4 Replies Latest reply on May 3, 2016 2:08 PM by Hao Tang

    Weird static simulation results

    Hao Tang
    Hao Tang Apr 16, 2016 7:11 PM

      Hi. I'm doing a static simulation of 200 Newtons on a beam secured by bolts. There are three ways the beam is secured: two bolts, one bolt on the side, or one bolt on the front. The results are weird.

      Capture.PNG

       

      Two questions: Why would having two bolts and one bolt on the side create so much displacement as opposed to the one bolt on the front? Also, in general, what does the static simulation mean? Does it mean I am instantaneously applying 200 N of force on the beam, say like dropping a 200 N brick onto it? Or?

       

      Any help is appreciated, thanks.

        • Re: Weird static simulation results
          James Riddell
          James Riddell Apr 18, 2016 3:23 PM (in response to Hao Tang)

          How did you model the bolt/screws?  SW bolt definition?  'Physical' model?  If so, did you use non-pen contact surfaces?  Did you apply a pre-load?  How did you model that force?

            • Re: Weird static simulation results
              Hao Tang
              Hao Tang Apr 19, 2016 12:22 AM (in response to James Riddell)

              The front faces are flat head screws and the side faces are pan head screws, both with a preload of 461 Newtons. I got the preload from the equation of permanent connection of .9*Ultimate Tensile Strength*Area, or something like that. The force is just a 200 Newton force on the beam. Not sure what you mean by "non-pen contact surfaces"

                • Re: Weird static simulation results
                  James Riddell
                  James Riddell Apr 19, 2016 6:15 AM (in response to Hao Tang)

                  non-pen ~ non-penetration contact sets. 

                  Mechanical parts that are discrete cannot "suck" up another part if the forces move them away from each other and they are not bonded/welded/glued, etc. to each other.

                  Again, how did you represent the bolts/screws?

                    • Re: Weird static simulation results
                      Hao Tang
                      Hao Tang May 3, 2016 2:08 PM (in response to James Riddell)

                      Hi James, sorry for the late reply, I just finished finals.

                       

                      I represented the screws using SolidWorks bolt definitions: just went to "Connections Advisor" --> "Bolt" --> "Standard Screw" (or "Countersink" for one side) --> Selected the surfaces.


                      I have the "Component Contact" as "Bonded", though now as I think about it I should probably set it as "No Penetration" right?

                       

                      I modeled the force, as you see it here, straight onto the board into the screen.