CN105590003A - Interior noise analysis and prediction method of high speed train - Google Patents

Abstract

The invention discloses a method for analyzing and predicting noise inside a high-speed train. Establish the train body model, the statistical energy analysis model of the body-in-white structure and the statistical energy analysis model of the internal and external acoustic cavity, and simplify and divide the subsystems; obtain the statistical energy analysis parameters of the body structure and internal acoustic cavity model and load them into the body structure model plate Subsystem and acoustic cavity model subsystem; obtain the energy of the external acoustic excitation source of the vehicle body and apply it to the statistical energy analysis model of the external acoustic cavity, and reach the interior of the vehicle after the attenuation of the sound insulation performance of the structural panels in the body-in-white structural model The acoustic cavity is used to obtain the structural noise energy radiated from the whole car body to the car under the action of the secondary suspension force of the car, and then analyze and predict the car interior noise. The invention overcomes the difficulties in predicting the noise inside the train, the limitations of the upper limit of the frequency domain, the complicated calculation process and incomplete incentive considerations in the existing methods, improves the calculation efficiency and prediction accuracy, and reduces the development and test costs.

Description

A high-speed train interior noise analysis and prediction method

technical field

The present invention relates to a noise prediction method, in particular to a high-speed train interior noise analysis and prediction method in the field of rail transit vibration and noise. The energy analysis technology proposes to analyze and predict the noise inside the train during the development and design stage of high-speed trains.

Background technique

At present, the coverage area of high-speed train lines in my country is gradually expanding, which brings convenience to people's travel and also brings noise problems. The essential difference between high-speed trains and ordinary trains lies in the qualitative change of the dynamic environment during train operation, that is, the dominant mechanical characteristics are changed to aerodynamic characteristics. Acoustic design has become an essential element in the design stage of high-speed trains with the increase of vehicle speed and the improvement of ride comfort requirements. If the traditional noise reduction method is used, that is, to evaluate the noise problem after the actual vehicle test operation and then take various countermeasures, this will further increase the post-optimization and production costs for high-speed trains that cost a lot of money. If the noise level in the train can be accurately predicted in the train design stage, it will provide a reference for promoting the short cycle, low cost and low noise of high-speed train design and manufacture.

For large-scale acoustic problems such as noise prediction in high-speed trains, structural-acoustic coupling (FEA-BEA—FiniteElementAnalysis-BoundaryElementAnalysis) and hybrid finite element analysis—statistical energy analysis (FEA-SEA) are currently used due to the limitation of the analysis frequency band. , Statistical Energy Analysis (SEA—StatisticalEnergyAnalysis) three methods to calculate the low-frequency, medium-frequency and high-frequency noise in the car respectively. Combining the above three methods can accurately predict the acoustics of each frequency band in the train car. However, due to the shortcomings of each method and the different models required by each method, the research efficiency is not high. When using FEA-BEA to study the low-frequency noise in the car, due to the large degree of freedom of the vehicle body, the degree of freedom of the acoustic model increases sharply with the increase of the frequency. As the upper limit of the analysis frequency domain increases, the resources and time required for the solution process Rapid increase. When FEA-SEA and SEA are used to study the medium and high frequency noise in the car, the aluminum profile of the body structure is usually equivalent to a flat or curved surface subsystem, which will cause a change in the sound insulation of the panel. In addition, the interior trim is equivalent to acoustic packaging or sound absorption. The coefficients ignore the constraints between interior parts and body-in-white, which will cause errors in the prediction of interior noise. On the other hand, the current research on interior noise prediction of high-speed trains has not fully considered the external excitation, and most of the research results are the excitation results of a single sound source. In this research background, there is a lack of an accurate and reasonable acoustic prediction method for large-scale acoustic research objects such as high-speed trains, which can ensure the accuracy of the excitation outside the vehicle, reduce the modeling workload and Broaden the analysis frequency band, that is, use as few analysis models as possible to predict the acoustic response of the full frequency band in the car, and provide a basis for the noise control in the high-speed train design stage.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the limitations of the upper limit of the analysis frequency domain, long calculation period, large calculation amount, complicated calculation process and low calculation accuracy in the existing three high-speed train interior noise prediction methods, and provide a A high-speed train interior noise analysis and prediction method, in order to broaden the interior noise analysis frequency band, improve calculation efficiency and prediction accuracy, provide a basis for train interior noise control, shorten the acoustic design cycle of high-speed trains, reduce development and test costs, and make trains The internal noise meets the design and standard requirements.

In order to solve the above-mentioned technical problems, the present invention adopts the technical scheme of following steps to realize, as shown in Figure 1:

1) Establish the body model of the high-speed train and the statistical energy analysis model of the body-in-white structure. The body-in-white model is obtained by coupling the finite element model of the body-in-white with the finite element model of the train interior system and the finite element model of the traction drive system;

2) Simplify the statistical energy analysis model of the body-in-white structure, obtain the simplified statistical energy analysis model of the body-in-white structure and divide the subsystems, establish the statistical energy analysis model of the internal acoustic cavity and the statistical energy analysis model of the external acoustic cavity for the interior space and the external space of the vehicle, respectively, And divide into subsystems;

3) Obtain the sound insulation performance parameters of each panel structure of the car body, and directly load them on the car body panel in the simplified statistical energy analysis model of the body-in-white structure, and obtain the statistical energy of each subsystem in the statistical energy analysis model of the internal acoustic cavity Analyze parameters and load them into each subsystem of the statistical energy analysis model of the internal acoustic cavity;

4) Obtain the energy of the external acoustic excitation source on the car body, apply it to the statistical energy analysis model of the external acoustic cavity, and reach the interior of the car after the attenuation of the sound insulation performance of the car body structural panels in the simplified statistical energy analysis model of the body-in-white structure The acoustic cavity is used to obtain the structural noise energy radiated from the whole car body to the car under the action of the secondary suspension force of the car, and then analyze and predict the car interior noise.

The present invention focuses on the process of the energy of the external acoustic excitation source reaching the acoustic cavity inside the vehicle after the attenuation of the sound insulation performance of the composite panel of the vehicle body, that is, the flow of sound energy from the outside of the vehicle to the inside of the vehicle. The above method can be called the statistical acoustic energy flow method ( SAEF), the model established by this method can be called SAEF model. Its simplified statistical energy analysis model of body-in-white structure is used to isolate the sound field outside the vehicle and the sound field inside the vehicle. Unlike the conventional statistical energy analysis model of panel structure, it does not need to define detailed panel material parameters, because the sound insulation performance It is directly defined on the connection surface between the body-in-white structural subsystem and the interior acoustic cavity subsystem.

The statistical energy analysis model of the body-in-white structure is simplified and divided into subsystems in the following manner: according to the basic assumptions of the statistical energy analysis model and the principle of subsystem simplification, the main basic panel structure of the train car is retained, and the body panel The aluminum profile structure is simplified into a flat plate and a curved plate structure, and then the train body is divided by the statistical energy analysis method to obtain several structural areas, and each structural area is further divided into several subsystems, and then the structural subsystems are divided according to their own The relationship between the mutual positions is established, and the SEA frame model of the simplified structure of the body-in-white is obtained, which is used as a simplified statistical energy analysis model of the body-in-white structure.

