5 Replies Latest reply on Mar 9, 2012 10:32 AM by Adrian Tayne

    DOF of a roller fixture

    Adrian Tayne

      I am working on a simulation of an assembly that is tied down to a floor. I assumed a frictionless floor and applied a roller fixture to the entire base of the assembly. When I applied a substantial inertia load to the assembly against the tie-downs, I expect the case to want to lift off the floor somewhere just from deflection of the base. However, the base of the assembly remains totally flat, almost as if it were restrained from moving vertically up. I would expect the roller to restrain the face from moving vertically down, or penetrating the floor. I noticed the roller fixture symbol is a simple arrow whereas a fixed geometry symbol is an arrow with a base. This indicates to me that a roller restrains it in one direction on that axis whereas the fixture restrains in both directions on that axis.

       

      Is my understanding of this type of fixture accurate?


      sim.JPG

        • Re: DOF of a roller fixture
          Adrian Tayne

          I should have done this first but the Solidworks help provided some insight with this.

           

          Roller/Sliding

          Use the Roller/Sliding restraint to specify that a planar face can move freely into its plane but CANNOT move in the direction normal to its plane. The face can shrink or expand under loading.

           

           

          This seems like a silly way to define this fixture. I guess I'll stay away from it and figure out another way to fixture it. Any thoughts on a better way?