5 Replies Latest reply on Aug 7, 2013 7:20 PM by Jared Conway

    Looking for some tips

    Ray Cardenas

      I have a concept here showing an Optical Window Assy and would like to get some tips/advise on how to best set this up to run this type of analysis. Basically, as I show in the Power Point File- it will have a thermal load of 75 deg C with a 1,000 psi pressure normal to the window as shown. The bondline between the Metal and the Glass is where I am having the most difficulty. It's such a thin bondline (approx .007 inches thick). One big question I have is can I model this separately as a Shell Mesh and then place it into my assy somehow? Also since this is almost symetrical would a 2D simplification be the way to go? What technique would give me the most accuracy? Run time could also be an issue, but I have not done this enough to know which procedure is the most efficient/accurate. I have so many other questions but felt it's best to seek the help of the pro's to see what reponse I get back, and go from there.

       

      Thanks in advance,

      Ray

        • Re: Looking for some tips
          Jared Conway

          "The bondline between the Metal and the Glass is where I am having the most difficulty. It's such a thin bondline (approx .007 inches thick)."

           

          where is this in the model? i don't see any overlaps or components that are disproportionalely larger or smaller than others

           

          "One big question I have is can I model this separately as a Shell Mesh and then place it into my assy somehow?"

           

          can you setup a shell in the part and then move it to others with the shell definition? only if it is sheetmetal. then the software will build the shells automatically. otherwise not currently possible.

           

          "Also since this is almost symetrical would a 2D simplification be the way to go?"

           

          2d symmetry nope. half symmetry yes. not sure where you're seeing 2d symmetry.

           

          "What technique would give me the most accuracy?"

           

          the software is accurate to your setup. as you add simplifications and setup your model, write down the assumptions and you'll be able to answer this question. within the software, just make sure to do some mesh checking and some variance studies on how BCs change the results and you'll know that if the trends go in the direction and in the magnitudes you expect, you'll have good accuracy.

            • Re: Looking for some tips
              Ray Cardenas

              I did not model the bondline.The adhesive is typically injected through small port holes, like the one I show in the top view and then it fills the void between the outer surface of the window to the inside surface of the cell housing.

               

              I thought I saw some mixed meshing videos, showing sheetmetal and solids all getting connected to shells.

               

              This assy is "almost symetrical" is what I had said, which is why I brought up 2D simplification.

               

              What are BC's?

                • Re: Looking for some tips
                  Jared Conway

                  BCs are boundary conditions

                   

                  i don't think 2d simplification is a fit. it isn't axisymmetric and isn't plane strain or plane stress. but i think you could get away with half symmetry. because of the angle you can't go with a slice or quarter.

                   

                  regarding mixed meshing, that is not a problem. you just can't build it in one place and leverage it in another which i thought is what you were asking about. i don't know if mixed meshing is a fit here either, most of the parts are the same size mostly. but you could go that way. it would bring the mesh count down a bit for some up front work on your part.

                   

                  regarding the bondline. what about a spring? you could bond them, but then it would be stiff. a spring would have some give and then you wouldn't have to mesh it.

                    • Re: Looking for some tips
                      Ray Cardenas

                      Thanks Jared - I know I can always count on your input. In this particular application I cannot use springs. I think just for grins I'll try a 2D Simplicfication. I know this isn't axisymmetric but besides getting some practice after making it symmetric, I may get some usefull results. What do you think? I'll have to find that video I saw that had some O-rings in there as well.