takes at least a half hour! Add a proof point? well, turning on proof labels is another haldf an hour at least, then cliclikng on the proof icon is another half, then clicking a point is another, and another half until the label appears... And then I want to switch from the stresses view to the deflection view - another hour or so... While Inventor only runs on one core of course, plenty of free memory, no disk or network activity... I can't even imagine what is taking so long? It literally takes less time to recalculate the results than setting up a frigging label! Remove a fixed constraint and put somewhere else? Oh, an hour...

I just started two analysis on two computers at 7 AM and it's done long ago yet I am not finished setting up things to make a few screenshots, and it's noon!

Do you have any idea how to speed this up or what is going on?

Re: FEA module extremely slow

JDMather — Mon, 06 Feb 2023 11:02:47 GMT

@bshbsh@bshbsh

Attach example file(s) here for diagnosis.

Re: FEA module extremely slow

bshbsh — Mon, 06 Feb 2023 11:43:36 GMT

@ JDMather

I can't, it's confidential and large models.

Re: FEA module extremely slow

JDMather — Mon, 06 Feb 2023 12:23:21 GMT

Can you reduce the analysis to specific geometry of interest rather than large scale analysis?

Re: FEA module extremely slow

bshbsh — Mon, 06 Feb 2023 12:39:32 GMT

This is already the reduced model, where I replaced most components with their substitued force-equivalent. I even had to deactivate welds to be able to do the analysis at all (it would be imporrtant though...)

Again, it's not the calculations, just what's after: I literally could not set a proof label in 3 hours, and then when I rage-hit ESC to abort, it took an hour to abort! While not doing anything. What the actual f... can it do in that long?! It could read and write the entire memory back and forth a billion times in that much time...

Re: FEA module extremely slow

ambrose — Mon, 06 Feb 2023 13:49:08 GMT

Hi @bshbsh, Are you having the problem with "Stress Analysis" environment, or the "Autodesk Inventor Nastran" environment? I don't usually have any problem with the former, but I do find Nastran to be unreasonably slow.

If we are talking about Nastran, then this is my take, with my computer science hat on and a good amount of guessing. I suspect that the Inventor Nastran UI was written by scientists and not by software engineers/UX experts. After all, if you are smart enough to write a physics simulator, surely you can stick a few buttons on screen and make a UI, how hard can it be! Turns out it is easy to do badly and surprisingly difficult to do well. Fusion 360 does a much better job on this front. I think the Nastran UI does some heavy lifting in it's event handling thread, which is very bad practise. If that last sentence makes no sense to you don't worry about it! I hope it makes sense to someone at Autodesk though, it is a problem and could do with improvement.

I will try to dig out a toy example that causes me the problem. I think I have one somewhere.

There are a couple of other things that could be a factor for you. Loading simulation results involves reading a lot of data from disk, so slow disk access can be a problem. I find that if I store large simulations on our network drive it can be very slow. The same model stored locally on my computer will load much more quickly.

The other thing that springs to mind is having enough RAM for the simulation you are viewing. If your RAM fills up then windows will start to use your hard drive as RAM, which is incredibly slow. Check Task Manager and make sure you're not using all your RAM.

Re: FEA module extremely slow

bshbsh — Mon, 06 Feb 2023 14:11:52 GMT

@Anonymous: the plain old stress analysys module.
after a finished calculation, I switched from the default von mises stress view to the displacement view before I went for lunch and it switched to it around 2PM, whiel half the ram was free, no hdd or network was used, only one cpu core.

Re: FEA module extremely slow

ambrose — Mon, 06 Feb 2023 14:39:20 GMT

@bshbsh Oh, in that case I don't have much to offer, sorry!

I have had crashes in that situation and they did not recover even after leaving it over the weekend. But I don't think they were easily reproducible, just random.

Re: FEA module extremely slow

johnsonshiue — Tue, 07 Feb 2023 00:48:35 GMT

Hi! The behaviors don't sound normal to me. Either the model is extremely complicated or there is somewhere else wrong. Please make sure all critical Windows updates are installed and the graphics driver is updated. Clean up %temp% and install the latest Inventor update applicable to your release. Try a simpler analysis. Does it work faster?

Many thanks!