Learning Forum

[Renir Reis Damasceno Neto]

 

Hi Akshay, thanks for your reply!

Please find below some new results considering your suggestions. I’ve reached convergence, but I’m not sure about the physical representation of those changes.

 

1. I’ve checked the contact/target selection and it’s well defined (also I’ve tried switching it with no success).

2. The solution fails after a few iterations, there are three warnings:

•    One or more bodies may be underconstrained and experiencing rigid body motion. Weak springs have been added to attain a solution.  Refer to Troubleshooting in the Help System for more details. (in the beginning of the simulation)
•    Contact status has experienced an abrupt change.  Check results carefully for possible contact separation. (around 4th iteration with no convergence)
•    One or more contact pairs exceeds contact small sliding assumption, check your results carefully.  Consider using Large Deflection or turning off Small Sliding on the offending contact pair(s).  You may select the first offending pair via RMB on this warning in the Messages window.  Additionally, you can use the “Number With Too Much Sliding” Contact Results Tracker to locate any additional pairs.

 

3. I’ve selected the normal stifness factor as 0,1 for both contacts, but I couldn’t find the detection method as combined.

 

New simulations run:

A: Applying normal stifness factor as 0,1, the Newton-Raphson residual plot shows residual force in the contact inner surface of the outer bigger shell:

B: Since the previous simulation showed residual force in the outer shell border, I’ve tried refining it. The residual force is low, but still present, still missing the convergence.

C: Finally, it’s reached convergence, adding the normal stiffness factor 0,1 and Detection Method as on Gauss point.

The question is: Do those changes in the model affect phisically the model? Are there any other changes that could be applied instead to reach convergence but still have a good physical representation?

In this case is very important to simulate the interactions between the components. Just for you to know it’s a real case in which the antirotative tabs (at the outside border of the small cup) have broken in use.