A structural layout design method for automotive acoustic package

Abstract

The present invention discloses a method for designing the structural layout of an automobile acoustic package, which includes: using VA One to perform acoustic package simulation, including model cleaning, SEA model establishment, acoustic package establishment, and acoustic package optimization. The present invention first removes irrelevant parts of the vehicle body and ribs through model cleaning, retains large-area FE system panels, and then establishes an acoustic package based on the whole vehicle SEA model in conjunction with the modeling of the vehicle's external acoustic cavity and the vehicle's internal acoustic cavity, and then continuously performs optimization work, which is highly efficient, accurate, and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile acoustic packages, and in particular relates to a structural layout design method of an automobile acoustic package. Background Art

[0002] The automotive acoustic package is an acoustic material package designed to achieve the NVH performance of the entire vehicle, such as the front sound insulation pad, carpet, engine hood insulation cotton, ceiling sound-absorbing cotton, spare tire cover, etc.; the acoustic package is a means of reasonable use in the propagation path from the noise source to the interior of the vehicle, and is a practical method to effectively block the transmission of noise during the propagation process.

[0003] The noise of the whole vehicle is mainly divided into engine noise, transmission system noise, road noise, intake and exhaust noise, fan noise, wind noise, etc. Different acoustic packages can be used to deal with each type of noise. For engine and transmission system noise, sound-absorbing and insulating materials and barrier sealing materials are mainly used. For road noise, damping and vibration reduction materials are mainly used. For intake and exhaust and fan noise, sound-absorbing and insulating materials and barrier sealing materials are mainly used. For wind noise, barrier sealing materials are mainly used. Different acoustic package materials are used in different positions of the whole vehicle, mainly including engine hood insulation pads, front and rear wheel covers (cotton felt, sound-absorbing cotton, etc.), ceiling sound-absorbing cotton, front and rear door sound-absorbing cotton, tailgate sound-absorbing cotton, front wall sound insulation pads, carpets, etc.

[0004] Every problem point in the actual vehicle model can be solved by whole vehicle acoustic package simulation. Currently, major OEMs use VA One software for acoustic package simulation, which effectively solves the vibration and noise problems of the whole vehicle. However, VA One directly imports existing CAD models or unprocessed FEA models, which is inefficient in creating acoustic models, and the acoustic analysis model has poor matching with the geometric model data. At the same time, since the nodes are selected manually, it is difficult to select the corresponding nodes when establishing the subsystem connection relationship, and it is very easy to make mistakes when establishing the connection. Since the VA-One software cannot update the selected nodes on the established connection, it is often necessary to delete the original connection and then rebuild the new connection. The node selection operation needs to be repeated, which is very time-consuming. In this process, analysts are prone to visual fatigue.

[0005] Therefore, developing an acoustic modeling method with high efficiency, accuracy and reliability is of great significance for the successful implementation of acoustic performance analysis of parts. Summary of the invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a method for designing the structural layout of an automobile acoustic package, thereby avoiding the troubles of low efficiency and insufficient accuracy in the previous layout design of automobile acoustic packages.

[0007] In order to solve the above technical problems, the present invention discloses a method for designing the structural layout of an automobile acoustic package, which comprises: using VA One to perform acoustic package simulation, including model cleaning, SEA model establishment, acoustic package establishment, and acoustic package optimization.

[0008] According to one embodiment of the present invention, the above-mentioned model cleaning includes performing finite element analysis on the whole vehicle, establishing a door FE model, a body FE model, and an interior FE model, and importing them into VA One to form a door SEA model, a body SEA model, and an interior SEA model, and VA One implements modal number check and free edge check to obtain the whole vehicle SEA model.

[0009] According to one embodiment of the present invention, the whole vehicle SEA model is subjected to finite element analysis to obtain a half vehicle model, a firewall model, a carpet model, a door model, and an interior trim model.

[0010] According to one embodiment of the present invention, the acoustic package is established by the whole vehicle SEA model through its internal and external acoustic cavity modeling and the internal acoustic cavity modeling.

