Subway vibration source intensity equivalent test method

Abstract

The invention discloses a subway vibration source strength equivalent test method, including: collecting target rail vertical vibration acceleration data, obtaining power spectrum density, total effective value and kurtosis through signal processing; determining target rail equivalent load spectrum; obtaining laboratory rail test signal and vibration source strength measurement point test signal, obtaining laboratory rail vibration data and vibration source strength measurement point vibration data according to total effective value and total effective value limit of excitation device; correcting vibration source strength measurement point vibration data according to target rail vertical vibration acceleration data and laboratory rail vibration data, obtaining laboratory vibration source strength measurement point response data; performing on-site and laboratory transfer function tests, obtaining on-site transfer function and laboratory transfer function, calculating transfer function correction coefficient; correcting laboratory vibration response data according to transfer function correction coefficient, obtaining laboratory vibration source strength. The method can be equivalent to the actual situation on site, has low operation difficulty, low test cost and high economic benefit.

Description

Technical Field

[0001] The invention relates to the technical field of track vibration reduction, and in particular to a subway vibration source intensity equivalent testing method. Background Art

[0002] With the rapid development of urban rail transit in my country, the environmental vibration and noise problems caused by subway train operations have become increasingly prominent, and residents' complaints have increased. In order to control the environmental vibration and noise problems caused by subway operation, a series of vibration reduction measures such as replacing elastic fasteners and vibration-reducing ballasts are often required.

[0003] The vibration reduction effect of vibration reduction products can generally be evaluated by field testing and laboratory testing. During field testing, the location of the vibration source strength measurement point is determined according to "HJ 453-2018 Technical Guidelines for Environmental Impact Assessment-Urban Rail Transit", and the vibration reduction effect of the vibration reduction product is evaluated by measuring the insertion loss of the vibration source strength before and after the use of the vibration reduction product. Field testing consumes manpower and material resources and is costly. During laboratory testing, a drop axle test is generally used, in which the wheelset is allowed to fall freely at a certain height to cause a vertical impact on the rail surface, and the vibration reduction performance of the vibration reduction product is evaluated by measuring the insertion loss of the evaluation point. The drop axle test ignores the wheel-rail excitation effect in the actual operation of the train, and there is a problem that the location of the vibration source strength measurement point in the laboratory and on-site cannot be equivalent. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a subway vibration source intensity equivalent testing method with low cost and accurate results.

[0005] To this end, the present invention adopts the following technical solutions:

[0006] A subway vibration source intensity equivalent test method comprises the following steps:

[0007] S1, when the subway train is in normal operation, vertical vibration acceleration data ZSR of the target rail in the subway line is collected on site, and vibration signal processing is performed on the vertical vibration acceleration data to obtain the power spectrum density psd, total effective value rms and kurtosis k of the target rail;

[0008] S2, determine the equivalent load spectrum spe of the target rail according to the total effective value rms, power spectrum density psd and total effective value limit lim of the excitation device obtained in S1:

[0009]

[0010] S3, input the equivalent load spectrum spe and the kurtosis k obtained in S1 into the excitation device, perform a laboratory excitation test, and obtain a laboratory test signal, wherein the laboratory test signal includes a laboratory rail test signal TLR and a vibration source strong measurement point test signal TLE; and calculate the laboratory rail vibration data ZLR and the vibration source strong measurement point vibration data ZLE according to the total effective value rms and the total effective value limit lim of the excitation device:

[0011]

[0012]

[0013] S4, correcting the vibration data ZLE of the strong vibration source measuring point according to the target rail vertical vibration acceleration data ZSR and the laboratory rail vibration data ZLR obtained in S1, and obtaining the laboratory vibration source strong measuring point response data ZCE:

[0014]

[0015] S5, conduct transfer function tests on site and in the laboratory respectively, obtain the field transfer function GS and the laboratory transfer function GL, and calculate the transfer function correction coefficient G:

[0016]

[0017] S6, correcting the laboratory vibration response data according to the transfer function correction coefficient to obtain the laboratory vibration source strength VL:

[0018] VL=ZCE×G.

[0019] In the above step S1, when collecting vertical vibration acceleration data, the rail vibration measurement point is located at the bottom of the rail.

[0020] In the above step S3, when the laboratory excitation test is performed, the vibration source intensity measurement point is located on the base of the subway track and the distance from the track plate is less than 1m.

