AnsweredAssumed Answered

Discrepancy between deflection driven method and applied force method.

Question asked by Mike Armstrong on Aug 4, 2014
Latest reply on Aug 6, 2014 by Mike Armstrong

I am trying to calculate the force required to deflect a S-shaped spoolpiece a distance of 50mm. I have tried the following two methods but the results do not tie-in.

 

  1. Enforced deflection – I applied a fixture to the end of the spoolpiece to be deflected and selected the displacement to be 50mm normal to the wall of the pipe. I then measure the resulting force in the x-direction to obtain the force required for the deflection. Results - Max Von Mises Stress 42.3MPa / Resultant Force 57.9kN.
  2. Force driven method – The same analysis except that I applied a force to the end of the spoolpiece to be deflected. The force applied is that obtained from the enforced deflection analysis (57.9kN). However, I do not get the same stress distribution or deflection.

 

I have added a virtual wall at each quadrant of the pipe, at the deflected end, to ensure the defection is in the x-axis only.

 

I will upload the force driven model and .CWR file in a following post.

Outcomes