Method and device for estimating random incident sound transmission loss of small-size sample and storage medium

Abstract

The invention relates to the technical field of material sound transmission loss measurement, in particular to a small-size sample random incidence sound transmission loss estimation method and device and a storage medium, and the method comprises the steps: obtaining a small-size sample of which the surface size accords with a measurement condition; obtaining a normal incidence sound transmission loss measurement result of the small-size sample, constructing a sound transmission loss difference calculation model according to the configuration layer number of the small-size sample, and obtaining a normal incidence and random incidence sound transmission loss difference result based on the sound transmission loss difference calculation model; and based on the normal incidence sound transmission loss measurement result and the normal incidence and random incidence sound transmission loss difference result, obtaining a random incidence sound transmission loss estimation value, and according to the random incidence sound transmission loss estimation value, evaluating the sound insulation effect of the small-size sample. According to the method, the random incident sound transmission loss of small-size samples with different configurations can be estimated, and the method has relatively high accuracy and applicability.

Description

Technical Field

[0001] The present invention relates to the technical field of material sound transmission loss measurement, and in particular to a method, a device and a storage medium for estimating the random-incident sound transmission loss of a small-size sample. Background Art

[0002] The sound insulation performance of buildings is an important parameter for evaluating the quality of construction projects. The reverberation chamber method and the impedance tube method are widely used in the measurement of sound transmission loss of materials. At present, the reverberation chamber method is mostly used for the detection of the sound insulation performance of building walls, because the test structure size and installation boundary conditions are closer to the actual use of the building, and the results are more authoritative, but it needs to be carried out in a special sound insulation laboratory, large-sized wall samples need to be installed, and large and complex equipment needs to be equipped, which is time-consuming, labor-intensive and costly. If the simple normal incidence sound insulation performance measurement results can be used to estimate the random incidence sound insulation performance that is closer to the actual use, a lot of costs can be saved.

[0003] Compared with traditional analytical methods such as modal superposition, numerical calculation methods based on high-order deformation theory are more suitable for the analysis of sound insulation performance of panels with more complex configurations. Existing studies on the relationship between normal incidence and random incidence sound transmission loss are mostly focused on the quality control area of ​​simple structures such as infinite panels, and rarely involve finite panels with more complex configurations and other sound insulation partitions. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method for estimating the random incidence sound transmission loss of small-sized samples, which aims to provide an efficient and accurate tool for predicting the random incidence sound transmission loss of small-sized samples (finite rectangular plates) in the stiffness control area and the quality control area, and is of great significance for improving the quality of construction projects and the efficiency of detection. The method comprises the following steps: S1: Obtain a small-sized sample whose surface size meets the measurement conditions, wherein the surface area of ​​the small-sized sample matches the inner cross-sectional size of the impedance tube used to place the small-sized sample; S2: obtaining the normal-incident acoustic transmission loss measurement result of the small-sized sample within the cutoff frequency of the impedance tube; and constructing an acoustic transmission loss difference calculation model according to the number of configuration layers of the small-sized sample, and obtaining the normal-incident and random-incident acoustic transmission loss difference results based on the acoustic transmission loss difference calculation model; S3: Based on the normal incidence sound transmission loss measurement result and the difference result between the normal incidence and random incidence sound transmission losses, an estimated value of the random incidence sound transmission loss is obtained, and according to the estimated value of the random incidence sound transmission loss, the sound insulation effect of the small-size sample is evaluated.

[0005] In one embodiment of the present invention, in step S2, the method for obtaining the normal-incidence acoustic transmission loss measurement result of the small-size sample is as follows: S21: placing the small-size sample in an impedance tube, scanning the impedance tube using a plane wave signal, and measuring the sound pressure and particle velocity at the front end and the end of the impedance tube respectively when the end of the impedance tube is open or closed, including: When the end of the impedance tube is open, the sound pressure and particle velocity are expressed as: , When the end of the impedance tube is closed, the sound pressure and particle velocity are expressed as: , in, is the transfer matrix of the small-size sample, Represents the front end of the impedance tube, is the front end sound pressure measured when the end of the impedance tube is open, is the end sound pressure measured when the end of the impedance tube is open, is the particle velocity at the front end measured when the end of the impedance tube is open, is the particle velocity at the end of the impedance tube measured when the end is open; Indicates the end of the impedance tube, is the front end sound pressure measured when the end of the impedance tube is closed, is the end sound pressure measured when the end of the impedance tube is closed, is the particle velocity at the front end measured when the end of the impedance tube is closed, is the particle velocity at the end of the impedance tube measured when the end is closed; S22: calculating the transfer matrix of the small-size sample according to the sound pressure and particle velocity at the front end and the end of the impedance tube; S23: Based on the transfer matrix, the normal-incident acoustic transmission loss of the small-size sample is obtained.

