9 Replies Latest reply on Feb 6, 2014 12:30 AM by Jared Conway

    Meshing issues

    David Dearing

      I'm desiging a wing for the back of a car.  I created a wing part, two strut parts, and a base part and put them together in an assembly.  It wouldn't mesh.  I tried everything I could with mesh settings, but nothing worked, so I decided to check each part individually.  I opened the wing part and it wouldn't mesh.  It said most of my extrusions were interfereing.  Well, yeah, I agree- for ease of modeling I just "merged" all the extrusions as I made them.  I would start on the same plane and just extrude through and existing part instead of setting an offest.

       

      So I take it I can't do that?  In other words, I made a mostly solid rib (it has holes in it) that is .1" thick.  I then opened a new sketch from the plane of the part I just extruded and drew the shape of the spar.  I then extruded the spar, which is also .1" thick, but 55 inches long- so .1" of the 55i inches is inside the rib.  I let the extrusion merge with the rib.  When I run Simulation mesh, it says my extrusion collide and stops.  So I have to make every extrusion so it doesn't go through an existing extrusion?  That seems tedius, especially on a complicated part.  My wing is made of composite material, so it will basically be one big piece of plastic once the glue dries, so I don't get why I can merge extrusions. 

       

      Can someone help me out here?  Thanks.  

        • Re: Meshing issues
          Robert D.

          If your able, attach assembly here. If not then a dummy model,assembly doing what your saying. After reading your question I would think you would have no issues if you merged your extrusions. Did you use extrude surface anywhere on the model?

          • Re: Meshing issues
            Jerry Steiger

            David,

             

            If it is an assembly with interfering parts, then you are screwed. If it really is going to end up as a single piece, then you are probably better off modeling it that way. You will need to end up with either a single body or a multi-body part where no bodies interfere or an assembly where no parts interfere. As you found later, you will also want to be sure that parts or bodies that are supposed to touch actually do touch. Simulation software (not just SolidWorks Simulation) is usually very fussy about such matters.

             

            Jerry S.

              • Re: Meshing issues
                David Dearing

                Yeah, that's what I figured.  I'm redoing everything, which is a serious pain.  I have overlapping parts because it is composite, and I have to model each overlap independently or it will "interfere". 

                 

                The reason I am doing it as an assembly is because the wing is adjustable, and I need to know the stresses on the assembly as I change the angle of attack on the wing. 

                 

                So my current line of thought is to make sure each indivicual part will mesh, and once they do, then make the assembly.  Is this a good strategy?  Thanks!

                  • Re: Meshing issues
                    Jerry Steiger

                    David,

                     

                    If the wing moves, but is a single composite part, then I would be inclined to build the wing as a single, possibly multi-body, part in the assembly with the other parts it mounts to. I say possibly multi-body because it might be easier to work out stresses if you keep at least some of the bodies separate. I'm not at all familar with analysis of composites, so someone else will have to help you with that.

                     

                    Actually, I am not at all familiar with SolidWorks Simulation, so you are best off to hope someone else answers.

                     

                    Jerry S.

                    • Re: Meshing issues
                      Jared Conway

                      If it is a composite in simulation you will want to use a shell element anyways, based on a surface. If you start with a solid, you will use the inside or outside face to define the shell. Regardless, model without interferences and it will help regardless of what idealization you use . If you aren't tuned into in context modeling, start with multibody.