Regular ArticleWheel-rail Noise Generation, Part I: Introduction And Interaction Model
Abstract
In this, the first of a series of papers on wheel-rail noise generation, a survey of relevant literature is first presented. The cause of wheel-rail noise is generally thought to be wheel and rail structural vibrations excited by a combination of the wheel and rail surface roughnesses. A detailed model of the noise generation process is then developed, which is based on the excitation by the roughness, which forms a relative displacement input at the wheel-rail interface. While not new in concept, this model is presented in a much more general form than previously, readily allowing alternative excitation mechanisms to be considered alongside the conventional mechanism. The model requires representations of the wheel and rail frequency response functions (receptances), as well as those of the contact zone between them. These are presented in later papers in this series.
References (0)
Cited by (182)
A model of a rotating railway wheel for the prediction of sound radiation
2023, Journal of Sound and VibrationThe axial symmetry of a railway wheel is taken into account to expand its vibrational response around the circumferential direction using Fourier series. This allows the vibroacoustic problem of the wheel to be formulated in a two-dimensional frame, solving for the dynamic and acoustic variables analytically in the circumferential direction. By adopting an Eulerian approach, the inertial effects associated with the rotation of the wheelset are included in the model, assuming a constant angular speed of rotation. To represent a railway wheelset, the wheel is constrained at the inner edge of the hub and the contribution of the rigid body motion of the wheelset is superimposed on its response. The latter is evaluated analytically under the assumption of small rigid body displacements. The computational efficiency of the proposed methodology is found to be three orders of magnitude greater than a full three-dimensional methodology, without compromising the accuracy. The results are compared in terms of acoustic radiation with the commercial package Ansys, showing similar sound power levels in almost all the frequency range apart from some differences at low frequencies due to the use of an acoustic model based on radiation ratios.
Influence study of rail geometry and track properties on railway rolling noise
2022, Journal of Sound and VibrationWheel/rail interaction generates an excitation due to the roughness present on the surface of both components that produces vibration and consequently rolling noise. In this work, the railway track properties that most influence rolling noise are identified and this influence is analysed to reduce noise emission. The acoustic calculation methodology consists of characterizing the wheel using finite element techniques and the track using periodic structure theory. The influence of the track properties on the sound radiation is analysed by means of statistical techniques applied to the acoustic power results of different track configurations. To achieve this, the rail cross-section geometry is parameterized and numerous simulations are carried out by modifying these geometric parameters and the viscoelastic properties of the track components. Considering the contribution of the wheel, rail and sleeper, the results obtained indicate that the total radiation can be reduced by up to 7.4 dB(A) through an optimal combination of the track design parameters, compared to the worst combination found. In particular, the rail pad stiffness is shown to be the most influential parameter in the sound radiation.
Beams on elastic foundations – A review of railway applications and solutions
2022, Transportation GeotechnicsBeam on elastic foundation theory is widely employed when studying railway track behaviour, for applications such as track dynamics, and noise and vibration. At a basic level, the use of a single continuous beam resting on a springs-in-series support is straightforward to implement and computationally efficient. However, it can also be extended to simulate the multi-layered and periodic nature of railway tracks, which typically comprise a variety of components. Further, these track models can also be coupled with both vehicle and subgrade models. Therefore, this paper presents a state-of-the-art technical review of beam on elastic foundation theory, including the exploration of recent advancements in the field. Firstly, a variety of modelling strategies and solution methods employed for the computation of track behaviour are reviewed. These include periodic and semi-periodic modelling approaches. Considerations for extending beam on elastic foundation approaches to include train-track interaction and track-ground interaction are then provided. Finally, using the aforementioned theory, benchmark solutions for three common problem types are given: railway noise, railway track dynamics and railway ground-borne vibration.
