Current Topic: Press Fit Pressure
Neil,
I'm also having trouble assuring myself of what to do once I get this pressure. Maybe just typing this will help me talk my way through it.
Once I have a Pressure acting at the interface of the two pieces (let's call it P for conversation sake) and an area created by the interface (A), then I can create a force (F)
F = P*A
Now, I'm thinking this force should be acting in a LOA through the center of the circle and can be constructed as a point force. This is where I come into trouble. Part of me is saying that, since the pressure acts equally (or at least theoretically equally) amongst every place on the area of interference, then a point force won't suffice. However, another part (and one I tend to agree more with is telling me that, since I incorporated a pressure and area for the entire interface, then it is ok to model it as a point force acting through the center of the circle. Similar to designing a brake shoe. Because, we are essentially desingin a brake that encompasses the entire 360degrees of the item we are trying to constrict.
OK, so I pretty much just talked myself into using a point force, derived from the pressure and total area, that has a LOA through the center of the circle. This force, in conjunction with the static coefficient of friction, will create a friction force. I can then figure out what amount of torque (moment) must be applied before slippage occurs.
Does this all sound correct to you? Sorry to bother you so much, but I'm a young engineer thrown into a position where I'm the only ME (read: I'm in a bit over my head) and just want to make sure I'm not overlooking anything.
Thanks again,
Dan
