Vibration engineering
terms

 

Amplitute A [m] Distance moved by a point on a vibrating body measured from its equilibrium position. The total vibration is therefore twice the amplitude
Frequency f [Hz] Number of oscillations in a given unit of time. Defined in cycles per second or Hz
Vibration generator frequency f [Hz] Usually the same as the rotational speed of the machine
Natural frequency fo [Hz] Number of oscillations of a free-running system per unit of time
Mass m [kg] Mass of the vibrating system
Spring force F [N] The resilient force transferred by a spring to a machine or vice versa
Spring excursion * [m] The deflection of a spring from a neutral position
Spring rate k [N/m] The force required to compress a vibration damper by 1m, expressed in newtons
Tuning Z The ratio of vibration generator frequency f to natural frequency fo
Disturbance force Fs [N] The force transferred to the base in the case of a spring-mounted machine
Impelling force Fi [N] The total force transferred to the base in the case of a rigid-mounted machine
Amplification factor B The degree of efficiency accompanying the transfer of the vibration force, i.e. the ratio of disturbance force Fs to impelling force Fi.
Isolation rate I The degree of efficiency of vibration damping by means of isolation, (1-B) or, in case B, expressed as a percentage (100-B).
Damping coefficient C [Ns/m] The reference value for linear viscous damping
Critical damping coefficient Ckr [Ns/m] The reference value for linear viscous damping for a critical application. A system is critically damped if it returns to its original position after displacement without overshooting displacement without overshooting
Reduction R [db] Reduction of structure-borne sound in dB.

 

EQUATIONS TAKEN AS A BASIS FOR CALCUATIONS
Input data: Gravitational acceleration g= 9.81 m/s²
Mass m [kg]
Impulse time tst [s]
Or shock class
Kinetic energy of excitation: Kinetische Energie der Anregung:
Energy absorption: Energieaufnahme
Stress analysis: Festigkeitsnachweis
Dynamic spring rate: Dynamische Federrate:
Static damper compression: Statische Einfederung
Natural frequency: Eigenfrequenz:
Residual acceleration: Restbeschleunigung
Vibration displacement amplitude: Schwingwegamplitude
Static damper compression
at prescribed
residual acceleration:
Statische Einfederung bei vorgegebener Restbeschleunigung