A simulation framework for theoretical analysis and virtual testing of longitudinal vibrations of trains

The vibrating among compartments in a train can cause safety relevant stresses in the mechanical couplers and thus negative effects on passengers' ride comfort. Detailed knowledge about the train dynamics is necessary for an eligible system design. In this paper, a multiple objective framework for simulating and analyzing longitudinal trainset kinetics is proposed. The framework uses an object-oriented modelling approach, featuring modular component models for e.g. the couplers, brakes, engines and the environmental resistance forces. A variable number of compartments can be adopted as well as flexible component composition and parameterization of the component models is possible. The framework will be validated by using characteristic operation scenarios in which the model parameters will be set to fit actual train behavior. The simulation results of the framework will be validated against experimental data and expertise. It will be proven that the simulated results meet the measured satisfyingly, regarding the occurring eigenfrequencies, amplitudes and damping characteristics. The vibrational behavior will be evaluated in terms of stress and displacement in the couplers as well as passenger comfort by analyzing the amplitudes and frequencies of the vibrations. The versatile applicability of the framework will be demonstrated by a successful reduction of vibrations through a modification of the excitation force behavior.