3 Replies Latest reply on Nov 21, 2012 3:42 AM by Mikael Martinsson

    natural frequency of the prestressed rod.

    Adam Kozial

      I need to find the natural frequency of the prestressed rod. Rod is placed at both ends of the pins. One pin is fixed (it is free only in the rotation pin), the other is free to rotate and free movement in the direction of the rod. Rod is tensioned force 400000N

      How best to specify fixtures?


      rod_View 1.jpg

        • Re: natural frequency of the prestressed rod.
          Bill McEachern

          You need to use a remote load as a restraint, ensure the axial directionis free so the load can tension the rod, use a fixed hinge restraint at the other end.

          • Re: natural frequency of the prestressed rod.
            Susheel W

            Hi Adam,


                      Greetings, Bill is right you have to ensure the axial direction free


            Try this first

            Mesh your part before loading

            Try to find natural frequency before loading

            What is the OBE and SSE constrains for your model rectify that

            the applicable Peak acceleration with respective to the amplitude must be 1.5 times  3.5g

            apply these loads first as you are pulling from one end

            What about the gravitational force I have gone through your model you have not defined them as gravitational force will act as restorting force.



            Hopefully this will help you and let me know if it works

            • Re: natural frequency of the prestressed rod.
              Mikael Martinsson

              The remote load restraint is interesting. I suppose you use the Displacement (Rigid connection) for this and allow only axial movement. The difference with this solution compared to using the hole surface directly with the reference geometry fixture is the possibility to allow rotation, or are there more benefits with the remote load approach?