The main foundation block panels include windows, window partitions, upper side walls, lower side walls, roof middle, both sides of the roof, passage door walls, equipment compartments and floors, and the number of structural areas is the same as that of the main foundation blocks. The number of panels is the same.

The train external acoustic cavity is discretized into various external small acoustic cavities according to the subsystem division of the simplified statistical energy analysis model of the body-in-white structure (the external small acoustic cavity is used to transmit the external excitation energy loaded in this area to the corresponding simplified statistical energy analysis model of the body-in-white body panels), each external small acoustic cavity corresponds to and couples with the outer surface of the subsystem of the simplified statistical energy model of the body-in-white structure, the coupling surfaces have the same size, and the adjacent small acoustic cavities are coupled to each other, so that The external acoustic cavity covers the entire body surface except the end, and the thickness of the external acoustic cavity of the train is 0.4-0.6m.

According to the division of subsystems of the simplified statistical energy analysis model of the body-in-white structure, the internal acoustic cavity of the train discretizes the interior space of the carriage into various internal small acoustic cavities (the internal small acoustic cavities are used to transmit the body panels corresponding to the statistical energy analysis model of the white body). to other acoustic cavities in the car), each internal small acoustic cavity corresponds to and couples with the inner surface of the subsystem of the simplified statistical energy analysis model of the body-in-white structure, and the dimensions of the coupling surfaces are the same. It is divided into three layers in height and width, and the dimensions are 0.8-1m and 0.9-1.1m respectively.

The external acoustic excitation source energy received by the car body includes wheel noise excitation, rail noise excitation, aerodynamic noise excitation and reverberation noise excitation in the equipment cabin.

The energy of the external external acoustic excitation source on the vehicle body is specifically calculated in the following manner:

1) Calculate and obtain the train wheel-rail interaction force and the secondary suspension force of the carriage:

1.1) Using the vehicle-track coupled rigid multi-body dynamics method, the multi-body dynamics model of the vehicle body is established;

1.2) Under the excitation of track irregularities, through the simulation calculation of rigid body dynamics, the wheel-rail mutual force in the direction of gravity of the train in the analysis frequency band and the force acting on the carriage after the attenuation of the bogie suspension system can be obtained when the train travels in a straight line at a constant speed. The second-series suspension force on the above; the analysis frequency band is in the range of 50-4000Hz.

2) Calculate and obtain the noise excitation of the wheel:

2.1) Establish a train wheel finite element model and form 4 wheel pairs;

2.2) The Lanczos method is used to calculate the constrained modal characteristics of a single wheel, and the above steps 1.2) are applied to the track model to obtain the wheel-rail mutual force in the direction of gravity as the vertical wheel-rail force, and then the modal superposition method or direct solution method is used to calculate the wheel at Vibration response under vertical wheel-rail force excitation;

2.3) Establish the wheel acoustic radiation boundary element model. Since the upper limit of the analysis frequency band is 4000 Hz, the maximum unit side length of the wheel acoustic radiation boundary element model is about 14mm, and the multi-pole boundary element method (FMBEM) is used to calculate the wheel structure radiation noise;

2.4) Establish the field point model of the car body surface, and extract the acoustic excitation formed by the wheel noise on the car body surface;

3) Calculate and obtain the noise excitation of the orbit:

3.1) Establish a complete track finite element model;

3.2) Apply the above steps 1.2) to the track model to obtain the wheel-rail mutual force in the direction of gravity as the vertical wheel-rail force, and use the direct solution method to calculate the vibration response of the track under the excitation of the vertical wheel-rail force;

3.3) Extract the track vibration response, establish the track acoustic radiation boundary element model, and use the multipole boundary element method (FMBEM) to calculate the track structure radiation noise;

3.4) Establish the field point model of the car body surface, and extract the acoustic excitation formed by the track noise on the car body surface;

4) Calculate and obtain the aerodynamic noise excitation:

4.1) Using computational fluid dynamics, namely the CFD method, to establish a CFD model for the simulated aerodynamic test of the high-speed train;

4.2) The standard κ-ε turbulence model is used to calculate the steady flow field, and then the large eddy simulation (LES) is used to solve the instantaneous flow field to obtain the pulsating pressure on the surface of the middle section of the vehicle body model;

4.3) After converting the pulsating pressure into a dipole sound source, the aerodynamic noise on the surface of the car body when the train is running at a constant speed is obtained by using indirect boundary element analysis (IBEA);

4.4) Establish the field point model of the car body surface, and extract the acoustic excitation formed by the aerodynamic noise on the car body surface;

5) Experimental measurement and calculation to obtain the noise excitation of the equipment cabin:

5.1) Arrange a sound pressure sensor near the cooling motor in the equipment cabin of the high-speed train to measure the noise of the equipment cabin;

5.2) The train runs at a constant speed, and the acoustic environment in the train equipment cabin is similar to a reverberation room. The measured equipment cabin noise is used as a reverberation excitation to act on the subsystem of the statistical energy analysis model of the internal acoustic cavity, and is calculated according to the sound pressure level formula Reverberation noise excitation in the equipment cabin:

$\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 20</span>}\mathrm{<span\; class="notranslate">\; lg</span>}\frac{\mathrm{<span\; class="notranslate">\; p</span>}}{{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}$

In the formula, Lp is the noise excitation sound pressure level in the equipment cabin, in dB; p is the sound pressure measured at the measuring point in the equipment cabin, in Pa; p ₀ is the reference sound pressure, p ₀ =20μPa in the air;

6) The above four excitations are coupled together to form the final external acoustic excitation source energy received by the vehicle body.

The statistical energy analysis parameters of the subsystems include the loss factor in the acoustic cavity in the vehicle, the sound absorption coefficient of the interior system, the sound insulation of the main basic blocks of the vehicle body, and the radiated noise of the train structure under mechanical excitation.

