Investigation into the Sitting Comfort of Railway Vehicle Seats by FEM Analysis

Abstract

To investigate sitting comfort is important to decrease fatigue due to long-term sitting on the railway seats. Measurement of deformation within the human body would provide valuable information because the sensory receptor detects internal deformation while sitting. Since it is difficult to measure the deformation within the human body, we utilized Finite Element Method (FEM) to estimate the deformation and stress distribution in the human body. We categorized three kinds of sitting posture, that is, Work posture, Read posture, and Rest posture, by sitting experiments. Based on these results, we developed three FEM models and performed sensory tests. By results of FEM analysis, maximum stress around intervertebral disks at the lumbar vertebrae was found for the Work posture, and minimum stress was observed for the Rest posture. By results of sensory test, increment of pain score at the waist region was the largest on the Work posture, and minimum score was found on the Rest posture. It is considered that increase of stress around the waist region leads to the low back pain while sitting.