[0011] According to one embodiment of the present invention, the above-mentioned acoustic package optimization adopts the optimization module in the VA One software, and the optimization module can optimize the node coordinates, material density and flow resistance, SEA plate thickness, acoustic package thickness, and acoustic package coverage.

[0012] According to one embodiment of the present invention, the process of the above-mentioned acoustic package optimization is to select the acoustic package optimization position, set the initial coverage, variables and upper and lower limits, set the analysis frequency range, calculate the target acoustic cavity system sound pressure level, set the optimization target, set the optimization algorithm, optimization target, optimization variables, constraints, and optimize the solution.

[0013] Compared with the prior art, the present invention can achieve the following technical effects: Through model cleaning, we first remove irrelevant parts of the car body and ribs, retaining large areas of FE system panels, and then establish an acoustic package based on the SEA model of the whole vehicle in conjunction with the modeling of the exterior and interior sound cavities, followed by continuous optimization work with high efficiency, accuracy and reliability.

[0014] Of course, any product implementing the present invention does not necessarily need to achieve all of the above-mentioned technical effects at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1It is a flow chart of a method for designing a structure layout of an automotive acoustic package according to an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0017] Please refer to Figure 1 , Figure 1 It is a flow chart of a method for designing a structure layout of an automotive acoustic package according to an embodiment of the present invention.

[0018] As shown in the figure, a method for designing the structural layout of an automotive acoustic package includes: using VA One to simulate the acoustic package, including model cleaning, SEA model establishment, acoustic package establishment, and acoustic package optimization.

[0019] Model cleaning includes finite element analysis of the whole vehicle, building door FE model, body FE model, and interior FE model, and importing them into VA One to form door SEA model, body SEA model, and interior SEA model. VA One implements modal number check and free edge check to obtain the whole vehicle SEA model. Remove irrelevant parts and ribs of the body, and retain large areas of FE system panels.

[0020] The whole vehicle SEA model is subjected to finite element analysis to obtain the half vehicle model, firewall model, carpet model, door model, and interior model. The exterior and interior sound cavities of the vehicle are determined, and the acoustic package is established accordingly.

[0021] The acoustic package optimization uses the optimization module in the VA One software. The optimization module can optimize the node coordinates, material density and flow resistance, SEA plate thickness, acoustic package thickness, and acoustic package coverage.

[0022] The process of acoustic package optimization is to select the acoustic package optimization position, set the initial coverage, variables and upper and lower limits, set the analysis frequency range, calculate the sound pressure level of the target acoustic cavity system, set the optimization goal, set the optimization algorithm, optimization goal, optimization variables, constraints, and optimize the solution. Example 1

[0023] Taking the performance improvement of the acoustic package of a modified car as an example, the whole vehicle acoustic package needs to be optimized and reach the level of the benchmark car. First, the whole vehicle SEA model of the modified car needs to be built, and the whole vehicle model needs to be cleaned up according to the modeling and simulation process, and important subsystem panels are retained. The firewall FE model, carpet FE model, four-door and two-lid model, etc. are imported respectively.

[0024] The key subsystems are modeled in detail, mainly including firewalls and floors. Taking the firewall as an example, different areas are divided according to the important areas of the excitation source, areas of different board thicknesses, key via areas, and reinforced plate areas, and a complete firewall SEA model is established.

[0025] The material parameter definitions of sheet metal parts and interior plastic parts mainly include plate thickness, density, elastic modulus, and Poisson's ratio. At the same time, it is necessary to focus on the damping loss factor and modal density of the plate. These two parameters can be obtained through testing. In addition, the damping loss factor can also come from the acoustic package material, and the modal density can also be obtained through simulation.

[0026] Acoustic packages mainly include two categories, fiber materials and foam materials. Fiber materials have six acoustic parameters, and foam materials have nine acoustic parameters. The sound insulation pad inside the front enclosure is fiber material, and the carpet is fiber + foam material. In addition, the acoustic package material can also be represented by the sound absorption coefficient and insertion loss.

