Introduction to standards:
GB/T 5111-2011 Acoustic Measurement of noise emitted by
railway locomotives and rolling stock
GB/T5111-2011
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This standard specifies the measurement conditions for the noise level and spectrum emitted by railway locomotives and rolling stock or other types of rolling stock, so as to obtain reproducible and comparable measurement results. However, it does not include line maintenance vehicles in operation.
This standard applies to:
———Type test;
———Periodic supervision inspection;
———Conventional noise test;
———Environmental assessment measurement.
The results can be used for:
———Characterizing the noise emission characteristics of the train under test;
———Comparing the noise emission of various types of vehicles in a special section;
———Obtaining the basic sound source data of the train.
The test method specified in this standard is engineering grade (level 2, accuracy is ±2dB). According to the provisions of GB/T19052, engineering grade is the preferred grade for noise disclosure.
The method specified in the acceleration or deceleration test is simple grade.
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This standard was drafted in accordance with the rules given in GB/T1.1-2009.
This standard
is modified to adopt ISO3095:2005 "Measurement of noise emitted by rail vehicles for rail application acoustics".
For the convenience of comparison, a comparison table of the chapter and article numbers of this national standard and ISO3095:2005 is listed in the informative Appendix E.
The technical differences between this standard and ISO3095:2005 have been incorporated into the text and marked with a single vertical line in the margin of the clauses to which they relate. A list of these technical differences and their reasons is given in Appendix F for reference.
This standard replaces GB/T5111-1995 "Acoustic Measurement of Radiated Noise from Railway Locomotives and Rolling Stock".
Compared with GB/T5111-1995, the main technical changes of this standard are as follows:
———The consistency degree of this standard with ISO3095:2005(E) is modification; the previous version adopts ISO3095:1994(E); the foreword of this standard is added;
———In "Scope", the scope of application of this standard, the application of measurement results and two test methods of engineering level and simple level are added;
———The contents of normative reference documents are added;
———"Train", "Type test of noise emitted by railway locomotives and vehicles", "Environmental assessment measurement", "Roughness level", "AF-weighted maximum sound pressure level", "Single event sound level", "Passing exposure sound level", "Measurement time period T 8 terms and definitions ("radiated noise of locomotive and rolling stock" and "railway background noise") (see 3.1, 3.2, 3.4, 3.6, 3.10, 3.13, 3.14 and 3.15 respectively); 2 terms and definitions ("radiated noise of locomotive and rolling stock" and "railway background noise") in the original standard have been deleted;
———"4 Basic Technical Requirements" and its contents in the original standard have been deleted;
———Relevant provisions on instruments have been added;
———In "Measured Quantities", the quantities measured by uniform speed trains, stationary vehicles, and acceleration or braking tests have been specified in detail; the technical requirements for frequency analysis have been specified in detail; the measurement requirements for the perception of noise with modulated characteristics have been specified in detail;
———Detailed provisions for "Test Conditions" have been added;
———Detailed provisions for "Test Procedures" have been added;
———In "Test Report", the contents that should be included in the test report have been detailed;
———Added Appendix B to Appendix F;
———Added additional tests for platform and parking noise and additional tests for bridge noise in Appendix A.
This standard is proposed by the Chinese Academy of Sciences.
This standard is under the jurisdiction of the National Technical Committee for Acoustics Standardization (SAC/TC17).
The drafting units of this standard: Energy Conservation, Environmental Protection, Labor and Health Research Institute of China Academy of Railway Sciences, Institute of Acoustics of Chinese Academy of Sciences, Shanghai Academy of Environmental Sciences.
The main drafters of this standard: Ma Yun, Cheng Mingkun, Sun Chenglong, Gu Xiaoan, Jiao Dahua, Lv Yadong, Zhou Yude, Zhu Wenying, Yin Xia, Peng Feng, Xu Xin.
The following documents are indispensable for the application of this document. For any dated referenced document, only the dated version applies to this document. For any undated referenced document, its latest version (including all amendments) applies to this document.
