Hello
I’ve been wondering about the best way to model the connection between a screw and a tapped hole. I’ve seen many things and topics about bolted connections (B below), but couldn’t find much about tapped connections (A).
In the case A, let’s call the top part the “plate” and the bottom part the “block”.
Until now, in order to model the case A, I’ve split (in the CAD-software) the screw a few millimeters above the block in order to later be able to apply a pretension. I then fused to bottom part of the screw with the block (holes and screw are modelled as cylinders). In PrePoMax, I then created a compound part containing the top part of the screw and the block and then followed the same procedure as for bolted connections.
This yielded good results I guess, but I’m not sure if this is representative enough of a tapped connection which is likely not as stiff at that. I imagine the bottom part of the screw could also be tied to the block in PrePoMax instead of fused, but I guess this would be equally as stiff as a fused connection and likely create problems by solving (I haven’t used tied connections a lot, but when I did, it didn’t work very well, but maybe the problem was between the screen and the chair)
I’ve recently heard of a feature in Ansys which uses specifically formulated contacts to emulate a tapped connection.
I believe there is no such feature in CCX/PrePoMax, but is there a way to formulate a contact resp. a surface behaviour with parameters that would emulate a tapped connection? Are there otherwise other methods to model a tapped connection?