3 Replies Latest reply on Jun 8, 2011 1:12 PM by Fernando diaz

    FOPS ANALYSIS

    Fernando diaz

      Could you guide me how I can proceed in this case of analysis.

       

      A specimen of 230 kg weight is dropped freely from a height of 5.22 meters. and hits the roof (specifically at the centroid), I need to know the plastic deformation of the roof, any suggestions?

       

      I attached the files, I appreciate much your help.

        • Re: FOPS ANALYSIS
          Anthony Botting

          Hi Fernando: I believe  you should be able to do it with the "Drop Test" study in Simulation (Simulation Professional), if you can build a plastic deformation rule. There is a material model in Simulation (in the materials dialog) that has a drop-down under heading "Model Type" that is labeled "Plasticity -von Mises". The rule allows for input of a tangent modulus and hardening rule. This is a kind of bi-linear stress-strain curve that's meant for typical metals - I'm assuming you have a metal roof.  Hope that helps get started. Tony

          • Re: FOPS ANALYSIS
            Bill McEachern

            I have done these before. You need to do a NL static analysis. You apply a force at the impact location and then run the analysis untill the displacement times the force gives the same anergy as the impact (ie its potential - mass x drop hieght). You typically need a plasticity model.

            • Re: FOPS ANALYSIS
              Fernando diaz

              Thanks for the comments and suggestions.
              I'm doing an nonlinear dynamic analysis but the model fails to converge and takes a long time, I'm having trouble setting the appropriate time steps, I will continue doing tests and I will be reporting