User Defined Distant Connection Properties Help (Pin Connection)

[Svillefan08]

So I recently switched to Catia because Solidworks couldn't give me the result I needed, and I have a question.

I am trying to create a "Pin" connection. IE a connection that allows one Part to rotate about another part about the axis of a hole. Catia does not have a preset connection for this that I am aware of and so I am using the "User Defined Distant Connection" property. However I do not understand quite how this connection is defined. Could anyone explain to me, or point me to a document that does, what is meant by "start" "middle" and "end" in this connection, and the difference between the option in this pull down menu, particularly the difference between "rigid" and "smooth"?

Or, if there is a type of preset connection that I am not aware of that can simplify accomplishing the connection I am trying to make, that would also be a great help.

Thanks

 

[franc11HD]

user defined connection allows you to include different values of properies in order to get the constraint needed.

What Catia is doing, it creates three points. One is located at the centroid of the first element selected (start) one at the centroid of the second element selected (end) and one in between if I recall.

Therefore, the option for the start and end, is how Catia will connect the two centroid points to that surface. Smooth = RBE3, Rigid=RBE2 (in Nastran terms). Rigid does not allow the surface to deform when Smooth allows it.

For the middle part, this is how is becomes tricky as it depends on what you want to modeled. It is how catia will link the two centroid to the middle point or basically how it will link the two centroids together. For example, rigid-spring-rigid will create a rigid element from both centroid to the middle point and link those two rigid element by a spring element. There, you can input stiffness values for DOf you want to transmit. If you want to "release" a DOF (rotation) just don't input any values for rotation stiffness.

In a nutshell, that is how it works. Catia V5 help is somewhat ok to explain this a little bit, but not in great details.

Everything depends on what you really want to do.

I usually fo a firs run only you smooth or rigid properties on a connection and release (uncheck) the DOF I want. That is when I do not really care about the load transfer and I just want the parts to be attached together representatively.

Hope this helps.