The main purpose of this paper is to present a comprehensive and systematically organized overview of the current state of vibration monitoring and measurement techniques used in railway stock. It aims to raise awareness of significant technological developments in recent years and their practical applications. The scope of the analysis is strongly informed by established European norms, fundamental research efforts across the continent, and the practical needs of the railway sector. Last but not least, we hope this paper serves as a valuable reference point for engineers, researchers, and decision-makers working within the complex context of railway system design, maintenance, and evolving regulations. For effective monitoring of railway vehicle vibrations, a combination of specialized measurement methods and system architectures is recommended. These approaches are carefully developed to capture the dynamic responses of critical components of the railway vehicle, thereby providing invaluable data. This information is essential for thorough condition monitoring, improved ride comfort, and a deeper structural understanding of vehicle quality throughout its lifecycle.

In this paper, the vertical vibration behaviour of an experimental scale demonstrator of a railway vehicle carbody fitted with an anti-bending bar system of innovative design is studied to highlight its ability to raise the bending natural frequency of the railway vehicle carbody and to reduce the intensity of the vibration. The anti-bending bar system has been previously proposed by the second author as a new passive method to improve comfort in passenger coaches with long carbodies that have a natural bending frequency located in the range of maximum sensitivity of human beings to vertical vibration. The experimental scale demonstrator consists of an aluminium plate supported on four rubber supports. The aluminium beam reproduces to a scale of 1:10 the length of a passenger coach carbody, and its thickness is set so that the first bending frequency of the plate is close to the usual value of real carbodies. The anti-bending bar system consists of two steel bars arranged longitudinally in the middle of the aluminium plate, near its side edges. Each anti-bending bar is fixed at the ends to the aluminium plate by joints consisting of a clamping arm welded to a fixing flange. The two anti-bending bars oppose the bending movement of the aluminium plate, thus increasing its bending stiffness. This results in increasing the bending natural frequency of the aluminium plate and reduction its vibration. Testing the effectiveness of the anti-bending bar system consists of experimentally determining the frequency response of the aluminium plate acceleration without/with the anti-bending bar system by the impact hammer method. The experimental results show the first bending natural frequency increases from 9.01 Hz to 13.4 Hz and the acceleration amplitude decreases by more than 50% when the anti-bending bar system is used. To confirm these results, a theoretical model of the experimental scale demonstrator based on the finite element method was developed. The results obtained with this model are in line with those obtained experimentally.

Rail transport comfort is ensured by predictive maintenance and continuous supervision of rail quality. Besides the specialized equipment, the authors are proposing a simple system that can be implemented on operational wagons while in service, aiming to detect irregularities in the rail and report them using the train’s online communication lines. The sensor itself is an acceleration sensor connected to an electronic microcontroller able to filter the inrush acceleration and send it to the diagnosis system of the wagon. This paper presents a study of real data recorded of the transversal and vertical vibrations of a standard tank wagon, measured on 2 axles and the car body, followed by the interpretation of the recorded data.

Track decay rate (TDR), meaning the rate of attenuation of bending waves through the rail, is the most important indicator of a track’s dynamic characteristic impacting the rail noise emission. TDR depends on various parameters related to the construction of the track, and it can be increased using rail dampers. These are mechanical devices working on the principle of dynamic absorbers and are attached to the rail. This paper addresses the track with light rails needing improvements to reduce the rail noise emission using a particular rail damper with a mixed damping system (rubber–oil). The bending waves that propagate through the rail, the frequency response function of the rail, and TDR are investigated considering different scenarios regarding the parameters of the track: soft/stiff rail pad, tampered/settled ballast, and sleeper bay. To this end, an analytic model of the track featuring rail dampers consisting of an infinite Timoshenko beam with discrete attached oscillators is used. Numerical results show the possibility to increase TDR of railway track with light rails for both soft/stiff rail pads from 4 to 500 Hz up to 1250–1600 Hz using rail dampers with a mixed damping system.

In this paper, the vibration of a wheel running on a light rail equipped with rail dampers that use a mixed damping system (rubber–oil) is investigated under the excitation of random roughness on the rolling surfaces, to demonstrate the influence of such rail dampers on the dynamic behaviour at the wheel–rail interface. For this purpose, a model is adopted in which a rigid wheel moves at constant speed over a rail modelled as an infinite Timoshenko beam, supported by elastic foundations with an internal degree of freedom that represents the behaviour of the rail pads, sleepers, and ballast. The rail dampers are represented as two-mass oscillators, while the internal friction in the elastic components of the wheel–rail system is modelled using hysteretic damping. To obtain the time series of the rail and wheel displacements, as well as the wheel–rail contact force, the convolution theorem is applied in a heuristic manner, making use of the relationship between Green’s functions in the time and frequency domains through direct and inverse Fourier transforms. The results show that (a) rail dampers primarily affect rail dynamics and the wheel–rail contact force over a relatively wide frequency range, while having little influence on wheel motion; (b) rail dampers are highly effective in reducing rail vibration and the wheel–rail contact force when the rail pads are stiff, but considerably less effective when soft rail pads are used; and (c) they may slightly amplify the contact force at the lower edge of their effective frequency range.