scholarly journals Optimization of Noise Transfer Path Based on the Composite Panel Acoustic and Modal Contribution Analysis

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Qiang Liu ◽  
Xuanyi Zhou ◽  
Jianxin Zhu ◽  
Xiaoping Gong
Keyword(s):  
Path Optimization ◽  
Composite Panel ◽  
Vehicle Body ◽  
Acoustic Model ◽  
Transfer Vector ◽  
Field Point ◽  
Transmission Path ◽  
Transfer Path ◽  
Contribution Analysis ◽  
Acoustic Contribution

The noise of a cab directly affects the comfort and labor efficiency of the operators. The optimization of the structure-borne transmission path can obviously reduce the cab noise. The method of panel acoustic contribution analysis (PACA) is used to reduce structure noise. However, most studies only consider the panel acoustic contribution of a single frequency, without considering the contribution of major frequencies synthesis to confirm the optimized panels. In this paper, a novel method is proposed based on composite panel acoustic and modal contribution analysis and noise transfer path optimization in a vibro-acoustic model. First, the finite element model (FEM) and the acoustic model are established. Based on the acoustic transfer vector (ATV) method, a composite panel acoustic contribution analysis method is proposed to identify the panels affecting the noise of the field point. Combined with the modal acoustic contribution of the modal acoustic transfer vector (MATV) method, the noise field point is confirmed in the area which has the most significant influence. Second, the optimization algorithm NLOPT which is a nonlinear optimization is applied to design the areas. The noise transfer path optimization with vibroacoustic coupling response can quickly determine the optimal thickness of the panels and reduce low-frequency noise. The effectiveness of the proposed method is applied and verified in an excavator cab. The sound pressure level (SPL) the driver’s right ear (DRE) decreased obviously. The acoustic analysis of the composite panel acoustic contribution and modal acoustic contribution can more accurately recognize an optimized area than the traditional PACA. This method can be applied in the optimization of the structure-borne transmission path for construction machinery cab and vehicle body.

Topology Optimization of Gearbox to Reduce Radiated Noise

2015 ◽  
Author(s):  
J. P. Wang ◽  
G. Liu ◽  
S. Chang ◽  
L. Y. Wu
Keyword(s):  
Topology Optimization ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Dynamic Loads ◽  
Field Point ◽  
Radiated Noise ◽  
Contribution Analysis ◽  
Acoustic Contribution ◽  
Mode Order

In this paper, topology optimization of gearbox to reduce the radiated noise is studied based on the analysis of modal acoustic contribution and panel acoustic contribution. Firstly, the bearing dynamic loads are obtained by solving the dynamic equations of gear system. Secondly, the vibration of gearbox is calculated using FEM and the radiated noise is simulated using BEM by taking these bearing dynamic loads as excitations. Thirdly, the panel having larger contribution to the sound pressure level (SPL) at a specific field point is found by panel acoustic contribution analysis (PACA), and this panel is taken as design domain. The mode order with larger contribution is determined by modal acoustic contribution analysis (MACA), and making corresponding natural frequency becomes far away from excited frequency is taken as a constraint. Finally, the topology optimization of gearbox is completed using SIMP method, and the ribs are arranged according to the optimization results. The results show that the equivalent sound pressure level at objective field point can be reduced obviously by using this method.

Simulation Analysis of an Ambulance Carriage Interior Noise

2014 ◽  
Vol 535 ◽  
pp. 581-585
Author(s):  
Shi Ke Hou ◽  
Song Bai ◽  
Hao Jun Fan ◽  
Hui Ding ◽  
Yong Zhong Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Boundary Element ◽  
Simulation Analysis ◽  
Coupled Model ◽  
Element Model ◽  
Simulation Software ◽  
Vehicle Body ◽  
Field Point ◽  
Acoustic Contribution ◽  
Multi Body

Based on the theory of multi-body system dynamics, the analytical method of finite element and boundary element, the finite element model of vehicle body, the rigid-flexible coupled model of vehicle and the acoustic boundary element model of carriage were established by applying a variety of simulation software. Road roughness was simulated and the SPL of field point in carriage under the excitation was computed at the frequency range of 20-150Hz. Considering the size and the positive /negative nature of panels acoustic contribution at SPL peak of field point, damping treatments were taken on different combinations of panels to decrease multiple field points SPL peak and the optimal treatment was finally confirmed. The results showed that noise reduction measures can generally decrease the SPL peak around the crew.