GB/T3222.1—2006 Description, measurement and evaluation of acoustic environmental noise Part 1: Basic parameters and evaluation methods (ISO1996-1:2003, IDT)
GB/T3222.2—2009 Description, measurement and evaluation of acoustic environmental noise Part 2: Determination of environmental noise levels (ISO1996-2:2007, IDT)
GB/T3240 Frequencies commonly used in acoustic measurements (ISO266:1995, NEQ)
GB/T3241—2010 Electroacoustic octave and fractional octave filters (IEC61260:1995, MOD)
GB/T3785.1—2010 Electroacoustic sound level meter Part 1: Specification (IEC61672-1:2002, IDT)
GB/T3785.2—2010 Electroacoustic sound level meter Part 2: Type evaluation test (IEC61672-2:2003, IDT)
GB/T3947—1996 Acoustic terminology
GB/T15173—2010 Electroacoustic sound calibrator (IEC60942:2003, IDT)
GB/T27025—2008 General requirements for the competence of testing and calibration laboratories (ISO/IEC17025:2005, IDT)
Foreword III
1 Scope1
2 Normative references1
3 Terms and definitions2
4 Measured quantity 5
5 Instrument 6
6 Test conditions 6
7 Test method 9
8 Test report 11
Appendix A (Normative) Additional tests 12
Appendix B (Informative) Technical requirements for rail roughness measurement 14
Appendix C (Informative) Procedure for determining the limit values of the rail roughness spectrum 18
Appendix D (Informative Appendix) Main influencing parameters of orbital noise including orbital dynamics 22
Appendix E (Informative Appendix) Comparison of chapter and clause numbers of this standard with those of ISO3095:2005 23
Appendix F (Informative Appendix) Technical differences between this standard and ISO3095:2005 and their causes 24
References 25
Some standard content:
ICS 17.140
National Standard of the People's Republic of China
GB/T5111—2011
Replaces GB/T5111—1595
Acoustics—Measurement of noise emitted by railbound vehicles
Acoustics—Measurement of noise emitted by railbound vehicles(ISO 3095:2005,Railway applications—Acoustics—Measurement of noise emitted by railbound vehicles, MOD)2011-12-30 Issued
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Standardization Administration
2012-05-01 Implementation
Normative references
Terms and definitions
Measured quantity
Test conditions
Test method
Test report
Appendix A (Normative Appendix)
Appendix B (Informative Appendix)
Appendix C (Informative Appendix)
Technical requirements for track roughness measurement
Steps for determining the limit values of rail roughness spectrum
Appendix D (Informative Appendix)
Main influencing parameters of track noise including track dynamics Appendix E (Informative Appendix)
Appendix F (Informative Appendix)
References
Comparison between the chapter and clause numbers of this standard and the chapter and clause numbers of IS0 3095:2005 Technical differences between this standard and ISO3095:2005 and their causes TTTKANTKACA
GB/T 5111—2011
This standard was drafted in accordance with the rules given in GB/T 1.1—2009. CB/T 5111—2011
This standard is modified to adopt IS03095:2005 "Measurement of noise emitted by track machines and vehicles for applied acoustics of tracks". For the convenience of comparison, a comparison table of the chapter and clause numbers of this national standard and the chapter and clause numbers of ISO3095:2005 is listed in the informative Appendix E.
The technical differences between this standard and ISO3095:2005 have been incorporated into the text and marked with a single vertical line in the margins of the clauses to which they refer. A list of these technical differences and their reasons is given in Appendix F for reference. This standard replaces GB/T5111-1995 Acoustic Test of Noise Emitted by Railway Locomotives and Rolling Stocks\. Compared with GB/T5111-1995, the main technical changes of this standard are as follows: The degree of consistency between this standard and IS03095:2005(E> is modification, and the previous version adopts ISO3095:1994(E); The foreword of this standard is added:
In "Scope", the scope of application of this standard, the application of measurement results and two test methods of engineering level and simple level are added
The content of normative reference documents is added; "Train\" "Type test of noise emitted by railway locomotives and rolling stock", "Environmental assessment measurement" and " 8 terms and definitions, including "roughness level", "AF-weighted maximum sound pressure level", "single event sound level", "passing exposure sound level", "measurement time section T and train passing time T" (see 3.1, 3.2, 3.4, 3.6, 3.10, 3.13, 3.14 and 3.15 respectively) Deleted 2 terms and definitions in the original standard, including "locomotive and vehicle radiated noise" and "railway background noise"; Deleted "4. Basic technical requirements" and its contents in the original standard - Added relevant provisions on instrumentation;
"--Detailed provisions on the uniform speed train in "measured quantity" The standard specifies the measurement of vehicle noise, the measurement of stationary vehicles, and the measurement of acceleration or braking tests; specifies in detail the technical requirements for rate analysis; the measurement requirements for the detection of noise with noise characteristics; - adds detailed provisions for "test conditions"; adds detailed provisions for "test steps": - in the "Test Report", the content that should be included in the test report is detailed! Added Appendix B~Appendix F+
- In Appendix A, additional tests for platform and parking noise and additional test content for bridge noise are added. This standard is proposed by the Chinese Academy of Sciences.||t t||This standard is under the jurisdiction of the National Technical Committee for Acoustic Standardization (SAC/TC17). Drafting units of this standard: Energy Conservation, Environmental Protection, Labor and Health Research Institute of China Academy of Railway Sciences, Institute of Acoustics of Chinese Academy of Sciences, Shanghai Academy of Environmental Sciences.
