DLoG DLoG X 10, Руководство пользователя

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Appendix C: Mechanical dynamic loading
138 Manual DLoG X Series
21.4.2. Approximate solution for determining insulating effects
A transmission function can be used to reach an exact calculation. However, we will not
detail this function here. The following equation is based on this transmission function
(damping factors of approx. 0.05 for natural rubber) and is good for making estimates.
Isolation degree Reaction acceleration / Suggestion acceleration
Whereby
λ
Excitation frequency / natural frequency
for
λ
unequal 1
Excitation frequency Natural frequency
λ
Degree of insulation
10 Hz 20 Hz 0.5 - 33 % Warning! Amplification!
20 Hz 20 Hz 1 Warning! Resonance, approx.
-500 % and greater!
High amplification!
ca. 28 Hz 20 Hz
√
2 0, no insulation
40 Hz 20 Hz 2 66 %
60 Hz 20 Hz 3 88 %
80 Hz 20 Hz 4 93 %
Based on this table, we can clearly expect very good insulation for excitation frequencies
that are twice as high as the system’s natural frequency
Consequently, the amplitude of the reaction accelerations of the DLoG X 10 / X 12 still
only reaches 67% of the amplitude of the excitation accelerations, which actually have an
effect twice that of the natural frequency.
The table also demonstrates the costs of achieving this, namely that all excitation
frequencies below the natural frequency are amplified – to a maximum when resonance
occurs.