4 Replies Latest reply on Apr 30, 2014 7:58 AM by Roy Dean

    Fatigue Analysis - "you need one or more static, nonlinear, blah blah blah"

    Roy Dean

      So I'm trying to run a fatigue analysis on a pressure vessal.    I've got a nonlinear analysis  that is run over 7.5 seconds, and has a "base pressure" and a "peak pressure".  That non-lin analysis runs perfectly.... lets call it "Nonlinear 2".  It's an axi-symetric 2d simulation, fwiw.

       

      So I created a fatigue study, and I go to "loading", right click and select "Add event".

       

      A window pops up that says:

      "You need one or more static, nolinear [sic] or linear dynamic to perform Fatigue Analysis."

       

      So I've got my "Nonlinear 2" analysis that works perfectly, but for whatever reason Fatigue doesn't like it.   I'll try running non 2-d simplification, but in the meantime I'd still like to know for sure if that's the issue.

       

      Additionally, I'm finding it all but impossible to apply S-N curves to the materials....   I can create new materials with S-N curves, but my EPDM managed materials won't let me save the S-N curves to the material definitions.   Additionally, you don't seem to be able to edit the S-N data in the generic materials interface....seems like you can only do it by accessing the material THROUGH a valid fatigue study (which seems ridiculous).

       

      Am I missing something here?

       

      ---Roy

      (yet again frustrated)