The subsystem statistical energy analysis parameters of the three models are calculated in the following manner:

1) Obtain the loss factor in the acoustic cavity in the car:

1.1) Determine the reverberation time of the acoustic cavity in the vehicle: the reverberation time of the acoustic cavity in the vehicle is measured by the random signal burst reverberation attenuation method, the acoustic cavity to be tested is divided into three sections and measured one by one, and the acoustic attenuation process of the measuring point is collected through the microphone;

1.2) According to the measured reverberation time, calculate and obtain the loss factor η of the acoustic cavity in the vehicle:

$\mathrm{<span\; class="notranslate">\; \&eta;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2.2</span>}}{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 60</span>}}\mathrm{<span\; class="notranslate">\; f</span>}}$

In the formula, T ₆₀ is the measured reverberation time, indicating the time it takes for the sound energy level in the acoustic cavity to decay by 60dB; f is the frequency;

2) Obtain the sound absorption coefficient of the train interior system:

The sound absorption performance of the train interior system is mainly reflected in the cold-proof/sound-absorbing layer, seats, carpets and other porous structures, which are processed and calculated in the form of sound absorption coefficients. The sound absorption coefficient is obtained by consulting literature such as "Noise and Vibration Control Engineering Handbook";

3) Obtain the sound insulation of each base plate of the train car body structure:

3.1) The sound insulation test of each panel of the car body is carried out in a sound insulation laboratory that meets the national standard (GB/T19889.1-2005);

3.2) The test of the sound insulation of each panel refers to the method stipulated in the national standard (GB/T19889.3-2005). The sound insulation is calculated by measuring the average sound pressure level on both sides of the test piece:

$\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; lg</span>}\frac{\mathrm{<span\; class="notranslate">\; S</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}$

In the formula, is the average sound pressure level of each acoustic measuring point in the acoustic room; The average sound pressure level of each acoustic measuring point in the receiving room; S is the area of the test piece; A is the sound absorption of the receiving room, the unit is m ² , which refers to the product of the sound absorption coefficient and the indoor surface area, where:

$\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 0.16</span>}\mathrm{<span\; class="notranslate">\; V</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}$

In the formula, V is the volume of the receiving room; T is the reverberation time of the receiving room;

For some composite panels and curved panels, it is impossible to test the sound insulation through experiments, and the automatic matching layer (AutomaticallyMatchedLayer-AML) technology is used to predict its sound insulation performance;

4) Obtain the radiated noise of the train structure under mechanical excitation:

4.1) Establish the finite element model of the high-speed train maintenance car body, including body-in-white, interior system and traction drive system;

4.2) Use the Lanczos method to calculate the overall modal frequency and mode shape of each order of the finite element model of the prepared car body, refer to the first order of the prepared car body in the "Interim Regulations on the Strength Design and Test Appraisal of Railway Vehicles with Speeds Above 200km/h" The regulation that the vertical bending natural frequency shall not be lower than 10Hz and the comparison of the modal test of the whole car body ensure the accuracy of the finite element model of the whole car body;

4.3) The secondary suspension force of the bogie is applied to the prepared car body to excite the vibration response of the car body, and the vertical vibration velocity of the inner surface of the car body is extracted. Based on the BEA calculation method, the structural response noise of the vehicle interior under the excitation of the secondary suspension force is predicted .

The analysis and prediction of the noise inside the car specifically adopts the following methods:

1) Add the calculated subsystem statistical energy analysis parameters such as loss factor in the acoustic cavity, sound absorption coefficient, and sound insulation of the panel structure, and the energy of the external acoustic excitation source to the simplified statistical energy analysis model of the body-in-white structure and the statistical energy analysis model of the external acoustic cavity and the statistical energy analysis model of the internal acoustic cavity to form a SAEF analysis and prediction model for acoustic excitation noise in the vehicle; such as wheel noise excitation, track noise excitation, aerodynamic noise excitation on the surface of the car body, and equipment cabin noise excitation are added to the train body structure and interior and exterior In the SEA model of the acoustic cavity, a complete SAEF analysis and prediction model of the interior acoustic excitation noise is obtained.

2) Apply the secondary suspension force to the curb vehicle body model and add the interior noise prediction boundary element model to obtain a structural vibration-acoustic coupling model for predicting interior mechanically excited noise;

3) The acoustic response of each acoustic cavity subsystem in the car is obtained by using the acoustic excitation noise analysis and prediction model inside the car. Referring to the national standard GB/T12816-2006 "Railway Passenger Car Interior Noise Limits and Measurement Methods", select the center of the car and 1.2m away from the floor Analyze the left and right acoustic cavity subsystems to obtain the interior noise under acoustic excitation;

4) Use the structural vibration-acoustic coupling model to predict the mechanical excitation noise in the vehicle to obtain the acoustic response of the vehicle body structure under mechanical excitation, select the center of the vehicle and a position about 1.2m away from the floor for analysis, and obtain the vehicle interior under mechanical excitation. noise;

5) Through the principle of sound wave superposition, the above-mentioned results of interior noise under acoustic excitation and interior noise under mechanical excitation are superimposed in the following way to obtain the total interior noise under complete excitation, and complete the analysis of high-speed train interior noise Analysis forecast:

Among them, L is the _total noise in the car, in dB; L _sound is the acoustic excitation noise in the car, in dB; L _machine is the mechanical excitation noise in the car, in dB.

Compared with prior art, the beneficial effect of the present invention is:

1. The method of the present invention proposes a statistical energy flow method based on statistical energy analysis, which can analyze and predict the noise in the car before the train development and design stage and the test car development, and use this method to analyze and predict the noise of different cars in the acoustic design stage of the train. Analyze and compare the effects of the interior noise control scheme to make the interior noise level meet the specified design and standard requirements. It overcomes the huge cost of post-optimization and production caused by the traditional noise reduction method after the noise problem is discovered, and reduces the development cycle.

2. The method of the present invention can simultaneously consider various excitation effects outside the vehicle. The excitation is composed of wheel noise, track noise, aerodynamic noise, equipment cabin noise and secondary suspension force. What can be achieved, that is, the calculation of boundary conditions can be considered more complete.

3. The advantage of the method of the present invention compared with the traditional FEA-SEA, SEA method is: in the process of building a model, the train body-in-white aluminum profile structure needs to be simplified into a flat or curved surface SEA subsystem, and the structural SEA subsystem in the FEA-SEA, SEA method needs Energy is transferred through the vibro-acoustic response between the simplified structure and the actual aluminum profile sandwich structure. There is a certain error in the equivalent process, and the SEA subsystem of the train body-in-white structure in the method of the present invention is only It is used to isolate the sound field outside the car and the sound field inside the car, so it has no impact on the accuracy of the acoustic response inside the car, thus eliminating the error caused by the simplification of the structure.

4. Compared with traditional FEA-SEA and SEA methods, the method of the present invention requires fewer SEA parameters to be set, reduces the workload of parameter solution and simplifies the solution process. The vibration-acoustic characteristics of the structural SEA subsystem in the method of the present invention are directly replaced by the definition of the sound insulation of the plate structure, so it is not necessary to solve the modal density, structural internal loss factor, and structural Coupling loss factor and structural acoustic cavity coupling loss factor greatly reduce the workload.

5. The method of the present invention is different from the traditional FEA-BEA, FEA-SEA, and SEA methods, which can only be applied in their respective applicable frequency bands. The method of the present invention only pays attention to the energy of the external acoustic excitation source after the sound insulation performance of the car body composite panel is attenuated The process of reaching the acoustic cavity in the car, that is, the flow of sound energy from the outside of the car to the inside of the car, requires only one set of analysis models to predict the acoustic response of the full frequency band in the car, greatly reducing the modeling workload and ensuring the prediction accuracy. Broadened the analysis frequency band.