The main drafters of this standard are Ma Du, Cheng Mingkun, Sun Chenglong, Xiang Xiaoan, Jiao Dahua, Lv Yadong, Zhou Yude, Zhu Wenying, Yin Xian, Peng Feng, Xu Xin.
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1 Fantuan
: Measurement of noise emitted by railway locomotives and vehicles
GB/T 5111-2011
This standard specifies the measurement conditions for the level and spectrum of the emitted sound from railway locomotives and other types of rolling stock, so as to obtain reproducible and comparable measurement results. However, it does not include line maintenance vehicles in operation. This standard applies to:
Type test:
-Periodic supervision inspection;
-》Conventional operation sound test,
-Environmental evaluation measurement. The results can be used for:
-Characterizing the characteristics of the noise emitted by the tested train;-Comparing the emitted sound of various types of vehicles in the special section;-Obtaining the basic sound source data of the train.
The test method specified in this standard is engineering level (level 2, accuracy is ±2 dB), in accordance with the provisions of GB/T19052, the engineering level is the preferred level for noise disclosure.
The method specified in the periodic operation deceleration test is simple level. Note 1: Although this standard is intended to characterize vehicle-emitted noise, the contribution of wheel rolling noise to track noise often occupies a major component, and in some cases an absolute component:
Note 2: This standard is intended to specify the measurement conditions for railway rolling stock noise in order to obtain reproducible and comparable test results. The specified method can also be used to monitor general traffic noise emissions, in which case the thermal and vehicle conditions do not have to meet the requirements of this standard, so these test results can only represent "specific" situations.
2 Normative references
The following documents are indispensable for the application of this document. For dated references, the version with the date of the reference applies to this document. For undated references, the latest version (including all amendments) applies to this document. GB/T 3222.1-2006 Description, measurement and evaluation of acoustic environmental noise Part 1: Basic parameters and evaluation methods (1S0 1996-1:2003, IDT)
GB/T 3222.2—2009
Acoustic environmental noise description, measurement and evaluation Part 2: Determination of environmental noise level (IS01996-2.2007, IDT)
GB/T3240 Bandwidth for noise measurement (ISO266:1995, NEQGB/T3241-2010 Electroacoustic octave and fractional octave filters ([EC61260,1995.MOD) GB/T3785.1—2010 Electroacoustic sound level meter Part 1: Specification (IEC61672-1:2002, ID T) GB/T3785.2-2010 Electroacoustic sound level meter Part 2: Type evaluation test (IEC61672-2: 2003, IDT) GB/T3917--1996 Acoustic terminology
GBT15173-2010 Electroacoustic calibrator (IEC60942: 2003, IDT) GB/T27025-2008 General requirements for the competence of testing and calibration laboratories (IS0/IEC17025: 2005, IDT) 1
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GB/T 5111-2011
3 Technical notation and definitions
The following terms and definitions apply to this document, 3.1
Train
Single or connected rolling stock/unit running on a ground rail transportation system. 3.2
Type test for noise emission of rail bound vehicles is used to test whether the locomotives and vehicles delivered by the manufacturer meet the noise technical indicators. Type test
Monitoring test for noise emission of rail bound vehicles is a measurement to check whether the noise emission of one or more locomotives and vehicles is measured by sampling one or more locomotives and vehicles from the delivered batch to check whether the noise emission meets the specified limit, or to check whether the noise emission of the locomotives and vehicles has changed due to initial transportation or modification. Monitoring testWww.bzxZ.net
Environmental assessment test is a measurement to collect data for environmental assessment noise prediction. 3.5
Roughness
The root mean square value of the amplitude change of the rough surface of a rail in the running direction (longitudinal surface), in μm. 3.6
roughnesslevel
roughness level
The expression of roughness level is shown in formula (1):
L, = 10 lg
Wherein:
roughness level, in decibels (dB);
root mean square value of roughness, in micrometers (um); reference roughness, F.=1 μm
This definition applies to the measured value of the wavelength spectrum calculated in m or a specific band with a central wavelength of λ. 3.7
soundpressuretre
The difference between the pressure in the medium and the static pressure when sound is emitted, in Pa. [GB/T 3947, definition 2. 21]
Sound pressure level sound pressure level
The logarithm of the ratio of the pressure to the reference sound pressure multiplied by 2 with the base 10, in bels [2, B. However, it is usually used as a unit, and the reference sound pressure 2
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must be specified.