[0021] In the above step S5, when conducting field tests, the vibration source strong measurement point is located on the tunnel wall of the subway track, 1.25m away from the top of the rail; when conducting laboratory tests, the vibration source strong measurement point is located on the base of the track, less than 1m away from the track plate. The transfer function test excitation point is located on the base, close to the track plate 4, generally within 0.5m.

[0022] The subway vibration source strength equivalent test method of the present invention acquires power spectrum density, total effective value and kurtosis by collecting target rail vibration data and performing vibration signal processing, thereby determining load spectrum according to total effective value, total effective value limit of excitation device and power spectrum density, inputting load spectrum and kurtosis into excitation device, performing laboratory excitation test, obtaining laboratory test signal, and obtaining laboratory vibration data according to total effective value and total effective value limit of excitation device, correcting laboratory vibration data according to target rail vibration data and laboratory rail vibration data to obtain laboratory vibration response data, performing transfer function tests in field and laboratory respectively, obtaining field transfer function and laboratory transfer function, calculating transfer function correction coefficient, and finally determining laboratory vibration source strength according to transfer function correction coefficient and laboratory vibration response data.

[0023] Compared with the laboratory drop shaft test in the prior art which does not consider wheel-rail excitation and the locations of the vibration source intensity measurement points in the laboratory and on-site cannot be equivalent, the present invention has the following beneficial effects:

[0024] 1. The present invention simulates the passing state of a live train in a laboratory for testing, which has low operation difficulty, low test cost and high economic benefit.

[0025] 2. The method of the present invention can be used to evaluate the actual situation on site in the laboratory, thus solving the problem of inaccurate laboratory evaluation results of the vibration reduction effect of vibration reduction tracks.

[0026] 3. The present invention innovatively proposes a laboratory simulation equivalent test method for subway vibration source strength and designs a vibration excitation device suitable for the simulation method. The method of the present invention is conducive to the evaluation of vibration reduction tracks and the development of new vibration reduction products and promotes the healthy development of the rail transit industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the subway vibration source intensity equivalent test method of the present invention;

[0028] Figure 2 Schematic diagram of the measurement point locations when collecting data on site;

[0029] Figure 3 This is a schematic diagram of the locations of measurement points for collecting data during laboratory testing;

[0030] Figure 4 , Figure 5 This is a schematic diagram of the installation structure of the vibration device in the laboratory;

[0031] Figure 6 It is a structural schematic diagram of the excitation device;

[0032] Figure 7 is the power spectrum density of the target rail in Example 1;

[0033] Figure 8 is the equivalent load spectrum in Example 1;

[0034] Fig. 9 are laboratory test signals at the rail vibration measurement point and the vibration source intensity measurement point in Example 1;

[0035] Fig.10 The laboratory vibration data at the rail vibration measurement point position and the vibration source strong measurement point position in Example 1;

[0036] Fig.11 The laboratory vibration source strong measurement point response data in Example 1;

[0037] Fig.12 is the transfer function correction coefficient in Example 1;

[0038] Fig.13 This is a comparison of the vibration source strength on site and in the laboratory in Example 1.

[0039] In the figure:

[0040] 1. Base; 2. Track plate; 3. Rail; 4. Vibration device 5. Rail vibration measurement point

[0041] 6. Transfer function test excitation point 7. Tunnel wall 8. Vibration source strength measurement point DETAILED DESCRIPTION

[0042] In order to make the objectives, technical solutions and advantages of the present invention more clear, the method of the present invention is described in detail below with reference to the accompanying drawings.

[0043] See also Figure 1 The subway vibration source intensity equivalent test method of the present invention comprises the following steps:

[0044] S1, when the subway train is in normal operation, vertical vibration acceleration data ZSR of the target rail in the subway line is collected on site, and vibration signal processing is performed on the vertical vibration acceleration data to obtain the power spectrum density psd, total effective value rms and kurtosis k of the target rail.

[0045] The power spectrum density PSD is a physical quantity that characterizes the relationship between the power energy and frequency of a signal; the total effective value RMS reflects the energy intensity of the vibration signal; and the kurtosis K reflects the numerical statistics of the distribution characteristics of the vibration signal, that is, the proportion of the peak instantaneous value.

[0046] See also Figure 2 , the track plate 2 is laid on the base 1, the rail 3 is laid on the track plate 2, and 7 is the tunnel wall. The rail vibration measuring point 5 is located at the bottom of the rail 3.