[0006] In one embodiment of the present invention, the normal incidence acoustic transmission loss of the small-sized sample is obtained. as follows: , in, is the normal incidence transmission coefficient, , To test the thickness of small size samples; 、 、 、 are all elements of the transfer matrix; is the characteristic impedance of air.

[0007] In one embodiment of the present invention, in step S2, the method for obtaining the difference between normal incidence and random incidence acoustic transmission loss is as follows: S24: Setting a preset threshold to determine whether the number of configuration layers of the small-size sample is greater than the preset threshold: If the number of configuration layers of the small-sized sample is greater than the preset threshold, in the quality control area, a normal incident sound wave and a random incident sound wave are incident on the surface of the small-sized sample to obtain an incident sound power of the normal incident sound wave and an incident sound power of the random incident sound wave; Based on the incident acoustic power of the normal incident acoustic wave and the incident acoustic power of the random incident acoustic wave, a finite element model of normal incident acoustic transmission loss and a finite element model of random incident acoustic transmission loss are respectively established in the quality control area; Since the difference between the normal-incidence sound wave and the random-incidence sound transmission loss in the stiffness control region is close to 0 dB, the sound transmission loss difference calculation model is obtained based on the finite element model of the normal-incidence sound transmission loss and the finite element model of the random-incidence sound transmission loss; If the number of configuration layers of the small-sized sample is less than or equal to the preset threshold, in the quality control area, under forced vibration, random sound waves are incident on the surface of the small-sized sample to calculate the random incidence transmission coefficient of the small-sized sample; According to the random incidence transmission coefficient, the random incidence sound transmission loss expression is obtained; Based on the known mass law expression of normal incidence sound transmission loss and the random incidence sound transmission loss expression, the sound transmission loss difference calculation model is obtained; S25: Based on the sound transmission loss difference calculation model, obtain the difference results of the normal incidence and random incidence sound transmission losses.

[0008] In one embodiment of the present invention, if the number of configuration layers of the small-sized sample is greater than the preset threshold, the acoustic transmission loss difference calculation model is: , in, is the finite element model of normal incidence sound transmission loss, is a finite element model of random incidence sound transmission loss; and stated The following sound transmission finite element model is used The expression is calculated to get: , in, is the incident sound power, , and are the incident angle and azimuth of the acoustic signal, respectively, S is the surface area of ​​the structure, For normal incident sound waves or random incident sound waves, when θ = 0 When , the incident sound power of the normal incident sound wave is obtained; represents the transmitted sound power, , represents transpose, is the amplitude of the normal vibration velocity of the structure; is the real part of the radiation impedance matrix Z, also called the radiation resistance matrix.

[0009] In one embodiment of the present invention, when When it is a normal incident sound wave, the normal incident sound wave is a plane sound wave, which is incident on the surface of the small-size sample at an angle θ, and its wave equation is: , in, is the plane acoustic wave amplitude, , , They represent the normal incident sound wave at x, y, z The wave vector component in the direction; when When it is a randomly incident sound wave, the randomly incident sound wave is the sum of N incoherent plane sound waves propagating in random directions, and its wave equation is: , in, is the plane acoustic wave amplitude, , , They represent the random incident sound waves at x, y, z The component of the wave vector in the direction.

[0010] In one embodiment of the present invention, if the number of configuration layers of the small-sized sample is less than or equal to the preset threshold, the acoustic transmission loss difference calculation model is: , in, is the known mass law expression for normal incidence sound transmission loss, is the frequency of the normally incident sound wave, is the surface density of the board, is the characteristic impedance of air; , is the random incidence transmission coefficient.

