NOISE-CON ... proceedings最新文献

On the radiation of sound from an immersed cylindrical shell close to the sea surface 靠近海面的圆柱壳的声辐射

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0048

Valentin Meyer

{"title":"On the radiation of sound from an immersed cylindrical shell close to the sea surface","authors":"Valentin Meyer","doi":"10.3397/no_2023_0048","DOIUrl":"https://doi.org/10.3397/no_2023_0048","url":null,"abstract":"Numerical methods for the prediction of underwater radiated noise from immersed structures play a key role in the naval and offshore industry to ensure high acoustic performance of systems or to preserve natural habitats. Most of the approaches so far assume that the surrounding fluid is homogeneous and unbounded. However, in many situations the structure can be close to interfaces, namely the sea surface and the sea bottom, such as navigation of underwater vehicles in shallow waters. The Lloyd's mirror effect describes the interference phenomena occurring when a sound source is close to the sea surface. This effect is easily accounted for with a source image approach, while the strong vibro-acoustic coupling between the structure and the interface is more complicated to deal with. In this context, an analytical method has recently been developed to predict the vibro-acoustic behaviour of an infinite length cylindrical shell close to the surface, based on the shell equations and Graf's addition theorem. In the present work, we compare this approach to a simplified one where the strong interactions between the surface and the structure are not considered. Results highlight these effects on a typical underwater structure","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"33 S1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135725639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Two methods to improve sound transmission loss in the coincidence region 两种改善重合区声传输损耗的方法

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0055

Andrew Hall

{"title":"Two methods to improve sound transmission loss in the coincidence region","authors":"Andrew Hall","doi":"10.3397/no_2023_0055","DOIUrl":"https://doi.org/10.3397/no_2023_0055","url":null,"abstract":"The building acoustics industry has seen little development away from traditional homogeneous materials. With the inevitable densification of housing, the severity of noise pollution within residential living environments is escalating. While the insulation of high-frequency audible sound through walls is often relatively good between 1 to 5kHz, the overall acoustic performance classification of lightweight wall systems often suffers in this region due to the coincidence effect. This effect results from a more efficient coupling between the incident sound waves and the bending waves initiated within the wall panels. We present an investigation into two contrasting methods to improve the coincidence region. These are i) a multi-layer approach, and ii) the introduction of periodic and quasi-periodic geometrical patterns in the distribution of the mass of the panels. These methods are intended to improve the attenuation of the bending waves by altering a panel's effective stiffness and creating band gaps due to back scattering. Diffuse field results were then used to verify computational models of vibroacoustic transmission based on two different approaches. The experimental and modelling results are in good qualitative agreement and indicate that the addition of impedance change features or surface variations sees a band of significantly attenuation within the targeted band indicating an effective method for either removing or shifting the coincidence effect outside of the most important part of the audible frequency region.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"33 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135725648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of nonlinear inertia and Duffing-type nonlinearity on the dynamic behaviour of nonlinear parametrically excited cantilever beams with tip mass 非线性惯性和duffing型非线性对具有尖端质量的非线性参数激励悬臂梁动力特性的影响

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0058

Mehrdad Aghamohammadi

{"title":"Effect of nonlinear inertia and Duffing-type nonlinearity on the dynamic behaviour of nonlinear parametrically excited cantilever beams with tip mass","authors":"Mehrdad Aghamohammadi","doi":"10.3397/no_2023_0058","DOIUrl":"https://doi.org/10.3397/no_2023_0058","url":null,"abstract":"The dynamic response of parametrically excited cantilever beams with a tip mass (PECBM) is investigated in this paper. Employing the Method of Multiple Scales (MMS) and the Method of Varying Amplitudes (MVA), the frequency-response equations are obtained and the stability of the response is analysed. MVA results show that, for frequency ranges around the principal parametric resonance, the term containing a linear combination of nonlinear inertia and Duffing-type nonlinearity in the frequency response equation can tend to zero, resulting in an exponential growth of the vibrations. These results are supported by numerical simulations obtained by direct integration (DI) of the equation of motion, while the MMS fails to predict the critical frequency at which this phenomenon occurs. Furthermore, based on the MVA, a criterion for determining the hardening and softening characteristics of PECBM is developed, showing that both Duffing nonlinearity and nonlinear inertia terms contribute to determining this characteristic. To verify the results, experimental measurements of the response of a PECBM are presented, showing good agreement with analytical and numerical results. It is shown that the mass added at the cantilever tip can change the characteristics of the system's dynamics, enhancing the softening behaviour of the PECBM.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"32 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135725650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New porous absorber simulation techniques in the context of finite element modelling 基于有限元模型的多孔吸收体模拟新技术