[0047] S2, determine the equivalent load spectrum spe of the target rail based on the total effective value rms, power spectrum density psd and total effective value limit lim of the excitation device obtained in S1.

[0048] The structure of the excitation device and its installation position are respectively shown in Figure 4-Figure 6 , whose structure will be described in detail later.

[0049] The total effective value limit of the excitation device reflects the maximum energy intensity that the excitation device can withstand. The total effective value limit of the excitation device has the same physical unit as the total effective value.

[0050] If the total effective value rms is less than the total effective value limit lim of the excitation device, the equivalent load spectrum spe of the target rail is equal to the power spectrum density psd of the target rail. Otherwise, the calculation formula of the equivalent load spectrum of the target rail is:

[0051]

[0052] Where: spe represents the equivalent load spectrum, psd represents the power spectrum density, rms represents the total effective value, and lim represents the total effective value limit of the excitation device.

[0053] S3, input the equivalent load spectrum obtained in S2 and the kurtosis obtained in S1 into the above-mentioned excitation device, and conduct a laboratory excitation test. The vibration output by the excitation device acts on the laboratory rail, so as to obtain a laboratory test signal. The laboratory test signal includes a laboratory rail test signal TLR and a vibration source strength measurement point test signal TLE.

[0054] If the total effective value rms is less than the total effective value limit lim of the excitation device, the laboratory rail vibration data ZLR is equal to the laboratory rail test signal TLR, and the vibration data ZLE of the vibration source strong measurement point is equal to the vibration source strong measurement point test signal TLE. Otherwise, the laboratory rail vibration data ZLR and the vibration source strong measurement point vibration data ZLE are calculated based on the total effective value rms and the total effective value limit lim of the excitation device:

[0055]

[0056]

[0057] See also Figure 3 When conducting the above test, the vibration source intensity measurement point 8 is located on the base 1, and the distance from the track plate 2 is less than 1m.

[0058] S4, correcting the vibration source strong measurement point vibration data ZLE according to the target rail vertical vibration acceleration data ZSR and the laboratory rail vibration data ZLR obtained in S1, and obtaining the laboratory vibration source strong measurement point response data ZCE.

[0059] Due to the output performance limitation of the excitation device and the influence of its own natural frequency, the laboratory rail vibration data is not completely consistent with the target rail vibration data. Therefore, it is necessary to correct the laboratory vibration data according to the target rail vibration data and the laboratory rail vibration data to obtain the laboratory vibration source strength measurement point response data ZCE, and the calculation formula is as follows:

[0060]

[0061] S5, conduct transfer function tests on site and in the laboratory respectively, obtain the field transfer function GS and the laboratory transfer function GL, and calculate the transfer function correction coefficient G.

[0062] See also Figure 2 and Figure 3 , the transfer function test excitation point 6 is located on the base 5, close to the track plate 4, generally within 0.5m. When conducting field tests ( Figure 2 ), the vibration source intensity measurement point 8 is located on the tunnel wall 7, about 1.25m away from the top of the rail. Figure 3 ), the vibration source intensity measurement point 8 is located on the base 5, and the distance from the track plate 4 is less than 1m.

[0063] Due to the different geological conditions on site and in the laboratory, the stiffness of the soil layer is quite different. In order to make the laboratory and the on-site vibration source strong measurement point have the same vibration response effect, such as Figure 2 As shown, the transfer function tests are carried out on site and in the laboratory respectively, and the transfer function correction coefficient G is calculated according to the on-site transfer function and the GS laboratory transfer function GL:

[0064]

[0065] S6, correct the laboratory vibration response data according to the transfer function correction coefficient G to obtain the laboratory vibration source strength result (subway vibration source strength equivalent value) that is equivalent to the subway on-site vibration source strength result. Subsequently, the vibration reduction performance of the vibration reduction product can be evaluated by measuring the vibration source strength of the ordinary track and the vibration reduction track respectively. The calculation formula of the laboratory vibration source strength VL (subway vibration source strength equivalent value) is:

[0066] VL=ZCE×G.

[0067] When conducting the above tests, the measurement point locations of the target rail vibration should be the same as the measurement point locations of the laboratory rail vibration. During laboratory testing, the test conditions should be the same as the track conditions during field testing.

[0068] See also Figure 2-Figure 4The vibration excitation device 4 used in the measuring method of the present invention includes: a support 41, a column 42, an upper cover plate 43, a limiter 44, a shock absorber 45, an electromagnetic exciter 46, a motor 47, and a wheel 48.

