Noise Control Engineering Journal最新文献_第10页

Identification of uncertainty levels of acoustic properties of biocomposites under different mounting conditions in impedance tube tests 阻抗管试验中不同安装条件下生物复合材料声学特性不确定度的识别

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-09-01 DOI: 10.3397/1/376936

H. Koruk, Y. Saygili, Garip Genc, K. Sanliturk

{"title":"Identification of uncertainty levels of acoustic properties of biocomposites under different mounting conditions in impedance tube tests","authors":"H. Koruk, Y. Saygili, Garip Genc, K. Sanliturk","doi":"10.3397/1/376936","DOIUrl":"https://doi.org/10.3397/1/376936","url":null,"abstract":"Impedance tube method is widely used to measure acoustic properties of materials. Although this method yields reliable acoustic properties for soft textured materials, uncertainty levels of measured acoustic properties for hard materials, including biocomposites, can be quite large,\u0000 mainly due to uncertain mounting conditions. Here, the effects of mounting conditions on the acoustic properties of biocomposites in an impedance tube are investigated. First, nominally identical biocomposite samples with a diameter equal to the inner diameter of impedance tube are manufactured\u0000 and their acoustic properties are determined. As hard materials practically cause fitting problems in the impedance tube, the diameters of samples are reduced, as in practice, by small amounts and acoustic properties of modified samples are determined. Furthermore, in order to match the diameters\u0000 of samples to the inner diameter of impedance tube, different materials such as tape, petroleum jelly and cotton are applied around samples to close the air gap between the samples and the tube's inner wall. All the results are compared, and the uncertainty levels caused by different mounting\u0000 conditions on the acoustic properties of biocomposites are identified. The results show that the transmission loss (TL) measurements are dramatically affected by the mounting conditions while the sound absorption conditions are less sensitive to the mounting conditions. The deviations in the\u0000 measured TL levels are highest for the samples with tape and wax (10–15 dB). On the other hand, the deviations in the measured sound absorption coefficients are highest for the samples with cotton and tape (1–2%).","PeriodicalId":49748,"journal":{"name":"Noise Control Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44964267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prediction and measurement of acoustic transmission loss of acoustic window with composite sandwich structure 复合材料夹层结构声窗传声损失的预测与测量

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-09-01 DOI: 10.3397/1/376939

C. M. Lee, K. Jeon, B. Jung, Y. M. Lee, M. Kang

{"title":"Prediction and measurement of acoustic transmission loss of acoustic window with composite sandwich structure","authors":"C. M. Lee, K. Jeon, B. Jung, Y. M. Lee, M. Kang","doi":"10.3397/1/376939","DOIUrl":"https://doi.org/10.3397/1/376939","url":null,"abstract":"Underwater acoustic detection sensors are mounted on the outside of the submarine; the acoustic window for protecting these sensors must be structurally robust while also minimizing any deterioration of sensor's sound detection performance. These two conditions are typically satisfied\u0000 simultaneously by using composite materials with acoustic window materials. However, since such composite material is manufactured by laminating fibers, there is the probability that delamination occurs, in which an air layer is formed inside, due to manufacturing process errors. Delamination\u0000 inside the acoustic window degrades the sensor's acoustic performance and results in a failure of military operations. In the case of composites composed of sandwich structures located in the central part, the possibility of internal delamination is higher than in a single composite material.\u0000 Therefore, it is very important to discriminate the presence or absence of internal delamination after producing an acoustic window. This article uses numerical and analytical methods to determine the internal delamination of the acoustic window fabricated with a sandwich structure. In addition,\u0000 the results were analyzed and compared through ultrasonic measurement and acoustic transmission loss test.","PeriodicalId":49748,"journal":{"name":"Noise Control Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49030501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental design for verification and validation of harmonic vibration control systems 谐波控制系统验证与验证的实验设计

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-09-01 DOI: 10.3397/1/376942

J. Wang

引用次数: 0

Station facilities and noise assessment: A multilevel analysis on light rail train stations 车站设施与噪声评价:轻轨列车站的多层次分析

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-07-01 DOI: 10.3397/1/376933

