fem mesh crashes laptop instantly

[Lt72884]

I dont understand why i am having so many dang issues with freecad. it shouldnt be this complicated haha. Attached is a simple block i made. I go to the FEM menu, click on the N so it can generate the netgen mesh, i have chosen course, moderate, and very course and all of them instalty crash freecad and then freeze the laptop for about 10 seconds.

i have done fem on this laptop on simple parts before but i have no idea why its crashing. I am not at home where i can use my 32GB ram machine with 12 cpus...

i am trying to find out why its crashing freecad.

thanks

[thschrader]

I dont understand why i am having so many dang issues with freecad. it shouldnt be this complicated haha. Attached is a simple block i made. I go to the FEM menu, click on the N so it can generate the netgen mesh, i have chosen course, moderate, and very course and all of them instalty crash freecad and then freeze the laptop for about 10 seconds.

i have done fem on this laptop on simple parts before but i have no idea why its crashing. I am not at home where i can use my 32GB ram machine with 12 cpus...

i am trying to find out why its crashing freecad.

thanks

Why i have so many dang issues with freecad...
Why its crashing...

Sorry for your tears.
In this post you act like a teacher, who wants to solve a problem for his class:
viewtopic.php?t=82769

What about this:
viewtopic.php?p=469857#p469857

Nothing learned?

Can you tell why you are in this forum?

[Lt72884]

Not sure i understand where you are going with that?

I have learned lots but that doesnt tell me why freecad is crashing when i try to make an FEM mesh on a simple solid.

But thanks for finding all my posts that i received help with. Not sure why you did that.

Is there a log that freecad dumps to so i can see why it crashed and closes itself?

[NewJoker]

Unfortunately, the approach with modeling parts in Sketchup, exporting them to STL format and converting to CAD geometry in FreeCAD should be avoided whenever possible, especially if you want to use FEM. Those parts are simple so I would advise modeling them in FreeCAD. Then you will have clean geometry without those narrow faces that force the mesher to use very small elements, leading to freezes, crashes and meshing failures.

[thschrader]

Not sure i understand where you are going with that?
...

Sorry, was stress reaction.
Too much workload I guess...

[Lt72884]

Unfortunately, the approach with modeling parts in Sketchup, exporting them to STL format and converting to CAD geometry in FreeCAD should be avoided whenever possible, especially if you want to use FEM. Those parts are simple so I would advise modeling them in FreeCAD. Then you will have clean geometry without those narrow faces that force the mesher to use very small elements, leading to freezes, crashes and meshing failures.

ohhh, ok, so its the small narrow faces that are causing the issue. That is excellent to know. Thank you for that information. Yes, it is a simple part, but i can see what you mean.

During my research i found a website https://intact.design/ that will accept an stl file and do FEM on it. It worked for this part, SO i wonder how they were able to do it? Maybe the website is not as accurate as i think it is haha

thanks

[Lt72884]

Not sure i understand where you are going with that?
...

Sorry, was stress reaction.
Too much workload I guess...

lol, well, if it helps. I did reread my post and i could see why you said what you said. I didnt really ask in my original post "What is causing freecad to freeze" i intended too but forgot. So it looked like my post was a rant of sorts. I pulled a double on sunday from 6am to 1030Pm...

I really wish i could get the sketchup>mesh>freecad>solid>fem to work because my brain does not do well with the way solidworks, freecad etc work. I used to be a certifide solidworks pro years ago but had to leave because i cant stand the way the system works and how i have to constrain everything, pick a plane, draw a sketch etc etc. Its not freecad or solidworks fault, just my brain does not work that way haha

[NewJoker]

During my research i found a website https://intact.design/ that will accept an stl file and do FEM on it. It worked for this part, SO i wonder how they were able to do it? Maybe the website is not as accurate as i think it is haha

They are using some meshless method, that's why it works for any geometry

I really wish i could get the sketchup>mesh>freecad>solid>fem to work because my brain does not do well with the way solidworks, freecad etc work. I used to be a certifide solidworks pro years ago but had to leave because i cant stand the way the system works and how i have to constrain everything, pick a plane, draw a sketch etc etc. Its not freecad or solidworks fault, just my brain does not work that way haha

The models you shared so far aren't that complex, I'm pretty sure that you wouldn't need a lot of time to learn how to make them and to actually make them in FreeCAD. Especially since you have experience with engineering CAD software. There are many helpful tutorials.

[Lt72884]

During my research i found a website https://intact.design/ that will accept an stl file and do FEM on it. It worked for this part, SO i wonder how they were able to do it? Maybe the website is not as accurate as i think it is haha

They are using some meshless method, that's why it works for any geometry

I really wish i could get the sketchup>mesh>freecad>solid>fem to work because my brain does not do well with the way solidworks, freecad etc work. I used to be a certifide solidworks pro years ago but had to leave because i cant stand the way the system works and how i have to constrain everything, pick a plane, draw a sketch etc etc. Its not freecad or solidworks fault, just my brain does not work that way haha

The models you shared so far aren't that complex, I'm pretty sure that you wouldn't need a lot of time to learn how to make them and to actually make them in FreeCAD. Especially since you have experience with engineering CAD software. There are many helpful tutorials.

LOL, i do agree with you, it wouldnt take long. Just need to get over the hump and pattern of "why do i have to do it this way?" mentality hahaha.

i mean this part is literally 2 extrusions and thats it.

What is this meshless method you speak of? i have just begun my journey with FEM, even in solidowrks, it was all drafting work, no fem.

thanks

[NewJoker]

What is this meshless method you speak of?

Meshless methods, as the name suggests, solve structural mechanics problems without discretizing the geometry to a finite element mesh consisting of elements having simple shapes like tetrahedrons and hexahedrons. For example, some of those meshless methods discretize the geometry to arbitrarily shaped sub-volumes without nodes so complex designs can be easily analyzed. There are some commercial solutions using those methods. Of course, their vendors claim that they are accurate and provide various benchmark results. But they are unlikely to become a serious alternative to FEM in the near future. From what I know, they aren't accurate enough in practice.