6 Replies Latest reply on Sep 30, 2013 2:40 PM by Jared Conway

    Impact Test Simulation

    Ray Cardenas

      Hello SolidWorkers,

      I have a question for someone out there that has experience in simulations for Impact Testing. I have an optics window 3 inches in dia x .75 inches thick in which I need to drop a 2 lb spherical mass onto. The drop height is appox 10.5 inches high. I already know I cannot simulate this using Drop Test, or at least I have not figured out a way to do this in the Drop Test module. This is part of a Standard for this type of equipment that it must pass. I have calculated the impact force, however I would like to validate this using a simulation if possible. Any help on this would be appreciated.

       

      Regards,

      Ray Cardenas

        • Re: Impact Test Simulation
          Jared Conway

          hi ray, if you want to test it the way you describe, you'll need sim prem for a nonlinear dynamic analysis.

           

          the other option is to go with a time history analysis in sim prem where you replace the ball with an impact force vs time curve.

           

          you could do this with a static analysis with some statically equivalent force but you'd have to be good with the assumption that the load is applied slowly. which for impact isn't really a good one.

           

          but before you go down this path, have you decided how you're going to evaluate stress/strain to determine failure for glass? i think that is the challenging part here. also, do you have different designs that you are considering and want to figure out which is best before testing or do you need absolute answers?

            • Re: Impact Test Simulation
              Ray Cardenas

              Hi Jared,

              Thanks for the response. I do have stress/strain info for the particular glass we will be using regarding failure. I also have been doing some static analysis on various design concepts as well. So I do have an idea of which ones are working better, however I need to be sure at this point of the design that the glass will meet Impact Requirements. Do you think using Motion Analysis would give results equal to Non-Linear Dynamic Analysis? Just curious.

               

              Regards,

              Ray

                • Re: Impact Test Simulation
                  Jared Conway

                  motion will tell you how the ball rolls after it hits the glass but the glass won't deform to tell you the stresses. also exporting the motion info to simulation for an impact probably also won't tell you much about what is happening. it defintely won't be as good as a nonlinear dynamic.

              • Re: Impact Test Simulation
                Bill McEachern

                Hi Ray,

                If you calculated the impact force then, I would suspect that it should be pretty easy to use sim to get what you want. Apply the load you calculated to the model of the glass and see if the strain energy (1/2 deflection at load x load) is equal to the impact energy. Then you would know how close your calc is. If that all works out then as long as your P1 stress is less than the tensile strength you should have some confidence it will pass the test I would think.