FEMAP Geometry Export and Import Issues

[WorcesterSorcerer]

I am encountering an issue with FEMAP. When I export a model to a STEP file and save it, the scale of the geometry seems to change when I open the newly saved STEP file in FEMAP.


This issue also occurs when I try to import and merge the saved STEP file into an existing model.

The original geometry is in millimiters. The export should remain in mm, but on import to another FEMAP model, it reduces in scale by 1000.

We've checked the preference settings and explored all other available options, but we haven't been able to resolve the issue.

Does anyone have any recommendations for how to address this problem.

 

[rb1957]

something easy to test (with a model with one linear element) and demonstrate. have you asked the help desk ? (they can be surprisingly useful.)

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[BlasMolero]

Dear Worcester,
I have tested the issue but at my end FEMAP is running correctly, so is a local problem related with your geometry, probably you have in your FEMAP model a mix of solid parts with different scale factors, list your solids using command LIST > GEOMETRY > SOLIDS, you will see something like this:

List Solids
1 Solid(s) Selected...
   Solid          1 - 1                                                                                 Address: 34022  Scale: 1000.       Type: Solid

I base my comments in the following:

1.- I have imported the STEP file located in the FEMAP EXAMPLES directory that every FEMAP user have in the computer: mp.STP
2.- I see the thickness of the ribs & walls is 125 mm (I run solid scale factor = 1000, ie, millimeters).
3.- Edited the geometry model, for instance the radious of the holes.
4.- Saved in FEMAP V2406 and exported again as STEP file as mp-rev1.STP
5.- Imported the new STEP file in a new FEMAP model, and the thickness is correct: 125 mm

Please post your FEMAP model here and we can investigate to see the real reason of the error, thanks!.
Best regards,
Blas.


~~~~~~~~~~~~~~~~~~~~~~
Blas Molero Hidalgo
Ingeniero Industrial
Director

IBERISA
48004 BILBAO (SPAIN)
WEB:

http://www.iberisa.com

Blog de FEMAP & NX Nastran:

http://iberisa.wordpress.com/

 

[WorcesterSorcerer]

Hi Blas,

We've sort of resolved the issue. The geometry imports fine on one of our computers, but not another with seemingly exact same preference settings.
Our FEMAP supplier technical support team suggested we export the geometry from the computer that is fine as a parasolid (not a STEP) and then re-import into the faulty computer. They believe it is a bug within FEMAP since version 11.

He also showed me the Tools>Convert units function which I was unaware of until now. Is very useful.

We can't really share the geometry with you as it is client sensitive. I will however try to find some other geometry that has the same issue. Could be some time tho.

 

[BlasMolero]

Dear Worcester,
FEMAP geometry engine is based in Parasolid, is the native format, then if you want the maximum precission in geometry use Parasolid (*.X_T files), but STEP is a valid "neutral" geometry format very useful to share solids, I never have had any problem sharing or importing geometry. Is true the typical action with FEMAP is importing geometry from CAD systems to prepare the geometry (midsurfaces, curves of solid centerlines) to mesh with Finite Elements, not exporting, but never detect any problem regarding importing/exporting. Is more, for exporting I use a lot STEP FORMAT because I prefer to use FEMAP instead CAD to create geometry for CFD fluid flow analysis to run FloEFD for SOLID EDGE, and never found this error.

In summary: please see if you can isolate the problem. I am pretty sure the question is related with geometry scale factor of a solid part stored internally in the FEMAP database, it could be easy "accidentaly" to import FEA models or geometry using different geometry scale factor, and have one part or component in meters, another in inches, another in millimeters, .. etc, typical question when sharing FEA models between USA in PSI and Europe where we work in millimeters, or in meters when using international system of units (SI). FEMAP complaints, the warning is written in the message area, but FEMAP users does not pay attention or does not realize of the error written in the message area. I have reported this situation to FEMAP development team that when inconsistentcy is detected to write the problem in the message area using red color to alert the end user.

Geometry Scale Factors are inconsistent with current model.
Attempting to adjust inconsistent Geometry Scale Factors.
Beginning Update of Database...
Database Update Completed. No Errors.

The problem is that FEMAP modify internally the solid geometry scale factor based in the option choosed in FILE > PREFERENCES > GEOMETRY/MODEL and the user is not aware of the problem. Only you can detect the problem is you meassure or do LIST > GEOMETRY > CURVE and check the length of the geometry.

In fact, I use a lot command TOOLS > CONVERT UNITS to convert the FULL DATABASE, typically from psi to MPa: not only geometry is scaled, but also material properties, loads, etc.. click in LOAD and you will be able to load predefined *.CF files like USCS2SI.CF or IDEAS_from_m_N_degK_to_mm_N_degC.CF to adjust conversion parameters for your FEMAP model, OK?

Best regards,
Blas.

~~~~~~~~~~~~~~~~~~~~~~
Blas Molero Hidalgo
Ingeniero Industrial
Director

IBERISA
48004 BILBAO (SPAIN)
WEB:

http://www.iberisa.com

Blog de FEMAP & NX Nastran:

http://iberisa.wordpress.com/