6 Replies Latest reply on Sep 16, 2010 8:19 AM by 1-GVUGDA

    SW Simulation Fixtures

      I am having some issues trying to understand what is meant by some of the fixture choices when I am trying to restrain a cylindrical surface.  I have a cylinder with an axis along the z-axis and I only want to restrain it from moving in the y-direction (translation only)  It is free to rotate in any direction.  Does anyone have any ideas on how to do this?  It seems like an easy thing to do, but I am stumped.

       

      Also, does anyone have a good reference for what the different translation and rotation restraints mean for cylindrical surfaces?  The animation at the top of the feature manager tree doesn't explain it very well.

        • Re: SW Simulation Fixtures
          Jack Lynch

          I'm not sure I 100% understand your description, can the cylinder translate along the Z axis (axis of rotation) and what about the X axis?

          A picture may help.  Would a "bearing" fixture work? 

            • Re: SW Simulation Fixtures

              I have attached a picture of what I am trying to do.  The area marked "BEARINGS" are pinned together and are free to rotate since they are on a common shaft.  The area marked "PIN" have a pinned connection and there is a hydraulic cylinder mounted between them that is at a fixed extension so I need to restrain the translation in the direction noted.  The pin can move or rotate in any other direction, especially if a side load is placed on the ends marked "FORCE"  I am haveing a hard time setting this up and getting realistic results.

                • Re: SW Simulation Fixtures
                  Ryan Werner

                  Michael,

                   

                  The picture helped explain what you meant.

                   

                  I would set my restraints and loads up in the following manner for your problem:

                  1. For the holes marked BEARING I would add fixed hinges.  This would allow them to rotate about their central axis but lock all other rotations and translations.  I would also add a pin connection between them.  This will keep them "connected" and ensure that they deform "together".
                  2. For the PIN holes I would create a plane that represents the axis of the cylinder.  Than I would add a Use Reference Geometry fixture along that plane.  I would again add a Pin Connection between the holes to make sure them connected.
                  3. I would treat the FORCE the same as the PIN.  Just create a plane along the direction of the force and add a load along that plane.  You can add another Pin Connection here if you think that the ends where the load is applied are deforming too much or too independently of each other.

                   

                  Hopefully this helps.

                   

                  Ryan W.

              • Re: SW Simulation Fixtures
                Ryan Werner

                If you use the Use Reference Geometry Fixture you can restrain you model in whatever direction you want.

                 

                Ryan W.