Yalcin Yildirim, D. Allen

{"title":"Station facilities and noise assessment: A multilevel analysis on light rail train stations","authors":"Yalcin Yildirim, D. Allen","doi":"10.3397/1/376933","DOIUrl":"https://doi.org/10.3397/1/376933","url":null,"abstract":"Noise is one of the most frequent consequences of traffic. Public transportation systems, such as the Dallas Area Rapid Transit (DART) authority provides various modes of transportation. Even though the availability of commuting service for the public is a boon to communities, mass\u0000 transit systems are potential sources of excessive sound levels in daily urban life. This article examines the nexus between the transit station facilities of light rail train (LRT) stations and noise implications at both station and neighborhood scales by studying selected LRT stations. A\u0000 multilevel linear analysis was conducted to understand the degree of train station amenities and neighborhood characteristics that affect sound levels. Using a type II sound pressure level (SPL)meter, sound measurements were obtained during the weekdays and weekends over several weeks. Upon\u0000 examining the station amenities, and built environment and sociodemographic characteristics of the neighborhood, findings of this comprehensive research reveal significant implications for sound levels. Stations with ticket vending machines and informative message boards include a higher degree\u0000 of significance on SPLs, while shelters, crew rooms, bike lockers, restrooms, and windshields are significantly and negatively associated with the noise levels. Additionally, neighborhoods with dense roads, higher speed limits, more neighborhood facilities, and a higher number of transit routes\u0000 have an increased likelihood of noise levels. Recommendations include creating transformative policies for implementation, and approaches addressing noise for transit authorities, transportation engineers, and planners are presented. Planning and engineering aspects of comfort, aesthetics,\u0000 safety, and public health, as train stations are daily use spaces for commuters and surrounding communities, should also be considered.","PeriodicalId":49748,"journal":{"name":"Noise Control Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44280922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Broadband low-frequency noise reduction using Helmholtz resonator-based metamaterial 基于亥姆霍兹谐振腔的超材料的宽带低频降噪

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-07-01 DOI: 10.3397/1/376932

Jhalu Gorain, C. Padmanabhan

{"title":"Broadband low-frequency noise reduction using Helmholtz resonator-based metamaterial","authors":"Jhalu Gorain, C. Padmanabhan","doi":"10.3397/1/376932","DOIUrl":"https://doi.org/10.3397/1/376932","url":null,"abstract":"Achieving broadband noise attenuation at low frequencies is still a significant challenge. Helmholtz resonators offer good low-frequency noise attenuation but are effective only over a narrow band; the cavity volume required at these frequencies is also larger. This article proposes\u0000 a new broadband acoustic metamaterial (AMM) absorber, which uses polyurethane (PU) foam embedded with small-size resonators tuned to different frequencies. The AMM design is achieved in three phases: (1) develop a transfer-matrix-based one-dimensionalmodel for a resonator with intruded neck;\u0000 (2) use this model to develop a novel band broadeningmethod, to select appropriate resonators tuned to different frequencies; and (3) construct a unit cell metamaterial embedded with an array of resonators into PU foam. A small-size resonator tuned to 415 Hz is modified, by varying the intrusion\u0000 lengths of the neck, to achieve natural frequencies ranging from 210 to 415 Hz. Using the band broadening methodology, 1 unit cell metamaterial is constructed; its effectiveness is demonstrated by testing in an acoustic impedance tube. The broadband attenuation characteristics of the constructed\u0000 unit cell metamaterial are shown to match well with the predicted results. To demonstrate further the effectiveness of the idea, a metamaterial is formed using 4 periodic unit cells and is tested in a twin room reverberation chamber. The transmission loss is shown to improve significantly,\u0000 at low frequencies, due to the inclusion of the resonators.","PeriodicalId":49748,"journal":{"name":"Noise Control Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42148486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Case study: Purdue University's "Clapping Circle": An acoustical investigation 案例研究：普渡大学的“拍手圈”：声学调查

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-07-01 DOI: 10.3397/1/376928

Elspeth A. Wing, Steven J. Herr, Alexander D. Petty, Alexander K. Dufour, Frederick H. Hoham, Morgan E. Merrill, Donovan W. Samphier, Weimin Thor, Kushagra Singh, Y. Xue, D. Huston, J. Bolton

{"title":"Case study: Purdue University's \"Clapping Circle\": An acoustical investigation","authors":"Elspeth A. Wing, Steven J. Herr, Alexander D. Petty, Alexander K. Dufour, Frederick H. Hoham, Morgan E. Merrill, Donovan W. Samphier, Weimin Thor, Kushagra Singh, Y. Xue, D. Huston, J. Bolton","doi":"10.3397/1/376928","DOIUrl":"https://doi.org/10.3397/1/376928","url":null,"abstract":"The perplexing acoustical properties of a landscape architecture feature of Academy Park on the Purdue University campus have long been the subject of speculation. The feature, known informally as the \"Clapping Circle\", consists of sixty-six concentric rings of stone tiles.\u0000 When someone claps while at the middle of the circle, they hear a high-pitched squeak immediately afterwards. Experiments were conducted by the Purdue student chapter of the Acoustical Society of America to characterize this effect. The response to a clap played from an omnidirectional speaker\u0000 placed at the center of the circle was recorded using a microphone positioned above the loudspeaker. Spectrograms of the recorded responses revealed the squeak to consist of a descending tone and its harmonics. This tone disappeared from the spectrogram when the tiles were covered with absorbing\u0000 blankets. A model based on scattering from the bevels between the tile rings reproduced the descending frequency of the squeak. Similarly to famous stepped structures with notable acoustics, the tiles were found to scatter sound best when the wavelength was not larger than the tiles' spatial\u0000 period. Thus, it was concluded that the squeak is an example of an acoustical diffraction grating which creates a repetition pitch caused by scattering from the tile formation.","PeriodicalId":49748,"journal":{"name":"Noise Control Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45637494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sound absorption of a thick micro-perforated panel with tapered sections 具有锥形截面的厚微孔板的吸声性能