Description of drawings

In the following, the SEA model of the body structure is established in combination with the characteristics of the high-speed train, the SEA model of the interior acoustic cavity and the exterior acoustic cavity is established, the SEA parameters of the body structure and the interior acoustic cavity subsystem are determined, the external excitation energy on the body is determined, and the interior of the high-speed train is determined. Noise prediction, and the present invention is further described in conjunction with relevant accompanying drawings:

Fig. 1 is a block diagram of an analysis process of an embodiment of the present invention.

Fig. 2 adopts the method of the present invention to divide the body-in-white of the train into structural areas, each area includes a plurality of SEA plate and curved plate structural subsystems, and then divides into several structural subsystems, and connects the structural subsystems according to the corresponding relationship One of the simplified SEA model diagrams of the high-speed train body structure is obtained.

Fig. 3 adopts the method of the present invention to divide the body-in-white of the train into structural areas, each area includes a plurality of SEA plate and curved plate structural subsystems, and then divides into several structural subsystems, and connects the structural subsystems according to the corresponding relationship The second part of the simplified SEA model diagram of the high-speed train body structure is obtained.

Fig. 4 adopts the method of the present invention to divide the external acoustic cavity into several acoustic cavity subsystems on the basis of the above-mentioned train body structure SEA model so as to set up the SEA model of the external acoustic cavity;

Fig. 5 adopts the method of the present invention to divide the interior acoustic chamber into several subsystems on the basis of the train body structure SEA model in Fig. 2 so as to set up the SEA model of the interior acoustic chamber;

Fig. 6 is the dimensional drawing of the external acoustic cavity of the high-speed train obtained by adopting the embodiment of the present invention;

Fig. 7 is the dimensional drawing of the sound cavity in the high-speed train car obtained by adopting the embodiment of the present invention;

Fig. 8 is the change curve of the loss factor in the acoustic cavity in the vehicle with frequency obtained by adopting the embodiment of the present invention;

Fig. 9 is the variation curve of the sound absorption coefficient of the carpet with frequency obtained by adopting the embodiment of the present invention;

Fig. 10 is the variation curve of seat sound absorption coefficient with frequency obtained by adopting the embodiment of the present invention;

Fig. 11 is the change curve of the sound insulation of the car window with frequency obtained by adopting the embodiment of the present invention;

Fig. 12 is the variation curve of the sound insulation of the side wall, middle and lower part of the train car with frequency obtained by adopting the embodiment of the present invention;

Fig. 13 is the change curve of sound insulation with frequency in the middle part of the roof of the train carriage and on both sides of the roof by adopting the embodiment of the present invention;

Fig. 14 is the variation curve of the sound insulation of the train compartment glass partition, corridor roof and ventilation roof with frequency obtained by adopting the embodiment of the present invention;

Fig. 15 is the variation curve of the wheel-to-rail force of the train front bogie with frequency obtained by adopting the embodiment of the present invention;

Fig. 16 is the change curve of the secondary suspension force of the train front bogie with frequency obtained by adopting the embodiment of the present invention;

Fig. 17 is the analysis model of the acoustic excitation formed on the surface of the car body after the wheel noise obtained by adopting the embodiment of the present invention propagates through the air;

Fig. 18 is a nephogram of the sound pressure level distribution with a frequency of 2000 Hz formed on the surface of the car body after the wheel noise is transmitted through the air by the embodiment of the present invention;

Fig. 19 is the third octave result of the sound pressure level at the center of the bogie and the center of the car body surface of the wheel noise obtained by adopting the embodiment of the present invention;

Fig. 20 is an analysis model for the formation of acoustic excitation on the surface of the car body after the track noise obtained by adopting the embodiment of the present invention propagates through the air;

Fig. 21 is a cloud map of the sound pressure level distribution with a frequency of 2000 Hz formed on the surface of the car body after the track noise is transmitted through the air by the embodiment of the present invention;

Fig. 22 is the third octave result of the sound pressure level at the bogie center and the car body surface center of the track noise obtained by the embodiment of the present invention;

Fig. 23 is a wind tunnel CFD model for calculating train aerodynamic noise excitation obtained by adopting an embodiment of the present invention;

Fig. 24 is a cloud map of the distribution of the pressure level on the surface of the car body at a frequency of 2000 Hz when the running speed of the high-speed train is 350 km/h obtained by the embodiment of the present invention;

Fig. 25 is the third octave result of the sound pressure level of the aerodynamic noise formed at the center of the side of the bogie and the car body when the running speed of the high-speed train obtained by the embodiment of the present invention is 350 km/h;

Fig. 26 is the one-third octave band result of the sound pressure level excited by the equipment noise near the cooling motor in the equipment cabin when the running speed of the high-speed train obtained by the embodiment of the present invention is 350km/h;

Fig. 27 is the one-third octave frequency result of the radiated noise sound pressure level of the vehicle interior structure under the action of the secondary suspension force obtained by adopting the embodiment of the present invention;

Fig. 28 is the high-speed train interior noise SAEF analysis model obtained after setting SEA parameters and applying various noise excitations obtained by adopting the embodiment of the present invention;

Fig. 29 is a third-octave result of the noise sound pressure level at the center of the car when the high-speed train is running at a speed of 350km/h obtained by the embodiment of the present invention and a comparison curve with the experimental test results.

The marks in the figure are: window 1, window partition wall 2, side wall upper part 3, side wall lower part 4, roof middle part 5, roof sides 6, passage door wall 7, equipment compartment 8, floor 9, wheel noise Prediction site model 10, wheel noise prediction bogie center observation point 11, wheel noise prediction side center observation point 12, wheel vibration-acoustic coupling model 13, track noise prediction site model 14, track noise prediction bogie center observation point 15 , track noise prediction side central observation point 16, track vibration-acoustic coupling model 17, wind tunnel air inlet 18, train to be tested 19, lead car 20, tail car 21, wind tunnel 22, wind tunnel air outlet 23.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

As shown in Figure 1, the high-speed train interior noise analysis and prediction method described in the present invention proposes the Statistical Acoustic Energy Flow (SAEF) method on the basis of the Statistical Energy Analysis (SEA) method according to the provisions of multiple relevant national standards, which can be used in In the train design stage, the noise inside the train is analyzed and predicted to provide a reference for noise control inside the train. The analysis and prediction methods of vehicle interior noise include SEA modeling of body-in-white structure, SEA modeling of train internal acoustic cavity and external acoustic cavity, determination of SEA parameters of body structure and internal and external acoustic cavity subsystems, determination of train external excitation energy, and analysis and prediction of vehicle interior noise. steps.