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0020

Mariia Bronzova

{"title":"New porous absorber simulation techniques in the context of finite element modelling","authors":"Mariia Bronzova","doi":"10.3397/no_2023_0020","DOIUrl":"https://doi.org/10.3397/no_2023_0020","url":null,"abstract":"Porous liners are widely used as vibration and acoustics isolation materials due to their high absorbing qualities in a wide frequency range. In a car body porous plates are laid on top of a metal structure to prevent vibroacoustic wave propagation inside the passenger cabin. Unfortunately, currently used FEM (finite element method) simulation models for poroelasticity Biot's equations are still unable to efficiently describe such coupled structure-liner-fluid systems due to the lack of modelling precision. The current paper focuses on the importance of the phenomena taking place on the structure-liner interface during dynamic excitations in the frequency range of 10-1000 Hz. Measurements of transfer functions for numerous foam samples with varying boundary conditions have been conducted in a vacuum chamber to estimate the effect of interface conditions. New simulation approaches are presented to account for the observed phenomena. Moreover, the issues of measurement uncertainties regarding foam material parameters (or Biot parameters) and poor measurement reproducibility have been addressed and corresponding parameter optimization schemes have been implemented. As a result, a significant improvement in the agreement between simulation and measurement results has been achieved. All simulations have been conducted in a custom FEM code based on the open-source Deal II library.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"32 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135725653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterising non-linear elements with free-free and fixed boundary conditions for dynamic substructuring 动态子结构中具有自由-自由和固定边界条件的非线性单元

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0022

Alessandro Zucchini

{"title":"Characterising non-linear elements with free-free and fixed boundary conditions for dynamic substructuring","authors":"Alessandro Zucchini","doi":"10.3397/no_2023_0022","DOIUrl":"https://doi.org/10.3397/no_2023_0022","url":null,"abstract":"In the context of dynamic substructuring applied to the automotive field, a crucial aspect for determining the noise property of a vehicle is the evaluation of the transfer behaviour of the rubber elements connecting the different components of a car. The goal of this research is to extract the frequency dependent dynamic stiffness for different models of rubber bushings presenting a similar architecture. In particular we will compare two different methods for characterising the dynamic behaviour of non-linear elements using the virtual point transformation. Firstly, a free-free measurement with hammer impacts will be performed. Here, particular attention will be given to the weighting matrices of the virtual point transformation to explore how those terms could improve the method. Secondly, on the same bushings, we modify the experiment by clamping the rubber mounts to the ground and creating fixed boundary conditions. Here, the system is excited both with hammer impacts and shaker excitation and we will highlight comparable results with the previous experiment. The different approaches will be compared in terms of accuracy, experimental effort, and numerical stability.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"34 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135726948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Use of DL Model to Capture Noise Variance of EV Motor by Eccentricity 利用DL模型捕捉电机偏心噪声方差

