1 Reply Latest reply on Oct 4, 2018 11:09 AM by James Riddell

    trailer hitch boundary conditions?

    Sean Johnson

      I'm analyzing a two wheel cart that looks a lot like one of those small two-wheel motorcycle trailers.  It has a body that attaches to the trailer frame with some sheet metal brackets.  I'm concerned with bracket stresses with a high load on one side of the trailer (someone standing on it).

       

      I need to analyze the brackets between trailer body support and the trailer frame.

       

      The boundary conditions for the wheels are easy.   But how to model the hemispherical trailer hitch?  It can rotate, but can't deflect vertically.

       

      Right now I have the edge of a hole restrained vertically and horzontally, but it's artificially stiffening the hitch end against rotation along the long trailer axis.  I think that's causing artificially high stresses in the body support.

       

      Any help appreciated.

        • Re: trailer hitch boundary conditions?
          James Riddell

          I need to analyze the brackets between trailer body support and the trailer frame.

           

          The boundary conditions for the wheels are easy. But how to model the hemispherical trailer hitch? It can rotate, but can't deflect vertically.

           

          Right now I have the edge of a hole restrained vertically and horzontally, but it's artificially stiffening the hitch end against rotation along the long trailer axis. I think that's causing artificially high stresses in the body support.

           

          Any help appreciated.

          Can you model in the ball and run a non-penetrating surface?  You'd have to make sure it was the same/matching surface but then you could fix the bottom of the bolt face.

           

          How are you doing the wheels?  I frequently put a small flat on those to avoid any Hertzian contacts.