Research on Vehicle-Bridge Vertical Coupling Dynamics of Monorail based on Multiple Road Excitations

In order to study the vertical dynamic behavior of the monorail-bridge system, the vehicle-bridge coupling dynamic equation and train simulation model are established based on the principle of dynamics; the train simulation model is established based on the multi-body dynamics; the track model is established based on the finite element theory, and the compression deformation of PC beam and the effect of finger band on train are equivalent to load spectrum on train axle by means of dynamic equivalence principle, and finally, the train-track interaction model is established; the vertical vibration of the train before and after adding the influence of the compressive deformation of the track beam is simulated and calculated respectively, the results show that the influence of the compressive deformation of the track beam on the vertical vibration of the train is significant, and the simulation data under multiple road excitations are very close to the real value.

Modelling energy consumption in diesel multiple units

This study presents a train simulation tool for the evaluation of a train journey and its energy consumption. The simulation tool consists of a train motion model and an energy consumption model, specifically developed for a diesel multiple unit. The underlying equations are numerically solved following the finite difference method. The models’ performances are tested against a set of measured data including fuel consumption and speed profiles from real operation services. The results yield adjustment errors below 9% in all simulations, including simplified route profiles. The consideration of wind speed and direction further contributes to improve speed adjustment by 1.5% in those stretches where such variables are taken into account. Hence, the simulation tool can be used to predict the travel time and fuel consumption in any potential railway service even at an early stage design.

Method for validating the train motion equations used for passenger rail vehicle simulation

Train simulation software is conventionally validated by checking simulation results against equivalent data collected from real train runs. It is typically expected that these results will be within 5–10% accuracy of the recorded data. However, such a large margin could allow errors in the programming to be overlooked, resulting in an inaccurate model. This paper presents a method for error checking and validating the kinematics of train simulators based on comparison with calculated results, which are found by solving the fundamental equations governing train motion. A typical train run comprises of a combination of two or more of the four stages: accelerating, cruising, coasting and braking. Each stage is considered as a separate scenario for which the equations must be solved, in order to find the running time, distance travelled and energy consumption of the vehicle. This validation method is applied to two train movement simulators currently used for research. Certain specific scenarios for which analytical solutions are available are run in each simulator. The differences from the analytical solution in each test case are quantified, allowing the simulators to be compared to each other and the exact solution.