The apparent mass of the human body exposed to non-orthogonal horizontal vibration

摘要: Abstract Apparent masses of 15 male and female subjects have been measured during exposure to various directions horizontal vibration. Twenty vibration conditions were used in the experiment. In each five (0, 22.5, 45, 67.5 90° mid-sagittal plane) exposed random frequency range 1.5–20 Hz at 0.25, 0.5 1.0 m s−2 r.m.s. The remaining selected give measurements whereby magnitude x-component was fixed y-component changed vice-versa. Two peaks observed apparent masses. first peak occurred about 3 Hz reduced with increases magnitude. also as direction from 0 90°. increased increased. second 5 Hz decreased both There no change direction, although angle plane Increasing whilst using a but did not or any characteristics peak. contrast, increasing frequencies magnitudes peaks. Predictions response 45° by applying principle superposition data showed that body linear. This implies mass non-orthogonal axes cannot be predicted orthogonal directions.