According to different conditions, various excitation offices can be used to make vibration sources, such as using eccentric wheel to rotate and drive the slider to generate reciprocating displacement excitation, using centrifugal force generated by unbalanced rotor to excite, using compressed air blower parts to excite, using loudspeaker to excite, using electromagnetic induction to excite, or using special oscillation table to excite, etc.
The parameters to be measured during the oscillation test include frequency, amplitude, velocity, acceleration, etc., and sometimes the stress or strain of some parts of the machine. Different industrial sectors and different machine products have different requirements for oscillation. Damping is one of the three fundamental elements of controlling oscillation.
However, its performance parameters are difficult to test and its damping effect is difficult to predict. Therefore, in general, the first way to stop the vibration control is to add mass, change stiffness, add vibration isolators or dynamic vibration absorbers, and in some special cases, the damping method is required.
For example, some thin plate structure shock absorbers, which make people feel helpless, can achieve satisfactory results by adopting damping methods. Damping shock absorbers have the following advantages: they can stop the oscillation peak at resonance frequency; Reducing the transmission of oscillation along the structure; Reduce structural noise. It is worth pointing out that damping is useful for suppressing oscillations in the resonant region, but not significant for non resonant regions. Damping tension spring vibration damping has two layers of advantages, such as the low frequency of the tension spring vibration damper and the large damping of the vibration damper, which separates the advantages of the two points, eliminates the scene of amplitude surge when the tension spring vibration damper resonates, and also deals with the natural frequency of the vibration damper. High challenges.