Research on the comfort degradation mechanism of high-speed railway passengers: a field study using dynamic interface pressure

Discomfort caused by long-term sitting decreases the passenger experience and may lead to musculoskeletal diseases, and this has become one of the main problems for passengers of high-speed railways. However, the comfort degradation mechanism during long-term sitting in high-speed railways is still unknown. This study aimed to reveal passengers' sitting comfort degradation mechanism in high-speed railways. By carrying out long-term sitting tests on high-speed trains running on the Shanghai-Kunming line, the dynamic interface pressure and subjective comfort including overall and regional comfort of seven participants were obtained. Machine learning models and statistical analysis methods were combined for data analysis to reveal the effect of regional comfort and the contribution of sitting duration during the process of sitting comfort degradation. The results show that overall comfort is most significantly influenced by the comfort of the shoulders, waist and buttocks. The seats play different roles before and after 20 minutes during long-term sitting and there is a lag between the fatigue occurring and being offset. Therefore, the structure of seats affects overall comfort by affecting important regional comfort, and a long-term sitting test is necessary for accurate seat assessment. The comfort degradation mechanism can be used to define standards for long-term sitting comfort or provide guidance for seat evaluation, and the design and evaluation plan mentioned in this article for second-class seats can be applied to other cases with limited accommodating space.