Modeling and Evaluation of the Critical Speed of Tank Cars in Operational Environments: The Simultaneous Effect of Track Geometry and Tank Filling

Authors

School of Railway Engineering, Iran University of Science and Technology, Tehran, Iran

10.22044/jsfm.2026.16858.4013

Abstract

The railway transportation of hazardous materials is a significant safety concern due to the high risk of accidents. This study presents a comprehensive modeling and evaluation of the critical speed of railway tank cars by considering the interaction between two key parameters: track geometry (a range of curve radii from 250 meters upwards) and the liquid filling percentage of the tank (at three distinct levels). The system was simulated using the multi-body dynamic method in the UM software, and the dynamic behavior of the liquid inside the tank was modeled using the equivalent pendulum model. The results of the parametric analysis indicate that the critical speed of the railcar demonstrates a linear increasing trend with an increase in the curve radius, while it shows an inverse and non-linear relationship with the liquid filling percentage. Further analysis suggests that the combined effect of these two factors on railcar stability is considerable. In low-radius curves, the increased fluid mass leads to a significant decrease in critical speed. This phenomenon persists in large-radius curves as well, even with higher allowable speeds, making precise management essential. The findings of this research emphasize the necessity of revising safety standards and designing control protocols based on real-time track conditions and tank filling levels. The results indicate that the critical speed in a 250-meter curve with 95% filling is 30 m/s, while increasing the radius to 1000 meters and reducing filling to 20% raises it to 62 m/s

Keywords

Main Subjects

Journal of Solid and Fluid Mechanics
Volume 16, Issue 2
July and August 2026
Pages 91-99

Files

Share

How to cite

Statistics