5 Replies Latest reply on Oct 29, 2015 9:06 AM by Richard Dyar

    Fixtures on Weldment

    Richard Dyar

      Hey guys,

       

      I've got a weldment that I'm having a hard time running some fairly simple FEA on. Attached is a screenshot that shows the Fixture in RED, that fixture point is a plate on which a Pillow Block Bearing is bolted. These bearings hold a shaft that is fixed.

       

      Showing in Green are points to which a cylinder, the type of which is inconclusive is mounted. This cylinder pushes up on the frame and forces it to rotate about the fixed shaft.

       

      The cylinders produce 1200 lbf, and the CG of the frame and the components mounted on it weight 800lbf and I've ran statics to get the summed forces. The two loading conditions I'm trying to investigate are F_x = 498lbf  F_y =291lbf and F_x = 364lbf  F_y =343lbf

       

      I've having some issues fixture this setup and I'm not sure what trick could use to get a decent result.

       

      Thank you in advance,

      Richard

        • Re: Fixtures on Weldment
          Nandish Datti

          Hello Richard,

           

          I have reviewed the attached model and I see that the issue is related to contact definitions between the parts.

          The overall model is created using sheet metal features and weldment features. The components which are created using sheet metal will be meshed with shell elements automatically. Keeping the global contact to bonded wont help you to solve this problem. To resolve the issue you will have to define bonded contact sets between beam and shell elements. You have to be cautious while defining bonded type of contact between the edges/ faces of shell elements and beam body/ joints. If you want to make life easier, you can mesh the sheet metal components using solid elements (For this RMB on each component in Simulation study tree and select 'Treat as Solid'). If you do so you will be able to select the faces which are in contact with other components. I have defined around 24 bonded contact sets and the tree looks like this

           

          The attached drawing file contains the results for this study.

           

          -Nandish.

            • Re: Fixtures on Weldment
              Nandish Datti

              To know more about how to set up the model watch this video here.

              Hope this is enough for you to successfully build model for simulation.

              Else let me know your concerns.

              -Nandish.

                • Re: Fixtures on Weldment
                  Richard Dyar

                  Nandish,

                   

                  Thanks for the reply, I've attempted to recreate the simulation knowing that it can indeed work. I've having trouble with the contact sets (beam to plate face). I'm sure it works simply when bonding the beam to a plate when both faces are parallel to each other, but in this case we have the top of the "diamond" profile against a flat plate and it's generating an error when I run. I've also excluded all the irrelevant plates from analysis, leaving just the Bearing Mount and the Rod Mount plates.

                   

                  Also than's for the video, that's a very good resource.