Mechanica analysis gets so far then stops

[RAFHH]

Hi all,


I am new to the forum and to Pro-engineer. I am a complete noob to FEA having only done a few analyses on a few basic assemblies to get into using it.


I have been trying to analyse a structure I designed, I built an separate FEA model, simplifying as much as possible and modelling the welds but I am having problems when I run the analysis. It starts ok but when it gets to "Pre-processing volume features", it runs for a few seconds then just stops for no apparent reason, no error message, just goes from "running" to "not running".


I have tried altering the accuracies in the parts to get the tolerances closer together but this hasn't helped and thoughts would be much appreciated.

 

[RAFHH]

Any tips on what to include/avoid in an FEA model would also be appreciated.

 

[Ray Ellender]

The first thing to do is to check for interfering volumes in Pro/E. If you have any get rid of them by changing your model, as Mechanica does not like them. Then try meshing again.

 

[rbehne]

I don't know if you are analysing an assembly but I have had this happen and got around it by exporting the assembly to a parasolid, then opening the .x_t file as a part. It does require resetting up the analysis. It didn't work once but has worked a couple times. I talked to PTC about it and they thought itmight bea memory problem.

 

[RAFHH]

Ray, thanks for the suggestion, I did have a couple of interfering volumes so I corrected them, however, still had the same problem.


Rbehne, when I was using Unigraphics NX2 it used to be possible to turn an assembly into a single solid within the file so that it was easier to do machining operations on a welded part for example (it was possible to add proper welds as well but that's just one of many winges with Pro-e). Is the parasolid method the only way of doing it in Pro-e?


I wondered about memory myself as I tried changing mode setting up some mesh controls (just basic max and min size ones, not really sure what the others do) and re-meshing and it said out of memory. However, I had a rib that was a blend shape mating directly to a flat surface, I tried putting a 1mm straight bit on the bottom to mate with the flat surface and this seems to have done the trick although the analysis does still take over an hour to run.