Research on an Abdominal Oppression for Occupant at 4Hz Vertical Vibration

Abstract

This paper describes a possible cause of discomfort in the abdomen region of an occupant due to vibration at a frequency of 4 Hz. A human body FE model, THUMS Version 1, was used to explain the skeletal motion. The pelvis was rotated by a vertical load mostly acting to the ischium from the seat cushion. The abdomen part was compressed with the spine moved back and forth. When the vertical load to the ischium was decreased by changing the seat cushion property, the magnitude of pelvis rotation and the abdominal compression were reduced.