Development of multi-band tuned rail damper for rail vibration control
2021, Applied AcousticsThe intense interaction force between the wheel-rail causes the vibration of wheel and rail, and generates rolling noise. Increasing the rail damper is an effective way to suppress rail vibration. In this paper, a shear-type multi-band tuned rail damper (MTRD) consist of internal mass bars and external resilient layer to reduce rail vibration is proposed. Mass bars are wrapped inside resilient layer and placed along the length of rail. Resilient layer between two adjacent mass bars can enforce them perform shearing motion corresponding to the layer along the main vibration direction of rail. Different oscillation frequencies corresponding to different mass bars can be tuned by adjusting the structure of MTRD. It achieves an increase in the operating frequency band and a widening of the operating frequency range of MTRD. The influence of parameters of MTRD on its performance is investigated by the finite element method (FEM). One of three designed MTRD models is selected for prototype production after comparative analysis. Laboratory measurements are conducted on a rail specimen and 12 m track platform. Results show the main operating frequency band of designed MTRD is in the range of 200 Hz–800 Hz, achieves the goal of the desired frequency band. Frequency response function tests of rail on 12 m platform show the MTRD could suppress rail vibration in the range of 100–2000 Hz. To estimate the practical reduction effects of MTRD on vibration, a small radius curve of metro line is selected for field measurements. The measured track decay rate (DR) shows MTRD could increase DR at frequencies above 80 Hz with a max increment of 5 dB/m and 9.3 dB/m in vertical and lateral direction respectively. Reduction of rail vibration and rolling noise when trains pass is also measured. The overall vibration level of rail achieves a max reduction of 10.9 dB and 6.3 dB in vertical and lateral directions respectively. The overall sound pressure level is reduced by 5.9 dB(A) at the speed of 60 km/h.
Identification of vertical wheel-rail contact force based on an analytical model and measurement and its application in predicting ground-borne vibration
2021, Measurement: Journal of the International Measurement ConfederationCitation Excerpt :As an essential link, fruitful research focusing on wheel-rail interaction have been reported in the past decades. To characterize the noise generation process, Thompson [7] established a linear wheel-rail interaction model. In this model, the roughness is chosen as the excitation and forms the relative displacement at the wheel-rail interface.
Wheel-rail interaction plays an important role in the study of railway engineering. The wheel-rail contact forces (WCFs) are the key factors in the models addressing wheel-rail interaction. However, it is sometimes difficult to be measured, so an indirect identification methodology is proposed in this paper. Based on an analytical model and measurement, the vertical WCF can be determined. Using measured rail accelerations as input data, a calculation program is developed. The vertical WCF and the excitation forces transmitted from the vehicle-rail system to the roadbed can be obtained. The latter forces are used to predict the train-induced ground-borne vibrations. A case study of predicting ground-borne vibration in Beijing Metro is presented to verify the effectiveness of this method. The results show that the vertical WCF can be obtained efficiently and accurately, and the predicted ground-borne vibrations have good agreement with the measured ones.
Simulation and experimental study on vibration and acoustic characteristics of a continuous supported embedded track
2021, Applied AcousticsWith urban rail transit developing fast, there is an increasing demand for riding comfort and reduction of vibration and noise. Metro being the main public transportation facility of urban rail transit in China, faces more severe challenges. Metro tracks use a range of different vibration isolating ballasted track structures. Environmental vibration along metro lines is controlled by using so-called vibration isolating track structures. In doing so, many problems arise in the train-track system of metro lines, such as strong vibration and excessive wear of wheel/rail systems, causing vibration fatigue and noise. Embedded track is used as an option to reduce vibration and noise, usually applied for tramways. When applied to metro lines, embedded track faces challenge due to high speed, large axle load and more complex line conditions. When applied to metro lines, the acoustic characteristics of embedded track need to be re-evaluated. These characteristics were investigated through a combined method of simulation and experiment. In this study, the wheel and track acoustic radiation of the embedded track designed for metro is predicted firstly. Then the tests of vibration and acoustic of the embedded track are carried out to verify the accuracy of the model on the one hand, and compare with the common fastener track to obtain more aspects of vibration and noise on the other hand. This study can provide a basis for the application of embedded track in metro systems.