Hypermesh custom beam section with Sketches issue

andre_f_a_silva97

Hi everyone,

I am attempting to create CBEAM elements (Nastran) to represent some tubes which have an oval shape. The way I am doing it is by line meshing a line with CBEAMs and then assigning a PBEAM property which reference a beam section collector which references a beam section which I defined using a sketch.

The problem is that when I create the sketch, Hypermesh realizes the sketch as 2 surfaces (the wall thickness surface and the inner diameter surface). I am only interested in having the wall thickness surface. How can I delete or de-select the inner surface?

Here you see the beam section definition. Note the Number of Parts showing as 2 (the 2 surfaces).

Here we can see the 2 surfaces created. The idea is to have just a oval loop.

Any idea?
Thanks and have a nice day.

Fred_Juras

Hi,

Realizing sketch as surfaces and asing sketch in a beamsection are two different things.
You can realize your sketch as lines or even unrealize it, it doesn't have any impact on the beam section.
Even if your sketch doesn't show any holes, HyperMesh defines a single solid section from this sketch. It can be noticed from the tabular data ⇒ "Material with -1" means the closed loop represents a hole.
If you assign your current beam section to a beam element and display the 3D representation of 1D element, you should see the right section.

Please take a look at this really useful video from our Altair How To Youtube channel. The main topics are covered in it => replacement of hyperbeam with the sketcher, the way to deal with tabular data for thinwall os solid section etc.

https://youtu.be/u08Ub4duul0?si=-0nqXqLxYrlDRCOH

Regards,
Fred.