I. Establishment of SEA model of body-in-white structure

Referring to Figure 2 and Figure 3, according to the basic assumptions of the statistical energy analysis model and the principle of subsystem simplification, the body-in-white can be divided into several structural regions by using the statistical energy analysis method, and then the structural region is divided into several structural subsystems. The structural subsystems are connected according to their mutual relations to obtain the simplified SEA model of the body-in-white structure of the high-speed train (as shown in Figure 2 and Figure 3). The body-in-white structure of the train is actually very complicated, and the structural system divided by the SEA model is obtained after ignoring the local complex structure and simplifying the aluminum profile sandwich structure into a flat or curved plate structure on the basis of retaining the large plate structure of the train. The body-in-white is divided into several structural areas as shown in Table 1 below:

Table 1

Figure number Structural area structural properties Material 1 window flat Glass 2 window partition flat Aluminum profile 3 upper side wall curved panel Aluminum profile 4 lower side wall flat Aluminum profile 5 roof center flat Aluminum profile 6 Roof sides curved panel Aluminum profile 7 Passage door wall flat Aluminum profile 8 equipment compartment Flat and Curved Panels Aluminum profile 9 floor flat Aluminum profile

II. Establish the SEA model of the interior and exterior acoustic cavity of the vehicle

Referring to Figures 4 to 7, on the basis of the SEA model of the body-in-white structure of the high-speed train described above, the SEA model of the acoustic cavity is established inside and outside the carriage, including the external acoustic cavity on the body surface and the internal acoustic cavity (as shown in Figures 4 and 5).

The external acoustic cavity of the car should be discretely divided into small acoustic cavities according to the division of the structural subsystems of the SEA model of the train body structure. Coupling to ensure the energy transfer between the acoustic cavities, the external acoustic cavity on the surface of the vehicle body should cover the entire train carriage (except the two ends of the carriage). The thickness of the external acoustic cavity, that is, the distance between the outer surface of the acoustic cavity and the surface of the vehicle body, will not affect the calculation, and the thickness range can be set between 0.4 and 0.6m.

The interior acoustic cavity of the car is also discretely divided into small acoustic cavities according to the division of the structural subsystems of the SEA model of the car body. Viewed from the side, the sound cavity in the car interior fills the entire interior of the car and is roughly divided into 9 equal parts. The inner surfaces of the system are coupled to each other, and the adjacent acoustic cavities are also coupled to each other to ensure the internal energy flow. The thickness of the internal acoustic cavity is the distance from the surface of the acoustic cavity close to the structure to the surface of the structure, which is approximately one-third of the width and height of the compartment, approximately between 0.9-1.1m and 0.8-1m.

The sound cavity in the center of the car and about 1.2m away from the floor is set as the sound cavity for analysis and prediction, which is based on the provisions of the national standard GB/T12816-2006 "Railway Passenger Car Interior Noise Limits and Measurement Methods" for the position of the measuring point. Finally, the SEA model of the interior and exterior acoustic cavity of the car is connected with the SEA model of the body structure to obtain the SAEF model for the analysis and prediction of the interior noise of the high-speed train. The dimensions of the interior and exterior acoustic cavity are shown in Figure 7.

III. Determine the SEA parameters of the body structure and the interior and exterior acoustic cavity system

1. Determine the loss factor in the acoustic cavity of the train

1) Determine the reverberation time of the sound cavity in the car

The so-called reverberation time refers to the time it takes for the sound energy level in the acoustic cavity to decay by 60dB. The reverberation time of the sound cavity in the train car is tested by the B&K data acquisition system acquisition system. The main equipment includes a notebook computer, B&K data acquisition front-end, microphone, sound source, etc. The reverberation time of the acoustic cavity in the car is measured by using the random signal burst reverberation attenuation method.

Due to the rectangular shape of the train car body, when the sound source is used to excite the entire acoustic cavity, the distribution of the response is likely to be uneven, and individual acoustic measurement points may be less than 60dB. Therefore, during the test, the acoustic cavity is divided into 3 sections and measured one by one. When measuring the reverberation time for each acoustic cavity area, a spherical sound source emits white noise. After the signal is stable, the sound source is turned off, and multiple height-adjustable microphones collect the acoustic attenuation process at different positions.

2) According to the measured reverberation time, calculate and obtain the loss factor of the acoustic cavity in the vehicle:

$\mathrm{<span\; class="notranslate">\; \&eta;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2.2</span>}}{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; 60</span>}}\mathrm{<span\; class="notranslate">\; f</span>}}$

In the formula, T ₆₀ is the measured reverberation time, indicating the time it takes for the sound energy level in the acoustic cavity to decay by 60dB; f is the frequency. The calculation results of the loss factor test in the acoustic cavity of the train car are shown in Fig. 8.

2. Determine the sound absorption coefficient of the train interior system

The sound absorption performance of the train interior system is mainly reflected in the cold-proof/sound-absorbing layer, seat and other porous structures, and the calculation process is processed in the form of sound absorption coefficient. The sound absorption coefficient of the seat and the porous structure of each area in the car is obtained by consulting the "Noise and Vibration Control Engineering Handbook" and other documents. The sound absorption coefficients of the interior system including carpets and seats are shown in Figures 9 and 10.

3. Determine the sound insulation of each foundation plate of the train body structure

As the basic component of the train car body structure, the base plate has a direct impact on the ability of the car body to block the noise outside the car from entering the car. The base plate involved in the present invention includes windows, glass partitions, floors, and corridors. Roof panels, side wall composite panels and cabin roof panels. Since the present invention directly defines the sound insulation of each panel of the car body to characterize the vibration-acoustic response characteristics that usually need to be defined and calculated by attribute parameters, it is very important to ensure the accuracy of the sound insulation of each panel. The sound insulation test is carried out in a sound insulation laboratory that meets the national standard "Measurement of Sound Insulation of Buildings and Building Components Part 1: Laboratory Test Facility Requirements for Suppressed Lateral Sound Transmission" (GB/T19889.1-2005) by a It consists of a sounding room and a receiving room. Placing sound sources in the two corners of the sounding room is to achieve the effect of reverberation in the room, and five microphones are arranged in the area symmetrical to the specimen in the sounding room and the receiving room to collect acoustic signals.

The test of the sound insulation of the foundation plate refers to the national standard "Sound Insulation Measurement of Buildings and Building Components Part III: Laboratory Measurement of Airborne Sound Insulation of Building Components" (GB/T19889.3-2005), and the sound insulation can be measured by measuring the specimen The average sound pressure level on both sides is calculated as:

$\mathrm{<span\; class="notranslate">\; S</span>}\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; lg</span>}\frac{\mathrm{<span\; class="notranslate">\; S</span>}}{\mathrm{<span\; class="notranslate">\; A</span>}}$

In the formula, is the average sound pressure level of the five acoustic measuring points in the sound chamber, in dB; The average sound pressure level of the five acoustic measuring points in the receiving room, in dB; S is the area of the specimen; A is the sound absorption of the receiving room, in m ² , which refers to the product of the sound absorption coefficient and the indoor surface area, where

$\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 0.16</span>}\mathrm{<span\; class="notranslate">\; V</span>}}{\mathrm{<span\; class="notranslate">\; T</span>}}$

In the formula, V is the volume of the receiving room; T is the reverberation time of the receiving room, and its measurement method is the same as that of the reverberation time in the vehicle mentioned above.

