Structural-acoustic sensitivity analysis of radiated sound power using a finite element/ discontinuous fast multipole boundary element scheme

2016 ◽  
Vol 82 (12) ◽  
pp. 858-878 ◽  
Author(s):  
Leilei Chen ◽  
Haibo Chen ◽  
Changjun Zheng ◽  
Steffen Marburg
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Boundary Element ◽  
Sound Power ◽  
Fast Multipole ◽  
Element Scheme ◽  
Radiated Sound ◽  
Acoustic Sensitivity ◽  
Radiated Sound Power

Acoustic Radiation Simulation of Marine Sliding-Thrust Bearing Shell Based on SYSNOISE

2011 ◽  
Vol 291-294 ◽  
pp. 1961-1964
Author(s):  
Guang Liang Zhao
Keyword(s):  
Dynamic Analysis ◽  
Boundary Element ◽  
Thrust Bearing ◽  
Acoustic Radiation ◽  
Element Model ◽  
Sound Power ◽  
Supporting Structure ◽  
Radiated Sound ◽  
The Impact ◽  
Radiated Sound Power

This paper takes marine Kingsbury sliding thrust bearing as the research object and conducts the finite element dynamic analysis with the aid of ANSYS software. On this basis, the acoustic boundary element model of a sliding thrust bearing shell is established with the ANSYS dynamic analysis results as the boundary excitation conditions. Besides, the radiated sound power of the shell is calculated by indirect boundary element method in SYNOSISE software. The influence of different condition parameters on the radiated sound power of the shell is perceived through the analysis of several rotation-thrust conditions. As for the special structure of this kind of sliding-thrust bearing, this paper states the impact of the supporting structure performance parameters, the pad number and damp of shell on the shell radiated sound power. The optimized measure for the supporting structure and the plan concerning the pad number’s selection lays the theoretical basis for damping and noise-reducing research on marine sliding-thrust bearing and its rotor system.

ENFORCING RECIPROCITY IN NUMERICAL ANALYSIS OF ACOUSTIC RADIATION MODES AND SOUND POWER EVALUATION

2012 ◽  
Vol 20 (03) ◽  
pp. 1250005 ◽  
Author(s):  
HERWIG PETERS ◽  
NICOLE KESSISSOGLOU ◽  
STEFFEN MARBURG
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Acoustic Radiation ◽  
Sound Power ◽  
Impedance Matrix ◽  
Radiated Sound ◽  
The Asymmetry ◽  
Power Evaluation ◽  
Radiated Sound Power ◽  
Element Method

By identifying the efficiently radiating acoustic radiation modes of a fluid loaded vibrating structure, the storage requirements of the acoustic impedance matrix for calculation of the sound power using the boundary element method can be greatly reduced. In order to compute the acoustic radiation modes, the impedance matrix needs to be symmetric. However, when using the boundary element method, it is often found that the impedance matrix is not symmetric. This paper describes the origin of the asymmetry of the impedance matrix and presents a simple way to generate symmetry. The introduction of additional errors when symmetrizing the impedance matrix must be avoided. An example is used to demonstrate the behavior of the asymmetry and the effect of symmetrization of the impedance matrix on the sound power. The application of the technique presented in this work to compute the radiated sound power of a submerged marine vessel is discussed.

Analysis of Structural Acoustic Design Variables for a Periodically Stiffened Plate Using the Finite Element Method

2019 ◽  
Author(s):  
Joseph A. Blochberger
Keyword(s):  
Finite Element ◽  
Fourier Transforms ◽  
Plate Thickness ◽  
Sound Power ◽  
Stiffened Plate ◽  
Element Analysis ◽  
Design Variables ◽  
Radiated Sound ◽  
Insight Into ◽  
Radiated Sound Power

Abstract Investigating the acoustic radiation of stiffened plate structures is significant to the advancement of aircraft, automobile, and marine vehicle design. Plate and stiffener design variables affect how the global structure vibrates and radiates sound. The objective of this paper is to provide insight into how sensitive a periodically stiffened plate radiates sound in air with respect to its design variables. This paper examines a clamped plate that is periodically stiffened along one direction. Finite element analysis is used to quantify the structural acoustic behavior of the plate subject to a harmonic point load at the plate’s center. Fourier transforms are performed along the plate’s surface to reveal the wavenumber content of the plate. Lastly, radiated sound power from the plate surface is computed. A baseline plate without stiffeners is used for finite element modeling validation. Next, periodically spaced beams used for plate stiffening are inserted and varied in thickness. In addition, the plate thickness is also varied. Varying the plate thickness and the stiffener thickness provides insight to each design variable’s contribution to vibration and radiated sound power. The quantified findings from these parametric case studies serve as an insight into the structural acoustic performance of periodically stiffened structures.

scholarly journals An Adjoint Operator Approach for Sensitivity Analysis of Radiated Sound Power in Fully Coupled Structural-Acoustic Systems

2017 ◽  
Vol 25 (01) ◽  
pp. 1750003 ◽  
Author(s):  
Leilei Chen ◽  
Steffen Marburg ◽  
Haibo Chen ◽  
Hao Zhang ◽  
Hongbo Gao
Keyword(s):  
Sensitivity Analysis ◽  
Adjoint Operator ◽  
Design Sensitivity ◽  
Sound Power ◽  
Operator Approach ◽  
Design Variables ◽  
Structural Density ◽  
Radiated Sound ◽  
Radiated Sound Power ◽  
Element Method

Full interaction between structural and fluid domains must be considered for light structures immersed in heavy fluid (e.g. thin steel shells in water). The structural-acoustic design sensitivity analysis provides information on the effect of the design variable on acoustic performance, which makes it a key step for noise control and structural-acoustic optimization. This study uses the finite element method (FEM) to model the structure domain, while the fast multipole boundary element method (BEM) is applied to the exterior acoustic domain. An adjoint operator approach is developed to calculate the sensitivity of the radiated sound power with respect to the design variables, which can be any structural or fluid parameter (e.g. fluid or structural density, Poisson’s ratio, Young’s modulus, and geometric measures). Numerical examples are presented to demonstrate the validity and efficiency of the proposed algorithm.

A Study on Relevance between Distortion of Distributed Mode Loudspeaker and Characteristic of Sound Panel

2011 ◽  
Vol 291-294 ◽  
pp. 2105-2110
Author(s):  
Liang Jin Luo
Keyword(s):  
Vibration Frequency ◽  
Sandwich Panel ◽  
Flexural Vibration ◽  
Sound Power ◽  
Impedance Matrix ◽  
Cell Ratio ◽  
Radiated Sound ◽  
Sound Sensitivity ◽  
The Relationship ◽  
Radiated Sound Power

From flat-plate flexural vibration and radiated sound power discussed the inherent relationship between panel vibration frequency of distributed mode loudspeaker and geometric parameters, impedance matrix of soundboard and studied the relationship between soundboard structure of polyester foam sandwich panel and distortion of loudspeaker. Experimental results showed that distortion increases as the cell size and compress modulus, cell ratio, cell open ratio and thickness increases, but the sound sensitivity decreases as the compress modulus increases.

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