generalized spot welds

[nanemo]

Hallo to all

forgive me for the continuous questions

but I'm in trouble...

I've to create 2 attached by spot welds composite plates

ansys offers me two options:

-massless sw, I don't like to it cause I have a lot of node to attach

-generalized sw

about the last option, can I use as nodal component common line between the 2 plates, or only coincident node must be cosidered?

 

[Wecos]

We had a similar homeworok problem in school. It involved coupled nodes. It's been a while since and I'm a bit rusty so you might want to check the ansys help for further information.

 

[nanemo]

tnx for your answer

Ansys help says:

For a spotweld, N1 and N2 are the nodes which are connected by the spotweld. For a generalized weld, input a nodal component name in N1 and leave N2 blank. The nodal component should contain all nodes that are to be included in the generalized weld.


For a generalized weld, coincident nodes are permitted, but CID must be specified when using coincident nodes. EDWELD is not updated after a node merge operation; therefore, node merging [NUMMRG,NODE] should be done before any EDWELD definitions


my problem was the correct nodal component selection

 

[Wecos]

Did you create a component of the nodes that will be coupled (welded) by the EDWELD command?

 

[nanemo]

yes, I kept the node attached to the 2 overlapped lines belonging to the 2 surfaces to "weld":

SELECT--->LINES--->APPLY---->NODES ATTACHED TO---->LINES---->CREATE COMPONENT---->MADE OF NODES


then I created generalized spot weld

I made a test this morning, it seems to go


Is it the correct way?

 

[Wecos]

Are the selected lines just the perimeter of a circle? Would your component miss nodes inside the circle that are part of the weld?

The approach seems fine to me, but I can't claim to be an expert. As with all FEA its a good idea to run a quick hand calc to see if you're results are reasonable.

 

[nanemo]

yes, The lines I selected are parts of the perimetres

since I have a lot of node to weld I supposed genrlzd spot weld option was quick and simple, but I was not able to understand the procedure fully

 

[nanemo]

damn, I made a test with generalized spot welds like I described above, all ok...then I applied to my model and that's the result:

*** Warning nodal pairs are defined for GENERAL and
COMBINED welds only. NPR is reset to 0. Keyword:
*CONSTRAINED_GENERALIZED_WELD_SPOT

anyone knows what it means?