Note: The reference sound pressure is: 20 μP= (in air). [GB/T 3947, definition 2. 47]
A-weighted sound pressure levelA-weighted soand pressure levelLpa
The sound pressure level measured using an A-weighting network.
[GB/T 3947, definition 13.6]
AF-weighted maximum sound pressure levelAF-weighted sound pressure level
I-nmua
GB/T 5111—2011
The maximum value of the A-weighted sound pressure level determined by time weighting F (fast gear) during the measurement period T (see GB/T 3785.1~-2010), in dB.
Equivalent continuous A-weighted sound pressure levelequivalent continupus A-weighted sound pressure levelLAea.T
In a specified time, the A-weighted sound pressure of a continuous steady-state sound has the same square A-weighted sound pressure as the time-varying noise, then the sound level of this continuous steady-state sound is the equivalent sound level of the time-varying noise, in B. Note 1: The expression of equivalent sound level is shown in formula (2); where:
ta —
Lamr = 10 leL-,]h A
equivalent sound + unit is dB);
specified time period, unit is second (5) +
instantaneous A-weighted noise pressure, unit is Pascal (Pa); reference sound pressure + P. = 20 rPa.
犯2: When the A-weighted sound pressure is expressed by A-sound level L (dB), as shown in formula (3): LAea,7 = 10 lg(
[GB/T 3947, definition 13. 7]
Note 3: LT is usually simplified to 1
equivalent continuous A-weighted sound pressure level during the pass-by time equivalent continuous A-weighted sound pressare level thepass-by time
LA-T, expressed by formula (4):
wherein,
equivalent continuous A-weighted sound pressure level during the pass-by time, in decibels (dB); the time period of measurement, T,—t, represents the start and end., in seconds (s): instantaneous A-weighted sound pressure, in Pascals (Pa) reference sound pressure, p. = 20μPa.
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GB/T 5111—2011
single event sound level single event sound level SEL
sound level of a single event measured in time period T and normalized by T. Time period T should include all sound energy related to the event, that is, at least the sound energy at the point 10 dB lower than the lower value of Lα should be considered. SEL is expressed by formula (5): at
SEL =10 1g
武中?
pa(e)-
A weighted explosive sound level, in decibels (dB) 3 reference time, T. =1 5
-Measurement time period, in seconds (s);
-Instantaneous A sound pressure, in Pascals (Pa)
--Reference sound pressure, force-20μPa. SEL and LAg. meet the relationship shown in formula (6):
SEL-Laeq,r + 10 lg
Transit exposure sound leveltransitexposurelevelTEL
(5)
The A-weighted sound level of a single train passing through the time period T and normalized to T, the time period T should be long enough to include all the energy related to the event, that is, at least the sound energy at the point 10dB lower than the lower value of L in the time period T should be considered. TEL is expressed by formula (7)·
TEL = 10 lg
wherein,
train passing exposure sound level, in decibel (dB); -…measurement time period, in seconds (s);
-time of a train passing, that is, the length of the whole train divided by the speed, in seconds (s); pa(t)-
-A-weighted sound pressure, in Pascals (Fa)+Po
---reference sound pressure, -20 μPa,
The relationship between the passing exposure sound level TEL and the single event level SEL and the equivalent continuous A-weighted sound pressure level is expressed by equations, see equations (8) and (9):
TEL=SEL+10 Ig(T)
TEL=LAs.? +10 Ig(
wherein:
reference time, T. =1 s.