[0011] In one embodiment of the present invention, the random incidence transmission coefficient The calculation method is as follows: , in, A is the surface area of ​​the small sample, is the side length ratio of the small size sample, ≤1, , n Number the layers for small-size samples; represents the critical frequency of the panel supporting the shear stress; is the characteristic impedance of air; c is the speed of sound wave propagation in the medium.

[0012] Based on the same inventive concept, the present invention also provides a device for estimating the transmission loss of random-incidence sound of a small-sized sample, the device comprising an impedance tube, a signal generator, a power amplifier, a sound source amplifier and a digital acquisition and analysis system, the digital acquisition and analysis system being used to implement the steps of the above-mentioned method for estimating the transmission loss of random-incidence sound of a small-sized sample; The small-sized sample to be measured is installed in the impedance tube, and the signal generator is used to generate the initial sound wave signal required in the measurement process; the initial sound wave signal is amplified by the power amplifier to obtain a first sound wave signal; the sound source amplifier performs signal processing on the first sound wave signal to obtain a second sound wave signal; the second sound wave signal is transmitted to the impedance tube, so that the second sound wave signal and the sample to be measured interact with each other; The digital acquisition and analysis system processes and analyzes the collected sound wave signals to obtain the normal-incidence sound transmission loss of the sample to be tested; according to the number of configuration layers of the small-size sample, the digital acquisition and analysis system constructs normal-incidence and random-incidence sound transmission loss difference calculation models based on the finite element numerical analysis model and the theoretical prediction formula, and obtains the normal-incidence and random-incidence sound transmission loss difference results based on the sound transmission loss difference calculation model, and obtains the random-incidence sound transmission loss estimation value based on the normal-incidence sound transmission loss measurement results and the normal-incidence and random-incidence sound transmission loss difference results.

[0013] The present invention also provides a computer storage medium, which stores a computer software product. The computer software product includes several instructions for enabling a computer device to execute the steps of the above-mentioned method for estimating random-incidence sound transmission loss of small-size samples.

[0014] The above technical solution of the present invention has the following advantages compared with the prior art: The present invention can more accurately estimate the random-incidence sound transmission loss of small-sized samples by combining the normal-incidence sound transmission loss measurement results of small-sized samples and the constructed sound transmission loss difference calculation model. This method not only takes into account the physical properties of the sample, but also takes into account the directionality of the incident sound wave, thereby improving the accuracy of the sound insulation effect evaluation. In addition, the present invention is applicable to small-sized samples of various configurations and layers, whether single-layer or multi-layer structures, which can be adapted by adjusting the sound transmission loss difference calculation model. This increases the versatility and practicality of the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 is a flow chart of a method for estimating the transmission loss of random-incident sound of a small-size sample provided in the first embodiment of the present invention; Figure 2 It is a specific flow chart of the method for estimating the transmission loss of random-incident sound of a small-size sample provided in the first embodiment of the present invention; Figure 3 It is a comparison diagram between the finite element numerical calculation model of the present invention and the actual measurement result; Figure 4 This is the result diagram of normal incidence and random incidence sound transmission loss obtained by constructing the finite element numerical analysis model of the sandwich panel in the quality control area; Figure 5 This is a comparison result diagram of the difference in sound transmission loss of a single-layer aluminum plate in the quality control area based on the finite element numerical analysis model and the theoretical formula prediction; Figure 6 Schematic diagram of the structure of a device for estimating the transmission loss of random-incident sound of a small-size sample provided in the second embodiment of the present invention; Explanation of the reference numerals in the specification: 10. Impedance tube; 20. Signal generator; 30. Power amplifier; 40. Sound source amplifier; 50. Digital acquisition and analysis system. DETAILED DESCRIPTION

