Seating Dynamics

TITLE ABSTRACT
Evaluation of Mathematical Models for the Apparent Mass of the Seated Human Body Exposed to Vertical Vibration
The Authors propose the discussion of nonlinearity of the human body’s dynamic response. The variables that affect nonlinearity of the human body’s dynamic response in the experimental measurements can be distinguished in two categories: intrinsic variables, relating to the individual subjects; and extrinsic variables, relating to the experimental conditions. International Standard 5982 : 2002 gives idealized values for the apparent mass and the seat–to–head transmissibility of seated people exposed to vertical vibration. The values are intended for the development of mechanical models to represent the body. Many mathematical models of the vertical apparent mass of the seated human body are developed. Single and two–degree–of–freedom models obtain a good agreement with experimental seat transmissibility by nonlinear least squares method and Trust–Region algorithm. The comparison between single and two–degree–of–freedom models by goodness-of-fit statistics suggests that two–degree–of–freedom model is recommended for best results. [DOI:10.12866/J.PIVAA.2013.12.002]
The effects of outliers on relative difference thresholds for automobile seat vibration with tarmac and pavé conditions In this research, we examine the methodologies proposed to analyze the data set in the presence of outliers. We review methods of determining outliers. We propose general principles for how to proceed. Most observations seem to follow a pattern or seem to satisfy a model. The outliers remain outside the pattern. Thus experimental data requires further investigation. [DOI:10.12866/J.PIVAA.2015.12.01]
Evaluating normality of procedure up–down trasformed response by Kolmogorov–Smirnov test applied to difference thresholds for seat vibration Drivers and passengers appreciate the vibration of vehicles. Their subjective rating of discomfort may affect their opinion of the vehicle. This study investigated the difference threshold required for a change in vehicle ride to be perceived. We propose the Kolmogorov–Smirnov test to decide if the sample comes from a population with a specific distribution and to evaluate the variability of the data. [DOI:10.12866/J.PIVAA.2015.09.01]