General Mechanical

General Mechanical

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Unable to converge

    • Zohreh
      Subscriber

      Hello every body!
      I'm working on Box girder model. I wanna apply force until it will be broken. The box Girder has 2 arms. forces are applied on arms. But the solution can't converge. I checked everything like materials, mesh size , changed sub steps, load steps and NSF(Normal stiffness factor) and etc but they didn't work. how can i solve it? could you help me?

    • pgl
      Ansys Employee

      Sounds like a large deflection buckling simulation? If you are using Workbench then take a look at the product documentation Static Structural Analysis section starting on page 316. In that section review the following:



      • Establish Analysis Settings (page 318) - See the note about Large Deflection 


      Also see these important sections



      • Large Deflection (Page 843)

      • Nonlinear Controls (page 860)


      If you are old school and using ANSYS M-APDL then lookup the command NLGEOM,ON


      Here's some scholarly articles on box girder simulations using ANSYS found on the web: 


    • Zohreh
      Subscriber

      Hello Dear pgl!


      Thank you for helping. Yes, It's a large  deflection buckling simulation. I'm using workbench. I don't know where is product documentation. How can I find it?


      Thank u...

    • pgl
      Ansys Employee

      On Windows 10, go to your Windows/Start menu, select "All apps" then "ANSYS 18.0" scroll down the list of ANSYS applications and select  "ANSYS Help 18.0"

    • ding
      Subscriber

       You can also change the criteria of convergence. If your model is concrete, please try to select displacement criteria of convergence. You can achieve it by using "CNVTOL,u,1,0.001,2"

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