2 Replies Latest reply on Jun 16, 2014 1:48 PM by Roy Dean

    Structural member simulation.. again!

    Jack Potter

      Hi again,

       

      I have analysed a vehicle crash structure by appling a weight of 15KG (converted to Newtons and divided by number of points the load is being picked up from.)

       

      And a force of nearly 6,000 N is applied as an impact force

       

      For stress values the max Im getting is 525,561,152 NM^2... Is this correct!?

       

      Thanks, Jack.

        • Re: Structural member simulation.. again!
          Jared Conway

          are the displacements reasonable?

          are you getting a large displacement warning when running the solution?

           

          i haven't downloaded your files but if you look at many of the discussions where the results are far too high, often soft springs or the large displacement error have cropped up and the solution needs to be looked at carefully before taking them for what is on the screen

           

          also there are locations of high stress like singularities, if you are just looking at the max plot, you might be gettting caught. look at the displacements, look at the forces being balanced. if those are true, then evaluate the stresses and where they are.

           

          only you can tell us if the stresses are true based on your experience and back of the envelope calcs  you're backing your FE up with

          • Re: Structural member simulation.. again!
            Roy Dean

            Impact is a tricky simulation, as there is a time based reaction that is difficult to simulate.

             

            Two questions:  Are you sure the 6000N load is correct?  Or is that load only present in the first milliseconds of impact (prior to major deflection/deformation)?

            Second question:  What are the loads acting on?   A load of 1N placed on a theoretical "point" would cause infinate stress....

             

            [edit] and now I realize that Jared already basically pointed out both points above.  duh.