Research on the effect of vertical installation angle and layout of anti-yaw damper on the dynamic performance of high-speed EMUs

With the increase in operating speed of high-speed electric multiple units (EMUs), the regulatory role of anti-yaw dampers in vehicle operational stability has become critical. This paper establishes a dynamic model of a high-speed EMUs to investigate the influence of installation angles and anti-yaw damper layouts on dynamic performance. A root locus analysis was conducted by linearizing the vehicle system and the wheel rail interaction to reveal the modal characteristics under different wheel rail matching conditions and rail deviations. The results show that increasing the installation angle can significantly reduce the critical speed. When the installation angle increases from 0° to 25°, the nonlinear critical speed under worn wheel rail contact conditions decreases with increasing angle, resulting in a 13.63% reduction. The inner high rail, combined with worn wheels with higher equivalent conicity, tends to induce secondary hunting instability. Reducing the installation angle enhances stability. The symmetrical layout with upward openings demonstrates superior performance under worn wheel rail conditions, with higher nonlinear critical speeds and improved ride indexes than other layouts. This paper provides theoretical guidance for optimizing anti-yaw damper installation angles and arrangement modes.