Interference Fit Question

[Ashu28]

Hello all,
I am trying to model a ring shrunk fit (by heating up, but that doesnt really matter) on a pipe to figure out what are the stresses in it.
I use *CONTACT INTERFERENCE option and use *SURFACE BEHAVIOR, pressure-overclosure=HARD, SURFACE TO SURFACE CONTACT PAIR with master and slave as pipe and ring mating surfaces

I have observed that if I use:
1) *CONTACT INTERFERECE
slaveSurface, masterSurface, initialRadialInterference
This makes the simulation complete in just ONE iteration (havent checked with elastic theory yet) but doesnt seem quite right
2) *CONTACT INTERFERENCE, SHRINK
slaveSurface, masterSurface
This makes the simulation run for some iterations and time increments and then completes (again havent checked with elastic theory yet) but seems a little better.

The question is that if using the first option that I did wrong? I have to also apply a thermal expansion in the next step. Has anyone done anything like this before, if yes, please shed some light.

Regards,

 

[sticksjoerd]

I have a little experience with SHRINK for cold-installing interference fit fasteners, it works like a charm. Often it is recommended to combine it with SURFACE SMOOTHING.

Hard to judge your model without seeing it. At t0, is the ring smaller than the rod? If so, SHRINK seems the option to use to me (and no need for the thermal step anymore).

But it should be the other way around, the ring is heated up to be larger at t0, right? Then there is maybe no contact at all at t0?

 

[Ashu28]

Thank you stickjoerd,
You are correct. The ring is heated up, installed in place and then they cool down to come at room temperature. I was thinking that if I am interested in stresses, then I can just model it by using SHRINK fit as I know what was the diameter before installing for all the parts.

I thought my approach was gonna give me the same end result and I would not have to deal with no temperature change at all. Am I not correct?