I have a model I have built that is giving me some strange CPRESS stresses, (my first proper Calculix model but I am coming for quite a bit of experience with Abaqus although it has been a couple years since used it every day)
This is created and post processed in PrePoMax, I have not tried to postprocess the results in any other software yet which should probably be my first step if I had anything else installed
This is a cam/piston lock mechanism. It is basically an an offsent pin turns in a slot and drives a piston which moves linearly. It took a while to get the model running correctly but it does what I expect now although it is a bit large and takes 12 hours on my fairly powerful computer. (this is run 17 so I have been working on it off and on for a while I forgot to request the reaction force on the rotation BC on the pin but will do that next time I run it.
The attached pictures show the issue. The cam pin is slightly (0,02mm smaller than the hole it is in) and I think I have contact adjustment turned off. At the step shown in these pictures there should be near zero load as the cam is just rotating a few degrees and is not yet touching the slot wall. If I plot load on the cam surface or load on the working end of the piston there is no real load at this point but I see these very high stresses all around the bearing ends of the cam pin.