User manual

Appendix F: Mechanical Dynamic Loading
Determining Insulating Effects
8580/8590 Vehicle-Mount Computer User Manual F-7
F.7 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 (very
small damping factors of approx. 0.05) and is good for making estimates:
Based on this table, we can clearly expect very good isolation for excitation frequencies that
are twice as high as the system's natural frequency.
Consequently, the amplitude of the reaction accelerations of the 8580/8590 still only reaches
66% 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 frequen-
cies below the natural frequency are amplified - to a maximum when resonance occurs.
Excitation Fre-
quency
Natural Fre-
quency
Degree Of Isolation
10Hz 20Hz 0.5 -33% Warning! Amplification
20Hz 20Hz 1 Warning!Resonance, approx. – 500%
and greater! High amplification!
Approx. 28Hz
20Hz 2 0, no isolation
40Hz 20Hz 2 66%
60Hz 20Hz 3 88%
80Hz 20Hz 4 93%