EFFECT OF PHASE BETWEEN THE TWO COMPONENTS ON DYNAMIC RESPONSE OF SEATED SUBJECTS EXPOSED TO DUAL-AXIS WHOLE-BODY VIBRATION

摘要

In exposure to whole-body vibration in real cases, vibration is multi-axial and the phase difference between arbitrary two components exists and is random. The effect of the phase difference between two vibration components on the dynamic responses of seated subjects was examined in this study. Subjects were exposed to dual-axis vibrations at six frequencies (1-20 Hz) with changed phase differences. The magnitude of vibration in each axis was 0.6m/s~2 r.m.s.. The motion of the subjects' body was measured at the seat pan and at the head. The effects of phase differences were observed to be fully nonlinear. Dynamic responses of seated subjects exposed to dual-axis whole-body vibration could not be obtained by superposition of dynamic responses of subjects exposed each single axis vibration.