4 Replies Latest reply on Aug 4, 2014 11:50 PM by Jared Conway

    Load Test Frame Help

    Robert Smith

      Hi Guys,

       

      I'm trying to run an A-frame design load test frame for our container and reeler units that we make.

       

      The frame dimensions are based on the width and length of our containers and the height by our type 5 reeler so they are pretty fixed at what they are going to be. The max Proof load it will need tested to is 55,000KG'S hung from the center of the top beam.

       

      I seem to having some issues with the model running and was wondering if anyone could take a look at it.

       

      Any input would be much appreciated.

       

      thanks

        • Re: Load Test Frame Help
          Lee Brown

          Greetings!

           

          First, you have a metric boatload of redundant component contacts in your model.  Keep in mind that the global contact condition is bonded; you do not need to explicitly add any bonded joints, such as pieces that are welded together.

           

          Second, unless you really need to evaluate the stresses in each bolt all those bolted connections take a lot of processing time.  Remember, a well-designed bolted connection can often be treated as a bonded or a fully constrained condition.  For example, it is apparent by inspection that your foot pads aren't going anywhere; using a fixed constraint will give adequate results.  The only bolted connections that may be of concern are the ones attaching your gusset elements.  Run the model with the default contact conditions, examined the strains and deformation in the areas of contact, and then assess whether the bolts need to be considered in the analysis.  Using the above modifications to your model, I was able to get solutions in about ten seconds.

           

          Third, your model as originally given is not adequately constrained; that is why it keeps wanting to go into Large Displacement Mode and then ultimately failing to find a solution.  I did not bother to track down the cause.

           

          Best Regards,

          Lee E. Brown

           

          Senior Mechanical Engineer

          Electronics Development Corporation

          9055 Guilford Road Suite F

          Columbia, MD 21046

          • Re: Load Test Frame Help
            Nicholas Luyster

            Hi Robert,

             

            In addition to what Lee said, I would add that there are a lot of bodies in this simulation which are being treated as solids.  I suggest simplifying the model in a few ways.

             

            First, it appears that the loads and the geometry are symmetric in two planes.  This means that you can cut the model so that 1/4th of the frame is being modeled.  You can then apply a symmetry fixture to the symmetrical faces.  This way, you can devote much more processing power to the section of frame modeled and reduce the simulation time. 

             

            The second thing that I would suggest is that you treat some of the members as beams after you run a preliminary simulation and figure out where you should concentrate your efforts. 

             

            It's always best to start off simple and then get more complex as you go.  So my final suggestion is that you start out with only a few parts modeled and then gradually add more parts into subsequent simulations.

             

            All the best,

             

            Nick

            SolidWorks Simulation Training

            • Re: Load Test Frame Help
              Jared Conway

              what's the goal of the analysis?