7 Replies Latest reply on Nov 17, 2010 1:38 PM by Bill McEachern

    Pressurizing a container

      I would like to simulate pressurizing a container with an internal pressure of 150psi but I am not sure how to fix the container since it will just be sitting on the floor? Any suggestions?

        • Re: Pressurizing a container
          Ryan Werner

          Hi David,

           

          Haven't tried an analysis like this before but I think you could create a plane to represent the floor and then use a virtual wall with the contacting surfaces on the bottom of the bottle.  Then turn on gravity.  I am not totally sure but that might be enough.  If it is not and the bottle is still "moving" than try turning on Soft Springs.  This will stabilize the model but should not interfere with your pressure loading.

           

          Ryan W.

            • Re: Pressurizing a container

              Thanks for the idea Ryan. I tried it out but the analysis seems to fail unless I actually fix a point on the model. Problem is that the whole container rotates (stretches) about whatever point on the model that I fix. Is there any other way that I can constrain the model without introducing these unrealistic stresses?

               

              Thanks,

              Dave

            • Re: Pressurizing a container
              Bill McEachern

              most pressure vessels are usually symmetric for obvious reasons. Make a 1/4 symmetry model and on the floor say nothing normal to the floor on the bearing surface. If 1/2 symmetry take one of the floor feet and tie up another direction (stick to one node if you can), or use soft springs in the solver options. If the restraint is hot work on the problem it till you find a restraint system that isn't hot. I would think you should avoid contact as it isn't a requirement.

                • Re: Pressurizing a container

                  Thanks for the idea Bill. Unfortunately my model is not symmetrical (it's a flanged rectangular box with a lid -14"x10"x5"). I can't seem to find point to fix on the model. Problem is that the whole container rotates (stretches) about whatever point on the model that I fix. Is there any other way that I can constrain the model without introducing these unrealistic stresses?

                   

                  Thanks,

                  Dave

                    • Re: Pressurizing a container
                      Bill McEachern

                      The short answer is yes but you would need to us to see what it looks like. It does sound like the load is not balanced as it should be. You should make sure the load sums to zero.- the areas need to identical.

                       

                      You should get the reactions and see what sort of out of balance moment is being seen. It might give a clue as what the problem is. There are many ways to go at this but without seeing it...it is just speculation.