General Mechanical

General Mechanical

Fracture in model

    • mekafime
      Subscriber

      Hello,


      I have this curve which I get as a result of analyzing in Ansys, my question is, until when should I stop analyzing, I am increasing the strength and the curve continues to grow, but how do I define the fracture, under what criteria to stop increasing the force acting on the model ?.


       


      Thanks


       


    • peteroznewman
      Subscriber

      This is the force-displacement curve which says nothing about fracture.


      I assume you have defined a material using plasticity.


      The material has a property called elongation.


      Fracture occurs when the Total Equivalent Strain > Elongation.


      Plot Total Equivalent Strain vs Displacement.


      Increase the force until the Total Equivalent Strain > Elongation then you will have reached fracture.

    • mekafime
      Subscriber

      Hi Peter,


      the curve : Eq Total Strain - Total deformation


    • mekafime
      Subscriber

      Hi Peter


      The next curve : Equivalent Stress -  Equivalent Total Strain


    • peteroznewman
      Subscriber

      What is the Elongation material property for your material?


      I wonder if the top graph has mislabeled axes?  Isn't the vertical axis showing deformation in mm and the horizontal axis showing equiv. total strain?

    • mekafime
      Subscriber

      Hi Peter,


      A500 Gr.B 


      YS: 315 MPa


      US: 400 MPa


      23% Elongation


       


      The graph was update.

    • peteroznewman
      Subscriber

      Since Elongation is 0.23 and Total Strain > 0.23, that means the simulation has gone past the point where fracture would have occurred. 

    • mekafime
      Subscriber

      Hello Peter


      In my curve I still do not reach 0.23 I am at 0.0035, I increase the strength and I am very far. To obtain the curve I am taking an analysis point (node) from which I also take the deformation, is the approach correct or should I take the strain of the entire model?


       



       

    • peteroznewman
      Subscriber
      It's the maximum total strain in the model that is compared to elongation.
Viewing 8 reply threads
  • You must be logged in to reply to this topic.