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Damping Parameter Converter

Convert between loss factor η, damping ratio ζ, quality factor Q, logarithmic decrement δ, and half-power bandwidth.

Mechanical damping is expressed in five equivalent but dimensionally distinct forms across different engineering disciplines and measurement standards: loss factor η (structural damping coefficient, common in vibration isolation and material datasheets), damping ratio ζ (fraction of critical damping, used in control systems and modal analysis), quality factor Q (resonance sharpness, used in mechanical and electrical resonators), logarithmic decrement δ (decay ratio per cycle, measured from free-ring-down experiments), and half-power bandwidth Δf (Hz, measured from a frequency-response function). All five are related by η ≈ 2ζ ≈ 1/Q ≈ δ/π ≈ Δf/f_n for light damping. This converter accepts any one parameter and returns all five, including both the small-angle approximation and exact form for η and δ. The tool also reports the number of cycles required to decay to 10% amplitude.

Input Parameter
All Damping Parameters
Loss factor η (approx)
0.0300
Loss factor η (exact)
0.0300
Damping ratio ζ
0.0150
Quality factor Q
33.333
Log decrement δ (approx)
0.0942
Log decrement δ (exact)
0.0943
Half-power bandwidth Δf
5.700Hz
Derived Quantities
Cycles to 10% amplitude
24.431
Abridged Optics — Damping Parameter Converter v1.0Approximate: η = 2ζ = 1/Q = δ/π = Δf/fₙ. Valid for light damping (ζ < 0.1).

All information, equations, and calculations have been compiled and verified to the best of our ability. For mission-critical applications, we recommend independent verification of all values. If you find an error, please let us know.