FEM Workbench Error: No nodes found in Frd file.

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user1234
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Joined: Mon Jul 11, 2016 5:08 pm

Re: FEM Workbench Error: No nodes found in Frd file.

Post by user1234 »

din743 wrote: Sat Mar 25, 2023 8:27 pm This is the solver output I got when I ran the model provided by CopperGenie.
So it is the same model? That was not clear to me.


din743 wrote: Sat Mar 25, 2023 8:27 pm What solver output do you get when you run his model?
With the original file from CopperGenie, the same as message as CopperGenie.


din743 wrote: Sat Mar 25, 2023 8:27 pm I also have 16 GB of RAM. Can Calculix not use memory swapping when it uses up all the RAM? Is allowing swapping an option you have to activate?
That is too less. The original file from him needs for CCX ~ 25GByte, for the run only. For loading and postprocessing it needs a little bit more. From my experience this needs ~ around the factor 1.25 to 1+1/3 more. Just a little bit too big with my 32GByte. I have swapping deactivated per system, because a have a SSD and the lifetime of a SSD depends, how often it is rewritten (not reread). It is a general a bad idea, to swap to a SSD (except, it is any kind of special and made for it). Swapping to a HDD would need endless time. If CCX swaps, i do not know, i can imaging, that it does not, because for a calculation like FEM, RAM is a general requirement. Maybe there is an option, which must be activated.


din743 wrote: Sat Mar 25, 2023 8:27 pm Would the Elmer or Z88 solver also have an issue with CopperGenie's model on a computer with 16GB RAM?
No idea, i did not tested it.



But just be clear, the original mesh is way too fine for a 2nd order mesh, especially because everything is that fine, which is completely unnecessary. For FEM you should generally optimize the mesh to your hardware and needs and general circumstances. Also a 1st order mesh needs much much lesser RAM with the same count of nodes, if then the calculation is valid, is an other case (depends on the loading and their directions, geometry, and so on. As i posted the file above, i have optimized the 2nd order mesh in that way, that it need not really much RAM, but runs (except a peak in the mesh, which comes from a particular not good geometry (sharp edge fillet)) pretty well.



Greetings
user1234
din743
Posts: 26
Joined: Sat Sep 22, 2012 8:28 pm

Re: FEM Workbench Error: No nodes found in Frd file.

Post by din743 »

user1234 wrote: Sun Mar 26, 2023 11:10 am
din743 wrote: Sat Mar 25, 2023 8:27 pm This is the solver output I got when I ran the model provided by CopperGenie.
So it is the same model? That was not clear to me.
Yes.
din743 wrote: Sat Mar 25, 2023 8:27 pm What solver output do you get when you run his model?
With the original file from CopperGenie, the same as message as CopperGenie.
CopperGenie only posted the Freecad output not the solver output. So I'm very interested in the solver output he gets and in the solver output you get.
din743 wrote: Sat Mar 25, 2023 8:27 pm I also have 16 GB of RAM. Can Calculix not use memory swapping when it uses up all the RAM? Is allowing swapping an option you have to activate?
That is too less. The original file from him needs for CCX ~ 25GByte, for the run only. For loading and postprocessing it needs a little bit more. From my experience this needs ~ around the factor 1.25 to 1+1/3 more. Just a little bit too big with my 32GByte. I have swapping deactivated per system, because a have a SSD and the lifetime of a SSD depends, how often it is rewritten (not reread). It is a general a bad idea, to swap to a SSD (except, it is any kind of special and made for it). Swapping to a HDD would need endless time. If CCX swaps, i do not know, i can imaging, that it does not, because for a calculation like FEM, RAM is a general requirement. Maybe there is an option, which must be activated.


din743 wrote: Sat Mar 25, 2023 8:27 pm Would the Elmer or Z88 solver also have an issue with CopperGenie's model on a computer with 16GB RAM?
No idea, i did not tested it.



But just be clear, the original mesh is way too fine for a 2nd order mesh, especially because everything is that fine, which is completely unnecessary. For FEM you should generally optimize the mesh to your hardware and needs and general circumstances. Also a 1st order mesh needs much much lesser RAM with the same count of nodes, if then the calculation is valid, is an other case (depends on the loading and their directions, geometry, and so on. As i posted the file above, i have optimized the 2nd order mesh in that way, that it need not really much RAM, but runs (except a peak in the mesh, which comes from a particular not good geometry (sharp edge fillet)) pretty well.



Greetings
user1234
It would be nice if FreeCAD threw a more meaningful error then now. How is the user supposed to know that they don't have enough RAM for a certain model? Some warnings/tips in the wiki would also be nice.
user1234
Veteran
Posts: 3345
Joined: Mon Jul 11, 2016 5:08 pm

Re: FEM Workbench Error: No nodes found in Frd file.

Post by user1234 »

din743 wrote: Sun Mar 26, 2023 8:14 pm CopperGenie only posted the Freecad output not the solver output. So I'm very interested in the solver output he gets and in the solver output you get
He probably gets no solver output, when the run runs successful, there is no one. The output from him was after the CCX and from FreeCAD. Your output was from CCX and it is showing

Code: Select all

The numbers below are estimated upper bounds 
which means probably too less RAM (which is definitely is, it needs ~25GByte).



din743 wrote: Sun Mar 26, 2023 8:14 pm It would be nice if FreeCAD threw a more meaningful error then now. How is the user supposed to know that they don't have enough RAM for a certain model? Some warnings/tips in the wiki would also be nice.
FreeCAD is written from people who work on this on their spare time. Do not await wonders, calculate time to time small circumstances. Also it was ~ 10 years ago, that i used a commercial FEM last time, there was also no hints or RAM estimations, besides an estimation of the needed RAM would be pretty hard (and RAM consuming). Also looking on the RAM time to time in FEM is normal, since it is one of the limits. This is the task of the user, not of the program. Like machining, it is not the task of the workpiece to fit in the machine, especially when it gets close, it is to the constructor/machinist.



Greetings
user1234
CopperGenie
Posts: 19
Joined: Wed Mar 16, 2022 12:44 am

Re: FEM Workbench Error: No nodes found in Frd file.

Post by CopperGenie »

user1234 wrote: Sat Mar 25, 2023 3:09 am Also just a question out of interest. Is that a inner shields of a copper barrel (looks like it)? Because there was no material specification set by you and this was always hard chrome casting (and this material was really extreme to machine and a pain for the lathe).
Hi, sorry for late response. This is a part made entirely from spring steel.
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