ANCF Analysis of Multibody Pantograph/ Catenary Systems

The high speed trains today most commonly use pantograph-catenary systems for power delivery. The dynamics of the pantograph-catenary system plays a crucial role in the current collection quality and, therefore, thorough computational modeling is required to correctly predict the dynamical behavior of this complex system. In this investigation, a multibody pantograph model is used along with the absolute nodal coordinate formulation (ANCF) based catenary model to simulate the pantograph-catenary system in the multibody dynamics environment. To this end, the ANCF cable elements are used to model the contact wire and the messenger wire. Furthermore, a new contact formulation based on the penalty force approach is presented to study the interaction between the pan-head and the contact wire. This new formulation is derived from the sliding joint model proposed in the literature. The contact model developed in this work can be employed with the fully parameterized as well as the gradient deficient ANCF based finite elements. The loss of contact between the pan-head and the overhead contact line can be modeled with this new contact formulation. On the other hand, the pantograph model is mounted on a detailed rail- vehicle model allowing to evaluate more realistic situations. The contact between the rail vehicle wheels and the track is modeled using the elastic contact approach. One of the other major factors affecting the contact force is the external aerodynamic forces acting on the pantograph components and the catenary system as well. Two scenarios are considered where crosswind loading is applied on just the pantograph components, and aerodynamic forces applied on the pantograph and also the flexible catenary. In this study, the time varying nonlinear aerodynamic forces are modeled, thereby capturing the influence of the aerodynamic forces on the dynamical behavior of the pantograph-catenary system. For the configuration considered in this work, the effect of the crosswind is that it assists the uplift force exerted on the pantograph mechanism increasing the mean contact force value. Numerical results are compared for the cases for with and without the wind forces.