10 Replies Latest reply on Feb 11, 2010 2:46 PM by Ian Hogg

    Fun and games with edge welds

    Derek Bishop

      Just had a look at Simulation 2010 SP2. Tried to create edge welds on curved surfaces. This is what I noticed and what happened.

       

      1. Shell meshing with global bonded contact defined and compatible mesh selected for the global bond and using curvature mesh still results in an incompatible mesh.

       

      2. In order to get a compatible mesh with shells you still have to split surfaces.

       

      3. The automatic selection of contact sets apparently doesn't work for shells.

       

      4. With the global contact set to bonded some shells do not bond and still fall off when the study is run.

       

      5. Unable to save a data set of values for the edge weld. See attached Excel files.

       

      6. Unable to define an edge weld plot showing a graph of computed values.

       

      7. While splitting a face the computer crashed.

       

      8. When I created a shell using an on surface sketch and the surface extrusion feature it was not possible to create an edge weld. An error message occured that said - Invalid edge selection for weld. Select a different intersecting edge on Face Set1. The same message occurs regardless of the surfaces selected. Extruding a surface from a plane to the matching surface face enable the edge weld to be created.

       

      This was all discovered and encountered in the space of about an hour.

       

      Interested to hear other user experiences.

        • Re: Fun and games with edge welds
          Loic Ancian

          Can anyone from SW answer this?

           

          This is (again) a new feature that was only introduced for demonstrations, not use.

          • Re: Fun and games with edge welds
            Ian Hogg

            Hi Derek,

             

            From what I can tell, there is something in the 3-D edge curve that is not being handled/detected correctly by the edge weld feature. Can you please submit this via your reseller so it is investigated and addressed by the developers.

             

            I did not look into the automatic edge bonding issue, but it may relate to the same problem in detecting that the edge lies on the surface.

             

            One point to remember is that edge weld is designed for sizing the welds based on forces and moments acting on the joint (it is really a post processing calculation for a bonded connection). It is not going to give you accurate stress results on the elements in the region that reflect the true 3-D load path. To do that you can look at Vince Adams suggestions on the COSMOS Companion area of the customer portal (I haven't checked it for a while, but I believe it's still up there).

             

            Was this geometry representative of an actual weld you are interested in, or just a test model? The reason I ask is that I've not seen the same challenges when working with more planar geometry and using the edge welds. There is an accuracy limitation with respect to the intersecting angle  of the parts. In the instance of a t-join for example, it's assuming the faces are near perpendicular. I forget the angle range, but can dig it up if you're interested.

             

            Cheers,

             

            Ian

              • Re: Fun and games with edge welds
                Derek Bishop

                Thanks Ian.

                 

                Why am I not able to obtain weld stress plots? Does this work for other more conventional shapes? I don't believe it does. Why not? During Beta testing I was able to obtain weld stress plots ie graphs of stresses along the weld.

                 

                Was it intended that compatible meshing be provided for the intersection of shell surfaces with curvature meshing? Is it possible on more connventinal shapes? I don't believe it is. It was supposed to be possible between beams and surfaces and solids and solids. Why not shells?

                 

                Can I request that SolidWorks check these matters out and advise the intended capabilites of the software in this regard. Please also address the the current questions and those raised above. I did a fair bit of work during Beta testing around these issues. Since the original post I have done further testing on more conventional shapes.

                  • Re: Fun and games with edge welds
                    Ian Hogg

                    Hi Derek,

                     

                    I'm not quite sure what you mean about weld stress. The tool is using the AWS1.1 standard to verify weld size based on the forces acting on the joint. It will give you a weld and weld throat size, along with the force components. I don't believe we ever showed stress along the weld. Now theoretically you can plot the stress results along the element edges at the bonded joint, but the results are of no use since stress results are not going to be accurate close to the weld line.

                     

                    As far as automatic bonded contact. It will work when the edges of 2 surfaces touch, but it is not supported for edge to surface (ie as in your example without the split lines). The compatible mesh worked with the curvature based mesher for edge to edge contact. I took a look at this with your model and had no issue.

                     

                    Aside from the issue of the 3dsketch generated surface not being recognized for the edge weld (I used a bonded contact for that join in my test, I had no issues with plotting weld size, exporting results to csv or having compatible meshing between the surfaces.

                     

                    If you have a repeatable series of steps where the split line is crashing, please report the issue via your reseller.

                     

                    Am I missing answering any of your questions?

                     

                    Cheers,

                     

                    Ian