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-07-01 DOI: 10.3397/1/376930

H. Liyan, Chenxi Li, Hu Ying, Haitao Wang, Ran Qing, Haiquan Wu

引用次数: 0

Case study: Correlation between boundary and finite element determination of large silencer transmission loss 案例研究:边界与大消声器传播损失有限元计算的关系

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-07-01 DOI: 10.3397/1/376927

K. Ruan, T. Wu, D. Herrin

{"title":"Case study: Correlation between boundary and finite element determination of large silencer transmission loss","authors":"K. Ruan, T. Wu, D. Herrin","doi":"10.3397/1/376927","DOIUrl":"https://doi.org/10.3397/1/376927","url":null,"abstract":"Silencers used in the power generation industry generally have large ducts entering and leaving the silencer. With large cross-sectional dimensions, the plane wave cutoff frequency will be exceeded at a low frequency so that transmission loss can no longer be evaluated by assuming constant\u0000 sound pressure over a cross-section. More sophisticated calculation and processing approaches are necessary. In this research, the boundary element method is used in conjunction with a reciprocal identity method to determine the transmission loss for rectangular and circular cross-sections:\u0000 the two configurations that cover most real-world designs. The boundary element method is compared to a finite element method strategy where the transmission loss is determined using an automatically matched layer boundary condition at the inlet and outlet. This approach can be used in most\u0000 commercial software. Although these two approaches have little in common, transmission loss results compare well with one other. Validation by comparison is helpful because analytical solutions are only available for simple axisymmetric cases. Methods are compared for practical configurations\u0000 like parallel-baffle silencers and reactive silencers.","PeriodicalId":49748,"journal":{"name":"Noise Control Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46300818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimal design of noise reduction and shape modification for traction gears of EMU based on improved BP neural network 基于改进BP神经网络的动车组牵引齿轮降噪改形优化设计

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-07-01 DOI: 10.3397/1/376934

Zhaoping Tang, Min Wang, Xiaoying Xiong, Manyu Wang, Jianping Sun, Li Yan

{"title":"Optimal design of noise reduction and shape modification for traction gears of EMU based on improved BP neural network","authors":"Zhaoping Tang, Min Wang, Xiaoying Xiong, Manyu Wang, Jianping Sun, Li Yan","doi":"10.3397/1/376934","DOIUrl":"https://doi.org/10.3397/1/376934","url":null,"abstract":"Under high-speed operating conditions, the noise caused by the vibration of the traction gear transmission system of the Electric Multiple Units (EMU) will distinctly reduce the comfort of passengers. Therefore, analyzing the dynamic characteristics of traction gears and reducing noise\u0000 from the root cause through comprehensive modification of gear pairs have become a hot research topic. Taking the G301 traction gear transmission system of the CRH380A high-speed EMU as the research object and then using Romax software to establish a parametric modification model of the gear\u0000 transmission system, through dynamics, modal and Noise Vibration Harshness (NVH) simulation analysis, the law of howling noise of gear pair changes with modification parameters is studied. In the small sample training environment, the noise prediction model is constructed based on the priority\u0000 weighted Back Propagation (BP) neural network of small noise samples. Taking the minimum noise of high-speed EMU traction gear transmission as the optimization goal, the simulated annealing (SA) algorithm is introduced to solve the model, and the optimal combination of modification parameters\u0000 and noise data is obtained. The results show that the prediction accuracy of the prediction model is as high as 98.9%, and it can realize noise prediction under any combination of modification parameters. The optimal modification parameter combination obtained by solving the model through\u0000 the SA algorithm is imported into the traction gear transmission system model. The vibration acceleration level obtained by the simulation is 89.647 dB, and the amplitude of the vibration acceleration level is reduced by 25%. It is verified that this modification optimization design can effectively\u0000 reduce the gear transmission.","PeriodicalId":49748,"journal":{"name":"Noise Control Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42976222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of multiple-layer versus multiple-cavity microperforated panels for sound absorption at low frequency 多层与多腔微孔板低频吸声性能的比较

IF 0.4 4区工程技术

Noise Control Engineering Journal Pub Date : 2021-07-01 DOI: 10.3397/1/376931

P. Cobo, F. Simón, C. Colina

引用次数: 1