A high-speed railway noise full-band fine prediction method

Abstract

The present application relates to high-speed railway noise control technology field, especially to a kind of high-speed railway noise full-band fine prediction method, comprising the following steps: S1: first, establish car-track-bridge coupling vibration model, S2: using finite element engineering simulation software respectively establishes wheel, rail, bridge finite element three-dimensional model, S3: using statistical energy analysis to calculate the wheel-rail noise sound pressure level of each field point 200~5000Hz, obtains the noise distribution of wheel-rail noise;Then boundary element method is used to calculate bridge structure noise, obtains the distribution of 20~200Hz bridge structure noise;S4: comprehensive wheel-rail noise and bridge structure noise, obtain the full-band comprehensive noise of high-speed railway at any field point.The comprehensive noise prediction method of the present application is accurate and reliable, greatly improves the calculation efficiency, reduces the memory occupation, can effectively save the cost of calculation.

Description

Technical Field

[0001] This invention relates to the field of high-speed rail noise control technology, and particularly to a method for refined prediction of high-speed railway noise across the entire frequency band. Background Technology

[0002] As a vital pillar of the national economy, controlling railway noise is of great significance for providing passengers with a comfortable travel environment and reducing the impact of noise on the lives of residents along railway lines and the natural environment. Currently, research on railway noise control mainly faces the following challenges:

[0003] (1) In terms of the source research of railway noise, only single noise sources such as wheel-rail noise or bridge structure noise are generally considered, and there is a lack of comprehensive noise prediction methods for high-speed railways that take into account the coupling of multiple factors.

[0004] ② Regarding the prediction of wheel-rail noise, the TWINS model for predicting wheel-rail rolling noise only considers specific wheel and track conditions and does not take into account important factors affecting wheel-rail interaction, such as sprung mass, primary spring stiffness, and damping. Sprung mass, primary spring stiffness, and damping affect vehicle vibration and rail corrugation development, which in turn affect wheel-rail interaction and sound radiation.

[0005] ③ In the acoustic radiation prediction model of the track structure, the actual analysis using the Timoshenko beam 2.5D finite element model, a special case, cannot exceed 3000Hz in noise frequency range. To increase the frequency range, the rail must be described using 2.5D finite element analysis, which will inevitably greatly increase the computational cost.

[0006] The above issues require that railway noise prediction models address shortcomings in considering multi-factor coupling, comprehensive wheel and track conditions, increasing noise analysis frequency, and saving computational costs. Summary of the Invention

[0007] The purpose of this invention is to address the problems existing in the prior art by proposing a refined prediction method for high-speed railway noise across the entire frequency band.

[0008] The technical solution of this invention: A method for refined prediction of noise across the entire frequency band of high-speed railways, comprising the following steps:

[0009] S1: First, establish a vehicle-track-bridge coupled vibration model. In the model, consider the influence of changes in factors such as short-wave irregularity R, axle load G, vehicle speed V, and primary spring stiffness K on the wheel-rail interaction force F, which in turn affects railway noise. Based on the actual vehicle and track structure parameters, calculate the wheel-rail interaction force considering factors such as measured track irregularity or empirical values ​​of track irregularity, axle load, vehicle speed, and primary spring stiffness.

[0010] S2: Using finite element engineering simulation software, establish finite element 3D models of the wheel, rail, and bridge respectively. Under the excitation of wheel-rail interaction force, obtain the vibration response of the wheel, rail, and bridge. The time-domain vibration response of the wheel and rail is used to calculate the frequency domain mean square velocity of each node of the wheel and rail, and then the average mean square velocity of the corresponding element is obtained. The specific steps are as follows:

[0011] S2.1 Establish finite element three-dimensional models of wheels, rails, and bridges;

[0012] S2.2 Apply wheel-rail interaction force to the finite element three-dimensional model of wheel, rail and bridge to obtain its time-domain vibration response;

[0013] S2.3 The frequency domain mean square velocity of each node of the wheel and rail is obtained through FFT calculation, and then the average mean square velocity v of the corresponding element is obtained. i .

