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[muruep00]

I have a steel structure made up of beams connected by welds in SpaceClaim.

The beams must not be welded, but the welds must be welded to the beams. Thus, the welds need to be merged in shared topology with the beams in order for the elements of both objects to match. But the contact between the beams must no be merged in shared topology so that I can make a frictionless contact in Mechanical.

I can only manage to either separate all bodies so that they all make contacts between each others (but mesh does not match because there is no shared topology),

or merge all bodies so that everything is welded and mesh matches (but no contact surfaces are created and I cannot make the beam-beam contact frictionless):

 

 

May I be missing a correct way to configure the shared topology in SpaceClaim for what I want to do?

 

Thank you

 

[peteroznewman]

Please reply with inserted images of what you are talking about. Label the items in the image.

[muruep00]

Done.

[Aniket Chavan]

try using node merge tool in Mechanical. Bring all bodies as separate bodies without using shared topo. Delete contacts between body and welds. and merge the nodes using the tool more info at:

https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v195/wb_sim/ds_node_merge_group_o_r.html

-Aniket

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[peteroznewman]

When evaluating the strength of a welded structure, a conservative approach is to ignore contact and let the welds carry all the load. That way, if the structure is found to be strong enough in the analysis, the real assembly will have a greater margin of safety in a physical test.

One way to automate the creation of bonded contact between the welds and the beams is to put the weld bodies in one Named Selection and the beams in another Named Selection then create a Bonded Contact between Named Selections.

You may want to use smaller elements in the Bonded Contact zone. You can do that by dragging a Bonded Contact onto the Mesh branch of the outline to make a sizing mesh control on the bonded contact.

[muruep00]

try using node merge tool in Mechanical. Bring all bodies as separate bodies without using shared topo. Delete contacts between body and welds. and merge the nodes using the tool more info at:

https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v195/wb_sim/ds_node_merge_group_o_r.html

-Aniket

Guidelines on the Student Community

How to access ANSYS help links

 

Aniket your link does not work. How do I use merging nodes tool in Mechanical?

[muruep00]

Hello peteroznewman. In the real case of the model, the welds carry all the load. I want to simulate that exact case, so I must not ignore the contact by supposing is welded.

If I create a bonded contact between named selections, there is no node merging (nodes from beam and weld do not match!).

[peteroznewman]

You misunderstand my method. This illustration will help.

There is no node merging in my method, just Bonded Contact.

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[muruep00]

I thought about that method, but Im pushing the welds to their elastic limit (400 MPa) so deformations are not very very small, and I'm afraid that it could result in contact between the beams. And I'm not sure whether Ansys would be able to give a coherent result.