[0016] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1

[0017] See also Figure 1 and Figure 2 As shown, the present invention provides a method for estimating the transmission loss of random-incidence sound of a small-sized sample, the method comprising the following steps: S1: Obtain a small-sized sample whose surface size meets the measurement conditions. To ensure that the transmission path of the sound wave is not disturbed, the surface area of ​​the small-sized sample matches the inner cross-sectional size of the impedance tube used to place it; S2: obtaining the normal-incident acoustic transmission loss measurement result of the small-sized sample within the cutoff frequency of the impedance tube; and constructing an acoustic transmission loss difference calculation model according to the number of configuration layers of the small-sized sample, and obtaining the normal-incident and random-incident acoustic transmission loss difference results based on the acoustic transmission loss difference calculation model; S3: Based on the normal incidence sound transmission loss measurement result and the difference result between the normal incidence and random incidence sound transmission losses, an estimated value of the random incidence sound transmission loss is obtained, and according to the estimated value of the random incidence sound transmission loss, the sound insulation effect of the small-size sample is evaluated.

[0018] Further, in step S2, within the cutoff frequency of the impedance tube, the method for obtaining the normal-incident acoustic transmission loss measurement result of the small-size sample is as follows: S21: The small-sized sample is placed in an impedance tube for an experimental test of normal-incidence sound transmission loss. A plane wave signal is used to scan the inside of the impedance tube. Within the cutoff frequency of the tube, for small-sized samples with different properties on the front and back sides, two measurements are generally performed using the end-opening and end-closing methods. The impedance of the tube end during the second measurement should be different from that during the first measurement, specifically: Under the condition that the end of the impedance tube is open or closed, the sound pressure and particle velocity at the front end and the end of the impedance tube are measured respectively, including: When the end of the impedance tube is open, the sound pressure and particle velocity are expressed as: , When the end of the impedance tube is closed, the sound pressure and particle velocity are expressed as: , in, is the transfer matrix of the small-size sample, Represents the front end of the impedance tube, is the front end sound pressure measured when the end of the impedance tube is open, is the end sound pressure measured when the end of the impedance tube is open, is the particle velocity at the front end measured when the end of the impedance tube is open, is the particle velocity at the end of the impedance tube measured when the end is open; Indicates the end of the impedance tube, is the front end sound pressure measured when the end of the impedance tube is closed, is the end sound pressure measured when the end of the impedance tube is closed, is the particle velocity at the front end measured when the end of the impedance tube is closed, is the particle velocity at the end of the impedance tube measured when the end is closed; S22: calculating the transfer matrix of the small-size sample according to the sound pressure and particle velocity at the front end and the end of the impedance tube; S23: Based on the transfer matrix, obtain the normal-incident acoustic transmission loss of the small-size sample ,as follows: , in, is the normal incidence transmission coefficient, , To test the thickness of small size samples; 、 、 、 are all elements of the transfer matrix; is the characteristic impedance of air.

[0019] Further, in step S2, the method for obtaining the difference between normal incidence and random incidence sound transmission loss is as follows: S24: Set a preset threshold t=3 to determine whether the number of configuration layers of the small-size sample is greater than the preset threshold: If the number of configuration layers of the small-size sample is greater than 3, a finite element numerical analysis model of the difference in acoustic transmission loss is constructed by using the equivalent single-layer method and the mixed layer-by-layer method, including: In the quality control area, a normal incident sound wave and a random incident sound wave are incident on the surface of the small-size sample respectively to obtain an incident sound power of the normal incident sound wave and an incident sound power of the random incident sound wave; Based on the incident acoustic power of the normal incident acoustic wave and the incident acoustic power of the random incident acoustic wave, a finite element model of normal incident acoustic transmission loss and a finite element model of random incident acoustic transmission loss are respectively established in the quality control area; Since the difference between the normal-incidence sound wave and the random-incidence sound transmission loss in the stiffness control region is close to 0 dB, based on the finite element model of the normal-incidence sound transmission loss and the finite element model of the random-incidence sound transmission loss, the sound transmission loss difference calculation model is obtained as follows: , in, is the finite element model of normal incidence sound transmission loss, is a finite element model of random incidence sound transmission loss; and stated The following sound transmission finite element model is used The expression is calculated to get: , in, is the incident sound power, , and are the incident angle and azimuth of the acoustic signal, respectively, S is the surface area of ​​the structure, For normal incident sound waves or random incident sound waves, when θ = 0 When , the incident sound power of the normal incident sound wave is obtained; represents the transmitted sound power, , represents transpose, is the amplitude of the normal vibration velocity of the structure; is the real part of the radiation impedance matrix Z, also called the radiation resistance matrix.

