NOISE-CON ... proceedings最新文献_第5页

Elastic wave reflection in beams with acoustic black hole termination under axial excitations 轴向激励下声黑洞终端光束的弹性波反射

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0031

Shahrokh Sepehrirahnama

{"title":"Elastic wave reflection in beams with acoustic black hole termination under axial excitations","authors":"Shahrokh Sepehrirahnama","doi":"10.3397/no_2023_0031","DOIUrl":"https://doi.org/10.3397/no_2023_0031","url":null,"abstract":"The wave speed in structures can be controlled by altering their stiffness through variations of the geometry and dimensions of the cross-section along its length. Theoretically, slowing down the elastic waves can lead to a zero-reflection effect, which is referred to as acoustic black hole (ABH). ABH has been demonstrated in metallic structures with isotropic-like material properties; while the effects of material anisotropy such as wood mechanical properties on the ABH effect are yet to be explored. We demonstrate numerically and experimentally the ABH effect in wood beams (Pinus radiata) of different lengths by applying an exponential reduction of the circular cross-section. The beams are knot-free and made of cuts of 40mm, 80mm, 100mm, 120mm and 160mm length along the grain, which could lead to a small Poisson ratio by about one order of magnitude. An increase in moisture content of the ABH wood beams by about 8-10% of the dry weights(N=5 samples) and a higher volume fraction of fibrous grains have been shown to reduce the wave reflection, as the drier and lower volume fraction the fibre, the higher the reflection becomes. This work can lead to design of novel elastic wave-guides for timber structures as used in buildings and wooden infrastructure or construction processes","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"35 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":"135725920","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

A neural network-augmented two-microphone impedance tube method to estimate sound propagation characterisics 一种神经网络增强双传声器阻抗管估计声音传播特性的方法

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0040

Martin Eser

{"title":"A neural network-augmented two-microphone impedance tube method to estimate sound propagation characterisics","authors":"Martin Eser","doi":"10.3397/no_2023_0040","DOIUrl":"https://doi.org/10.3397/no_2023_0040","url":null,"abstract":"Two-microphone impedance tubes are a popular method to measure the normal incidence sound absorption coefficient. However, a single measurement with this method does not offer enough information to identify the sound propagation characteristics, i.e. the characteristic impedance and the wave number of absorbent samples. Instead, more elaborate measurement techniques that require more time, more equipment and enhanced user knowledge need to be applied. This contribution presents a technique combining neural networks and the two-microphone impedance tube method to estimate the propagation characteristics of a highly porous sample from a single two-microphone impedance tube measurement. The measured surface impedance serves as input to a U-net architecture, which preserves the high frequency resolution of the data and returns an estimate of the surface impedance mimicking an air cavity attached behind the sample. Then, the two cavity method is used to calculate the propagation characteristics from the measured and the networks predicted surface impedances. The presented approach gives precise estimates of the propagation characteristics of simulated highly porous samples and for two different, physically measured melamine foam samples, while drastically reducing the required resources and expenses. In this way, it provides an efficient way to estimate the propagation characteristics of absorbent samples.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"35 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135725923","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

Sound transmission reduction of double walls using porous and viscoelastic materials 多孔粘弹性材料双壁减声性能研究

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0010

Soraya Bakhouche

{"title":"Sound transmission reduction of double walls using porous and viscoelastic materials","authors":"Soraya Bakhouche","doi":"10.3397/no_2023_0010","DOIUrl":"https://doi.org/10.3397/no_2023_0010","url":null,"abstract":"Double-walled structures separated by an acoustic cavity are widely used in many applications for sound insulation purposes. Their sound transmission loss is estimated by calculating the ratio between the incident sound power on the first wall and the radiated sound power by the second. The introduction of a melamine foam associated with heavy masses brings a better sound insulation against external noise. In this context, this work deals with the numerical prediction of the sound transmission of a roller shutter box equipped with porous and viscoelastic materials. Such system can be modeled, at first approximation, as a double-walled structure. The proposed approach is based on the use of the finite element method for the modeling of the different solid and fluid domains of the problem. A mixed displacement pressure formulation of the Biot poroelasticity equations is used to model the poroelastic domain. The structure is excited by a diffuse field represented by a superposition of plane waves with random phases and directions. The acoustic power radiated by the second wall is calculated by applying the Rayleigh integral method. The results show the importance of optimizing the position of the porous and the heavy layers to maximize the sound insulation.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"34 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":"135726944","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

