Discomfort estimation for vertical whole-body vibration in the aircraft cabin considering the duration and static sitting comfort

This paper investigated the discomfort caused by vertical whole-body vibration (WBV) over 20 minutes using data recorded at the front, middle, and rear seats of the passenger cabin in civil aviation during a cruising flight. Twenty-four subjects experienced each stimulus at 0.5 ms^-2 r.m.s. and judged discomfort at various moments (i.e. 1/6, 5, 10, 15, and 20 min) using a category-ratio method. The difference in discomfort due to high-frequency vibration components vanished after 10 min. Based on Stevens' power law, a method is developed to estimate long-term vertical WBV discomfort by considering the static discomfort and an interaction coefficient between vibration and static discomfort as parameters. The proposed estimation method showed high accuracy with determination coefficients (R²) higher than 0.97 and good linearity with values of growth rates 0.95, 1, and 0.95 for the vertical WBV discomfort at the front, middle, and rear seat positions in the aircraft cabin.Practitioner summary: An estimation method for the discomfort caused by vertical WBV considering the duration and static sitting discomfort is developed. This method can provide accurate discomfort estimating for long-term vibration exposure, e.g. in civil aviation during a cruising flight, by introducing an 'interaction term' between static and dynamic discomfort.