# Vibration engineeringterms

 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: Energy absorption: Stress analysis: Dynamic spring rate: Static damper compression: Natural frequency: Residual acceleration: Vibration displacement amplitude: Static damper compression at prescribed residual acceleration: 