Contact/Enforced Displacement

Altair Forum User

Hi,

 

I've been trying to find the force required to create an interference fit between two parts. I'm fully constraining one of them, and placing an SPCD upon the other. The contact between the parts is a sliding one (I've tried different values of friction, but nothing seems to help). I'm using a non-linear implicit analysis.

The solver gets quite far down the line, but then crashes at some point because it cannot converge. One of the parts begins to deform (as it is supposed to), but then the solver doesn't get any further. Chamfering the goemetry to avoid sharp edges helped some, but not enough.

 

Any thoughts, or a location where I can share a large .fem file?

 

Thanks,

Jai

 

Altair Forum User

This may actually belong in the RADIOSS thread, as that is the solved ultimately being used.

Altair Forum User

Hi Jai,

 

Can you introduce EXPERTNL PARAM card and check if you are through the error

 

Go to Analysis page>> Control cards>> PARAM>>EXPERTNL>>YES

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Thanks for the suggestion.

Just gave that a try, but no luck. I tried both YES and CNTSTB. It does say at the bottom that 'This parameter does not apply to geometric nonlinear solution sequences (NLGEOM, IMPDYN or EXPDYN).'

I'm using NLGEOM, so that's probably why.

Altair Forum User

Hi Jai,

 

Please share the model using the dropbox link in the below signature.

 

I will also forward your query to commercial support in US and someone will get in touch with you soon.