8 Replies Latest reply on Feb 17, 2016 6:40 PM by Keith Frankie

    Beam and shell contact

    Fabio Santilli

      Hi everybody,

      I’m trying to simulate a frame in a static analysis with Simulation 2016. I want to simulate this stuff with a mixed mesh technique but I have some trouble. In particular, in a part of the frame there’s a connection between a shell body and a beam body as shown in the figure.

       

      Immagine.png

       

      I’ve isolated the two parts and I’ve tried to simulate the stuff but something doesn’t work properly. The shell loses contact from the beam and doesn’t transmit the torque to it. I can’t understand why. The connection types are shown in the figures.

       

      Immagine1.png

       

      Immagine2.png

       

      Thank you very much in advance.

        • Re: Beam and shell contact
          Phill Zaza

          hello

          you have to add a contact set between the solid and the beam

           

          Manual contact set

          select bonded

          select beam

          select corresponding face

           

          i do like thislook it is working good

            • Re: Beam and shell contact
              Fabio Santilli

              Hi Mr Zaza, thank you for the answer.

               

              In my model there isn’t any solid body. There are two kind of bodies: one is a shell and one is a beam. I’ve added a manual contact set between a line of a shell (2 dimensional body) and a beam body (1 dimensional body). I’ve generated a shell body by the command “define shell by selected faces”.

              You can see what I’ve done by looking the second figure and the model inside the .zip file.

            • Re: Beam and shell contact
              Keith Frankie

              It looks like your study is actually working fine.

               

              Resultant forces at the fixed joints look appropriate.  The resultant displacements look reasonable enough.  If you change the scaling for the displacement plot you can see the beam is indeed bending.  Bonding between beams and shells is kind of a pain, but generally if it isn't working the model is unstable as the plate attempts to fly off unconstrained.  That isn't happening here.

               

              Certainly your included screenshot does look wrong, but I believe that's a display issue only.  If you switch the plot deformation scale from "automatic" to "user defined" at 70 (a similar value)  the beam twist actually shows up (though it's going the wrong direction).  In a new part I can replicate the lack of rotation bug, but I can't replicate the reversed direction bug.

                • Re: Beam and shell contact
                  Fabio Santilli

                  Hi Mr Frankie, thank you for your reply.

                   

                  “It looks like your study is actually working fine”, I don’t think so. In my model the deformation isn’t congruent with the applied load. May I ask you what version of Solid works you’re using? In our office we’re using the latest version of Simulation standard (2016 SP1).

                  There are two matters of fact:

                  1)   The shell loses its contact from the beam

                  2)   There is a reverse deformation of the beam

                   

                  Please, look at the following images. They're very strange. In a beam model I’ve applied a torque in a joint and a fix constraint in the other one. The achieved deformation is reverse although in the 3D model the deformation is congruent with the load.

                  Parte2.JPGParte3.JPG

                    • Re: Beam and shell contact
                      Keith Frankie

                      I'm using SW 2016 SP 1 also.

                       

                      The beam twist not showing with automatic scaling was confirmed as a bug by my reseller.  SPR is 933801

                       

                      The beam twist showing up as going in the wrong direction looks like a bug too.  I'll send that along to SW also and see what they say.  (see attached example file, similar to yours but with a force couple applied instead of a torque).

                       

                      I've seen this kind of thing before; a few years ago SW had problems with previews and renderings of shell thickness.  They seem to have that all straightened out now.

                        • Re: Beam and shell contact
                          Fabio Santilli

                          I’ve also contacted the customer service to ask information concerning this issue. I’m still waiting for an answer. Anyway it seems that this new version has a lot failures and bugs. In my opinion these bugs are very serious. I’ve seen your example file and the model behaves similarly to mine. I’ve noticed this “strange“ behavior while I was analyzing a frame with a mixed mesh technique so I’ve isolated a part of the frame to understand what was happening…

                          We have to wait for an answer from DS. I hope in the new SP there won’t be such problems

                          • Re: Beam and shell contact
                            Keith Frankie

                            SW confirmed the incorrect beam twist direction as a display bug.  Depending on the orientation of the beam it may show correctly or it might show opposite.  If you use a displacement/rotation plot you can verify the beam is actually twisting in the correct direction.