Guilio,
The UK's internet died yesterday and am busy now. But as lunchtime meanderings I summarise what I did below if any help.
Jonathan got further than me. Can you upload your model?
Following the process of 'simplify simplify simplify until it works then gradually make it more complex as we build up confidence'
I adjusted your model as follows:
- Rebuilt the assy without constraining using connections
- Removed all finite friction. Contacts are now frictionless.
- Removed all your mesh controls and volume regions and made it mesh with very few tetrahedral elements (might be poor answers but we know they work)
- As Jonathan noted, I found and removed the planar constraint on the underside of the block (I can't see sure how the software works out what would happen between this and the contact).
- Put planar constraints either side of the block to guide it when pushed. I did not use the planar constraint I used the displacement constraint (we know these work)
- To stop the block from moving back freely : In the block I created 2 datum points behind the back surface, a weighted link to the back surface from one, a simple spring (1000N/mm) between the points and fully constrain the point furthest away (including rotations else the spring spins)
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- Create a spring force measure.
- Created a cylindrical csys for the blue part.
- Created a cylindrical constraint for the pin joint with an Theta enforced displacement of '-1' only. Should be degrees right? (note I did not check the 'interpret as radians' check box)
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- Created a timestep function to multiply the constraint
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- Ran a SMALL deflection study and got the following silliness
(I could have used symmetry but forgot)
What's the block doing over there?
The pin joint isn't working properly. The inside cylindrical surface has various values of Theta and should all be 4deg in the final timestep.
15. I then ran LDA and things seem much more sensible up to a point ...
Theta is good @ a value of '4'
But displacement linear ... ?
22mm block movement from 4 degrees of rotation?
I would have expected about 3.5mm for 4 degs
The spring force measure comes out as 22kN; so that's working.
And anyway, we should be able to do this sum on paper. (or spreadsheet)
So is Theta degs or rads? I vaguely recall a thread on here about this somewhere.
22mm equates to about 26 degs or roughly half a radian
It can't be rads or the part would have rotated 230degs
At this point I ran out of time.
Can someone point out my error (fallible human)?
If not, I will raise a call or two
(Depending on your objective I would consider Mechanism Dynamics if you have access to it)
Atb.