Broede P, Bruening T, Griefahn B
Institute for Occupational Physiology at the University of Dortmund, Germany.
Aviat Space Environ Med. 1998 Oct;69(10):986-91.
To evaluate the effects of whole body vibration on discomfort, the sensitivity to different frequencies as well as to different vibration axes must be regarded. This experimental study investigates the significance of lateral relative to vertical motions in the sensation of dual axis sinusoidal vibrations in sitting posture. The results are discussed in the context of the evaluation procedure proposed in the international standard ISO 2631 (13).
The experiments, in which 31 volunteers (16 female, 15 male, 19 51 yr) participated, used the method of adjustment. The subjects compared a single axis reference motion (aw = 1.25 ms(-2) rms) with a dual axis test motion of the same frequency. The magnitude of the test signal's component along the reference axis was kept constant at a fractional level of the reference magnitude (10, 25, 50, 75 or 90%). The component perpendicular to the reference axis was adjusted by the subjects until the test signal was rated as being equally strong as the reference. Both vertical and lateral reference motions were applied. The frequencies used were 1.6, 3.15, 6.3 and 12.5 Hz.
The shape of the resulting right-downwards bent equivalence curves was reasonably well fitted using the frequency weightings and evaluation procedure of ISO 2631. However, there were considerable quantitative discrepancies for frequencies above 1.6 Hz with an underestimation of the effects of lateral vibrations by a factor of 1.5-2. Therefore, it is concluded that lateral vibrations above 1.6 Hz need more weight in the evaluation of discomfort caused by multi-axis whole body vibrations.
为评估全身振动对不适感的影响，必须考虑对不同频率以及不同振动轴的敏感度。本实验研究探讨了坐姿下双轴正弦振动感觉中横向运动相对于垂直运动的重要性。在国际标准ISO 2631（13）提出的评估程序背景下对结果进行了讨论。
31名志愿者（16名女性，15名男性，年龄19 - 51岁）参与了实验，采用调整法。受试者将单轴参考运动（aw = 1.25 ms(-2) rms）与相同频率的双轴测试运动进行比较。测试信号沿参考轴的分量大小保持在参考大小的分数水平（10%、25%、50%、75%或90%）不变。受试者调整垂直于参考轴的分量，直到测试信号被评定为与参考信号强度相同。施加了垂直和横向参考运动。使用的频率为1.6、3.15、6.3和12.5 Hz。
使用ISO 2631的频率加权和评估程序，得到的右下弯曲等效曲线形状拟合得相当好。然而，对于频率高于1.6 Hz的情况存在相当大的定量差异，横向振动的影响被低估了1.5 - 2倍。因此，得出结论，在评估多轴全身振动引起的不适感时，频率高于1.6 Hz的横向振动需要给予更多权重。
