Tie Constraint for Welded Edges

[mvp23]

Hello,

I was wondering if it is possible to apply a tie constraint in a particular step in Abaqus ( while running a multi step analysis).

My simulation is a 3 step process. The first step involves the assembly of 2 concentric cylinders, by making a plug move through the inner tube, expanding its outer surface and thereby closing the interfacial gap between the inner and the outer cylinder.

The second step involves removal of the plug from the simulation and I used the 'model change' option to deactivate the elements of the plug.

Now, after step 2 and before step 3(which involves application of heat to the outer cylinder) I would like to introduce the tie constraint to simulate the welded edges of the cylinder ends.

So my problem here is in trying to introduce a tie constraint after step 2. Can this even be done or can constraints be applied only at the beginning of an analysis and not after a particular step ?

Thanks in advance for any help

 

[mvp23]

Any suggestions ?

 

[corus]

Obviously you have contact between the inner and outer cylinders so you could apply 'no separation' after contact is made but apply this only to partitioned off surfaces close to the welded end.

 

[mvp23]

Thanks a lot.