Stability and ride comfort are fundamental features of high-speed rail vehicles. The first must be assured to guarantee a safe ride, the second is important to offer a comfortable experience to the passengers. Yaw dampers proved to significantly influence both the vehicle stability and the ride comfort. Nevertheless, it is not trivial to optimize the damper layout to face different wheel/rail and operating conditions. In this context, this paper presents a numerical methodology to assess the influence of different yaw damper layouts on the vehicle stability, with a special focus on both carbody and bogie hunting motions. Different combinations of yaw damper layout, equivalent conicity, vehicle speed, primary longitudinal stiffness and environmental conditions will be tested. The effect of the yaw damper on the arising of different kind of unstable motions will be assessed, and the main unstable phenomena will be presented by comparing their damped frequency and mode shapes. Finally, a stable region describing the layout of yaw dampers able to guarantee stable running conditions will be defined, highlighting the limits of standard passive solutions.
Effect of yaw damper on different hunting motions of high-speed trains under various vehicle configurations
Gioele Isacchi;Francesco Ripamonti;
2024-01-01
Abstract
Stability and ride comfort are fundamental features of high-speed rail vehicles. The first must be assured to guarantee a safe ride, the second is important to offer a comfortable experience to the passengers. Yaw dampers proved to significantly influence both the vehicle stability and the ride comfort. Nevertheless, it is not trivial to optimize the damper layout to face different wheel/rail and operating conditions. In this context, this paper presents a numerical methodology to assess the influence of different yaw damper layouts on the vehicle stability, with a special focus on both carbody and bogie hunting motions. Different combinations of yaw damper layout, equivalent conicity, vehicle speed, primary longitudinal stiffness and environmental conditions will be tested. The effect of the yaw damper on the arising of different kind of unstable motions will be assessed, and the main unstable phenomena will be presented by comparing their damped frequency and mode shapes. Finally, a stable region describing the layout of yaw dampers able to guarantee stable running conditions will be defined, highlighting the limits of standard passive solutions.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
