摘要 |
The x- and y-direction vibration components of radial vibration of a rotational shaft 106 obtained by measurement from x and y directions are transformed into frequency sample values {XkYk, k=0, 1, . . . N-1} by discrete Fourier transform. RMS amplitude values {2<½|F>ki(2jpi/M)|, j=0, 1, . . . M/2-1} are calculated at azimuths {thetaj=2jpi/M, j=0, 1, . . . M/2-1} corresponding to 0 to pi on the basis of frequency sample values at frequency points {ki, i=1, . . . P} corresponding to specific frequencies {fi, i=1, . . . P} of NRRO vibration components selected from the x- and y-direction frequency sample values obtained by the discrete Fourier-transform. RMS evaluation values Aki are selected from these RMS amplitude values.
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