Influence of System Boundary Condition on the NVH Behaviour of Bogie Brake Simulation

As in many other industries, weight reduction also plays an important role in the product development of train manufacturers and suppliers. Due to the ongoing weight reduction of the bogie and the components, they are becoming increasingly sensitive to NVH phenomena. A particularly critical component here is the brake, as the non-linear friction contact between the brake pad and the disc makes it predestined for self-excited vibration phenomena and thus for NVH phenomena. In this paper, vibration phenomena known from field tests will be investigated with respect to their systemic influence. Three different models of bogie brakes are considered to perform a complex eigenvalue analysis (CEA), where the level of detail of the model and the boundary conditions are different. The first model is a very detailed model of the brake with highly simplified boundary conditions. The second model is an extension of the first model where an additional wheel axle has been added. By including the axle, the brake disc gets additional degrees of freedom, where additional vibrations can be considered. The third model includes an entire wheel set with brake units. This model has been simplified to investigate phenomenologically vibrations of the entire wheelset and to consider systemic influences. With these three models an evaluation of the influence of the boundary conditions on the NVH behaviour should be carried out. For all modal analyses, the real part of the eigenvalue is used as an essential evaluation criterion and is applied to evaluate the impact of the boundary conditions on the observed vibration phenomena or the stability of the eigenfrequencies. Thereby a sensitivity analysis of the individual boundary conditions with respect to the eigenfrequencies is also a target