Structural Dynamics

Structural Dynamics

Is the damping value specified by the DMPSTR command related to the value specified by the DMPRAT command in a full harmonic analysis?

    • FAQFAQ
      Participant

      Yes, the DMPSTR value is equivalent to 2 times the value specifed by DMPRAT in a full harmonic analysis. See the explanation from development about why we have switched to DMPSTR for Full Harmonic: Prior to the documentation of the DMPSTR command, we *interpreted* DMPRAT as structural damping in a FULL harmonic analysis and included a factor of 2:
      C=2*DMPRAT/omega*[K]
      DMPRAT was never a “damping ratio”. When we introduced DMPSTR, it was to clearly state that this was structural damping and to make it consistent with the rest of the engineering community removed the factor of 2:
      C=DMPSTR/omega*[K]