FEMAP Geometry Edit Questions 3

[SolidworksFan]

I have been posting in the FEA section by mistake.

OK folks by now you have figured out that I a brand new to FEMAP. This software is making me feel like a total idiot. I have been thru all of the examples and I still can not get off of the ground. I am trying to build a very simple model, a plate with 4 mounting holes.

For practice, I want to build the model in FEMAP not import it. So I used Geometry/Surface/Corners and made the surface no problem.

The next item I tried was to add a hole in the corner. I used Geometry/Curve-Circle,diameter and created a sketch of a hole in the corner.

Now I want to turn the sketch into a hole. I am using Example 4 as reference. I tried Geometry/Boundry Surface/From Curves, picked the circle, OK, then cancel.

Then I tried, Geometry/Surface/Extrude picked the hole curve, choose the Remove radial button, then OK, Cancel.

Problem 1: The hole curve does not look like a hole!
Problem 2: I typed in the wrong number for the location of the hole and need to move it. How do you edit the location and diameter?
Problem 3: I also want to pattern this hole. I see the pattern choice in a solid but not in a surface.
Problem 4: Say I need to change the overall size of the plate due to a design change. How do you edit the size of the surface.

I have not defined the material yet. That was going to be my next step after building the geometry. I have figured out how to assign material.

All of this seems like it should be 3rd grader work but my mind must be stuck in Solidworks land. FEMAP can not be this difficult to use! I blame the operator (me) not the software.

Please no more replies suggesting I go thru the examples. I have and I am truly trying to figure this stuff out.

Thanks in advance for the assistance.

Frustrated to the point of implosion,

RS

 

[BlasMolero]

Hello!,
FEMAP is not parametric as a CAD, then directly you create the geometry you need for mesh, surfaces to mesh with Shells, solids to mesh with CHEXA/CTETRA solid elements, curves to mesh with CBEAM/CBAR elements, etc... Here you are some suggestions (I understand you run FEMAP V10.3.1):
• To create holes: simply project the circle curves onto the surface using "Geometry > Curves - On surface > Project", this will make an imprint in the surface. Simply delete the inner hole surface using "Delete > Geometry > Surface"
• To resize holes: simply go to "MESHING TOOLBOX > FEATURE EDITING". In selection method = feature edges, and in operation = resize holes, and enter the Hole Diameter.
• To pattern hole use "Geometry > Copy > Curve"
• To modify the size of the surface: simply use "Geometry > Midsurface > Extend > Extend to: Distance", select the edges to extend and use a distance value.

Etc..
The "MESHING TOOLBOX" works better with solids instead surfaces, for instance if you want to move holes to a different position simply extrude the surface in a solid and then you are able to use "Meshing Toolbox > Feature Editing" and translate/rotate surfaces interactively, with or without mesh. Enjoy!!

Best regards,
Blas.

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

IBERISA
48011 BILBAO (SPAIN)
WEB:

http://www.iberisa.com

Blog de FEMAP & NX Nastran:

http://iberisa.wordpress.com/

 

[BlasMolero]

Hello!,
FEMAP is not parametric as a CAD system, then directly you need to create the geometry required for mesh: surfaces to mesh with Shells, solids to mesh with CHEXA/CTETRA solid elements, curves to mesh with CBEAM/CBAR elements, etc... Here you are some suggestions (I understand you run FEMAP V10.3.1 + NX NASTRAN 8.1):
• To create holes: simply project the circle curves onto the surface using "Geometry > Curves - On surface > Project", this will make an imprint in the surface. Simply delete the inner hole surface using "Delete > Geometry > Surface"
• To resize holes: simply go to "MESHING TOOLBOX > FEATURE EDITING". In selection method = feature edges, and in operation = resize holes, and enter the Hole Diameter.
• To pattern hole use "Geometry > Copy > Curve"
• To modify the size of the surface: simply use "Geometry > Midsurface > Extend > Extend to: Distance", select the edges to extend and use a distance value.

Etc..
The "MESHING TOOLBOX" works better with solids instead surfaces, for instance if you want to move holes to a different position simply extrude the surface in a solid and then you are able to use "Meshing Toolbox > Feature Editing" and translate/rotate surfaces interactively, with or without mesh. Enjoy!!

Best regards,
Blas.

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

IBERISA
48011 BILBAO (SPAIN)
WEB:

http://www.iberisa.com

Blog de FEMAP & NX Nastran:

http://iberisa.wordpress.com/

 

[SolidworksFan]

Blas:

Thanks for the advise. FEMAP is nothing like the CAD packages I have used. It is a wonder they have not embraced a better parasolid module to make modeling easier and faster. I imagine it is all tied into the mesher.

Randy

 

[dwallace1971]

I think the general assumption Siemens have made is that you will have access to powerful 3D modeling software and will choose to create or edit complex geometry in that. One of the selling points for FEMAP is price. Including a parametric 3D modeling package would drive up that cost significantly. That being said, imo, the modeling tools in FEMAP are a sight better and easier to use than those in PATRAN. Now that I think about it, I believe NEi offers a package containing NEi/NASTRAN, FEMAP and a basic version of Solid Works.

 

[BlasMolero]

Dear Randy,
FEMAP is a powerful & speciallized preprocessing tool for FE meshing & postprocessing FEA results, this is the main task: to create quality finite element models. You have many CAD modelers out there, plenty of CAd features, then FEMAP do not try to compete with any CAD system, but to use the geometry created by them. Please take a look to the powerful features you have in FEMAP for creation of midsurfaces based in solid geometry, for triming & stiching solids & surfaces, the capability to create NonManifold entities, etc.. the main target is to produce quality Shell QUAD mesh or HEX solid mesh, 1-D bar/beam, mesh, creating FE assemlies without any limit, etc, this is the best way to achive accurate FE results ..., OK?.
Best regards,
Blas.

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

IBERISA
48011 BILBAO (SPAIN)
WEB:

http://www.iberisa.com

Blog de FEMAP & NX Nastran:

http://iberisa.wordpress.com/

 

[SolidworksFan]

Thanks folks. This all makes sense. I think I will make sure to import the geometry. It will save me a lot of time.

 

[dwallace1971]

One thing to keep in mind is that a 3D model meant for FE meshing and one meant for creating production drawings are, almost always, quite different. Taking time and effort to optimize the model for meshing, in your CAD software, before exporting for use in FEMAP can save you hours of work trying to modify and mesh the geometry in FEMAP.

Also, what sort of analysis you're doing drives the complexity and completeness required of your 3D model. For instance, there's little value in trying to incorporate a tooling hole in the middle of an aluminum housing if you're conducting a static stress analysis, or incorporating detailed fillets and chamfers in a model intended to return only fastener loads. However, in a fatigue model, these features might be essential.

You also want to eleminate all the "junk" geometry that sometimes ends up in the model. For example, I once saw a guy trying to clean up a transmission housing using the Ansys pre/post processor. It contained thousands of little "slivers" that made meshing it impossible. The modeler hadn't bothered to clean them up because the part was to be a cast part, and a clean model wasn't necessary for the manufacturing process. The same model was a nightmare to mesh.

Anyway, I'm beginning to ramble. Good luck!