Find load at failure

- May 28, 2020 at 3:47 pm
  
  ashishchache
  Subscriber
  
  1) That hinge is made up of plastic and pin is of steel.
  
  2) I wanted to find out the load over which it will fail ( I do not have experimental data) so how can I find it out? , also how will have to verify results?
  
  3) I have fixed two holes of left side of hinge and wanted to apply a force on two holes of right side. I have used 2 revolute joint bet left side hinge & pin AND between pin and right side hinge. 3 frictional contact have also applied (coeffi. of friction=0.2) bet pin pin and both sides of hinge Will you give me some suggestion to find out the load at failure.
- June 3, 2020 at 2:38 pm
  
  Sai Deogekar
  Ansys Employee
  
  Hi,
  
  You mentioned that you don't have experimental data. At the very least, you will need the yield stress of the two materials that you are using. Then you can perform a number of analyses with different loads and if the peak stress in any case exceeds the yield stress of the material, then you can say that plasticity has set in for that load (which might lead to failure).
  
  Hope this helps,
  
  Sai
- June 4, 2020 at 3:58 pm
  
  ashishchache
  Subscriber
  
  Thank you for your response, I did as you mentioned, but whenever I refine the mesh by reducing size of elements, stress is increasing , so then how can I find it out load with respect to yield strength?
- June 5, 2020 at 8:05 pm
  
  Sai Deogekar
  Ansys Employee
  
  Hi,
  
  If the stress increases when you refine the mesh, it most likely means that the mesh is not fine enough. When the mesh is fine enough, refining the mesh should not increase the stress values much. (There might be a small change, but the change should be very small as compared to the magnitude of the stresses).
  
  I did not understand the last part of your question properly. Could you please rephrase it?
- June 5, 2020 at 9:35 pm
  
  ashishchache
  Subscriber
  
  Thank you again
  
  Last part is that I am comparing stress generated in model with yield stress of hinge leaf material.
  
  I have some more questions
  
  1) what is use of large deflection , what kind of changes it makes ? [When should I tern it on ? ]
  
  2) do I have to use joint between leafs of hinge and pin or not ? [Can we use both contact and joint at same place ]
  
  3) which kind of stepping is good to use in analysis ?
  
  4) does ansys automatically knows that our problem is nonlinear or do we have to turn something on ?