Analysis of the impact on pedestrian emergency evacuation under ship motion conditions considering dynamic forces and gait adjustments

The dynamic motion environment of a ship subjects pedestrians to more complex forces, and the unstable ship environment presents obstacles to the evacuation process. To quantify the dynamic impact of ship motion on pedestrian evacuation, this study first conducted evacuation experiments under motion conditions using a six-degree-of-freedom ship motion simulator, analyzing the impact of ship motion on pedestrian movement characteristics. Subsequently, an improved social force model, suitable for evacuation analysis under ship motion conditions, was proposed. This improved model adds dynamic tilt force and inertia force to the original social force model. Based on experimental data, a functional relationship between gait parameters and ship motion parameters was established. A gait model was proposed to describe the influence of gait adjustments on the evacuation process, and a self-propulsion correction factor function was introduced to describe the pedestrian's dynamic speed adjustment strategy. Through model validation and simulation analysis, the reliability of the proposed model was verified. Typical phenomena, such as the arching of exits and the fast-slow physical phenomenon, were successfully reproduced, and the impact of ship motion angle and period on evacuation time was quantified. This study provides important theoretical and data support for optimizing evacuation strategies in ship motion environments.