Measurement time interval T and train pass-by time T measurement time interval T and train pass-by time T. The measurement starts when the A-weighted sound pressure level is 10 dB lower than the value when the front end of the train is facing the microphone position, and ends when the A-weighted sound pressure level is 10 dB lower than the value when the rear end of the train passes the microphone position. This period of time is the measurement time interval T, as shown in Figure 1. 4
Time/s
Figure 1 Selection of measurement time T for measuring a certain train GB/T 5111-—2011
Note: Since T cannot be derived from the relative relationship between sound pressure level and time, this case shows that a separate device is required to measure the basic train pass-by time. When measuring a certain section or several carriages in a train, the measurement time interval T from the beginning when the front end of the vehicle faces the microphone to the end when the rear end of the vehicle faces the microphone is the pass-by time T of a certain section or several carriages of the test train. 。 When measuring a non-powered covered vehicle, the measurement time period T is the time from the middle of the first tested car to the middle of the last tested car passing the microphone. Figure 2 shows the measurement time period T or the measurement of a single non-powered car. At the same time, Figure 2 also shows the change of the A sound level L over time when the train passes. 8S
time/y
Figure 2 When measuring part of the train car, the selection of the measurement time is noise with impulsive character. Noise containing an isolated event or a series of such events. If the difference between Larg.- and Lae.I is greater than 3 dB,It is usually considered to have impulse characteristics,
Noise with tonal characteristics
Noise with tonal characteristics
Contains audible tonal noise.
4 Quantities to be measured
4.1 Overview:
The quantities to be measured at all microphone positions are detailed as follows. GB/T 5111—2011
4.2 The quantities to be measured for high-speed trains are:
a) For the entire train (including a train with a single carriage), the passing noise level TEI. or the equivalent continuous A-weighted sound level LaTp can be measured as appropriate
b) For some carriages in the train, the equivalent continuous A-weighted sound level during the passing period is measured, expressed as L+. 4.3 The measurement quantity for stationary vehicles is the equivalent continuous A-weighted sound level LAg.T. 4.4 The measurement quantity for acceleration or braking test shall be the A-weighted maximum sound pressure level LA with time weighting F. 4.5 If spectrum analysis is required, at least 1/3 octave band in accordance with GB/T3240 shall be used. The typical frequency range is 31.5Hz~8kHz. It is important to select the lower frequency limit to ensure that the product of the narrowest bandwidth and the signal duration exceeds 1. 4.6 If noise with modulated characteristics is detected, it is recommended to perform spectrum analysis measurement at each microphone position according to the requirements of 4.5. For train noise with modulated characteristics, the measurement method can refer to the relevant provisions in GB/T3222.2-2009. 4.7 When measuring stationary vehicles, if there is suspected impulse noise, it is recommended to make two measurements for each microphone position, one with time weighting S (slow gear) and the other with time weighting I impulse gear> [see GB/T3785.12010]1 For train noise with impulse characteristics, the measurement method can refer to the relevant provisions in GB/T3222.1-2006. 4.8 Additional measurements on stationary vehicles, platforms, stops and bridges are described in Appendix A. 5 Instruments
The instrument system including microphones, electronic systems and recording equipment shall comply with the technical requirements for equipment in GB/T3785.1-2010.
The microphone should have an almost straight frequency response in the free field. The 1/3 octave filter should meet the requirements of Class 1 instruments in GB/T3241. A suitable windshield should also be used.
Before and after the measurement (before and after the measurement), a sound calibrator that meets the GB/T15173-2010 standard should be used to calibrate the whole measurement system at one or more frequencies in all relevant frequency ranges. If the difference between the two calibrations is greater than 0.5dB, the measurement result is invalid.
