8 Replies Latest reply on Apr 13, 2009 4:52 PM by 1-E9V5A2

    Chain

    Oscar Bowman
      How  do you mate the links in a chain for a static stressanalysis?
        • Chain
          Peter Gillespie
          It's going to depend on what your goal is. You can use a pin connector if you're not looking at the local stresses around the hole. If those stresses are of importance to you, use a Contact Constraint of no penetration for the pin-to-hole surfaces.

          This is just general info to get you going hopefully!

          Also, the way your model is setup in solidworks will be the basis for COSMOS. if you have a pin in your chain mated concentrically in Solidworks, when you go into COSMOS, they will be concentric, but the mate itself doesn't influence the analysis. That's where my previous comments come into play.
            • Chain
              Oscar Bowman
              I am not trying to analyze a roller chain but a straight link chainlike a logging chain.
              I am having trouble getting the two cylindrical surfaces at 90degrees to mate.

              TIA
                • Chain
                  Jamie Myrhum
                  I'm not to sure about your exact goal, but If you are trying to determine the stress in the chain from tensile loading, I think you might do better to calculate the maximum tensile load in the chain and apply that to only one link. This would really simplify the problem.

                  • Chain
                    Peter Gillespie
                    Not quite sure what you're going for. I suppose it would help if I knew what a logging chain looked like. Can you post a jpg of the area you're working on? I'm using 2004, so a part file wouldn't help me, but maybe someone else could look at the part file.
                      • Chain
                        Oscar Bowman
                        See attached .jpg picture of the chain.
                        I am trying to mate the links so they will carry a tension load.
                          • Chain
                            Peter Gillespie
                            Oh...just a chain! : ) Okay! If I were running the analysis, I would draw one loop and do a split line to create a face that is the most that would be contacted with another loop, and do that on both ends. You could put your loads and restraints on those two split line faces to get a general idea.
                            But for what you're asking, in Solidworks you're going to need to tangent mate for joining links. If it doesn't let you, you can probably put in a reference point and mate the two links. Then define contact between components as No penetration or surface to surface. Your restraints are going to be important here, as a chain probably doesn't naturally have full restraints, but in COSMOS it will need it.
                            Your mates shouldn't be the problem, but rather your contact constraints and restraints could be.

                            I would consider making a full loop and two half loops on either side. Fix the ends of the half loop, and apply the load on the other half loop, and restrain both half loops in the two other directions that the force is not applied. The stresses in the half loop may not be quite right, but in the full loop I think it should.

                            Let us know what else you come up against.
                    • Chain
                      What Vince said is important. your chain has 1/4 symmetry available, since it is periodic in the axial direction, and the left side is the same as the right, top is the same as the bottom. You can do an extruded cut in your assembly file that only leaves 1/4 of what Peter suggested, and apply symmetry to all the faces that were cut by the extruded cut feature. Then cut your Tensile force by 1/4 as well or you will over-stress your model. By cutting the volume in 1/4, you can cut your mesh size in half, and still run the analysis faster than it would have before!