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Partition of a Surface

Valued Contributor
Valued Contributor

Hi,

 

I was wondering regarding best practices for partitioning a surface.

 

Problem Statement:

 

I came across this problem where I extracted the surfaces of a rectangular box and when I meshed it (after non-manifold add) the element edges did not line up at the boundaries. Furthermore, I wanted to partition a few areas of interest so that I can mesh the area with refined elements.

 

Possible Solutions:

 

1) I created points and connected the points with curves. Then I used Geometry->Midsurface-> Trim with Curve

 

Let me know if you guys have a better solution.

 

Regards,

 

Saptarshi

4 REPLIES

Re: Partition of a Surface

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear Saptarshi,

Please post a picture of the problem, this way we will be able to help you better, I don't understand the question very well, thanks!.

 

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: Partition of a Surface

Valued Contributor
Valued Contributor

Hi Blas,

 

For example, I want to partition this surface:

 

Face to Partition.PNG

 

I created points along the curve, connected the curves and projected them onto the surface, which resulted in:

 

Face after Partition.PNG

 

I was wondering if there was a better way to do this.

 

For example: 

 

I also used the command Midsurface -> Trim with Curve to get a similar result (trim with curve partitioned the entire solid and not just the surface).

 

 

Regards,

 

Saptarshi

Re: Partition of a Surface

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Dear Saptarshi,

In FEMAP you can make things and arrive to the same result using many, many different ways, this is the good of FEMAP, but the result is exactly the same:

  • The method used to split the surface base by command GEOMETRY > CURVES - FROM SURFACE > PROJECT is correct, I use it a lot, you simply create curves and project normal to the base surface.
  • In the same TOOLBAR "Curves on Surfaces" take a look to command GEOMETRY > CURVES - FROM SURFACE > SLICE, is really powerful and I am sure that not many people use it: not need to create curves by advanced, you simply define a plane and you are done. The problem with this command is that the splitting is extended to the full sheet body, not only the surface selected, so caution!!.
  • Also another command very interesting located in the same TOOLBAR "Curves on Surfaces" take a look to command GEOMETRY > CURVES - FROM SURFACE > PARAMETRIC CURVE, is really, really powerful as well: you select the surface and next enter a location (not need to exist a physical point, use METHOD options), and the surface you selected is splited in either the u or v parametric direction. The advantage here is that the splitting task is performed only in the selected surface, not expanded to the full body.

Well, also the command GEOMETRY > MIDSURFACE > TRIM WITH CURVE is really powerful, in the past I use it a lot but nowadays not too much, you need to run with caution, the split is extended to the full body, and some times the result cause a disaster in the geometry integrity!!

 

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: Partition of a Surface

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hello!,

Also you can do the job with only ONE command: GEOMETRY > CURVES - FROM SURFACE > OFFSET CURVE/WASHER: the OFFSET mode can be used for oblong holes, slots, and other “general shapes” on many different types of geometric surfaces. FEMAP will ask you to select the appropriate curves to offset (Use METHOD>On Surface) and the result is the following picture:

 

offset-curve.png

 

Of course, this is valid for CONSTANT OFFSET, if this is not your case then the "classic" method of creating curves and then project curves normal to surface is the most flexible one.

 

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/