element based surfaces from 2D/3D mesh

Nikolay Todorov

Hello all,

I have a question regarding the creation of surface element interfaces for Abaqus based on 2D/3D mesh. I am right now using HyperMesh 2020.2, the previous version I used was 2017. I see what previously was called surface groups now is called set segments and from this tab you can create element based surface interfaces for contact definition. However, I have a couple of issues:

- most of my interfaces are defined based on 3D tetramesh which works fine. For the most complex ones I extract 2D surface mesh form the underlying 3D elements (Tool --> Faces) and define the element based surface by organizing those 2D elements in a separate collector. The problem is that those segment sets seem to be associated only to those 2D elements and as soon as I delete them the defined surfaces disappear as well. This was not the case with 2017 version. Can someone please provide a solution. I need to keep the surfaces and 3D mesh and when exporting to have the associativity between them.

-the funny thing is that those surface elements defined on the mesh are no longer recognized as elements so for example I can't delete the from the F2 panel. Where did all this functionality go? How can I pick and delete single surface elements to trim the interfaces?

Hope I managed to explain my issues. If not - I can provide additional information. Thanks in advance.

Adriano Koga_20259

Hi,

 

- do you have any other reason to create faces, other than for creating contacts? This is definetely not necessary. When you have a 3D mesh you can select the solid faces directly when editing your set segments (contactsurfs).

If you need more control, you can either use limit nodes, or change the selection, instead of 'faces' to use elements and 'face nodes'. By selecting a few 3D elements you can limite the covered area.

 

For your second question, also the same function solves it. To remove some elements from a set segment, use the 'remove faces and edges'. Change the selector to 'elems' and just pick the elements you want to remove. By selecting the 3D elements, HM will remove the associated contact surfs (pyramids) from the set segment.

Adriano Koga_20259

Adriano Koga_20259 said:

Hi,

 

- do you have any other reason to create faces, other than for creating contacts? This is definetely not necessary. When you have a 3D mesh you can select the solid faces directly when editing your set segments (contactsurfs).

If you need more control, you can either use limit nodes, or change the selection, instead of 'faces' to use elements and 'face nodes'. By selecting a few 3D elements you can limite the covered area.

 

For your second question, also the same function solves it. To remove some elements from a set segment, use the 'remove faces and edges'. Change the selector to 'elems' and just pick the elements you want to remove. By selecting the 3D elements, HM will remove the associated contact surfs (pyramids) from the set segment.

by the way, newer version use the 'Contac Browser' (Tools>>Contact Browser) or Model>>Contact Browser.

Or just Ctrl+F >> contact Browser.

 

This takes care of all your contact definition in replacement to the old 'Contact Manager'

Nikolay Todorov

Hi Adriano,

 

thanks for your fast reply.

 

The reason to create surfaces rather than contacts is because I am using Hypermesh mainly for meshing and the definition of contact interfaces. Everything else (incl. contact definitions) is done in the Abaqus input deck since it is a lot faster as we already have some templates. You literally define a complex model ready for the simulation in a couple of minutes. The workflow with extracting surface elements and trimming them to get to the desired element surface works a lot easier and faster as the method you mention (btw this was possible in previous releases as well). For very complex parts there is no way you can define a proper ambient surface by choosing solid elements and nodes with feature angle or limiting nodes. Or you have to spend 30 min. selecting and deselecting elements.

To your second answer - I have seen that there is the option to remove some segments from the same panel. Apart from being more complicated and IMO a step backward compared to the old method where you could delete single elements or arbitrary selection of elements, there are some practical limitations as well. In the image below I want to delete the segments on the top surface but keep those on the side. As you see they belong to the same solid element, but lie on different side faces. If I go and remove those elements all connected segments are removed from the surface definition which is not what I intend to do.

To the contact manager - as already mentioned, I do not use the contact manager at all because it takes more time to setup the model as in the text editor (Abaqus). 

SAGAR MOTWANI_20932

Hello Nikolay and Adriano, 

Nikolay, I am facing same issue, in which I was creating macro (tcl script) for creating setsegment, since faces associativity is there. Thus, I had to come-up with another solution. In solid faces, we can select 3D faces (manually), it is possible. It will give result, just like selcting 2D faces.

But, when creating macro of it, is there any api for selecting 3D faces...

I need to create Setsegments  (Contacts in HM v2020 or above), so directly from 3D faces, there is manual button option (Analysis > Setsegments >  Solid faces > in element selection choose 3D Faces) as seen in image,

But, i need to use same selection in automation with TCL script, what is api for face selection for 3D Element

P.S. -  *createmarkpanel elems 1 >> by Face is giving different selection thus different end result of setsegment.

by *createmarkpanel elems 1 > (option - 3D elems by faces) will result in selection of 3D elements not faces,


So, is there any api for having selection panel as above one (3D faces selection)..

Also How you overcame your problem.

Thanks in advance.