Distinguished from the physical phenomenon, the damping can be roughly dividedinto the following 6 categories:
(1) engineering material damping
Engineering materials of various kinds, although the micro mechanism of theenergy difference, the macro effects are basically the same, are to have a vibration damping system, because of the damping originated in the medium, it is known as the engineering material damping.
(2) of viscous liquid
In practical engineering, various structures are often in contact with the fluid, andmost of the fluid has a certain viscosity, when these structures relative to thesurrounding fluid motion, the latter for the resistance to motion, do negative work on the vibrating object, the loss of a portion of the mechanical energy, mechanical energy into heat energy.
(3) the structural damping and Coulomb damping
The two surfaces are pressed with the sliding trend, or relative sliding occurs, the two surface immediately produces a pair of opposite force, this is the dry friction,also called the Coulomb damping force.
(4) impact damping
Shock damping is another kind of structural energy dissipation method. The project can be obtained by setting the impact damper impact damping, such as sand, fine stone, lead pills or other metal block, so that the hard alloy and so on, which can be used as the impact block, in order to obtain the impact damping.
(5) the radiation damping
When the vibrating object driven around a continuum when motion, vibration part of the object motion energy in waves. The energy of the most do not return to thevibrating object, therefore, this part of the energy loss of the vibrating object, themacro performance is equivalent to the existence of damping force negative work,this is the radiation damping.
(6) the magnetoelectric effect of damping
Mechanical energy is changed into electric energy, produced by themagnetoelectric effect damping, damping structure of household meter is theessence of mechanical energy to electrical energy converter, magnetoelectric effect it produces can be called eddy current damping.
The brief principle of damping is, damping the attenuation along the vibrational energy transfer structure, can also reduce the vibration near the resonant frequency. Damping materials commonly used are those with a significant loss,friction material, such as asphalt, typical rubber and other polymeric materials.