Train kinematics for the design of railway vehicle components

The kinematic analysis of railway vehicles and trainsets allows for the evaluation of the relative motion between the train vehicles and to calculate relative angles and distances which are of fundamental interest in the design of train components. A general methodology based on Cartesian coordinates is proposed for the kinematic analysis of multibody systems being further used to develop the planar models of the trainsets and to perform their kinematic analysis. Besides the standard revolute and composite joints a trajectory following constraint is developed and implemented to guide the vehicle wheelsets on the railroad, which in turn is described by using cubic splines to interpolate a given set of keypoints. The methodology is implemented in a general purpose computer program and applied to the study of a complex trainset. Finally, the methodology and the models developed in this work are validated with respect to the classical procedures used in industry. The objectives of the application of the methodologies proposed are the evaluation of the relative orientation and positions between the carbodies and the appraisal of the feasibility of insertion of the trainset in the geometry of the railroad. Such results are used in the design of vehicle components such as couplers and gangways or railroad functional envelope studies.