Structural Dynamics

Structural Dynamics

Why is damped frequency is lower than undamped frequency with viscous damping but larger with structural damping?

    • FAQFAQ
      Participant

      The 2 forms of damping are really different:
      Structural damping enables you to incorporate hysteretic behavior due to internal material friction by specifying a coefficient on the stiffness matrix. In this type of damping, the damping force is proportional to the displacement rather than the velocity as in the other damping options (alpha and beta included).
      Vicious damping in the air is much smaller than the damping due to internal material friction but historically only viscous damping was available and we used to put all damping into viscous damping.