After a while I dig into FEA simulations. However, I am not quite familiar with Solidworks.
I downloaded some simulation case studies. However, I guess there is something was wrong with the case studies.
I compare the result of two studies.
001 - Results on the top ( The default contact conditions - global bonded contact, bolted connection and no penetration contact)
002 - Results on the bottom. ( I just thought - that is not a welded part - so I suppressed the bonded contact)
Which of the analysis should be correct?