6 Replies Latest reply on Apr 22, 2014 11:59 PM by Mark Biasotti

    Cannot knit surfaces

    Leo Galang

      Hi everyone

       

      I'm kinda new to surface modelling in SW and I'm trying to model a lobetype pressure vessel, which has partitions between lobes. I've been trying to knit the surfaces so I eventually end up with a merged model. So far I've been using the Check feature to see where I have open surfaces, yet when I try to knit & merge the surfaces that are open I keep getting the error "The selected faces and surfaces cannot be knitted into one surface" and I'm kinda lost to what I should do to solve this problem. I can knit the outer surfaces together, but when it comes to knitting the partitions to the outer surfaces I get this problem.

       

      The whole point of doing this modelling is to load my model as an IGES file into Ansys Mechanical and do a FE analysis. If it helps I've attached the file.

       

      Can anyone here please help me with this problem?

       

       

       

      - Leo

        • Re: Cannot knit surfaces

          Hi Leo,

           

          Just go to Insert>Surface>knit and select all the surface bodies (in the surface body folder in the feature manager) EXCEPT "surface_trim29[1]" and "surface_trim29[2]".  Now you'll have a single solid volume.

           

          Mark

            • Re: Cannot knit surfaces
              Leo Galang

              Hi Mark

               

              Just want to say thanks for the quick reply it's greatly appreciated. The thing is I need to include "surface_trim29[1]" and "surface_trim29[2]" to the single solid volume, since these "partition" is a necessary part of the FE analysis I'm gonna do afterwards.

               

              Can it be that the problem is due to the fact that I have 2 arc'ed surfaces and a straight one that intersects at the same point?

                • Re: Cannot knit surfaces

                  H Leo,

                   

                  Understood, then go ahead an shell the main volume (that is knited) by the wall thickness you need. then do a thicken of surface_trim29[1] and surface_trim29[2] to create your partions.

                   

                  the reason you can not knit it all at once (like your first request) is that it is impossible for parasolids to knit three surface edges togther.


                  Mark

                • Re: Cannot knit surfaces
                  Aryati Kamalrudin

                  Hye Mark,

                   

                  I am also new to SW. I watched the videos in youtube to convert surfaces into solid but again, I had the same problem with Leo. I tried to knitted all the surfaces altogether to form solid but yet it ended up only able to merge. However, when I tried to merge those knitted-surface, an error occured saying the rebuild errors. I don't know how to solve the problem. Can you please help me to take a look at the file. Below is the attached of my file. Thanks in advance.

                   

                  rebuild_error.JPG

                • Re: Cannot knit surfaces
                  Jerry Steiger

                  Leo,

                   

                  I assume that you need to keep your model as surfaces so that you can use a Shell model in your FEA. In that case you will have to leave your internal partitions as separate surfaces, since SolidWorks can't have a single surface at a T where surfaces meet. This shouldn't be a problem with your FEA software, you will just have to tell it to bond the edges.

                   

                  Jerry S.