Optimal Rib Layout Design of Gearbox for the Reduction of Radiated Noise

2017 ◽  
Author(s):  
G. Liu ◽  
J. P. Wang ◽  
S. Chang
Keyword(s):  
Topology Optimization ◽  
Optimization Model ◽  
Sound Pressure ◽  
The Finite Element Method ◽  
Field Point ◽  
Radiated Noise ◽  
And Topology ◽  
Contribution Analysis ◽  
Acoustic Contribution ◽  
Element Method

In this paper, a method to determine the optimal rib layout of gearbox for the noise reduction is proposed based on acoustic contribution analysis and topology optimization. Firstly, the radiated noise is simulated using the finite element method (FEM) and boundary element method (BEM). The field point with maximum sound pressure is taken as the objective field point. Secondly, the surface of gearbox is divided into different regions and the region with maximum acoustic contribution to the sound pressure on the objective field point is found by acoustic transfer vector analysis and acoustic contribution analysis. Thirdly, the topology optimization model is established to reduce the velocities on the region with maximum acoustic contribution. Lastly, the topology optimization model is solved using the SIMP method and the ribs can be arranged according to the results of topology optimization. The simulation results show that the sound pressure on objective field point is reduced remarkably by using this method.

scholarly journals Reliability Analysis of Random Vibration Transmission Path Systems

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Zhao ◽  
Yi-Min Zhang
Keyword(s):  
Random Vibration ◽  
Vibration Source ◽  
Vibration Transmission ◽  
Transmission Path ◽  
Transfer Path ◽  
Practical Project ◽  
Mathematical Expressions ◽  
The Matrix ◽  
Path System ◽  
Element Theory

The vibration transmission path systems are generally composed of the vibration source, the vibration transfer path, and the vibration receiving structure. The transfer path is the medium of the vibration transmission. Moreover, the randomness of transfer path influences the transfer reliability greatly. In this paper, based on the matrix calculus, the generalized second moment technique, and the stochastic finite element theory, the effective approach for the transfer reliability of vibration transfer path systems was provided. The transfer reliability of vibration transfer path system with uncertain path parameters including path mass and path stiffness was analyzed theoretically and computed numerically, and the correlated mathematical expressions were derived. Thus, it provides the theoretical foundation for the dynamic design of vibration systems in practical project, so that most random path parameters can be considered to solve the random problems for vibration transfer path systems, which can avoid the system resonance failure.

Structural-Acoustic Analysis of Automobile Passenger Compartment

2012 ◽  
Vol 236-237 ◽  
pp. 175-179 ◽  
Author(s):  
Shu Wen Zhou ◽  
Si Qi Zhang
Keyword(s):  
Frequency Response ◽  
Acoustic Analysis ◽  
Ride Comfort ◽  
Vehicle Body ◽  
Response Analysis ◽  
Passenger Compartment ◽  
Vector Method ◽  
Acoustic Cavity ◽  
Road Roughness ◽  
Acoustic Contribution

Besides the performances of handling, stability, ride comfort, power and fuel economy, the sound pressure levels in the automobile passenger compartments heavily influence the customer’s purchasing decision. The interior acoustics of automobile passenger compartment was analyzed in this paper. The frequency response analysis was performed on the vehicle body due to road roughness. The frequency response of vehicle body’s output spectrum, nodes’ velocity is used as the boundary condition of the acoustic cavity. With boundary element method and acoustic transfer vector method, the panel acoustic contribution was analyzed. By modifying the stiffness, damping or mass of the corresponding panel, the acoustic pressure levels at the driver’s and passenger’s ear were decreased.

Operational Transfer Path Analysis Based on Signal Decoupling

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Leiming Song ◽  
Qing Gui ◽  
Hao Chen ◽  
Haifei Bai ◽  
Yu Sun
Keyword(s):  
Path Analysis ◽  
High Speed ◽  
Peak Frequency ◽  
Experimental Comparison ◽  
Strongly Coupled ◽  
Transmission Path ◽  
Transfer Path ◽  
Decoupling Analysis ◽  
Multiple Unit ◽  
Transfer Path Analysis

Abstract This study proposes an input decoupling analysis method based on the pulse test and the traditional operational transfer path analysis (OTPA) method for the OTPA transmission path analysis when the input is strongly coupled, and the algorithm is verified for analysis optimization of results. An experimental model of the dual excitation source is established in the laboratory. Experimental comparison studies show that the OTPA method, which is based on signal decoupling, inhibits the influence of cross-coupling among the source signals during OTPA analysis and effectively improves the accuracy of the transmission path test and analysis. The OTPA method is applied to analyze the transfer path of the vibration and noise of the carriages of the electric multiple unit (EMU) train (a high-speed train in China). The false peak frequency in the traditional OTPA method is eliminated, and the accuracy of the analysis is improved.

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