Vibration Analysis of High-Pressure Pneumatic Compressor
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Fig. 10 Acceleration and FFT using two-stage compression at 40 bar
where
• ASD H is the highest value on the ASD (frequency) chart for each frequency
segment
• m is the slope
m =
10 log
ASD H
ASD L
log
F H
F L
log(2)
(2)
• ASD L is the lowest value on the ASD(frequency) chart for each frequency segment
• F H highest frequency for each considered segment
• F L lowest frequency for each considered segment
Having a random vibrations the ASD calculus was done numerically in GNU
Octave computing environment. Previously gathered data (Fig. 11) was dumped into
a custom parser to calculate the acceleration spectral density and evaluate the a rms
accelerations, taking into account the obtained pressure and number of compression
stages used.
Measurements performed with accelerometer Acc1 (Fig. 1) were reading values
on an axis perpendicular to the actuators shaft being parallel with the compressor
cylinder. Measurements made with accelerometer Acc2 were reading values on an
axis parallel with the actuators shaft being perpendicular to the compressor cylinder
(Table 1).