A calibrator that meets the requirements of GB/T15173-2010 shall be calibrated at least once a year. An instrument system that meets the requirements of GB/T3785.1-2010 and GB/T3785.2-2010 shall be calibrated at least once a year. The date of the last calibration in accordance with GB/T15173-2010 shall be recorded. 6 Test conditions
6. 1 Deviation from necessary conditions
The conditions specified for each test shall be kept as consistent as possible. Slight deviations from the specified test conditions are permitted: however, they shall be stated in the test report and will generally reduce reproducibility. 6.2 Test environment
6.2.1 Acoustic environment
The test site should meet the conditions of free sound propagation. The ground should be as flat as possible. The height relative to the rail surface should be between 0m and 1m. There should be no large reflective objects such as obstacles, hills, rocks, bridges or buildings around the microphone measuring points on both sides of the train within a radius of at least 3 times the measuring radius. There should be no obstacles that interfere with the sound field near the microphone: no one should be between the transmitter and the sound source, and the spectators should be in a position that does not affect the sound pressure level measurement.
GB/T 5111—2011
There should be no water accumulation between the vehicle and the microphone, and there should be no sound absorbing objects (such as snow, tall plants, other tracks or reflective coverings (such as water, ice) as much as possible. The ground covering should be described in the test report: Note: The suitability of the test site can be checked by a small sound source that can generate broadband noise. If there is a free field, the distance is increased and the sound level is attenuated by 6 dB
6.2.2 Meteorological conditions
The wind speed at the microphone height should be less than 5m/s, and there should be no rain or snow. The test report should state the temperature, humidity, air pressure, wind speed and wind direction during the measurement (give the measured data as much as possible). 6.2.3 Back noise pressure level
Care should be taken to ensure that the noise from other sound sources (such as other vehicles or industrial and wind noise) will not have a significant impact on the measurement. For type tests, the A-weighted background sound pressure level should be at least 10 dB lower than the noise emitted by the vehicle under test when the background noise exists. During harmonic analysis, the difference in each frequency band should also meet the above requirements. For supervisory inspection, the difference should be at least 5 dB. If the difference is less than 10 dB, the measurement result should be corrected according to Table 1. Table 1 Background noise correction value during supervisory inspection
Difference between the A-weighted sound pressure level of the vehicle under test and the A-weighted
background sound pressure level
6. 3 Microphone position
6.3.1 General requirements
The unit should be the negative
The positive value of the A-weighted sound pressure level obtained when the background noise is present
The microphone axis should always be in a horizontal position and point vertically to the track. The available standard microphone positions are shown in Figure 3. It is not necessary to measure at all positions, but one or more microphone positions should be selected according to this regulation. The microphone should be located 7.5m on both sides of the track axis, 1.2m ± 0.2m above the top of the track, and 25m on both sides of the track axis, 3.5m ± 0.2m above the top of the track. During the test, if there is an important sound source on the upper part of the vehicle being tested (such as an exhaust pipe or a pantograph), an additional microphone should be added 7.5m on both sides of the track centerline and 3.5m ± 0.2m above the top of the track. The unit is meter
Figure 3 Side microphone position for measuring high-speed trains 25
GB/T 5111—2011
6.3.2 Measurement of stationary vehicles
The microphone shall be placed 7.5 m from the centerline of the track and 1.2 m ± 0.2 m above the track surface, and facing the middle of the vehicle. 6.3.3 Measurement of trains running at high speed
Except for type tests that require measurement on both sides (such as asymmetric noise sources of trains), it is not necessary to measure on both sides at the same time. 6.3.4 Measurement of trains accelerating or decelerating from a stop For tests of trains accelerating and decelerating from a stop, the lateral and vertical positions of the microphones are the same as those described in 6.3.1, except that the positions are 7.5 m from both sides of the track axis.
The number of microphones and their distance from the direction of travel of the train are related to the type of train, that is, when the train starts to accelerate or brake, how far in front of it the microphones are placed.
