4 Replies Latest reply on Nov 14, 2017 7:44 AM by Joseph Sensenig

    deflection of a custom profile

    Joseph Sensenig

      I am new to simulation, and need to figure how many pounds we can support at the center of a custom profile which is supported at both ends.

       

      in the attached model, I have a force of 30 lb. applied at the center of the profile. It says this results in a max deflection of 1.168e+000, which I interpret to be 1.168" of deflection, (which i think is too much for the strength of this profile).

      If I enter 20 lb. as the force, it says max deflection is 8.504e-001, which I think means 0.00854" of deflection. Am I interpreting something wrong?

       

        • Re: deflection of a custom profile
          Keith Frankie

          1.168e+000 = 1.168 x 10^0 = 1.1668 x 1 = 1.168

           

          8.504e-001 = 8.504 x 10^-1 = 8.504 x 1/10 = 0.8504

           

          I often change my 'chart options' / 'format' from 'scientific' to 'floating' for easier interpretation.

           

          Perhaps you are triggering the 'large displacement' flag; otherwise the results would be linear and 20/30 would be equal to 0.8504/1.168

           

          This is a perfect study for beam elements.

           

          Your beam appears to be fixed on each end, and not just 'supported'.

           

          You should check your calculations with Roark's formulas for beams, or by using an online beam calculator.

           

            • Re: deflection of a custom profile
              Joseph Sensenig

              Thanks Keith.

               

              I looked for an online beam calculator, but what i found was for standard c-channel shapes, and nothing this small. I will be playing around with a few different shapes. We will be custom extruding the profile once we find what strength works.

               

              As far as the fixed ends, my VAR helped set this up, and the way he did it was to fix the one end in all directions using just the bottom edge. This allows the end to flex. On the other end, he fixed it up and down, but allowed it to slide in and out, so the beam is able to shorten as it flexes. Do you think that should work?