MICRO-VIBRATION TEST AND ANALYSIS FOR HIGH-TECH WORKSHOP

In this paper, micro-vibration tests at a display driver chips production workshop in Hefei were carried out lasting 24 hours. Vibration accelerations of each testing point on three directions were simultaneously recorded by a high-sensitivity type accelerometer. Internationally accepted one-third octave band analysis method was adopted to process the field test data. The variation of vibration over time was analyzed, and the attenuation characteristics of vibrations induced by traffic loads with distance were also studied by one-third octave band spectra. Results show that, vibration accelerations alter smoothly within 24 hours, and it should be noted that the peak acceleration in the daytime is slightly higher than that at night. Vibration amplitudes swing between 10-5 gal and 10-2 gal. In the low frequency ranges(2~8 Hz),the peak of vibration acceleration is 0.015gal. In the medium-high frequency ranges(8~250 Hz),the maximum value of vertical velocity reaches 0.5013ms-1,while the velocity touches higher to 0.6636ms-1 in horizontal direction. One-third octave band spectra of testing vibrations locate below the VC-B curve totally indicating that design requirements are satisfied. Besides, ground vibrations caused by traffic loads decay apparently with distance in the frequency from 15 to 60 Hz, which are regarded that ground layers play a role in the attenuation of vibration caused by traffic load.