According to whether the purpose of isolator is to isolate the response or the source, the methods of isolation can be divided into passive isolation
and active isolation
(1) passive vibration isolation. The purpose of reducing the vibration caused by the foundation motion is to isolate the response. If the isolator is designed according to the isolation requirements of the isolator, instead of analyzing the excitation signal of the vibration source to reduce the intensity of the vibration source, this isolation method is called passive isolation. For example, the vibration isolator used under the precise instrument on the ship is designed according to the vibration isolation requirements of the instrument. This kind of vibration isolation method is passive vibration isolation by weakening the influence of vibration source on vibration isolation object.
(2) Active vibration isolation. The purpose of reducing the vibration caused by the disturbance of a vibrating object is to isolate the source of vibration. On the contrary, if the isolator is actually based on the analysis of the excitation signal of the source to reduce the intensity of the source, rather than on the isolation requirements of the isolator, it is called active isolation. For example, vibration isolators are installed on the engine base to offset the impact of engine vibration on the base. This kind of vibration isolation method is active vibration isolation by restraining the influence of vibration source on vibration isolation object.
The classification of vibration reduction methods is based on the different mechanical properties of the interaction force between the damper and the damper. There are mainly the following types:
(1) Damping. The single damping force is used to dissipate the energy of the vibration system and the damping force is used to eliminate the vibration. Common damper isolators are mainly high damper materials, which have been widely used in engineering.
(2) Vibration attenuation by dynamic tuning. By using the inertia force and restoring force of the mass of the damper, the method of vibration elimination is called dynamic tuning vibration elimination. It is mainly used for vibration reduction of simple harmonic vibration system with constant frequency.
(3) Damping dynamic vibration attenuation. Damping dynamic vibration reduction is achieved by inertia force and motion damping force of the active mass of the damper.
(4) Shock attenuation. Using the moving mass of the damper and the incomplete elastic collision between the dampers to exchange momentum and dissipated kinetic energy, the vibration can be eliminated.
(5) Gyro vibration attenuation. The gyroscope vibration is eliminated by the gyroscope force generated by the high-speed rotating gyroscope rotor.
(6) Active vibration control. Active control is similar to active vibration isolation, which requires external equipment to provide energy.