Critical Damping 2
Critical Damping 2 :
Critical damping exists if the damping coefficient of the special damping device of an harmonic oscillator (nicknamed "dashpot"; See Fig. 5.5 in Chapter 5) is h = 1. This value marks the transition of free vibration of the oscillator from the under- damped case of exponentially decaying harmonic motion to a periodic motion that decays without changing algebraic sign. Widely used classical seismometers had damping values ranging from about 0.5 (WWSSN short-period and the Russian Kirnos seismographs SKM-III and SKD), 0.7 (modern electrodynamic seismometers such as GS13, CMG-3T or STS-2 and the re-calibrated Wood-Anderson standard response according to Uhrhammer and Colins, 1990), up to near critical 0.98 (WWSSN long-period). Systems with very low attenuation may experience damage when excited to resonance
