General Mechanical

General Mechanical

Modeling plastic behavior of AL 2024-T3 in ANSYS?

    • Mubashir
      Subscriber

      I am modeling a behavior of a simple rectangular bar(250mm X 15mm X 2mm) of  AL2024 T3. I want to see it undergo non-linear loading in the plastic region and get stress vs strain graph but when I get results my elastic stress region goes beyond the tensile yield strength and then stress drop to the starting point of plastic stress(). I have attached the picture of the properties, analysis setting, generated graph and faulty data points.


       

    • SaiD
      Ansys Employee

      Hi,


      Due to company policies Ansys employees cannot download any attachments. Could you use the "Insert Image" option to post some inline images?


       


      Sai

    • Mubashir
      Subscriber

      DONE


       

    • SaiD
      Ansys Employee

      Hi,


      Could you share an image showing the mesh you have? It would be helpful if you could find the node where the maximum stress is occurring and show the mesh near that node.


      Stress and strain values are calculated at the integration points (inside elements) and extrapolated to the nodes (point visible on the mesh) if the quantities are linear (i.e. yielding has not occurred yet). So if the stress at an integration point is just below the yielding point, it may get extrapolated to the node and that extrapolated value may be higher that the yield stress. This should not cause such a high discrepancy in the stresses as you are seeing. But checking the mesh would be the first thing to do.


      Sai

    • peteroznewman
      Subscriber

      To add to what Sai mentions, you can insert a Command Object: ERESX,NO to copy the integration point stress values out to the nodes instead of extrapolating them. This should almost eliminate the step change drop in the curve you show above.


      Since there is no extrapolation, you need small enough elements so the integration point is close enough to the surface of the body where the maximum stress occurs.

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