Dynamic Analysis of the Train-bridge Interaction: an Accurate and Efficient Numerical Method

The dynamic behavior of railway bridges carrying high-speed trains can be analyzed with or without the consideration of the vehicle's own structure. However, due to the amount of kinetic energy carried at high speeds, the train may interact significantly with the bridge, especially when resonance occurs. Equally important is the riding comfort and the stability of the track and train cars, which are usually the most critical limit states in the design of this type of structures. With the aim of studying this problem a computer code was developed, being the interaction between the bridge and the train implemented by means of contact conditions between each train wheel (nodal point) and the structure (point inside a finite element). The treatment of the interaction between a train wheel and a point on the surface of a finite element is directly and efficiently implemented by means of an extended stiffness matrix, which includes stiffness, flexibility and additional terms that stem from the compatibility equations between the displacements of the vehicle and the bridge. This methodology was applied to the study of the dynamic behavior of a bowstring arch bridge and proved to be very accurate and efficient.