Also found in: Dictionary, Thesaurus, Medical, Legal, Idioms, Wikipedia.


A term broadly used to denote either the dissipation of energy in, and the consequent decay of, oscillations of all types or the extent of the dissipation and decay. The energy losses arise from frictional (or analogous) forces which are unavoidable in any system or from the radiation of energy to space or to other systems. For sufficiently small oscillations, the analogous forces are proportional to the velocity of the vibrating member and oppositely directed thereto; the ratio of force to velocity is -R, the mechanical resistance. For the role of damping in the case of forced oscillations, where it is decisive for the frequency response, See Forced oscillation, Resonance (acoustics and mechanics), Harmonic motion, Oscillation, Vibration

An undamped system of mass m and stiffness s oscillates at an angular frequency &ogr;0 = (s/m)1/2. The effect of a mechanical resistance R is twofold: It produces a change in the frequency of oscillation, and it causes the oscillations to decay with time. If u is one of the oscillating quantities (displacement, velocity, acceleration) of amplitude A, then Eq. (1) holds in the damped case, whereas in the undamped case Eq. (2)

holds. The reciprocal time 1/α in Eq. (1) may be called the damping constant.

The damped angular frequency ωd in Eq. (1) is always less than ω0. According to Eq. (1), the amplitude of the oscillation decays exponentially; the time required for the amplitude to decrease to the fraction 1/e of its initial value is equal to 1/α.

A common measure of the damping is the logarithmic decrement δ, defined as the natural logarithm of the ratio of two successive maxima of the decaying sinusoid. If T is the period of the oscillation, then Eq. (3) holds. Then 1/δ is the number

of cycles required for the amplitude to decrease by the factor 1/e in the same way that 1/α is the time required.

The Q of a system is a measure of damping usually defined from energy considerations. The Q is π times the ratio of peak energy stored to energy dissipated per cycle and is equal to π/δ.

If α in Eq. (1) exceeds ω0, then the system is not oscillatory and is said to be overdamped. If the mass is displaced, it returns to its equilibrium position without overshoot, and the return is slower as the ratio α/ω0 increases. If α = ω0 (that is, Q = 1/2), the oscillator is critically damped. In this case, the motion is again nonoscillatory, but the return to equilibrium is faster than for any overdamped case.


Reducing or eliminating reverberation in a room by placing sound-absorbing materials on the walls and ceiling. Also known as soundproofing.
The dissipation of energy in motion of any type, especially oscillatory motion and the consequent reduction or decay of the motion.
The extent of such dissipation and decay.


The dissipation of energy with time, e.g., the dissipation of energy in a mechanical system whose free oscillations decrease with time, resulting in a decrease in its amplitude of vibration.


A technique for stabilizing an electronic or mechanical device by eliminating unwanted or excessive oscillations.
References in periodicals archive ?
Thus, the higher the damping in a structure, the less noise will radiate from it when it is struck by an object.
where M is mass matrix, C is viscous damping matrix for damping coefficient [kappa] = 1, and [D.
This production-proven system provides fast, smooth, continuously variable damping in a cost effective and reliable package that helps reduce body motion and increases tire contact with the road on all types of surfaces.
This on-off process can be controlled with great accuracy, allowing the creation of a near-infinite number of damping curves within the limits of the system.
SE dampers generate damping through relative linear motion between a specially designed plunger installed with interference fit into an elastomeric sleeve.
Up until now, there has not been a variable damping system that performs as quickly as MagneRide, or one that has enough authority and could be electronically linked to a vehicle's stability control system," said Dr.
Searching for a more robust damping grease, Nye engineers discovered that when the same high molecular weight base oils used in the NyoGel 774 series were mixed with PTFE, the new grease retained its damping characteristics after 153 hours of continuous high shear, which lead to the introduction of the Fluorocarbon Gel 868 series.
Since the theoretical resonance frequency is approximately 3 kHz (shear clamps) and the damping frequency is around 60 kHz, the system is ideal at frequencies up to 300 Hz.
Rare earths have long been known to increase magnetic damping in ferrite materials used in microwave devices.
Lodengraf(TM) damping offers the potential for a significant impact on noise and vibration in our ships, without requiring an expensive overhaul of our fleet," said Kurt Yankaskas, Deputy Director of Safety & Survivability, Office of the Assistant Secretary of the Navy, Installations & Environment.
Grafted near-gelation polymers having high damping properties
ACX) announces the introduction of a revolutionary electronic, microprocessor-controlled compression damping shock for mountain bikes.