Importing a shell geometry

[Tpintar]

Hi,

I am trying to import a Solidworks made model to Femap. The model is built with 2D shell elements (it is already used for analysis in Solidworks Simulation).

Upon importing, Femap seems to treat all the geometry as Solid, and always requesting Solid property. Even if I explode the 1 "solid" into a 1 surface it still refuses to mesh it without a Solid property.

All the resources I found online refer to converting solids into shell elements, I found nothing related to my problem. So either I am missing something super obvious or this is not possible. I understand the question must be very obvious, but I would appreciate some help here ?

 

[Naffoussi]

could you drop some screenshots of your geometry ? or maybe put a .stp file here?


Seif Eddine Naffoussi, Stress Engineer

http://www.Innovamech.com

33650 Martillac û France

 

[Tpintar]

I can, and have uploaded the image. But, and this is important I am really not looking for help solving the analysis; I have already done that.

I really want to understand the functionality of importing surface models to FEMAP....

The image has lots of details, but it doesn't matter. It could only be a portion of the model, or a single plate. But I want to know if it is possible to import a surface model into FEMAP, and how.

 

[Naffoussi]

Try to export / import the geometry in a Paraolid format (*x_t).

Seif Eddine Naffoussi, Stress Engineer

http://www.Innovamech.com

33650 Martillac û France

 

[Tpintar]

I have, I tried using parasolid and step. The result was the same

 

[BlasMolero]

Dear Tpintar,
You can import the native SolidWorks model in FEMAP, but this way FEAMP will import ALL the bodies of your solidworks database. If you have performed already in SolidWorks the midsurface extraction job then hide your SOLID bodies and let visible only the midsurfaces and EXPORT your model using PARASOLID (*.X_T) and click in PROPERTIES, you will see the option "Export only visible entities", this way the data that will receive FEMAP are only the midsurfaces, not the whole solidworks model, OK?.

Regarding the treatment that will give FEMAP to a misurface, is the same as any other surface, not history exist as imported from Solidworks, FEMAP don´t know the thickness of the source solid, then you will have to define Shell properties manually and associate to the geometry using the command "Mesh > Mesh Control > Attributes on Surface", select the surfaces with the same thickness and material, and clik in "Element/Property type", select PLATE and in the form define the material properties and thickness.

Also to achive continuity of displacements you need to stitch all midsurfaces in ONE Shell body: use command "Geometry > Surface > NonManifold-Add" using a stitiching tolerance of say 1e-4. Here you are some examples:

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/

 

[Tpintar]

As I mentioned above, the model is built out of surface elements... DIRECTLY. No solid elements exist in my model. For the same reason no midsurfacing is done, or is required in FEMAP.

As for surface stitching, the model is already a single part; already built for FEA analysis so surfaces are continious, edges joined. I can still however try to stitch the surfaces, maybe this is what causes the problem.

Assigning plate properties, Yes that part is very clear. As I mentioned I have already analyzed this model, meaning that I have had to do all the regular steps already (assign, material, thickness etc.)

However, the question from above still remains. Once imported, all geometry elements in the model are registered as solids. Even though they are not solids in the parasolid. They are not even displayed as solids in FEMAP.

 

[BlasMolero]

Dear Tpintar,
Well, without the model geometry in hand is difficult to understand the problem you have, post here the geometry in Parasolid coming from SolidWorks and I will take a look to it, 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/

 

[rob768]

try the explode command? this might create the surfaces you need.

 

[Tpintar]

I can look into creating a simpler shell element, testing it in FEMAP and exporting to here through the weekend. However my question was not related to a specific model, I just really wanted to know if importing shell element models into FEMAP was even possible.

I have, and it is mentioned in the first post. After exploding the message is "1 solid exploded into 1 surface"; and it still refuses to mesh with 2D properties. Also a solid which explodes into 1 surface can only be a surface. So you see my confusion

 

[BlasMolero]

Dear Tpintar,
This is a problem of communication, of concept definition, things in general are very easy in FEMAP, then to clarify the problem you have (and to be in position to help you!) simply define any geometry you like in Solidworks (not need to be the whole ship!!), export as parasolid, post it here, and we will take a look to it, my pleassure is to be of help to FEMAP users, simply, 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/

 

[stressebookllc]

FEMAP's geometry kernel is also parasolid. Meaning the surfaces are also solids, except boundary surfaces. Try removing any attributes on the surfaces, it is possible that there may be some attributes messing it up. It may also be that the surface definition coming out of the CAD program is not compatible. Post a piece of the geometry as an attachment if you can, I am intrigued.

http://www.stressebook.com

Stressing Stresslessly!

 

[GoGraphite]

OK, 5 months later, I am chiming in on this post. I anxiously await the answer. Tpintar, did you get it to work? Blas, thanks for your insight. stressbookllc, where do I access the attributes on the surface? Does this need to happen in SolidWorks or Femap? Where and how do I change the attributes? I am currently working a big modeling program is SolidWorks, but I need to import the models into FEMAP.

Greg Kress,

http://www.topflightaero.com