global bonded contact and contact sets

[rhmeng]

I am running solidworks simulation on an assembly. When I opened simulation it automatically assumed bonded contacts for all of the mates that I had, and it created a global bonded contact for everything. When I started going through the individual contact sets, because I needed to change/override many of these to allow penetration, I noticed that some of my screws in the assembly showed the global bonded contact as well as an extra contact set, and some screws just showed the global bonded contact set. It made me think that I needed to go through and add a contact set to each screw that does not have one. I was under the assumption that if it says global bonded under a component, then it will be bonded to any surface that it is touching. If this is true then why is there an extra contact set created for some of the screws? I uploaded a pic that shows the two screws, I did not add/change anything except the names, the contacts are all what solidworks anticipated. Thanks in advance.

 

[TheTick]

I usually set global contacts to allow penetration and manually set up contact sets. Takes more time to set up, but saves analysis time because then the solver isn't hunting for contacts.

It also helps to split faces on solids to isolate contact areas. E.g. if a tube end meets a plate face, I'll divide the plate face so there is a small patch that matches the tube end.

 

[rhmeng]

I am not sure why it gives me contact sets for some screws and not others. SW must not be recognizing certain features for some unknown reason. Regardless, I keep getting a failure saying "the iterative solver terminated, check boundary conditions" or something along those lines. I tried to do a gravity test, which is supposed to show not boundary defined components, and I still get the same error. Next step is to probably go through and define every surface, or start suppressing components and running again and again.