[0020] Furthermore, when When the incident sound wave is normal, the incident sound wave is a plane sound wave, with an angle of θ The wave equation incident on the surface of the small-size sample is: , in, is the plane acoustic wave amplitude, 、 、 They represent the normal incident sound wave at x, y, z The wave vector component in the direction; when When the incident sound wave is random, the diffuse sound field formed by the random incident sound wave can be regarded as the sum of N incoherent plane sound waves propagating in random directions, and its wave equation is:

[0021] in, is the plane acoustic wave amplitude, 、 、 They represent the random incident sound waves at x, y, z The component of the wave vector in the direction.

[0022] If the number of configuration layers of the small-sized sample is ≤3, a sound transmission loss difference calculation model is calculated using a theoretical formula, including: in a quality control area, under forced vibration, using random sound waves to be incident on the surface of the small-sized sample, and calculating the random incidence transmission coefficient of the small-sized sample; According to the random incidence transmission coefficient, the random incidence sound transmission loss expression is obtained; Based on the known mass law expression of normal incidence sound transmission loss and the random incidence sound transmission loss expression, the sound transmission loss difference calculation model is obtained as follows: , in, is the known mass law expression for normal incidence sound transmission loss, is the frequency of the normally incident sound wave, is the surface density of the board, is the characteristic impedance of air; , is the random incidence transmission coefficient of the forced vibration lower plate in the quality control area. Specifically, the random incidence transmission coefficient The calculation method is as follows: , in, A is the surface area of ​​the small sample, is the side length ratio of the small size sample, ≤1, , n Number the layers for small-size samples; represents the critical frequency of the panel supporting the shear stress, , B is the bending stiffness of the plate; for a single-layer homogeneous plate, the formula can be further expanded into an expression for the plate material properties: , ρ is the density, λ is Poisson's ratio, E is Young's modulus; is the characteristic impedance of air; c is the propagation speed of sound waves in the medium; S25: Based on the sound transmission loss difference calculation model, obtain the difference results of the normal incidence and random incidence sound transmission losses.

[0023] In order to verify the good accuracy of the finite element numerical analysis model, the equivalent single layer method and the mixed layer-by-layer method theory were used to construct the finite element numerical analysis model of the 2mm aluminum plate under the simply supported boundary conditions, and the finite element simulation results of the normal incidence sound transmission loss were calculated; in the laboratory, the four-microphone method was used to measure, and two microphones were placed at the front and end of the impedance tube with the same aluminum plate to obtain the measurement results of the normal incidence sound transmission loss. After the measurement was completed, the experimental measurement results were compared with the finite element simulation results. Figure 3 As shown in the figure, the agreement between the two is high, indicating that the established finite element numerical analysis model has good accuracy.

[0024] Based on the equivalent single-layer method and the mixed layer-by-layer method, the finite element model of the normal-incidence sound transmission loss and the finite element model of the random-incidence sound transmission loss of the sandwich board with a fixed boundary condition surface size of 0.2m×0.2m and each layer being 2mm gypsum board + 2mm fiberboard + 2mm gypsum board in the quality control area were established respectively. The estimated normal-incidence sound transmission loss curve and the random-incidence sound transmission loss curve are shown in Figure 4 As shown, the difference in the stiffness control area is close to 0dB.

[0025] like Figure 5 As shown in the figure, based on the finite element numerical analysis model and theoretical prediction formula constructed above, a detailed calculation and analysis was carried out for two single-layer aluminum plates of different sizes under the fixed boundary condition (the specification of test plate 1 is 2m×2m, the thickness is 2mm; the specification of test plate 2 is 3m×3m, the thickness is 6mm). The specific calculation content includes the normal incidence sound transmission loss curve and the random incidence sound transmission loss curve, and the difference between these two curves is calculated as a calculation implementation example to verify the consistency of the results of the finite element numerical calculation model and the theoretical prediction formula.

