# Effect of the Anti-Yaw Damper on Carbody Vertical Vibration and Ride Comfort of Railway Vehicle
## 7 Conclusions  
The paper analyzes how the anti-yaw damper affects the vibration behaviour of the railway vehicle carbody and the ride comfort, based on the results derived from numerical simulations. The characteristics of the vertical vibration behaviour of the vehicle carbody are analyzed based on the results concerning the power spectral density of the vertical acceleration in three carbody reference points, located at the carbody centre and against the bogies. To evaluate the ride comfort at vertical vibrations, the ride comfort index is used, in the same carbody reference points.  
The effect of the anti-yaw damper upon the vertical vibration behaviour of the vehicle carbody is highlighted through the increase of the eigenfrequencies of the carbody vibration modes--bounce, pitch and bending.This increase comes from the anti-yaw damping and is more or less visible depending on the value of the anti-yaw damper stiffness. On the other hand, the anti-yaw damper has the effect of reducing the carbody vertical vibrations at the resonance frequencies of the three vibration modes. The decrease of the carbody vibrations is all the more efficient the higher the stiffness of the anti-yaw damper and the value of the anti-yaw damping minimize the power spectral density of the carbody acceleration. The mounting angle of the anti-yaw damper also affects the vertical vibrations behaviour of the carbody, highlighted through the amplification of the bending vibrations and the reduction of the bounce and pitch vibrations.  
The effect of the anti-yaw damper upon the ride comfort depends on the vehicle velocity, the damping and stiffness of the anti-yaw damper. The results concerning the ride comfort indices as a function of the damping and stiffness of the anti-yaw damper have shown that the ride comfort indices decrease in all the carbody reference points, except for narrow short velocity intervals, which means an  
Figure 15: Influence of the increase in the mounting angle of the anti-yaw damper upon the ride comfort index: (**a**) \(c\) = 1\(\cdot\)10\({}^{5}\) Ns/m; (**b**) \(c\) = 5\(\cdot\)10\({}^{5}\) Ns/m; (**c**) \(c\) = 1\(\cdot\)10\({}^{6}\) Ns/m.  
improvement in the ride comfort. The reduction in the ride comfort indices is more important for high values of the anti-yaw damper stiffness, as it can reach up to 35-40%, depending on velocity and the damping value.It was highlighted that is a value of the anti-yaw damping for which minimum values of the ride comfort are obtained, and that this value is correlated with the anti-yaw damper stiffness and the vehicle velocity.  
The analysis regarding the increase and the decrease in the ride comfort index due to the mounting angle of the anti-yaw damper is correlated with the anti-yaw damping and the vehicle velocity. The rise in the mounting angle leads to an improvement in the ride comfort on a high velocities range for low values of the anti-yaw damping, yet this improvement is moderate. High values of the anti-yaw damping trigger more visible improvement in the ride comfort on low velocities interval, whereas the ride comfort significantly deteriorates in the high velocities interval.  
Conceptual approach, M.D.; Methodology, M.D.; Software, M.D. and D.I.S.; Validation, M.D.; Formal analysis, M.D. and D.I.S.; Writing--original draft, M.D.; Writing--review and editing, D.I.S. All authors have read and agreed to the publishedversion of the manuscript.  
The authors declare no conflict of interest.