[0027] The whole vehicle SEA model calibration model calibration includes sound load (SPL) calibration and path sound reduction (PBNR) calibration. First, the firewall and floor need to be benchmarked with the sound insulation test, and the subsystem needs to be calibrated according to the sound insulation test results. Then the sound insulation simulation results are loaded onto the whole vehicle through surface connection, and the sound load and sound power are loaded respectively to calibrate the whole vehicle SEA model. The whole vehicle calibration includes surface connection adjustment, sound cavity surface area and perimeter correction, leakage application, acoustic package thickness, coverage and acoustic parameter correction, etc.

[0028] After the whole vehicle SEA model is built and adjusted, the acoustic package is optimized on this basis. The optimization is mainly based on PBNR optimization, and the optimization contents mainly include: (1) Optimization of acoustic packages of key subsystems. The acoustic package materials, coverage area, thickness, and coverage position of key subsystems such as firewalls and floors are optimized to meet the subsystem sound absorption and insulation goals.

[0029] (2) Optimization of the vehicle acoustic package. The performance optimization of the vehicle acoustic package mainly focuses on optimizing the layout, weight, and material composition (density, flow resistance, porosity, etc. are key acoustic parameters) of all the acoustic packages of the vehicle to meet the needs of reducing weight and costs while improving performance.

[0030] The optimization contents of the acoustic package of the optimized firewall and floor include: for the sound insulation pad inside the front enclosure, increase the thickness of the acoustic package and increase the coverage rate, increase the weight of the soft cotton felt and add a layer of sound-absorbing cotton on the surface of the hard cotton felt, and establish the weight and thickness; for the carpet, add a 1mm layer of EVA between the knitted fabric and PU foam, and increase the coverage rate.

[0031] After optimizing the vehicle acoustic package (the subsystem that contributes most to the path from the driver's head to the engine compartment is the firewall), the overall path sound insulation is improved and the sound insulation effect is greatly enhanced.

[0032] To summarize, the present invention first removes irrelevant parts of the vehicle body and ribs through model cleaning, retains a large area of ​​FE system panels, and then establishes an acoustic package based on the SEA model of the whole vehicle in conjunction with the modeling of the exterior sound cavity and the interior sound cavity, and then continuously optimizes the work with high efficiency, accuracy and reliability.

[0033] The above description shows and describes several preferred embodiments of the present invention, but as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. Changes and variations made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for designing the structure layout of an automotive acoustic package, characterized in that: include: VA One is used for acoustic package simulation, including model cleaning, SEA model establishment, acoustic package establishment, and acoustic package optimization.

2. The method for designing the structure layout of an automotive acoustic package according to claim 1, characterized in that: The model cleaning includes performing finite element analysis on the whole vehicle, establishing a door FE model, a body FE model, and an interior FE model, and importing them into VAOne to form a door SEA model, a body SEA model, and an interior SEA model. VA One implements modal number check and free edge check to obtain the whole vehicle SEA model.

3. The method for designing the structure layout of an automotive acoustic package according to claim 2, characterized in that: The whole vehicle SEA model is subjected to finite element analysis to obtain a half vehicle model, a firewall model, a carpet model, a door model, and an interior trim model.

4. The method for designing the structure layout of an automotive acoustic package according to claim 3, characterized in that: The acoustic package is established by the whole vehicle SEA model through its internal and external acoustic cavity modeling and internal acoustic cavity modeling.

5. The method for designing the structure layout of an automotive acoustic package according to claim 1, characterized in that: The acoustic package optimization adopts the optimization module in the VA One software, and the optimization module can optimize the node coordinates, material density and flow resistance, SEA plate thickness, acoustic package thickness, and acoustic package coverage.

6. The method for designing the structure layout of an automotive acoustic package according to claim 1, characterized in that: The process of acoustic package optimization is to select the acoustic package optimization position, set the initial coverage, variables and upper and lower limits, set the analysis frequency range, calculate the sound pressure level of the target acoustic cavity system, set the optimization target, set the optimization algorithm, optimization target, optimization variables, constraints, and optimize the solution.

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