For some composite panels and curved panels, the sound insulation cannot be tested through experiments, and the sound insulation performance can be predicted by Automatically Matched Layer (AML) technology. According to the above tests and simulations, the sound insulation of the basic panels and combined panels such as windows, glass partitions, corridor roofs, side wall composite panels, and passenger compartment roofs are obtained, as shown in Figures 11-14.

IV. Determining the external excitation energy on the high-speed train body

Since the measured value of the external noise excitation test is the result of the coupling effect of various sound sources outside the vehicle, it is difficult to separate them. Therefore, the simulation prediction method is used to calculate the excitation energy of each sound source.

1. Determine the train wheel-rail interaction force and the secondary suspension force of the carriage

When the train runs straight at a constant speed, the wheel-rail force is vertically dominant, which can be predicted based on vehicle-rail coupled rigid multibody dynamics. According to the actual parameters of the analyzed car body, a suitable rigid multi-body dynamics model of the car body is established.

Adding the track irregularity excitation, through the rigid body dynamics simulation calculation, the wheel-rail interaction force in the direction of the train's gravity and the force acting on the carriage after the train is attenuated by the bogie suspension system can be extracted when the train is running at a constant speed. Secondary suspension.

When the train speed is 350km/h, the wheel-to-rail force curve of the front bogie of the train with frequency (as shown in Figure 15), and the curve of the secondary suspension force of the front bogie of the train with frequency (such as As shown in Figure 16), since the secondary suspension force does not have a large peak above 200Hz, the results in the frequency range of 200-4000Hz are not shown in the figure.

2. Determine the noise excitation energy of the wheel

When the train runs straight at a constant speed, the wheel noise mainly refers to the rolling noise, without considering the impact noise and curve whistling noise. The vibration of the wheel under the action of the wheel-rail force will cause the vibration of the surrounding air medium, and then generate sound waves to radiate outward to form wheel noise excitation.

In order to predict wheel vibration and sound, it is first necessary to establish 8 wheel finite element models to form 4 wheel pairs. Train wheels are basically axisymmetric structures with fixed cross-sectional features along the direction of the azimuth angle, including shaft holes, hubs, webs, rims, rims and treads. In order to improve the consistency between the solid model and the simulation model, these The features must be reflected in the modeling. In addition, the wheels are discretized with tetrahedron elements, and the material properties of the wheels are defined. The restrained modal characteristics of each wheel are calculated by the Lanczos method, and then the vibration response of the wheel under the excitation of the vertical wheel-rail force is calculated by the mode superposition method or the direct solution method. The normal vibration velocity of the outer surface of the wheel is extracted as the boundary condition, and a wheel boundary element model with a maximum element side length of 14 mm is established, which forms a wheel structural vibration-acoustic coupling model with the wheel finite element model13. The radiated sound power level spectrum of the wheel is calculated by using the multi-pole boundary element algorithm. Using the field point model 10 shaped like the surface of the car body, the acoustic excitation formed by the wheel noise on the surface of the car body is extracted. After the wheel noise propagates through the air, the sound pressure level distribution cloud map with a frequency of 2000 Hz is formed on the surface of the car body (as shown in Figure 18 As shown), two observation points, bogie center 11 and car body side center 17, are selected to obtain the acoustic characteristics of wheel noise (as shown in Figure 19). Finally, the field point model is divided into regions according to the SEA subsystem of the car body structure. Each region Calculate the average value of the wheel noise sound pressure level as the sound pressure level result of the wheel noise excitation value corresponding to this area.

3. Determining the Noise Excitation Energy of the Orbit

Rail rolling noise plays a dominant role in track noise. When a train runs at a constant speed in a straight line, only the noise of the rail under the excitation of the vertical track force is considered. Based on the actual track structure, a complete finite element model of the slab structure is established. The track model includes rails, fasteners, track slabs and concrete bases. The rails are discrete using tetrahedral elements, the ballast bed is discrete using hexahedral elements, and the fasteners are simplified as spring damping elements.

The calculation of the vibro-acoustic response of the track is similar to the calculation of the vibro-acoustic response of the wheel. The track structure vibration-acoustic coupling model17 is composed of the track finite element model and the track boundary element model. The analysis model of acoustic excitation formed on the surface of the car body after the noise propagates through the air (as shown in Figure 20). ), the acoustic characteristics of the track noise at the two observation points of the bogie center 15 and the car body side center 16 (as shown in Figure 22), and finally the field point model is divided into regions according to the SEA subsystem of the car body structure, and the track noise in each region Calculate the average value of the sound pressure level as the sound pressure level result of the track noise excitation value corresponding to this area.

4. Determination of aerodynamic noise excitation energy

Computational Fluid Dynamics (CFD) method is used to establish a wind tunnel model of the high-speed train (as shown in Figure 23). The wind tunnel model is used to simulate the interaction between the air flow field and the train surface, and extract the pulsating pressure and aerodynamic noise. The wind tunnel model includes an air inlet 18 , a vehicle under test 19 , a leading vehicle 20 , a trailing vehicle 21 , a wind tunnel profile 22 and an air outlet 23 . When the width and height of the wind tunnel reach 5 times the width and height of the vehicle, the profile of the wind tunnel has little influence on the flow field on the surface of the vehicle body. In addition, the frequency domain upper limit f _max of the calculation results is determined by the calculation step size Δt in the time domain. Table 2 below shows the parameters of the train wind tunnel model and large eddy simulation.

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; t</span>}}$

Table 2 Train wind tunnel model and large eddy simulation parameters

Since the large eddy simulation (LES) has certain requirements for the initial flow field, the standard κ-ε turbulence model is first used to calculate the steady flow field, and the cloud map of the fluctuating pressure level distribution on the surface of the tested vehicle is obtained by using the LES calculation (the results at 2000 Hz are shown in Figure 24 shown). After converting the pulsating pressure into a dipole sound source, combined with the indirect boundary element method (IBEA), the aerodynamic noise on the surface of the car body when the train is running at a speed of 350 km/h can be obtained, and extracted through a field point model shaped like a car body.

According to the above simulation method, the acoustic characteristics of the aerodynamic noise at the center of the bogie and the center of the side of the car body are obtained (as shown in Fig. The average value of the regional aerodynamic noise sound pressure level is calculated as the corresponding aerodynamic noise excitation value sound pressure level result of the region.

5. Determine the noise excitation energy in the equipment compartment

The characteristics of the noise source in the equipment compartment are very complex, including the rotational noise of the fan, the electromagnetic noise of the traction converter/transformer, the air noise of the apron fence, and the mechanical noise of the equipment operation, etc. It is difficult to extract various noise sources based on simulation methods , the total noise in the cabin can be directly measured by arranging acoustic sensors at different positions in the equipment cabin. Since the acoustic environment in the equipment cabin is similar to the reverberation sound field when the train runs at a certain speed, the noise measured at the measuring point can be used as a reverberation excitation to act on the acoustic cavity subsystem in the cabin; the equipment calculated according to the sound pressure level formula Cabin reverberation noise stimulus:

$\mathrm{<span\; class="notranslate">\; L</span>}\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 20</span>}\mathrm{<span\; class="notranslate">\; lg</span>}\frac{\mathrm{<span\; class="notranslate">\; p</span>}}{{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}$

In the formula, Lp is the noise excitation sound pressure level in the equipment cabin, in dB; p is the sound pressure measured at the measuring point in the equipment cabin, in Pa; p ₀ is the reference sound pressure, and p ₀ =20μPa in the air.