[0069] Specifically, the support 41 is the platform foundation of the excitation device, and is a rectangular parallelepiped made of metal (such as steel). There are four columns 42, which are symmetrically arranged on the support 41 and are all cylindrically made of metal. The upper ends of the columns 42 are connected to the upper cover plate 43. The upper cover plate 43 is a rectangular parallelepiped plate made of metal.

[0070] The limiter 44 has the function of limiting the movement range of the electromagnetic vibrator 46 to protect the safety of the vibrator and the staff, and can be a mechanical or photoelectric limiter.

[0071] There are four vibration dampers 45, which are respectively arranged adjacent to the four columns, for buffering the vibration impact of the electromagnetic exciter 46 and protecting the safety of the exciter and the staff. The vibration damper 45 can be an air spring type, a steel spring type or a rubber spring type vibration damper.

[0072] The electromagnetic exciter 46 is installed on the support 41 and has the function of processing the input equivalent load spectrum and kurtosis into a time domain excitation signal and outputting the signal.

[0073] The motor 47 is used to drive the wheels 48 to rotate. There are four wheels, which are installed on both sides of the bottom of the support 41. The wheels are in direct contact with the rails. The distance between the wheels on the left and right sides is equal to the track gauge, which is used to realize the movement of the excitation device on the rails.

[0074] The excitation signal output by the electromagnetic exciter 46 acts on the support 41 and is applied to the rail 3 through the wheel 48 .

[0075] The track slab 2 is laid on the base 1 , and the rails 3 are laid on the track slab 2 .

[0076] Example 1

[0077] A subway vibration source intensity equivalent test method comprises the following steps:

[0078] S1, when the urban rail transit train is in normal operation, the vertical vibration acceleration data ZSR of the target rail in the urban rail transit is collected on site, and the collected vertical vibration acceleration data of the target rail is processed for vibration signal to obtain the power spectrum density psd, total effective value rms and kurtosis k of the target rail.

[0079] See also Figure 2 ,When collecting data, the rail vibration measurement point 1 is located at the bottom of the rail.

[0080] The working conditions and conditions of the target rail test section are as follows: the tunnel is a circular shield tunnel with an outer diameter of 6m, the track surface is buried at a depth of 15m, the line is a straight line, the rail is a 60kg / m rail, the roadbed forms are ordinary rails and steel spring floating plate vibration reduction rails, and the train passes through the test section at a speed of about 75km / h. The rails are in good condition, without corrugation, the tunnel has no cracks, water seepage and other diseases, the roadbed has no empty hanging, cracking, mud and other diseases, the test section is more than 10m away from the rail joint (weld), and the rail joint has no misaligned teeth. The test sections of the ordinary track and the vibration reduction track are in the same direction (left line) and the same section. When the same train passes through these two sections, the wheel out of roundness is consistent and the train axle weight is consistent. All trains are subway type B vehicles with 6 carriages.

[0081] The power spectral density psd of the target rail is as follows: Figure 7 As shown in the figure, after calculation, the kurtosis k = 3.26 and the total effective value rms = 0.15.

[0082] S2, according to the total effective value rms, power spectrum density psd and total effective value limit lim of the excitation device obtained in S1, determine the equivalent load spectrum spe of the target rail:

[0083]

[0084] The total effective value limit of the excitation device lim=0.2. Since the total effective value rms=0.15, which is less than the total effective value limit lim of the excitation device, the equivalent load spectrum spe of the target rail is equal to the power spectrum density psd of the target rail, such as Figure 8 shown.

[0085] S3, input the equivalent load spectrum obtained in S2 and the kurtosis obtained in S1 into the above-mentioned excitation device to perform a laboratory excitation test, and the vibration output by the excitation device acts on the laboratory rail to obtain a laboratory test signal. The laboratory test signal includes a laboratory rail test signal TLR and a vibration source strength measurement point test signal TLE, such as Fig. 9 shown.

[0086] If the total effective value rms is less than the total effective value limit lim of the excitation device, the laboratory rail vibration data ZLR is equal to the laboratory rail test signal TLR, and the vibration data ZLE of the vibration source strong measurement point is equal to the vibration source strong measurement point test signal TLE. Otherwise, the laboratory rail vibration data ZLR and the vibration source strong measurement point vibration data ZLE are calculated based on the total effective value rms and the total effective value limit lim of the excitation device:

[0087]

[0088]

[0089] In this example, since the total effective value rms = 0.15, which is less than the total effective value limit lim of the excitation device, the laboratory rail vibration data ZLR is equal to the laboratory rail test signal TLR, such as Fig.10 shown.