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0103

Hyeri Kim

{"title":"Use of DL Model to Capture Noise Variance of EV Motor by Eccentricity","authors":"Hyeri Kim","doi":"10.3397/no_2023_0103","DOIUrl":"https://doi.org/10.3397/no_2023_0103","url":null,"abstract":"In the era of mass-production of EVs, the expectations of performance and NVH performance required for power electric(PE) motors are gradually increasing. In order to satisfy the noise requirement and to prepare countermeasures, it is necessary not only to verify the nominal design value, but also to analyse the characteristics due to manufacturing variance. However, it was not easy to thoroughly examine the tilting and eccentricity issues that affect the noise characteristics of the axial type motor due to time and computational costs. To overcome this limitation, a machine learning model was developed to predict the electromagnetic(EM) excitation force of the motor eccentric condition. The training set of 2D EM FE results were generated with various eccentricity condition and RPMs. Using spatial-temporal frequency analysis and unbalanced magnetic pull analysis, the tendency of the excitation forces due to eccentricity was analysed. The distribution of electromagnetic force by time was predicted using random forest model. It showed R2 value of 0.999. The prediction model reduces the computational time within 5 minutes from 31 hours and enables the realistic analysis of tilting and eccentric condition. The 3D EM force distribution as Vibro-Acoustic FE model input could be predicted by putting the eccentricity value into the machine learning model.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"34 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135726949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Physics-informed neural networks for solving the Helmholtz equation 求解亥姆霍兹方程的物理信息神经网络

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0049

Johannes Schmid

引用次数: 0

Elastic wave propagation in one-dimensional phononic crystal with defects 含缺陷一维声子晶体中的弹性波传播

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0068

Victor Santos

{"title":"Elastic wave propagation in one-dimensional phononic crystal with defects","authors":"Victor Santos","doi":"10.3397/no_2023_0068","DOIUrl":"https://doi.org/10.3397/no_2023_0068","url":null,"abstract":"The possibilities of manipulating the behavior of propagating waves using only the appropriate choice of materials is a field of interest in engineering. Phononic Crystals (PnCs) come precisely as a proposal for a device to work with waves, defined as artificial materials obtained from a periodic arrangement of unit cells. This configuration can provide frequency bands where waves cannot propagate (bandgaps). However, this property can be directly influenced by the break in the periodicity pattern of the structure when geometric and/or material parameters are changed in a single part of the unit cell. New propagating modes appear inside the bandgaps, presenting characteristics of localized modes. Different length and diameter combinations are applied to establish the defective cell and verify the existence of defect modes that reveal the degree of influence on the creation of these new modes within the bandgap region. Spectral Element (SEM) and Finite Element (FE) methods are adopted to model the PnCs analysis and the frequency response functions (FRFs). The initial results show that the PnCs with geometric defects have an expressive sensitivity to variations in geometric parameters, mainly variations in the length of the defective cell. A break in periodicity in terms of material will also be performed.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"31 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135728285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Application of acoustic metamaterial for tire noise reduction 声学超材料在轮胎降噪中的应用

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0065

Felix Kronowetter

引用次数: 0

Modelling of noise due to impulsive excitation using nonlinear time series analysis 基于非线性时间序列分析的脉冲激励噪声建模

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0062

Christian Adams

{"title":"Modelling of noise due to impulsive excitation using nonlinear time series analysis","authors":"Christian Adams","doi":"10.3397/no_2023_0062","DOIUrl":"https://doi.org/10.3397/no_2023_0062","url":null,"abstract":"Early acoustic machine design phases should target safety and comfort requirements, minimising the risk of hearing damage and noise exposure and ensuring a pleasant machine sound. Therefore, physical mechanisms of sound generation, propagation and radiation need to be modelled. Today, nonlinear physical relations in vibroacoustic models such as contact problems are mostly linearised. The aim of this paper is to increase the prediction quality of vibroacoustic models so that physical mechanisms behind sound generation due to complex physical, nonlinear phenomena can be better understood. The focus is on sound generation due to impulsive excitation, which is a significant sound generation mechanism in machinery, e.g. considering gears, forming processes (e.g. punching), or road loads of vehicles. We describe a model setup to simulate impulsive excitation on a laboratory scale, where structural vibrations can be analysed. Physical correlations including nonlinear correlations could be identified using nonlinear time series analysis. Recurrence plots will be used to identify features such as phase space contraction, e.g. to identify damping. These features form the basis to deepen the physical understanding of machinery noise, to contribute to enhanced acoustic machine designs and to enhance data-driven modelling using sparse regression in future research.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"33 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135725640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0