[0026] The calculation results show that within the quality control area, for samples with relatively simple structures and small sizes (i.e., test plate 1), the results obtained by the finite element numerical calculation model are highly consistent with the results obtained by the theoretical prediction formula. The normal incidence sound transmission loss curve obtained by both is consistent with the trend of the random incidence sound transmission loss curve, with an error of less than 2dB.

[0027] This result fully verifies the accuracy and reliability of the finite element numerical calculation model in predicting the sound transmission loss of single-layer aluminum plates, and also shows the applicability of the theoretical prediction formula under specific conditions.

[0028] In step S3, based on the normal incidence sound transmission loss measurement result The difference between the normal incidence and random incidence sound transmission loss results , and obtain the estimated value of random incidence sound transmission loss . Random-incidence sound transmission loss The main sources are the inevitable systematic errors and random errors in the actual measurement of normal-incidence sound transmission loss, the truncation errors in establishing the finite element numerical model, and the errors caused by simplification when deriving analytical expressions.

[0029] The random incidence sound transmission loss estimate As an indicator to measure the sound insulation performance of small-sized samples in practical applications, the sound insulation effect of the small-sized samples is evaluated. This evaluation result can provide a strong reference for material selection, structural design and construction quality control in construction projects, thereby ensuring that the construction projects meet the expected standards in terms of acoustic performance. Embodiment 2

[0030] Based on the same inventive concept as the first embodiment, the present invention also provides a device for estimating the transmission loss of random-incidence sound of a small-sized sample. Figure 6 As shown, the device includes an impedance tube 10, a signal generator 20, a power amplifier 30, a sound source amplifier 40 and a digital acquisition and analysis system 50, and the digital acquisition and analysis system 50 is used to implement the steps of the random incident sound transmission loss estimation method for small-size samples described in the first embodiment above; The impedance tube 10 usually has a specific size and shape to ensure that the propagation of sound waves in the tube meets the expected acoustic characteristics, providing a controllable acoustic test environment for the sample to be tested. The small-sized sample to be tested is installed in the impedance tube 10, and the signal generator 20 is used to generate the initial sound wave signal (normal incident sound wave or random incident sound wave) required in the measurement process.

[0031] In order to optimize the transmission of the acoustic wave signal in the impedance tube 10 and minimize the signal attenuation and the absorption of the acoustic wave signal by the sample to be tested, the power of the initial acoustic wave signal is amplified by the power amplifier 30 to obtain an amplified first acoustic wave signal to form an effective acoustic wave field in the impedance tube 10; the sound source amplifier 40 further enhances the power and stability of the acoustic wave signal, that is, the first acoustic wave signal is subjected to signal processing operations such as filtering and phase adjustment to obtain a second acoustic wave signal; the second acoustic wave signal is transmitted to the impedance tube 10 to promote the interaction between the second acoustic wave signal and the sample to be tested.

[0032] The digital acquisition and analysis system 50 integrates multiple sensors, data acquisition equipment and data analysis modules. Two sensors are placed at the front end and the end of the impedance tube 10 respectively. The sensors are used to collect the sound wave signal after passing through the small-sized sample to be tested; the data acquisition equipment converts the collected sound wave signal into digital data for storage; the data analysis module processes and analyzes the collected sound wave signal to obtain the normal-incident sound transmission loss of the sample to be tested.

[0033] Furthermore, according to the number of configuration layers of the small-size sample, the data analysis module constructs a calculation model for the difference in sound transmission loss under normal incidence and random incidence based on the finite element numerical analysis model and the theoretical prediction formula, respectively, and obtains the difference result of the sound transmission loss under normal incidence and random incidence based on the sound transmission loss difference calculation model. Based on the normal incidence sound transmission loss measurement result and the difference result of the sound transmission loss under normal incidence and random incidence, an estimated value of the sound transmission loss under random incidence is obtained, and according to the random incidence sound transmission loss value, the sound insulation effect of the sample to be tested is evaluated. Embodiment 3

[0034] The present invention also provides a computer storage medium, which stores a computer software product. The computer software product includes several instructions for enabling a computer device to execute the steps of the method for estimating random-incidence sound transmission loss of small-size samples described in the above-mentioned embodiment 1.