Impact sound insulation prediction and uncertainty quantification using a detailed source model in the modal Transfer Matrix Method 模态传递矩阵法中详细源模型的碰撞隔声预测与不确定性量化

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0030

Jasper Vastiau

{"title":"Impact sound insulation prediction and uncertainty quantification using a detailed source model in the modal Transfer Matrix Method","authors":"Jasper Vastiau","doi":"10.3397/no_2023_0030","DOIUrl":"https://doi.org/10.3397/no_2023_0030","url":null,"abstract":"The main goal of this work is to provide an efficient and accurate prediction of the impact sound insulation of layered structures for the entire building acoustics frequency range (50-5000 Hz). To this end, the modal Transfer Matrix Method (mTMM) has been developed to predict the impact sound radiation from layered floors resulting from tapping machine impacts, while accounting for simply supported boundary conditions. A detailed source model is presented which accounts for both the impact locations of the individual hammers and the discrete 2 Hz force spectrum. It is also discussed how this detailed source model can be implemented into the mTMM. Monte Carlo simulations provide insight into the uncertainty of the radiated sound power and the impact sound insulation improvement for bare and layered floors, resulting from the impact force location. Numerical validation is provided by comparison to finite element models of various floors. Narrow-band sound pressure level measurements on a layered floor have been performed to validate the detailed source model and its use in the mTMM. A comparison of measured and predicted results indicates the importance of a detailed source approach, especially at low frequencies","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"34 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":"135726947","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

Vibro-acoustic optimisation of composites with multiple parameters 复合材料多参数振动声优化研究

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0034

Matthias Klaerner

{"title":"Vibro-acoustic optimisation of composites with multiple parameters","authors":"Matthias Klaerner","doi":"10.3397/no_2023_0034","DOIUrl":"https://doi.org/10.3397/no_2023_0034","url":null,"abstract":"Composites, light and stiff, are sensitive to propagate structure borne sound but simultaneously offer a wide range of adjusting the material behaviour. Thereby, stiffness and damping are contradictory material properties related to the fibre orientation. Commonly, the composite design is based on FEA simulations requiring special modelling efforts. In contrast, the multi-dimensional optimisation of a laminate with numerous layers requires very fast numerical solutions for numerous repetitions. Using a complex but efficient vibro-acoustic simulation model is essential in optimising composites. Therefore, the FEA is extended by a strain energy based modal damping approach for the layerwise accumulation of the anisotropic damping. In addition, the radiated sound power is determined by a velocity-based approach directly on steady state structural simulations avoiding a complex multi-physical modelling. Moreover, the frequency dependent radiation is consolidated to a single scalar optimisation objective with analytical formulations of amplification factors of the modal power contributions. This methodology is applied to design a vibro-acoustically optimised composite part. The achieved results emerge the NVH potential of thermoplastic composites compared to a steel reference case.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"31 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135728294","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

Complex band structure in viscoelastic thin plate phononic crystals 粘弹性薄板声子晶体的复杂能带结构

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0107

Jose Maria Dos Santos

引用次数: 0

Locally resonant metamaterials with multimodal resonators for sound insulation improvement 具有多模态谐振器的局部谐振超材料的隔声性能

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0054

Daniele Giannini

引用次数: 0

Determination of Johnson-Champoux-Allard model parameters with machine learning techniques 用机器学习技术确定Johnson-Champoux-Allard模型参数

