Transmissibility Calculator
Calculate vibration transmissibility, isolation percentage, and dB attenuation for single-degree-of-freedom isolation systems.
A vibration isolation system attenuates floor excitation only above √2 times its natural frequency f₀; below that crossover the payload motion is amplified, and at resonance the transmitted vibration peaks near Q = 1/(2ζ). Transmissibility for a single-degree-of-freedom viscous system is T = √[(1 + (2ζr)²) / ((1 − r²)² + (2ζr)²)], where r = f/f₀ is the frequency ratio. This calculator evaluates T at a single excitation frequency and reports isolation percentage and dB attenuation; displays the full log-log transmissibility curve across r = 0.1 to 20 with reference curves for common damping ratios; and solves the inverse problem of finding the required isolator natural frequency to achieve a specified isolation percentage at a given disturbance frequency. Inputs are natural frequency f₀, damping ratio ζ, and excitation frequency — covering pneumatic isolators (f₀ ≈ 1–2.5 Hz) through stiffer mechanical and elastomeric systems.