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.

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.

scholarly journals Structure-Acoustic Coupling Analysis of Vibration and Underwater Acoustic Radiation of a Ring-Stiffened Conical Shell

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qingtao Gong ◽  
Zhanyang Chen ◽  
Hongbin Gui ◽  
Dong Yu
Keyword(s):  
Acoustic Field ◽  
Conical Shell ◽  
Sound Pressure ◽  
Field Model ◽  
Acoustic Radiation ◽  
Rear Side ◽  
The Finite Element Method ◽  
Underwater Acoustic ◽  
Acoustic Coupling ◽  
Element Method

The underwater acoustic radiation of the submarine power cabin has recently become a hot topic in the industry and also in the academia. In this article, the vibration and underwater acoustic radiation of a ring-stiffened conical shell with bases are investigated numerically by means of the combination of the finite element method and boundary element method. The acoustic radiation field is obtained by the traditional acoustic field model and ISO acoustic field model, respectively. A series of numerical examples are given, and the results are compared. Besides, the sound pressure at different positions with frequency is further studied. It is shown that the sound radiated by the structure mainly propagates to the side directions of the shell and propagates relatively less to the front side and the rear side.

Analysis for Vehicle Interior Noise Using Helmholtz Resonator

2005 ◽  
Author(s):  
Wakae Kozukue ◽  
Ichiro Hagiwara ◽  
Yasuhiro Mohri
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Resonance Frequency ◽  
Sound Pressure ◽  
Helmholtz Resonator ◽  
The Finite Element Method ◽  
Vehicle Interior ◽  
Vehicle Cabin ◽  
Set Up ◽  
Element Method

In this paper the reduction analysis of the so-called ‘booming noise’, which occurs due to the resonance of a vehicle cabin, is tried to carry out by using the finite element method. For the reduction method a Helmholtz resonator, which is well known in the field of acoustics, is attached to a vehicle cabin. The resonance frequency of a Helmholtz resonator can be varied by adjusting the length of its throat. The simply shaped Helmholtz resonator is set up to the back of the cabin according to the resonance frequency of the cabin and the frequency response of the sound pressure at a driver’s ear position is calculated by using the finite element method. It is confirmed that the acoustical characteristics of the cabin is changed largely by attaching the resonator and the sound quality is quite varied. The resonance frequency of the resonator can be considered to follow the acoustical characteristics of the cabin by using an Origami structure as a throat. So, in the future the analysis by using an Origami structure Helmholtz resonator should be performed.

Topology Optimization of Compliant Mechanisms Based on Interpolation Meshless Method and Geometric Nonlinearity

2019 ◽  
Author(s):  
Yonghong Zhang ◽  
Zhenfei Zhao ◽  
Yaqing Zhang ◽  
Wenjie Ge
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Topology Optimization ◽  
Galerkin Method ◽  
Meshless Method ◽  
Geometric Nonlinearity ◽  
Compliant Mechanism ◽  
Linear Convergence ◽  
The Finite Element Method ◽  
Element Method

Abstract In order to prevent mesh distortion problem arising in topology optimization of compliant mechanism with massive displacement, a meshless Galerkin method was proposed and studied in this paper. The element-free Galerkin method (EFG) is more accurate than the finite element method, and it does not need grids. However, it is difficult to impose complex boundaries. This paper presents a topology optimization method based on interpolation meshless method, which retains the advantages of the finite element method (FEM) that is easy to impose boundary conditions and high accuracy of the meshless method. At the same time, a method of gradually reducing step is proposed to solve the problem of non-linear convergence caused by low-density points in topology optimization. Numerical example shows that these techniques are valid in topology optimization of compliant mechanism considering the geometric nonlinearity, and simultaneously these techniques can also improve the convergence of nonlinearity.

DESIGN OF STRUCTURAL PARTS BY USING MODERN SIMULATION PROCEDURES

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Boštjan Harl ◽  
Jožef Predan ◽  
Marko Kegl ◽  
Dejan Dinevski
Keyword(s):  
Topology Optimization ◽  
Stress Fields ◽  
Lattice Structures ◽  
The Finite Element Method ◽  
Optimization Software ◽  
And Topology ◽  
Load Carrying ◽  
Domain Configuration ◽  
Structural Parts ◽  
Manufacturing Technologies

This paper discusses modern simulation procedures used in design of structural load-carrying parts that are based on the Finite Element Method. The specific focus of the paper is the topology optimization usage within the context of two currently very interesting topics: configuration and optimization of lattice structures and modern additive manufacturing technologies. Both types of structures are presented together with their limits as well as their potentials for optimization. The discussion is illustrated by two numerical examples and experimentally obtained results. In the examples, a simple beam with three points load is optimized regarding to the different topology setups. The stress fields for different loaded optimized versions of structures are presented and the solutions are discussed and compared to the results of the experiment. A standalone topology optimization software CAESS ProTOp is used for the domain configuration and topology optimization in both examples.

Finite Element Simulation of an Automotive Brake Rotor With Metallic Damping Inserts

2010 ◽  
Author(s):  
Shung H. Sung ◽  
M. David Hanna ◽  
James G. Schroth
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sound Pressure ◽  
Radiated Noise ◽  
Press Fit ◽  
Modal Damping ◽  
Brake Rotor ◽  
Radiated Sound ◽  
Automotive Brake ◽  
Element Method

A finite element method is developed for simulating the performance of an automotive brake rotor with metallic inserts that are used to dampen the vibration and radiated noise response. The metallic inserts are located in slots that are cast at the edge of the rotor circumference between the two rotor surfaces. Three different rotor configurations are evaluated: (a) an undamped solid rotor, (b) a damped rotor with an unconstrained press-fit metallic insert, and (c) a damped rotor with a constrained cast-in coated metallic insert. Comparisons of the predicted versus measured rotor surface vibration and radiated sound pressure are made to evaluate the effect of the insert and the accuracy of the finite element method. The comparisons show that significant modal damping of the rotor vibration and radiated noise can be achieved through the use of the coated metallic insert. A methodology is developed and applied to evaluate the damping of different metallic inserts and coatings from only the radiated sound pressure response.

scholarly journals Revised Level Set-Based Method for Topology Optimization and Its Applications in Bridge Construction

2017 ◽  
Vol 11 (1) ◽  
pp. 153-166
Author(s):  
Jing Wu ◽  
Li Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Topology Optimization ◽  
Level Set ◽  
The Finite Element Method ◽  
Bridge Design ◽  
Bridge Construction ◽  
Level Set Function ◽  
Set Function ◽  
Element Method

To cure imperfections such as low accuracy and the lack of ability to nucleate hole in the conventional level set-based topology optimization method, a novel method using a trapezoidal method with discrete design variables is proposed. The proposed method can simultaneously accomplish topology and shape optimization. The finite element method is employed to obtain element properties and provide data for calculating design and topological sensitivities. With the aim of performing the finite element method on a non-conforming mesh, a relation between the level set function and the element densities field has to be clearly defined. The element densities field is obtained by averaging the Heaviside function values. The Lagrange multiplier method is exploited to fulfill the volume constraint. Based on topological and design sensitivity and the trapezoidal method, the Hamilton-Jacobi partial differential equation is updated recursively to find the optimal layout. In order to stabilize the iterations and improve the efficiency of the algorithm, re-initiation of the level set function is necessary. Then, the detailed process of a cantilever design is illustrated. To demonstrate the applications of the proposed method in bridge construction, two numerical examples of a pylon bridge design are introduced. It is shown that the results match practical designs very well, and the proposed method is a helpful tool in bridge design.

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