According to the above-mentioned test and calculation method, the noise excitation of the equipment cabin is obtained (as shown in Figure 26).

6. Determine the radiated noise of the train structure under mechanical excitation

To predict structural radiated noise in a vehicle under the action of mechanical excitation, it is first necessary to establish a finite element model of the vehicle body, which mainly includes three subsystems of the body in white, interior system and traction drive system. The Lanczos method is used to calculate the overall modal frequency and mode shape of each order of the finite element model of the curb car body, referring to the first-order vertical direction of the curb car body in the "Interim Regulations on the Strength Design and Test Appraisal of Railway Vehicles with Speeds Above 200km/h" The regulation that the bending natural frequency should not be lower than 10Hz and the comparison of the modal test of the whole car body ensure the accuracy of the finite element model of the whole car body. The secondary suspension force of the bogie acts on the prepared car body to excite the vibration response of the car body, extract the vertical vibration velocity of the inner surface of the car body, and predict the structural response of the car under the excitation of the secondary suspension force based on the boundary element method (BEA) noise (as shown in Figure 27).

V. Analysis and prediction of interior noise

Referring to Figure 27 and Figure 28, the calculated SEA model parameters such as the loss factor in the acoustic cavity, the sound absorption coefficient, and the sound insulation of the panel structure, as well as the external input excitations received by the car body, such as wheel noise excitation, track noise excitation, car body The surface aerodynamic noise excitation and equipment cabin noise excitation are added to the SEA model of the train body structure and internal and external acoustic cavities to obtain a complete SAEF analysis and prediction model of interior acoustic excitation noise (as shown in Figure 28). The acoustic response of each acoustic cavity subsystem in the car can be obtained by using the SAEF analysis and prediction model of the acoustic excitation noise inside the car. Referring to the national standard GB/T12816-2006 "Railway Passenger Car Interior Noise Limits and Measurement Methods", select the center of the car and 1.2m from the floor The left and right acoustic cavity subsystems are predicted to obtain the acoustic excitation noise in the car.

Apply the secondary suspension force to the curb vehicle body and add the interior noise prediction boundary element model to obtain the structural vibration-acoustic coupling model for interior mechanical excitation noise prediction. Using this model, the mechanical excitation acoustic response of the body mechanism can be obtained. Refer to the national According to the standard GB/T12816-2006 "Railway Passenger Car Interior Noise Limits and Measurement Methods", the center of the car and the position in the car about 1.2m away from the floor are selected for prediction, and the mechanical excitation noise in the car is obtained.

Through the sound wave superposition principle, the results of the vehicle interior noise under the acoustic excitation and the vehicle interior noise under the mechanical excitation obtained by the SAEF method are superimposed to obtain the total interior noise under the complete excitation. The superposition principle is as follows:

Among them, L is the _total noise in the car, in dB; L _sound is the acoustic excitation noise in the car, in dB; L _machine is the mechanical excitation noise in the car, in dB.

Through the above formula, the curve of the total noise in the car with frequency can be obtained (as shown in Figure 29), and the total value of the weighted sound pressure level at the prediction point A can be obtained as 67.2dB(A). In order to verify the effectiveness of the prediction results of interior noise, according to the national standard GB/T12816-2006 "Railway Passenger Car Interior Noise Limits and Measurement Methods", the test car was tested for interior noise at a constant speed of 350km/h in a straight line, and the corresponding center position of the car was obtained The test results (as shown in Figure 29), the total value of the A-weighted sound pressure level is 65.0dB (A). It can be seen from the figure that in the analysis frequency range of 50-4000 Hz, the trend of the simulation and test sound pressure level curves of the central sound cavity in the car is generally consistent. Within 3dB, meet the engineering requirements. In addition, in the analysis frequency band, there is a difference of 2.2dB(A) between the simulation of the central acoustic cavity in the car and the total value of the A-weighted sound pressure level of the test, which is also controlled within a reasonable error range. The prediction result shows that the method of the present invention can solve its technical problems. problem, improving the calculation efficiency and prediction accuracy, and showing outstanding technical effects such as the reliability and effectiveness of the SAEF method of the present invention in predicting the acoustic response of high-speed trains under the excitation coupling of multi-physics fields.

Claims (9)

1. a noise analysis Forecasting Methodology in high-speed train, set up bullet train reorganize and outfit car body model andBody in white structures statistics model of energy, reorganizes and outfit car body model by body in white FEM model and train interior trimThe acquisition that intercouples of system FEM model and traction drive FEM model, is characterized in that:

Dialogue body structure statistic energy analysis model is simplified, and obtains body in white designs simplification statistics energyAnalytical model partition sub-system, set up respectively inner operatic tunes statistics energy by interior space and the car external space and divideAnalyse model and outside operatic tunes statistic energy analysis model, and carry out subsystem division;

Obtain the sound insulation property parameter of the each plate structure of vehicle body, and it is directly loaded into body in white designs simplificationOn car body plate in statistic energy analysis model, obtain each subsystem in inner operatic tunes statistic energy analysis modelThe statistic energy analysis parameter of system, and be loaded into each subsystem of inner operatic tunes statistic energy analysis modelIn;

Obtain the suffered outside acoustic excitation sources energy of car body, and be applied to outside operatic tunes statistic energy analysis mouldIn type, after the decay of body construction plate sound insulation property in body in white designs simplification statistic energy analysis modelArrive the operatic tunes in car, obtain reorganize and outfit car body under compartment secondary suspension power effect to irradiation structure noise energy in carAmount, then carries out internal car noise analyses and prediction.

2. noise analysis Forecasting Methodology in a kind of high-speed train according to claim 1, its feature existsIn: described body in white structures statistics model of energy is simplified and partition sub-system in the following ways:Retain the main foundation plate structure of railway car, and car body plate aluminium profile structure is reduced to flat board and songPanel construction, then adopts SEA method to divide train vehicle body, obtains several structuresRegion, each structural region is further subdivided into again several subsystems, then each structure subsystem according to them originallyIncidence relation is set up in body mutual alignment, obtains body in white simplified structure SEA frame model, ties as body in whiteStructure is simplified statistic energy analysis model.

3. noise analysis Forecasting Methodology in a kind of high-speed train according to claim 2, its feature existsIn: described main foundation piece plate comprise vehicle window (1), vehicle window partition (2), side wall top (3),Side wall bottom (4), roof middle part (5), roof both sides (6), access door wall (7), equipment compartment (8)And floor (9), the quantity of structural region is identical with the quantity of main foundation piece plate.