[0035] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0036] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0037] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0038] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0039] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for estimating the transmission loss of random-incidence sound for small-size samples, characterized in that: The following steps are involved: S1: Obtain a small-sized sample whose surface size meets the measurement conditions, wherein the surface area of ​​the small-sized sample matches the inner cross-sectional size of the impedance tube used to place the small-sized sample; S2: obtaining the normal-incident acoustic transmission loss measurement result of the small-sized sample within the cutoff frequency of the impedance tube; and constructing an acoustic transmission loss difference calculation model according to the number of configuration layers of the small-sized sample, and obtaining the normal-incident and random-incident acoustic transmission loss difference results based on the acoustic transmission loss difference calculation model; S3: Based on the normal incidence sound transmission loss measurement result and the difference result between the normal incidence and random incidence sound transmission losses, an estimated value of the random incidence sound transmission loss is obtained, and according to the estimated value of the random incidence sound transmission loss, the sound insulation effect of the small-size sample is evaluated.

2. The method for estimating the transmission loss of random-incidence sound of small-size samples according to claim 1 is characterized in that: In step S2, within the cutoff frequency of the impedance tube, the method for obtaining the normal-incident acoustic transmission loss measurement result of the small-size sample is as follows: S21: placing the small-size sample in an impedance tube, scanning the impedance tube using a plane wave signal, setting the end of the impedance tube to an open state and a closed state, respectively, and measuring the sound pressure and particle velocity at the front end and the end of the impedance tube for each state, respectively, including: When the end of the impedance tube is open, the sound pressure and particle velocity are expressed as: ， When the end of the impedance tube is closed, the sound pressure and particle velocity are expressed as: ， in, is the transfer matrix of the small-size sample, Represents the front end of the impedance tube, is the front end sound pressure measured when the end of the impedance tube is open, is the end sound pressure measured when the end of the impedance tube is open, is the particle velocity at the front end measured when the end of the impedance tube is open, is the particle velocity at the end of the impedance tube measured when the end is open; Indicates the end of the impedance tube, is the front end sound pressure measured when the end of the impedance tube is closed, is the end sound pressure measured when the end of the impedance tube is closed, is the particle velocity at the front end measured when the end of the impedance tube is closed, is the particle velocity at the end of the impedance tube measured when the end is closed; S22: calculating the transfer matrix of the small-size sample according to the sound pressure and particle velocity at the front end and the end of the impedance tube; S23: Based on the transfer matrix, the normal-incident acoustic transmission loss of the small-size sample is obtained.

3. The method for estimating the transmission loss of random-incidence sound of small-size samples according to claim 2, characterized in that: The normal-incident acoustic transmission loss of the small-size sample is obtained as follows: ， in, is the normal incidence transmission coefficient, , To test the thickness of small size samples; 、 、 、 are all elements of the transfer matrix; is the characteristic impedance of air.

4. The method for estimating the transmission loss of random-incidence sound of small-size samples according to claim 1, characterized in that: In step S2, the method for obtaining the difference between normal incidence and random incidence sound transmission loss is as follows: S24: Setting a preset threshold to determine whether the number of configuration layers of the small-size sample is greater than the preset threshold: If the number of configuration layers of the small-sized sample is greater than the preset threshold, in the quality control area, a normal incident sound wave and a random incident sound wave are incident on the surface of the small-sized sample to obtain an incident sound power of the normal incident sound wave and an incident sound power of the random incident sound wave; Based on the incident acoustic power of the normal incident acoustic wave and the incident acoustic power of the random incident acoustic wave, a finite element model of normal incident acoustic transmission loss and a finite element model of random incident acoustic transmission loss are respectively established in the quality control area; Since the difference between the normal-incidence sound wave and the random-incidence sound transmission loss in the stiffness control region is close to 0 dB, the sound transmission loss difference calculation model is obtained based on the finite element model of the normal-incidence sound transmission loss and the finite element model of the random-incidence sound transmission loss; If the number of configuration layers of the small-sized sample is less than or equal to the preset threshold, in the quality control area, under forced vibration, random sound waves are incident on the surface of the small-sized sample to calculate the random incidence transmission coefficient of the small-sized sample; According to the random incidence transmission coefficient, the random incidence sound transmission loss expression is obtained; Based on the known mass law expression of normal incidence sound transmission loss and the random incidence sound transmission loss expression, the sound transmission loss difference calculation model is obtained; S25: Based on the sound transmission loss difference calculation model, obtain the difference results of the normal incidence and random incidence sound transmission losses.

