General Mechanical

General Mechanical

USERMAT Variables not clear

    • janot.lubritz

      Hey Guys!

      I'm trying to modify a USERMAT and it's going pretty well but even though I checked all manuals and .pdf files I could find I can't get a clue about some of the variables. For instance I do not understand what "sigi" is and it's not described anywhere (I would think sigma at substep i but I'm not sure). Another one is "G" as well as "TWOG" and so on. I first thought that G is the shear modulus but thats "tsstiff". Furthermore "G" is an occupied variable that is never declared and does not get passed over. Where does it come from and what is it?


      Thank you so much in advance!

    • David Weed
      Ansys Employee

      Hello, 'sigi' is the stress at the integration points (see the get_ElmData function usage at line 813). 'G' is the shear modulus (see line 1871) and 'TWOG' is twice the shear modulus (see line 734).

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