NASTRAN In-CAD 2019 with Impossibly Slow Interface

[Anonymous]

Good Afternoon.

I have downloaded and installed NASTRAN IN-CAD 2019 along with Inventor Pro 2019. I'm working on the 30day trial as an evaluation of the software.

The model I'm working with is an assembly with 189 midsurfaced pieces, and 2 solid pieces, 14 connectors (2 springs, the rest are rigid). Part count is 227 discrete pieces. Overal model dimensions are 7'x7'x16' and I have it meshed with 2in elements throughout, not utilizing the mesh table for any refinements. The results log file shows 77220 elements. This is a "mid-size" model in comparison to the rest of the company.

The computer I'm working on is a rather new ThinkStation P320, i7-7700 @ 3.6GHz (8-core), 24.0GB RAM, Nvidia P2000 w/6GB RAM, and 256GB SSD running windows 10. The computer is screaming fast in all other programs, and even when doing advanced modelling within Inventor, advanced calculations in MathCAD, and even when compiling code in Visual Basic.

I'm finding the interface to be extremely difficult to work with. The solver appears to be running rather quickly, but the interface itself for viewing results, as well modifying part geometry (mid surfacing, meshing, etc) is impossibly slow. Saving once midplaned is also prohibitively slow (a single save took almost 10 minutes this morning). Other things like changing the visibility of the CAD bodies from the ribbon has taken several minutes as well. The solver ran in just under two minutes.

I found some threads here discussing disabling the integrated video card and seeing some improvements, and have done that. It worked.....sort of....There is still odd behavior and ridiculously slow times to do the most basic things basic things in the interface.

Is there anything I can do to speed up this model in the interface? Is there a guide I can be pointed to on how to optimize settings within NASTRAN to help with this odd situation? Should I be deriving a single part and doing the analysis on that instead of working within the Assembly directly? Any help would be greatly appreciated, as NASTRAN has some very real benefits over ANSYS in our situation, however if this interface isn't sped up it will be a non-starter.

[vmat8888]

Hi,

Same here, using 2021.1. I think the program needs a total redesign, in order to implement a much faster and stable interface, faster meshing, better and faster solver regular implementation of at least a few ideas from the top 10 most voted in every main release update.

AUTODESK/NASTRAN NEED TO PROVIDE MORE RESOURCES to the development team, in order to achive these goals and provide us a FEA PROGRAM THAT IS WORTH PAYING FOR.

[johnster100]

We've given up waiting for them to fix this. The problem has been there for years with no resolution. 

[Anonymous]

I'm the OP on this thread, and we have also moved on. 

InCAD could not compete when compared with some other FEA solutions. We maintain the subscription for small/short models, or quick checks on back of the napkin math. Anything with more than about 20 parts, especially if they are thin walled weldments is moved elsewhere in the department. The interface is clunky at best, and displaying results on large models is exceptionally time consuming. Unsure if Autodesk is unable, or unwilling to address the issue. 

All of our "heavy lifting" FEA is now down through MSC Apex (another NASTRAN solver with a MUCH better interface). I had high hopes for InCAD to work since we do all of our construction document modelling in Inventor, sadly it's just not great. 

[AlexGlew8741]

The problems are still here in 2021.  Large models and thin wall models are almost unworkable.

[irodaHZXWF]

I am an ANSYS user and am evaluating Inventor Nastran.

My model is not that big (764401 elements), but the interface is just painfully slow:

• Creating a new subcase and changing one force: 10 sec loading time (only for changing the force)
• Result creation: 30-60 sec
• Hiding the mesh: 50-70 sec
• etc...

Otherwise I really like it and I hope it will become faster sometimes.

Regards,

Szilveszter

[wbruinsma]

Even when using ''probes'', the interface is becoming unworkable. It works again after deactivating ''probes''. Anyone having the same? I already read this: https://knowledge.autodesk.com/support/inventor-nastran/troubleshooting/caas/sfdcarticles/sfdcarticl...

Having seen all this posts, started in 2018, I'm not having high hopes all this will be solved (soon) unfortunately...

[Anonymous]

I used NEi-In-Cad Nastran for 7 years dealing with composite structures as a senior engineer. Also other FEA codes. Now using Inventor Nastran 2021. This software is essentially the old one including new useful features. I work mainly with shell elements as with composites 99% of the times we use shell elements. I had great expectations with the new software as old NEi  solver was brilliant for composites.

I have been working for the last three weeks in a composite structure. I haven´t been able to finish up the calculation. It is the time now I will re-do everything in other FEA software. Among the reasons, there is no way to import a NAS file so your FEA model cannot be loaded into a fresh new geometry. 

Believe me, the slowness is the least of the issues when working with surfaces. For instance, apart from 10 or 15 crashes, every time you change a parameter in the geometry, you need to re define in the FEA. The worse is that you don´t know what fails until you run it. You need to search blind for the fault . A parametric design should be useful for this... MAke the story short, I suffered so many issues that it was impossible to ask for support.

My definitive conclusion is that this software cannot be used for a professional job in composites with surfaces. It is very very weak, not robust at all.

I don´t understand what Autodesk is offering here as Inventor Nastran, in my opinion, does not catch up with NEi in CAD NAstran, a simple code but very robust. 

I don´t understand also how Autodesk dares to release such a poor program for surfaces and composites. 

What I know is that I have had the most awful experience with software in my 40 years career.

Respectfully.

Jose Cristos

[John_Holtz]

Just an FYI. Inventor Nastran 2021.2 has been released. Some work has been done to improve the speed when loading a model into the Nastran environment when it contains many idealizations. (There is a difference between loading a model for the first session and loading it a second session. That is, if you exit the Nastran environment but leave the model open, entering the environment again is considered the "second time". If you close the model, going into the Nastran environment is considered the "first time".) Part models and assembly models are faster on the "second time". Part models are faster on the "first time".

Also, switching between results has been improved.

Let me know if you see improvements or still encounter lags for the issues described above.

[Anonymous]

@John_Holtz 

Thanks for the update. I appreciate the follow up. 

We'll be moving to Inventor 2021 over the holiday shutdown. I'll attempt to open some older models, and see what happens with the new updates. I'll be certain to report back here once I get a chance to test.

Thanks again!

[phill_scott]

So, I'm on my last day of the trial 30 day period and I have to say I'm astounded at how poor the experience has been.  I am working on a sheet metal assembly of around 150 parts.  Nastran cannot make mid surfaces for many of the parts which are not complex at all.  The error messages are useless.  I have crashes in the order of 5-6 times a day.  I have had to re-start the idealisation process 3 times.  It's now 0420 in the morning and I have been waiting for more than an hour for an old version of the assembly to open in the Nastran environment. I'm doing this because last night, the program corrupted the file I had gotten furthest with and it was unrecoverable with a segment error on opening.  The backup was also corrupt. When I ask the program to generate a mesh, regardless of the settings some parts will not mesh, and no error messages are given. 

PC is 8 core AMD, 32Gb RAM, nvidia 1070.  Latest drivers.  Win10 64Bit  All data saved on local SSD.

Autodesk want me to pay you over £400 pounds per month for this?!

On Monday I'm going to have got to my customer and say that I have to reassess my options.