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

Abstract

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.

Railways Passengers Comfort Evaluation through Motion Parameters: A Systematic Review

“…Results highlighted the hips as the most significant body part affecting whole-body discomfort, followed by the back, waist, and thighs (Figure 6a; [60]). A similar study by Peng et al [63] revealed the passengers' local and overall comfort degradation mechanisms on high-speed railways. Pressure map sensors measure the interface pressure between the user and the seat on a 2nd class Chinese high-speed rail seat (Figure 6b).…”

“…When a passenger sits down, more than 70% of their body weight is supported by the seat cushion, resulting in a significant concentration of pressure, particularly in the ischial tuberosity area, leading to pressure peaks. This interface pressure causes low oxygen content in cells, inducing fatigue, pain, and discomfort [10,60,62,63]. However, the literature has no consensus about the maximum pressure threshold.…”

“…In contrast, other authors state that a seat is considered comfortable if it presents a maximum of 43.50 mmHg pressure under the ischial tuberosities and 21.75 mmHg elsewhere. This highlights the fact that the mean pressure should never be above 37.75 mmHg; at this pressure, skin capillaries close [61,63]. Although no studies define the ideal body pressure distribution, there seems to be a consensus that a widely dispersed distribution without local concentration peaks represents the ideal foam [3,59,61,[63][64][65][66][67].…”

“…This highlights the fact that the mean pressure should never be above 37.75 mmHg; at this pressure, skin capillaries close [61,63]. Although no studies define the ideal body pressure distribution, there seems to be a consensus that a widely dispersed distribution without local concentration peaks represents the ideal foam [3,59,61,[63][64][65][66][67].…”

Comfort Assessment and Optimization Based on FE Simulation for High-Speed Train Seats: Comparison with Different Design Parameters

“…Interface pressure distribution, which can be read directly from the FE simulation results, seems to be the objective measure with the most obvious contribution to the subjective ratings [24,25]. In addition, it is highly correlated with the seat material and geometry and is suitable for optimal design [26]. However, evaluating comfort using objective methods is subject to uncertainty.…”