6 Replies Latest reply on Apr 27, 2016 10:33 AM by James Riddell

    Vacuum simulation

    Ari Cardoso

      Hi everybody,

       

      So, i'm trying to simulate the model that i show in annex but i've realized something and don't know what to think about it.

      I want to test the model to the vacuum pressure, and found that if the collar wall thikness is 1mm or 8mm there is no difference in the stress output.. how is this possible? Do i have to make this simmulation using pressure vessel conditions?

       

       

      Thank you in advance,

      Best regards.

        • Re: Vacuum simulation
          James Riddell

          Is this attached to something else?  Do you have your stress and deflection results?  Did you apply a negative pressure?  Seems more logical to apply a pressure to the outside but you should get about the same results.  Have you done any hand calculations?

          • Re: Vacuum simulation
            David Marsden

            I am not sure about how you applied the pressure. Like James asked is it negative pressure?

            Never tried negative pressure. I always apply 1 atmosphere of pressure to the outer surfaces.

            I think if you do that for your pressure, it will work fine.

            • Re: Vacuum simulation
              Ari Cardoso

              This is a sample of a bigger construction, but i want analyse just this part, thats why there is just this model. I made hand calculations and they are in agreement with a positive pressure.. but i want to analyse a negative pressure, and that i dont know how to calculate and the simulation seems not to be "working".  If i apply the pressure in the outer surface i should expect the same results, right? Should i use a buckling simulation so it considers that effect in the collar?

               

              Best regards.