Suppression of carbody hunting for a locomotive caused by low wheel–rail contact conicity by optimising yaw damper location

Abstract

This study addresses the issue of carbody hunting in an electric locomotive induced by low wheel-rail contact conicity. The main objective is to mitigate this unstable motion by optimising the location of yaw dampers while ensuring bogie stability under high conicity conditions. A field test was first conducted to observe the carbody hunting behaviour, and a detailed locomotive dynamics model was then developed and validated using experimental data. The impact of yaw damper locations on locomotive stability was investigated, taking into consideration different carbody modes. The findings reveal the mechanism behind the deterioration of carbody stability due to the yaw damper installation angle and two installation layouts were proposed to enhance the carbody stability. Comparisons were then made with traditional solutions using both linear and nonlinear analysis, and experimental validation confirmed the effectiveness of the optimised yaw damper locations in improving carbody stability. This research highlights the importance of optimising the yaw damper's location to suppress carbody hunting, providing valuable insights for railway engineers and offering a promising solution for enhancing stability in high-speed train.