If the distance between the center of the vehicle bogies is L, the microphone groups should be placed: a) In the case of a reverse power locomotive unit decelerating, place a group of microphones 20m in front of the train: 6) For a distributed power train in acceleration or any other type of vehicle decelerating, place 2 groups of microphones in total, one group in front of the vehicle + the other group at L/2 in front of the front of the vehicle. The measurement should be stopped when the tail of the unit under test passes 20m after the last group of microphones. For the acceleration test, the measurement should be stopped when the tail of the power unit passes 20m after the last group of microphones, or when its speed exceeds 30km/h. 6.4 Rolling stock conditions
6. 4. 1 General requirements
The vehicle should be in normal operating condition. For the speed test, the wheels shall have traveled at least 3000 km under normal operating conditions on the track in normal operation (at least 1000 km for trams or subways); for vehicles with tread brakes and disc brakes, they shall be in the running-in condition (the slider and tread are in full running-in condition under the test condition), and the wheel tread shall not be abnormal as much as possible, such as fanning. When measuring the shear trailer, it shall be ensured that the test invitation is not affected by the noise of other parts of the train (such as the EMU adjacent to the tested vehicle). 6.4.2 Load or running parts
The vehicle shall not carry goods or people except the crew. The power unit (such as locomotive) shall be the load under normal operating conditions. 6.4.3 Doors, windows and auxiliary equipment
During the measurement, the doors and windows of the vehicle shall be completely closed. During the test, the auxiliary equipment on the normally operating test vehicle shall be in working condition. However, if the noise from the auxiliary facilities occurs rarely and for a short time (less than 2% of the working time), and the impact on the sound pressure level from other sound sources is less than 5dB, it can be ignored when avoiding measurement.
The status of the auxiliary equipment during the test should be described in the test report. 6.5 Line conditions
6.5.1- General requirements
Measurements with gauge vehicles should be carried out on tracks with gravel ballast and wooden or reinforced concrete sleepers or for trains. The track should be dry and free of ice. The above test should be carried out on a specific railway section using a common rail section and sleeper design. If other track designs are integrated with the tested vehicle, they should also be included in the test. The track should be well maintained, the maximum line slope should not exceed 3%, and the track curve flat diameter is: 8
)rz1000m. Speed s70km/h;
b)=3000m, speed 70km/h≤120km/hzc)r≥5000m, speed u>120 km/h. GB/T 5111—2011
The rails in the test section should be continuously welded rails, with no obvious defects on the rail surface, such as burns caused by foreign objects squeezing between the rails and wheels, bumps, etc., and should not be affected by audible impact noise caused by welds or loose sleepers. Note: The noise generated by the vehicle is affected by the roughness of the rail head and the dynamic characteristics of the track. The measurement of track roughness can be carried out according to the content of the measurement section of this standard, but the dynamic characteristics of the track are still under research (see Appendix C). 6.5.2 Steel roughness
When the 1/3 octave band roughness level of the entire test section meets the requirements of Appendix B, the track condition should be considered to meet the type test requirements.
6.5.3 Special cases
For non-routine rolling stock tests, line conditions that differ from the general requirements of 6.5.1 should be explained in the report for the track structure.
Test method
7.1 General requirements
7.1.1 At each microphone position, measure the quantities to be measured and the related time interval T specified in Chapter 4. The train passage time T needs to be measured by a separate device, such as a grating plate or wheel detector. 7.1.2 Type test: Under each measurement condition, at least 3 tests shall be conducted for each microphone position. The arithmetic mean of the measured data shall be taken as the test result. The integer decibel value shall be taken according to the rounding rule. If the maximum difference of the readings under the same measurement condition exceeds 3 dB, the measurement shall be repeated.
For supervisory inspection, one measurement is sufficient. For conventional noise test and environmental noise measurement, at least 2 tests shall be conducted for each microphone position under each measurement case. The arithmetic mean of the measured data shall be taken as the test result. The integer decibel value shall be taken according to the rounding rule. If the maximum difference of the readings under the same measurement condition exceeds 3 dB, the measurement shall be repeated if conditions permit. 7.1.3 If the sound pressure levels measured on both sides of the vehicle are different, the higher sound level value shall be taken as the measurement result. 7.1.4 When testing a single trailer, there should be at least one vehicle with similar acoustic performance behind the motor vehicle, followed by at least two trailers to be tested and at least one vehicle with similar acoustic performance. During the tests of 7.1,5, the auxiliary equipment of all vehicles should be in normal load state. 7.2 Measurement of hook speed vehicles
7.2.1 The pushing or testing speeds are 20km/h, 40km/h, 60km/h, 80km/h, 100km/h, 120km/h, 140km/h, 160km/h, 200km/h, 250km/h, 300km/h, 320km/h and 350km/h. The following three situations apply:
a) Type test of train maximum speed ma ≥ 200k/h: the test should be carried out at = 160km/h and mr, or the lowest speed of the corresponding recommended test speed. If conditions permit, it is advisable to test at = 0 km/h: 80km/h
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