4 Replies Latest reply on Aug 23, 2011 10:52 AM by Anthony Botting

    Simulate a shaker test (Resonance)

    James Pare

      I am trying to figure out the best way to simulate a physical shaker test that we perform on our tooling

      basically a 5-200 hz frequency is swept across the tool at an ampltude of 1G, any resonance of the tool above 2G is considerd a resonant point, I thought I was doing this correctly but I have a case where my results are not being duplictaed by the physical results

      Anyone with any experience with this or ideas please advise

        • Re: Simulate a shaker test (Resonance)
          Michael Feeney

          I've run a physical shaker test on a model truss structure and simulated it in SW. My results were nearly identical, so it is possible in some cases. I used beam elements in my model and performed a simple natural frequency analysis (requesting the first 5 modes). As you have posted your question currently, I don't think there is nearly enough information to help you. What does your model look like? What type of elements? Are you running a noise signal or a frequency analsysis?

          • Re: Simulate a shaker test (Resonance)
            Kirby Meyer

            Hello

             

            We've been able to analyze and measure a calibration beam that was put on our shaker bench for sine sweep and random vibration.    This way, you can pre-determine the damping ratioes you would need for the dynamic analyses.

             

            Some helpful tips:

             

                If evaulating amplitudes, as it appears you are doing,  this would be a linear "harmonic analysis" not a frequency response analysis.  In this regard, assume the damping ratios are initially .05 (5%) for all modes.   The shaker bench may amplify effects at lower frequencies than at higher frequencies, so don't be surprised if the amplitudes vary if you have not pre-calibrated the bench with a test piece!

             

            One major observation:   We've found that fully bonding torqued bolts and other fasteners seem to provide closer values to the resonant modes.   I.e. bond the bottom head of the bolts to their contact surfaces.    In the real world, one would need to make sure the torque values don't cause the surface to move around under normal operation under a hand analysis, etc.

             

            Values above 1000 Hz can get real murky comparing to the shaker bench, and analysis results may not be great.

             

            Kirby

            • Re: Simulate a shaker test (Resonance)
              Kevin De Smet

              http://www.solidworks.com/sww/proceedings/proceedings-presentations.htm?proceedingsyear=2009&cat=&video=video_only

               

              Search on that page for the video Dynamic Analysis for Vibration Testing in SolidWorks Simulation Premium. It may be helpful for you.

              • Re: Simulate a shaker test (Resonance)
                Anthony Botting

                Hi James: We recently developed a video tutorial and put on our YouTube Channel (GoEngineer). It covers set up and walk-through. Title is:

                SolidWorks Simulation- Sine Sweep Dynamics Tutorial

                 

                http://youtu.be/WaVDiWYi3Tw

                 

                There are also some other videos on Harmonic Advanced settings and how they work on GoEngineer's YouTube Channel. I hope it can help, if even a little.

                -Tony