4 Replies Latest reply on Jul 28, 2015 9:21 AM by James Riddell

    Solidworks Simulation Pin Connector

    Matt Fritze

      Hello,

       

      As part of an FEA stress simulation I am modeling a clevis-blade-pin joint.

       

       

      Please note this is the exact scenario solidworks officially recommends to use the pin connector. (See below). I do not need to know the stress distribution in the pin but need to know the stress distribution in nearby components. They specifically recommend this is as an alternative to modeling contact in the joint with the only caveat that we cannot know exact local stresses in the pin.

       

       

      When I run this simulation I get absurd results.

       

       

       

       

      What am I doing wrong here?

       

      I believe what happening is the the 'pin connector' is really acting like a 'weld connector' -- 'welding' the cylindrical faces together. There is no provision for contact in the joint. This means that when a transverse load is applied to a joint with the pin connector (an extremely common scenario in mechanical design) the load distribution in adjoining components is ficitonal as the software is simplistically bonding cylindrical faces, not modeling the behavior of the pin bearing on one side of the face only.

       

      What do you all do to model this type of joint when doing analysis of assemblies?

       

      Thanks,

       

      Matt 

        • Re: Solidworks Simulation Pin Connector
          James Riddell

          Based solely on the pic just up from the bottom one, it appears as if your load force is headed the opposite direction and you are showing compressive stresses.

           

          Can you add a pic zoomed out?  Also, if the blade & clevis are close it might be helpful to make them 'non-penetrating' so they don't run into/through each other or 'adhere'.

          • Re: Solidworks Simulation Pin Connector
            Matt Fritze

            Ok. I made a test case to illustrate this point more clearly as in my original scenario I am doing something complicated things that I think would distract from the core issue.

             

             

            What we have is 2 plates (3x2in) with a .75dia hole and a pin connector. They are separated by a distance of .06 inches (so bonding is not an issue). The bottom of one of the plates is fixed and the opposite plate has a 1000lbf axial load applied. Roller/slider conditions are on one of the thin-sides of each plate for model stability.

             

             

            The stress from the pin connector is clearly being transferred into the part as if it is bonded to the hole's surface. IMO this connector and its documentation are grossly negligent as the stress distribution in vicinity of the connector will be wildly inaccurate.

             

            I think this test case answers my question as to why the results were off. What else do users do to model this pin-clevis joints?

             

            Thanks,

            Matt 

            • Re: Solidworks Simulation Pin Connector
              James Riddell

              Oh, BTW, there is the BIG caveat for pin connections (the same for bolted connections) about the stress w/in a diameter being "off".  This is an artifact of the rigid beam connection to the edge of the hole and the edge of the other hole.