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0050

Alessandro Casaburo

{"title":"Determination of Johnson-Champoux-Allard model parameters with machine learning techniques","authors":"Alessandro Casaburo","doi":"10.3397/no_2023_0050","DOIUrl":"https://doi.org/10.3397/no_2023_0050","url":null,"abstract":"Acoustic modelling of materials is a key aspect to perform reliable predictions of untested configurations and to implement optimal strategies, especially nowadays, due to the development of 3D printing techniques allowing to generate deterministic microstructures in porous materials. However, this modelling is not straightforward due to the number of parameters characterizing porous materials. Each one of these parameters can be estimated experimentally with its own setup and procedure, not always easy to execute. On the other hand, the use of inverse methods for the estimation of parameters relies on physical approximations and requires experimental procedures that are strongly sensitive to boundary conditions. Consequently, experimental determination of the parameters of porous materials may become financially expensive and very time consuming. The purpose of this work is to investigate the performances of machine learning techniques in determining the parameters of Johnson-Champoux-Allard model, in order to understand whether missing values can be predicted just relying on a set of already performed experimental characterizations when not all the experimental setups are available. In particular, Gaussian processes are used on a training set describing porous materials in terms of Johnson-Champoux-Allard parameters and the values of acoustic indices at fixed frequencies.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"31 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":"135728289","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

Beamformed Envelope Spectrum of acoustic signals for bearing diagnostics under varying speed conditions 变速条件下用于轴承诊断的声信号波束形成包络谱

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0036

Alexandre Mauricio

{"title":"Beamformed Envelope Spectrum of acoustic signals for bearing diagnostics under varying speed conditions","authors":"Alexandre Mauricio","doi":"10.3397/no_2023_0036","DOIUrl":"https://doi.org/10.3397/no_2023_0036","url":null,"abstract":"Rolling element bearings are critical components in rotating machinery. Early damage detection methods are usually based on vibration signals from accelerometers. Microphones provide an interesting alternative, as they acquire system level information and could allow reducing the number of sensors. However, the bearing signature is mixed in these signals with noise coming from other nearby sources. Beamforming methods can enhance the targeted bearing signature while suppressing the contributions of other noise sources in the environment. The bearing impulses related to the localized surface defects are function of speed, and thus under varying speed conditions become nonstationary. Angular resampling based methods are therefore needed to compensate for the speed fluctuations in order to detect bearing damages. The goal of this paper is to propose a method for bearing diagnostics under varying speed conditions using an array of microphones and an encoder. The method is based on angular resampling of the microphone signals in function of the shaft speed and enhancing them using delay-sum beamforming based on the known positions of the microphones relative to the tested bearing. The method is validated on an experimental dataset acquired at a KU Leuven bearing test rig, under varying rotating speed conditions.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"35 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135725924","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

Vibration mitigation using finite graded metamaterials: a rod with attached local resonators 使用有限梯度超材料的减振:带有附加局部谐振器的棒

NOISE-CON ... proceedings Pub Date : 2023-11-05 DOI: 10.3397/no_2023_0064

Ali Ihsan

{"title":"Vibration mitigation using finite graded metamaterials: a rod with attached local resonators","authors":"Ali Ihsan","doi":"10.3397/no_2023_0064","DOIUrl":"https://doi.org/10.3397/no_2023_0064","url":null,"abstract":"The paper concerns the analysis of vibration transmission and mitigation in a finite rod performing axial vibrations with attached multiple damped resonators. The resonators are not assumed to be periodically spaced or to have similar dynamic properties. The behaviour is analysed in terms of waves travelling between the discontinuities. Reflection and transmission coefficients of the rod with one local resonator attached are utilised in the analysis. Values of these coefficients for each of the attached resonators, along with the boundary conditions and field transfer function, are used to derive analytical expressions for the displacement of the finite rod at any point. Once the displacement is determined, the transmission loss is calculated. Moreover, the eigenfrequencies of the graded metamaterial finite rod are identified using the phase closure principle. The influence of the mass, the damping and the location of the resonators on the vibration attenuation are investigated. Numerical examples are presented. Good agreement is noted between the results of the analytical studies and finite element simulations in COMSOL. It is shown that the graded metamaterial rod can provide better vibration attenuation as compared to the conventional periodic metamaterial.","PeriodicalId":471330,"journal":{"name":"NOISE-CON ... proceedings","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135726563","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