5. The method for estimating the transmission loss of random-incidence sound of small-size samples according to claim 4, characterized in that: If the number of configuration layers of the small-sized sample is greater than the preset threshold, the acoustic transmission loss difference calculation model is: ， in, is the finite element model of normal incidence sound transmission loss, is a finite element model of random incidence sound transmission loss; and stated The following sound transmission finite element model is used The expression is calculated to get: ， in, is the incident sound power, , and are the incident angle and azimuth of the acoustic signal, respectively, S is the surface area of ​​the structure, For normal incident sound waves or random incident sound waves, when θ = 0 When , the incident sound power of the normal incident sound wave is obtained; represents the transmitted sound power, , represents transpose, is the amplitude of the normal vibration velocity of the structure; is the real part of the radiation impedance matrix Z, also called the radiation resistance matrix.

6. The method for estimating the transmission loss of random-incidence sound of small-size samples according to claim 5, characterized in that: when When it is a normal incident sound wave, the normal incident sound wave is a plane sound wave, which is incident on the surface of the small-size sample at an angle θ, and its wave equation is: ， in, is the plane acoustic wave amplitude, , , They represent the normal incident sound wave at x, y, z The wave vector component in the direction; when When it is a randomly incident sound wave, the randomly incident sound wave is the sum of N incoherent plane sound waves propagating in random directions, and its wave equation is: ， in, is the plane acoustic wave amplitude, , , They represent the random incident sound waves at x, y, z The component of the wave vector in the direction.

7. The method for estimating the transmission loss of random-incidence sound of small-size samples according to claim 4, characterized in that: If the number of configuration layers of the small-sized sample is less than or equal to the preset threshold, the acoustic transmission loss difference calculation model is: ， in, is the known mass law expression for normal incidence sound transmission loss, is the frequency of the normally incident sound wave, is the surface density of the board, is the characteristic impedance of air; , is the random incidence transmission coefficient.

8. The method for estimating the transmission loss of random-incidence sound of small-size samples according to claim 7, characterized in that: The random incidence transmission coefficient The calculation method is as follows: ， in, A is the surface area of ​​the small sample, is the side length ratio of the small size sample, ≤1, , n Number the layers for small-size samples; represents the critical frequency of the panel supporting the shear stress; is the characteristic impedance of air; c is the speed of sound wave propagation in the medium.

9. A device for estimating the transmission loss of random-incidence sound of a small-size sample, characterized in that: It includes an impedance tube, a signal generator, a power amplifier, a sound source amplifier and a digital acquisition and analysis system, wherein the digital acquisition and analysis system is used to implement the steps of the random-incident sound transmission loss estimation method for small-size samples as described in any one of claims 1 to 8; The small-sized sample to be measured is installed in the impedance tube, and the signal generator is used to generate the initial sound wave signal required in the measurement process; the initial sound wave signal is amplified by the power amplifier to obtain a first sound wave signal; the sound source amplifier performs signal processing on the first sound wave signal to obtain a second sound wave signal; the second sound wave signal is transmitted to the impedance tube, so that the second sound wave signal and the sample to be measured interact with each other; The digital acquisition and analysis system processes and analyzes the collected sound wave signals to obtain the normal-incidence sound transmission loss of the sample to be tested; according to the number of configuration layers of the small-size sample, the digital acquisition and analysis system constructs normal-incidence and random-incidence sound transmission loss difference calculation models based on the finite element numerical analysis model and the theoretical prediction formula, and obtains the normal-incidence and random-incidence sound transmission loss difference results based on the sound transmission loss difference calculation model, and obtains the random-incidence sound transmission loss estimation value based on the normal-incidence sound transmission loss measurement results and the normal-incidence and random-incidence sound transmission loss difference results.

10. A computer storage medium, characterized in that: The computer storage medium stores a computer software product, which includes several instructions for enabling a computer device to execute the steps of the method for estimating random-incidence sound transmission loss of small-size samples as described in any one of claims 1 to 8.

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