Modelling and linear analysis of high-speed articulated trainsets

The success of high-speed rail systems in Europe and Japan has led to the consideration of deployment of such systems in the United States. Since operating conditions in the United States are different from those in Europe and Japan, questions arise as to the safety-related behaviour of such systems. To address questions of dynamic behaviour, linear simulation models have been developed to compute the lateral stability of articulated trainsets on tangent track. These models include the essential features of articulated trainsets such as shared trucks and suspension characteristics such as car-to-car connections and car-to-truck yaw dampers. Parameter studies have been conducted for a trainset consisting of ten vehicles and having a critical speed of approximately 310 km/h. The studies show that consist stability is sensitive to the yaw damping between the trucks and the carbody, the conicity of the wheel profile, and the primary suspension. Other parameters affect the stability but to a lesser degree. The modal behaviour of the consist suggests that instabilities can occur in the form of whole consist modes, in some cases a wave-like motion, especially at low conicities.