4. noise analysis Forecasting Methodology in a kind of high-speed train according to claim 1, its feature existsIn: the described train exterior operatic tunes is divided according to the subsystem of body in white designs simplification statistic energy analysis modelSituation is discrete is each outside little operatic tunes, the little operatic tunes in each outside and the statistic energy analysis of body in white designs simplificationThe subsystem outer surface of model is corresponding and intercouple, coupling surface measure-alike, and adjacent little soundBetween chamber, intercouple, make the outside operatic tunes cover the whole bodywork surface except end.

5. noise analysis Forecasting Methodology in a kind of high-speed train according to claim 1, its feature existsIn: the inner operatic tunes of described train is divided according to the subsystem of body in white designs simplification statistic energy analysis modelSituation is each inner little operatic tunes by interior spatial spreading, each inner little operatic tunes and the letter of body in white structureThe subsystem inner surface of changing statistic energy analysis model is corresponding also to intercouple, and coupling surface measure-alike removesThe inner operatic tunes of train beyond equipment compartment on train height and width, be divided into three layers.

6. noise analysis Forecasting Methodology in a kind of high-speed train according to claim 1, its feature existsIn: the suffered outside acoustic excitation sources energy of described car body comprises the noise excitation energy of wheel, the noise of trackReverberation noise excitation energy in excitation energy, aerodynamic noise excitation energy and equipment compartment.

7. noise analysis Forecasting Methodology in a kind of high-speed train according to claim 1, its feature existsIn: the outside acoustic excitation sources energy of the described suffered outside of car body specifically calculates and obtains in the following ways:

1) calculate train wheel rail interaction forces and the compartment secondary suspension power of obtaining:

1.1) adopt vehicle-orbit coupling rigidity many-body dynamics method, set up the many-body dynamics mould of car bodyType;

1.2) under the excitation of track irregularity, by dynamics of rigid bodies simulation calculation, can obtain train withAt the uniform velocity under straight-line travelling, analyze the mutual power of wheel track on train gravity direction and the suspension of process bogie in frequency rangeThe secondary suspension power on compartment that acts on after system attenuation;

2) calculate the noise excitation that obtains wheel:

2.1) set up train wheel FEM model and form 4 wheels pair;

2.2) adopt Lanczos method to calculate the constraint characteristics of mode of single wheel, be applied with for each wheelState step 1.2) the mutual masterpiece of wheel track that obtains on gravity direction is vertical wheel rail force, then adopts mode stackMethod or direct solution calculate the vibratory response of wheel under vertical wheel rail force excitation;

2.3) set up wheel acoustic radiation boundary element model, adopt Multipole BEM (FMBEM) to calculate wheelStructure radiated noise;

2.4) set up car body surface field point model, extract wheel noise car body surface form acoustically-driven;

3) calculate the noise excitation that obtains track:

3.1) set up complete track FEM model;

3.2) model trajectory being applied to above-mentioned steps 1.2) the mutual masterpiece of wheel track that obtains on gravity direction is verticalWheel rail force, adopts direct solution to calculate the vibratory response of track under vertical wheel rail force excitation;

3.3) extract track vibration response, set up track acoustic radiation boundary element model, adopt multipole boundary elementMethod (FMBEM) is calculated track structure radiated noise;

3.4) set up car body surface field point model, extract track noise car body surface form acoustically-driven;

4) calculate and obtain aerodynamic noise excitation:

4.1) adopting Fluid Mechanics Computation is the pneumatic test of the simulation CFD mould that CFD method is set up bullet trainType;

4.2) adopt companied with k-s turbulence model to carry out steady flow field calculating, adopt subsequently large eddy simulation (LES)Solve instantaneous flow field and reorganize and outfit the fluctuation pressure on the middle node train body surface of car body model described in obtaining;

4.3) fluctuation pressure is converted into after sound source of the dipole, adopts indirect Boundary Element Method Analysis (IBEA) to obtainThe aerodynamic noise of train car body surface when at the uniform velocity travelling;

4.4) set up car body surface field point model, extract aerodynamic noise car body surface form soundExcitation;

5) noise in experimental measurement equipment cabin excitation:

5.1) near the cooling motor of high-speed trains cabin, arrange sound pressure sensor, measure equipment compartment and make an uproarSound;

5.2) train is according to traveling at the uniform speed, and the acoustic enviroment in train apparatus cabin is similar to reverberation chamber, will recordEquipment compartment noise as reverberation incentive action on the subsystem of inner operatic tunes statistic energy analysis model, pressReverberation noise excitation in sound pressure level formula computing equipment cabin:

$Lp=20lg\frac{p}{p_0}$

In formula, Lp is equipment interior noise excitation sound pressure level, and unit is dB; P is that equipment compartment measuring point place recordsAcoustic pressure, unit is Pa; p₀For reference acoustic pressure, p in air₀＝20μPa；

6) above-mentioned four excitations are coupled and form the suffered final outside acoustic excitation sources energy of car body.

8. noise analysis Forecasting Methodology in a kind of high-speed train according to claim 1, its feature existsIn: the sound insulation property parameter of the described each plate structure of vehicle body comprises the oise insulation factor of car body main foundation piece plate,In inner operatic tunes statistic energy analysis model, the statistic energy analysis parameter of each subsystem comprises the interior damage of the operatic tunes in carConsume the acoustic absorptivity of the factor, interior decoration system and reorganize and outfit the radiated noise of car body under mechanical excitation effect.

9. noise analysis Forecasting Methodology in a kind of high-speed train according to claim 1, its feature existsIn: described internal car noise analyses and prediction specifically in the following ways:

1) the subsystem statistic energy analysis parameter calculating and outside acoustic excitation sources energy are joined whiteBody structure is simplified statistic energy analysis model, outside operatic tunes statistic energy analysis model and inner operatic tunes statisticsModel of energy, forms acoustically-driven noise analysis forecast model in car;

2) secondary suspension masterpiece is used in and reorganizes and outfit on car body model and add internal car noise predicted boundary meta-model,Obtain structural vibration-acoustics coupling model of mechanical excitation noise in pre-measuring car;

3) utilize acoustically-driven noise analysis forecast model in car to obtain the acoustic response of each operatic tunes subsystem in car,With reference to standard GB/T/T12816-2006 " restriction of railroad coach internal noise and measuring method ", choose carInterior center, analyze apart from the operatic tunes subsystem of about floor 1.2m, obtain in the car under acoustic excitation and make an uproarSound level;

4) utilize mechanical excitation noise in pre-measuring car structural vibration---acoustics coupling model obtains body constructionAcoustic response under mechanical excitation, chooses Che Nei center, analyzes apart from the position of floor 1.2m left and right,Obtain the internal car noise level under mechanical excitation;

5), by sound wave principle of stacking, obtain under internal car noise under acoustic excitation and mechanical excitation above-mentionedInternal car noise result superposes in the following ways, obtains overall noise in the car under complete incentive action, completeNoise analysis prediction in high-speed train in pairs:

Wherein L_AlwaysFor overall noise in car, unit is dB; L_SoundFor acoustic excitation noise in car, unit is dB; L_MachineFor mechanical excitation noise in car, unit is dB.