Static Non-linear FEA simulation errors - Newton convergence could not be reached

[DaleKramer]

@rszoeke

your movement is defined in positive Z-direction, which won’t squeeze the coin, but lift the plate

Wow, I’m blaming that on the 1 am to 4 am time frame of project development

@rszoeke

but also fix the coin base with a constraint - this will probably over-constrain the system, but at least the contact is superfluous .

I tried initially without the x/y constraint on the bottom coin face but got errors that lead me to constrain it too and after constraining bottom coin face in x/y then the errors led elsewhere…

@rszoeke

if you remove the bottom coin constraint than you only have the coin constrianed by contacts and this does not restrict the movement at all in X and Y directions (imagine you use two plates of ice - the coin will definitely slip away). I would use a small elastic support on the side of the coin

Aha, elastic support the coin, will do

@rszoeke

your model is perfectly symmetric,

Yep, will get to symmetry eventually but I had issues with the 1/4 model on that airship FEA project (where the constraints at symmetry planes would not seem to let the envelope expand realistically) and I did not want to go there again until I got something working, besides this FEA stuff is so much quicker than the CFD stuff I started my SimScaling with

Thanks Richard as always

EDIT 1:

So I tried:
1. Fixed ram movement direction (not responsible for the error and I think I would have quickly seen the error in my ways when a sim was completed and ram move up )
2. Added x/y elastic support to bottom coin face (and removed fixed constraint an that face)

@rszoeke here is the run after those changes (I had to cancel it as Solver Log never appeared after 33 core hours), any ideas

I am working on symmetry as you know but still should work as is

Here is interesting quote from @nava which may have been my problem with my airship FEA :

@nava

IMPORTANT NOTE: It is preferable to use displacement boundary conditions (method 1) to apply symmetry, as using the symmetry plane boundary condition type (method 2) directly might result in an over constrained system when the nodes in the symmetry planes are also constrained by some other boundary conditions or are used as slave entity in physical contact. In that case, align the symmetry plane with the coordinate axis in a CAD software and apply symmetry conditions by fixing the DOF perpendicular to the symmetry plane.

EDIT 2:

So I have been able to add Cyclic symmetry to a circular die setup and it looks great but still errors in simulation and I am lost on a fix, any ideas on this separate sim and run error and fix

Edit 3 - re edit 2:

This is a way out there thought but, any chance this geometry display ‘bug’ could be an issue. The geometry shows a curved face (not curved in Rhino):
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BUT the mesh from that geometry is straight again: