6 Replies Latest reply on Feb 17, 2015 5:34 PM by Jared Conway

    Analyze Solid Plate as Shell?

    John Willett

      Is there a best way to analyze a relatively thin solid body as a shell?

       

      My geometry is modeled as a solid.  Inside the simulation study, I can right-click the solid body and select "Define Shell by Selected Faces..."  This seems to convert the solid into a shell for analysis purposes, at least it meshes as a shell, but here's the rub:  I can't seem to select the shell edges/faces to apply the fixtures/loads.  The faces of the solid are selected instead, and then the solver cannot find the fixtures/loads for the shell and fails.

       

      One work around I've stumbled on is to insert a "Mid Surface" feature for the shell and then a "Delete Body" feature to camouflage the solid for the analysis.  (Applying "Exclude from Analysis" to the solid body does not seem to do the job.)  Then I can select edges of the shell, but it seems a rather cumbersome approach:

      Plate to Thick Shell 2.png

      Thanks for any recommendations. -- John WIllett

       

      P.S. -- A "Circular Symmetry" fixture, as appropriate for this "pie slice" of a full disk, does not seem compatible with a shell.  (I found I had to apply "Rotation" = 0 fixtures around the two radial edges to simulate this.)  Is this true, or am I missing some trick? -- J.W.

        • Re: Analyze Solid Plate as Shell?
          Attilio Colangelo

          FWIW, I never create shells in the study.  Create separate surface bodies in the model and the resulting Simulation shells will be easier to work with.

            • Re: Analyze Solid Plate as Shell?
              John Willett

              >>FWIW, I never create shells in the study.  Create separate surface bodies in the model and the resulting Simulation shells will be easier to work with.<<

               

               

              Attilio -- Sorry to be dense.  So are you agreeing with my "work around" (including the Delete Body) or recommending something else? -- John Willett

                • Re: Analyze Solid Plate as Shell?
                  Attilio Colangelo

                  Yes, I guess your workaround is actually my main method for the surface/shell.  However I noticed you are creating a mid-surface based on the solid.  I don't quite follow because deleting the body would remove the surface also. Either way I would suggest creating the surface from it's own sketch.  Also, any solid bodies can be hidden instead of deleted.

                    • Re: Analyze Solid Plate as Shell?
                      John Willett

                      >>I don't quite follow because deleting the body would remove the surface also. Either way I would suggest creating the surface from it's own sketch.  Also, any solid bodies can be hidden instead of deleted.<<

                       

                       

                      Attilio -- Actually, if you use the "Delete Body" feature late in the design tree, the "deleted" body is still available to earlier features (like Mid Surface).  It just doesn't cause trouble for fixtures in the simulation -- very convenient, but I'm not sure this is the preferred method, and it may require vs. 2015 to work...

                       

                      I tried making a separate shell model (without the solid), and that works fine too -- just more work.  I don't know about hiding solid bodies.  I tried that in the simulation, but not in the FeatureManager itself.  Does that work too? -- John Willett

                • Re: Analyze Solid Plate as Shell?
                  John Willett

                  Sorry -- I made an error in the OP -- not enough fixtures.  The P.S. SHOULD have read as follows:

                   

                  "P.S. -- A "Circular Symmetry" fixture, as appropriate for this "pie slice" of a full disk, does not seem compatible with a shell.  (I found I had to apply "Rotation" = 0 and in-plane normal displacement = 0 fixtures on the two radial edges to simulate circular symmetry.)  Is this true, or am I missing some trick? -- J.W."