[0090] S4, correcting the vibration source strong measurement point vibration data ZLE according to the target rail vertical vibration acceleration data ZSR and the laboratory rail vibration data ZLR obtained in S1, and obtaining the laboratory vibration source strong measurement point response data ZCE.

[0091] After calculation, the response data of the laboratory vibration source strength measurement point is as follows: Fig.11 shown.

[0092] S5, conduct transfer function tests on site and in the laboratory respectively, obtain the on-site transfer function GS and the laboratory transfer function GL, and calculate the transfer function correction coefficient G. The transfer function test excitation point 6 is located on the base 5, close to the track plate 4, generally within 0.5m.

[0093] During the field test, the vibration source intensity measurement point 2 was located on the tunnel wall 7, 1.25 m away from the top of the rail.

[0094] When conducting laboratory tests, the vibration source intensity measurement point 2 is located on the base 5 and is less than 1 m away from the track plate 4 .

[0095] Due to the different geological conditions on site and in the laboratory, the stiffness of the soil layer is quite different. In order to make the laboratory and the on-site vibration source strong measurement point have the same vibration response effect, such as Figure 2 As shown, the transfer function tests are carried out on site and in the laboratory respectively, and the transfer function correction coefficient G is calculated according to the on-site transfer function and the laboratory transfer function:

[0096]

[0097] After calculation, the transfer function correction coefficient is as follows: Fig.12 shown.

[0098] S6, correcting the laboratory vibration response data according to the transfer function correction coefficient to obtain the laboratory vibration source strength result which is equivalent to the subway site vibration source strength result.

[0099] Comparison of vibration source intensity between the field and the laboratory Fig.13 As shown, it can be seen that the on-site subway vibration source strength is consistent with the laboratory subway source strength equivalent test results, which verifies the effectiveness of the method of the present invention.

Claims

1. A subway vibration source intensity equivalent test method, characterized in that: The following steps are involved: S1, when the subway train is in normal operation, collect the vertical vibration acceleration data of the target rail in the subway line on site ZSR , perform vibration signal processing on the vertical vibration acceleration data to obtain the power spectrum density of the target rail psd , total effective value rms Kurtosis k ; S2, the total effective value obtained based on S1 rms , power spectral density psd And the total effective value limit of the excitation device lim Determine the equivalent load spectrum of the target rail spe : ； S3, the equivalent load spectrum spe The kurtosis obtained by S1 k Input the vibration device, conduct laboratory vibration test, and obtain laboratory test signals, wherein the laboratory test signals include laboratory rail test signals. TLR And the vibration source strong test point test signal TLE ; According to the total effective value rms , the total effective value limit of the vibration device lim Calculate the laboratory rail vibration data ZL Vibration data of the strong measuring point of the vibration source ZLE : ； ； S4, target rail vertical vibration acceleration data obtained according to S1 ZSR and laboratory rail vibration data ZL Correct the vibration data of the strong measuring point of the vibration source ZLE , get the laboratory vibration source strong measurement point response data ZCE : ； S5, conduct transfer function tests on site and in the laboratory respectively to obtain the field transfer function GS and the laboratory transfer function GL , calculate the transfer function correction coefficient G : ； S6, correcting the laboratory vibration response data according to the transfer function correction coefficient to obtain the laboratory vibration source intensity V L : 。 2. The subway vibration source intensity equivalent test method according to claim 1 is characterized in that: In step S1, when collecting vertical vibration acceleration data, the rail vibration measurement point is located at the bottom of the rail.

3. The subway vibration source intensity equivalent test method according to claim 1 is characterized in that: In step S3, when conducting a laboratory vibration test, the vibration source intensity measurement point is located on the base of the subway track and the distance from the track plate is less than 1m.

4. The subway vibration source intensity equivalent test method according to claim 1 is characterized in that: In step S5, when conducting field testing, the vibration source strong measurement point is located on the tunnel wall of the subway track, 1.25m away from the top of the rail; when conducting laboratory testing, the vibration source strong measurement point is located on the base of the track, less than 1m away from the track plate.

5. The subway vibration source intensity equivalent test method according to claim 1 is characterized in that: In step S5, the transfer function test excitation point is located on the substrate, close to the track plate, within 0.5 m.

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