[0014] S3: Due to the high frequency of wheel-rail noise calculations, the hardware and time costs of using the boundary element method to calculate mid-to-high frequency noise are considerable, and its accuracy is not as high as that of the statistical energy analysis method. Therefore, the statistical energy analysis method has significant advantages in calculating mid-to-high frequency noise. The statistical energy analysis method is used to calculate the wheel-rail noise sound pressure level at various points in the 200–5000 Hz range, thus obtaining the noise distribution of wheel-rail noise. Meanwhile, since bridge structure noise is in the low-frequency range of 20–200 Hz, the boundary element method offers better accuracy and efficiency. Therefore, the bridge structure noise is calculated based on the boundary element method. The specific steps are as follows:

[0015] S3.1 uses the average mean square velocity v of the wheel and rail obtained in S2. i Calculate the sound power of the wheel and rail subsystem

[0016]

[0017] Among them, W i ρ is the acoustic power of the subsystem; ρ0 is the air density; c is the speed of sound in air; σ i and S i These are the radiation efficiency and surface area of ​​the wheel or rail, respectively. Then, the mean square sound pressure of subsystem i at a certain point can be expressed as:

[0018]

[0019] Where A is the area determined based on the distance from the field point to the center of the subsystem, then the total mean square sound pressure of the wheel-rail noise at a certain field point is:

[0020]

[0021] S3.2 Based on the indirect boundary element method, the velocity difference and sound pressure difference on both sides of the bridge structure boundary are determined. The Helmholtz integral equation is applied to both sides of the boundary surface to calculate the sound pressure p at any observation point. b .

[0022] S4: Combining wheel-rail noise and bridge structure noise, the comprehensive noise of high-speed railway across the entire frequency band at any field point is obtained:

[0023]

[0024] Where P0 is the reference sound pressure level for sound pressure level calculation, and SPL is the sound pressure level at any field point.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] (1) It takes into account both the coupling factors such as wheel-rail short-wave irregularity, vehicle speed, and axle load, as well as the important factors affecting wheel-rail action such as sprung mass, primary spring stiffness, and damping. It can further accurately analyze the impact of the above factors on the comprehensive noise of high-speed railways, and thus provide a reference for vibration reduction and noise reduction in rail transit.

[0027] (2) The boundary element method is used to calculate low-frequency bridge structural noise, and statistical energy analysis is used to calculate high-frequency wheel-rail noise. While ensuring the accuracy of the calculation, the noise analysis frequency is increased to 20-5000Hz, saving computational costs. The comprehensive noise prediction method of this invention greatly improves computational efficiency and saves computational costs. Attached Figure Description

[0028] Figure 1 A flowchart illustrating a refined prediction method for noise across the entire frequency band of high-speed railways;

[0029] Figure 2 A flowchart illustrating an example of a refined prediction method for full-frequency noise in high-speed railways;

[0030] Figure 3 This is a comparison chart of the predicted and measured noise levels.

[0031] Figure 4 Comparison chart of overall noise calculation efficiency. Detailed Implementation

[0032] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 and 2 As shown, a refined prediction method for high-speed railway noise across the entire frequency band includes the following steps:

[0034] S1: First, establish a vehicle-track-bridge coupled vibration model. In the model, consider the influence of changes in factors such as short-wave irregularity R, axle load G, vehicle speed V, and primary spring stiffness K on the wheel-rail interaction force F, which in turn affects railway noise. Based on the actual vehicle and track structure parameters, calculate the wheel-rail interaction force considering factors such as measured track irregularity or empirical values ​​of track irregularity, axle load, vehicle speed, and primary spring stiffness.

[0035] S2: Using finite element engineering simulation software, establish finite element 3D models of the wheel, rail, and bridge respectively. Under the excitation of wheel-rail interaction force, obtain the vibration response of the wheel, rail, and bridge. The time-domain vibration response of the wheel and rail is used to calculate the frequency domain mean square velocity of each node of the wheel and rail, and then the average mean square velocity of the corresponding element is obtained. The specific steps are as follows:

[0036] S2.1 Establish finite element three-dimensional models of wheels, rails, and bridges;

[0037] S2.2 Apply wheel-rail interaction force to the finite element three-dimensional model of wheel, rail and bridge to obtain its time-domain vibration response;

[0038] S2.3 The frequency domain mean square velocity of each node of the wheel and rail is obtained through FFT calculation, and then the average mean square velocity v of the corresponding element is obtained. i .

