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Structural Dynamics

Structural Dynamics

How can I get the modal contributions to my random vibration (PSD) one sigma values?

    • FAQFAQ
      Participant

      The square root of the variance can be used as a mode coefficient. The variance can be retrieved using the *GET,,mode,N,mcoef command. See the sample input below. For those commands to work in Mechanical, you need to save the modal results and MAPDL database file (set the “Keep Modal Results” to Yes under the Analysis Settings and set the “Save MAPDL db” to Yes).
      resume
      /post1
      *get,mcoef_3,mode,3,mcoef
      mcoef_3=sqrt(mcoef_3)
      /post1
      set,1,3,mcoef_3*3 ! contribution of mode 3 to 3 sigma results
      /show,png
      plns,s,eqv