Determination of Stability Conditions for High-Speed Electric Trains With Carbody Tilting When Negotiating Curved Track Sections

Abstract

The development of cost-effective solutions for increasing train speeds on conventional railway lines makes the study of carbody tilting systems highly relevant. The aim of this work is to investigate the influence of geometric parameters of a carbody tilting mechanism on running safety indicators of high-speed electric trains. The research is based on simulation modeling using the Simscape package in MATLAB, combined with a fractional factorial experimental design and regression analysis. A simulation model of the carbody tilting mechanism was developed, enabling the calculation of the stability coefficient and the carbody rotation moment relative to the instantaneous center of rotation at a tilt angle of 8°, with variable coordinates of lever attachment points. A fractional factorial experiment based on a 5⁴⁻¹ design was carried out, followed by the construction of third-order regression models with 31 coefficients. The obtained regression models demonstrated high adequacy, with coefficients of determination equal to 0.905 for the stability coefficient and 0.987 for the rotation moment. It was established that both parameters exhibit a strongly nonlinear dependence on the coordinates of the lever attachment points. A geometric interpretation of the operability region of the tilting mechanism was obtained, showing that initial lever angles below 52° ensure a significantly wider operability zone, while larger angles lead to its reduction. It was also found that the rotation moment generally increases monotonically with increasing coordinates of the upper attachment points. The results of this study can be used by researchers and designers in the development and optimization of carbody tilting systems for high-speed rolling stock operating on conventional railway lines.