[0039] S3: Due to the high frequency of wheel-rail noise calculations, the hardware and time costs of using the boundary element method to calculate mid-to-high frequency noise are considerable, and its accuracy is not as high as that of the statistical energy analysis method. Therefore, the statistical energy analysis method has significant advantages in calculating mid-to-high frequency noise. The statistical energy analysis method is used to calculate the wheel-rail noise sound pressure level at various points in the 200–5000 Hz range, thus obtaining the noise distribution of wheel-rail noise. Meanwhile, since bridge structure noise is in the low-frequency range of 20–200 Hz, the boundary element method offers better accuracy and efficiency. Therefore, the bridge structure noise is calculated based on the boundary element method. The specific steps are as follows:

[0040] S3.1 uses the average mean square velocity v of the wheel and rail obtained in S2. i Calculate the sound power of the wheel and rail subsystem

[0041]

[0042] Among them, W i ρ is the acoustic power of the subsystem; ρ0 is the air density; c is the speed of sound in air; σ i and S i These are the radiation efficiency and surface area of ​​the wheel or rail, respectively. Then, the mean square sound pressure of subsystem i at a certain point can be expressed as:

[0043]

[0044] Where A is the area determined based on the distance from the field point to the center of the subsystem, then the total mean square sound pressure of the wheel-rail noise at a certain field point is:

[0045]

[0046] S3.2 Based on the indirect boundary element method, the velocity difference and sound pressure difference on both sides of the bridge structure boundary are determined. The Helmholtz integral equation is applied to both sides of the boundary surface to calculate the sound pressure p at any observation point. b .

[0047] S4: Combining wheel-rail noise and bridge structure noise, the comprehensive noise of high-speed railway across the entire frequency band at any field point is obtained:

[0048]

[0049] Where P0 is the reference sound pressure level for sound pressure level calculation, and SPL is the sound pressure level at any field point.

[0050] Figure 3 A comparison chart of the comprehensive noise prediction value and the measured value of the present invention is given, which shows that the prediction method of the present invention has accurate prediction accuracy. Figure 4 Comparative data on the comprehensive noise calculation efficiency are presented using a 35m simply supported box girder as an example. It can be seen that the comprehensive noise prediction method of the present invention greatly improves the calculation efficiency, reduces memory usage, and effectively saves calculation costs.

[0051] The above specific embodiments are merely several preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A refined prediction method for high-speed railway noise across the entire frequency band, characterized in that, Includes the following steps: S1: First, establish a vehicle-rail-bridge coupled vibration model. In the model, consider the influence of changes in short-wave irregularity R, axle load G, vehicle speed V, and primary spring stiffness K on the wheel-rail interaction force F, which in turn affects railway noise. Based on the actual vehicle and track structure parameters, calculate the wheel-rail interaction force considering measured track irregularity or empirical values ​​of track irregularity, axle load, vehicle speed, and primary spring stiffness. S2: Using finite element engineering simulation software, establish finite element three-dimensional models of wheels, rails, and bridges respectively. Under the excitation of wheel-rail interaction force, obtain the vibration response of wheels, rails, and bridges. The time-domain vibration response of wheels and rails is calculated by FFT to obtain the frequency domain mean square velocity of each node of wheels and rails, and then the average mean square velocity of the corresponding elements is obtained. S3: Statistical energy analysis was used to calculate the wheel-rail noise sound pressure level at each field point in the range of 200–5000 Hz, thus obtaining the noise distribution of wheel-rail noise; then the boundary element method was used to calculate the bridge structure noise, obtaining the bridge structure noise distribution in the range of 20–200 Hz. Step S3 specifically includes the following steps: S3.1 uses the average mean square velocity v of the wheel and rail obtained in S2. i Calculate the sound power of the wheel and rail subsystem: Among them, W i ρ is the acoustic power of the subsystem; ρ0 is the density of air; c is the speed of sound in air; σ i and S i Let be the radiation efficiency and surface area of ​​the wheel or rail, respectively; then the mean square sound pressure of subsystem i at a certain field point can be expressed as: Where A is the area determined based on the distance from the field point to the center of the subsystem, then the total mean square sound pressure of the wheel-rail noise at a certain field point is: S3.2 Based on the indirect boundary element method, the velocity difference and sound pressure difference on both sides of the bridge structure boundary are determined. The Helmholtz integral equation is applied to both sides of the boundary surface to calculate the sound pressure p at any observation point. b ; S4: Combining wheel-rail noise and bridge structure noise, the comprehensive noise of high-speed railway across the entire frequency band at any field point is obtained: Where P0 is the reference sound pressure level for sound pressure level calculation, and SPL is the sound pressure level at any field point.

2. The method for refined prediction of high-speed railway noise across the entire frequency band according to claim 1, characterized in that, Step S2 specifically includes the following steps: S2.1 Establish finite element three-dimensional models of wheels, rails, and bridges; S2.2 Apply wheel-rail interaction force to the finite element three-dimensional model of wheel, rail and bridge to obtain its time-domain vibration response; S2.3 The frequency domain mean square velocity of each node of the wheel and rail is obtained through FFT calculation, and then the average mean square velocity v of the corresponding element is obtained. i .

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