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Incorrect PSOLID creation during .bdf export

Experimenter
Experimenter

I'm using several pieces of software to perform some multi-body fatigue analysis.  The process goes as follows: 

    1) Create geometry in CAD and export to Parasolid x_t 

    2) Import geometry to FEMAP.  Apply material properties, create mesh, define constraints, and export to .bdf

    3) Import to 3rd party software, apply load sets, export and solve in FEMAP. 

 

The problem occurs between Step 1 and Step 2.  When generating the psolids in the .bdf file, FEMAP combines some solid bodies (incorrectly) and does not generate psolids for other bodies. 

 

 

The attached files show 3 solid bodies, each with a separate material property definition.  FEMAP generates a psolid for Body1 and a psolid for Body2.  It then fails to generate a psolid for Body3 and instead combines all three bodies into a single psolid. 

 

What is causing FEMAP to combine all three bodies into a single psolid? 

 

Why is it not creating a separate psolid for Body 3? 

 

Thank you!

2 REPLIES 2

Re: Incorrect PSOLID creation during .bdf export

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hello!,

If I import the NX NASTRAN input file in a new FEMAP database and do "MODIFY > COLOR > PROPERTY  > setet all > select a color > RANDOM" and NEXT I do "F6 > Element > By Property Color" to plot each element by property color ....

props-by-color-f6.png

 .. what I see is that you have defined three properties, each one refering to  different parts, then if you export your NASTRAN inpout deck FEMAP will write different PSOLID cards, till now I don't anything wrong, please explain ...

props-by-color.png

I suppose this is a simply test, but parts are isolated, not any contact defined between parts, then depending the Loads & BCs precribed the solution will fail. Also, please mesh with CHEXA elements, improving mesh, using minimum two elements in the wall thickness.

Best regards,
Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: Incorrect PSOLID creation during .bdf export

Experimenter
Experimenter

Thank you for looking into this, Blas. 

 

I followed what you did, reimported the bdf, and applied colors by property.  -- That all looks good.  FEMAP is doing everything correcty. 

 

I then modified the bdf by hand to remove psolids 1 and 2 and opened it up in the third party software I'm using.  The third party now correctly shows just psolid3 when I highlight psolid3.  There must be a bug in the 3rd party software causing it to "display all" when I use the full bdf. 

 

Thank you!