Noise Control and Acoustics最新文献_第7页

Possibilities for a Silicon Model of the Cochlea 耳蜗硅模型的可能性

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.1115/imece2000-1604

C. Steele, Alissa Fitzgerald, T. Kenny, K. Lim, S. Puria

{"title":"Possibilities for a Silicon Model of the Cochlea","authors":"C. Steele, Alissa Fitzgerald, T. Kenny, K. Lim, S. Puria","doi":"10.1115/imece2000-1604","DOIUrl":"https://doi.org/10.1115/imece2000-1604","url":null,"abstract":"\u0000 The purpose of this study is to resolve questions regarding the fundamental physical behavior of the cochlea of the inner ear. We seek a convergence of measurement and computation on physical models that capture essential features. Since there are unique features in the performance of the cochlea, the physical models could lead to device development. A much longer-term goal is a device for the assistance of hearing impaired individuals. The cochlea can be modeled as a tube of fluid divided by a partition, a portion of which is elastic and called the basilar membrane (BM). In preliminary work, the cochlear partition is constructed on a silicon wafer using current capabilities for micro-machining. The silicon nitride partition is inserted into a chamber of Plexiglas which is filled with solute and has a “stapes” for acoustic input and a “round window”. The silicon BM has the correct length, but is wider and isotropic. The measurements, supported by calculations, show that the deviation from the actual structure has a detrimental effect on the sharpness of the spatial distribution of the response for a fixed input frequency. Possibilities for improved models and for an active non-linear model with distributed sensors and actuators are discussed.","PeriodicalId":387882,"journal":{"name":"Noise Control and Acoustics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123879388","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

Role of Vibration-Induced Streaming in Float-Zone Crystal Growth 振动诱导流在浮区晶体生长中的作用

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.2514/6.2001-614

A. Anilkumar, R. Grugel, C. P. Lee, M. F. Rose

引用次数: 0

Non-Linear Least-Squares Estimation of Material Properties and Structural Intensity in Non-Uniform Beams 非均匀梁材料性能和结构强度的非线性最小二乘估计

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.1115/imece2000-1620

P. J. Halliday, K. Grosh

引用次数: 0

Introduction to Acoustic Compressors 声学压缩机简介

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.1115/imece2000-1599

B. Lipkens, F. Lalande, D. Perkins

引用次数: 2

The Effect of Wave Number on the Performance of BGT Absorbing Boundary Conditions for Acoustic Scattering 波数对BGT声散射吸收边界条件性能的影响

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.1115/imece2000-1593

I. Harari, R. Djellouli

引用次数: 0

Sudden Drop Phenomena in Natural Frequencies of Composite Plates or Panels With a Non-Central (or Eccentric) Stiffening Plate Strip 具有非中心(或偏心)加强板带的复合板或板的固有频率突然下降现象

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.1115/imece2000-1634

U. Yuceoglu, V. Özerciyes

{"title":"Sudden Drop Phenomena in Natural Frequencies of Composite Plates or Panels With a Non-Central (or Eccentric) Stiffening Plate Strip","authors":"U. Yuceoglu, V. Özerciyes","doi":"10.1115/imece2000-1634","DOIUrl":"https://doi.org/10.1115/imece2000-1634","url":null,"abstract":"\u0000 In this study the free bending vibrations of compsite base plates or panels reinforced by a non-central (or eccentric) stiffening plate strip are considered. The base plate and the stiffening plate strip are dissimilar orthotropic plates. They are connected by a very thin and flexible adhesive layer. The dynamic equations of the entire composite plate system are obtained from the “Mindlin Plate Theory” for orthotropic plates. The set of the governing partial differential equations of the composite plate or panel system are reduced to a set of first order ordinary differential equations by the elimination of the time variable and one of the space variables. This final system of the first order differential equations in one space variable is integrated by the “Modified Version of the Transfer Matrix Method”. It was shown that the natural frequencies, at any mode, of the plate or panel system gradually increase at first with the increasing “Bending Cross Stiffness Ratio”. After then, for certain values of this “Ratio”, the natural frequencies for each mode, suddenly drop to a lower value and subsequently start to go up, although slowly, regardless of the support conditions. This unusual “Sudden Drop Phenomena” is explained in detail and, also, the mode shapes corresponding to the sudden drop are presented. The effect of the “hard” and the “soft” adhesive layer on the “Phenomena” are also shown.","PeriodicalId":387882,"journal":{"name":"Noise Control and Acoustics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123763769","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

Sensitivity of Stiffness and Damping to Various Aspects of Material and Structural Behavior 刚度和阻尼对材料和结构性能各方面的敏感性

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.1115/imece2000-1617

R. Gibson

引用次数: 3

The Use of Multifunctional Composite Materials in Large Scale Naval Applications 多功能复合材料在大规模海军应用中的应用

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.1115/imece2000-1631

R. Crane

引用次数: 0

Monitoring and Defect Detection of an All-Composite Road Bridge 某全复合材料公路桥梁的监测与缺陷检测

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.1115/imece2000-1628

R. Crane, J. Gillespie, D. Heider, D. A. Eckel, C. Ratcliffe

{"title":"Monitoring and Defect Detection of an All-Composite Road Bridge","authors":"R. Crane, J. Gillespie, D. Heider, D. A. Eckel, C. Ratcliffe","doi":"10.1115/imece2000-1628","DOIUrl":"https://doi.org/10.1115/imece2000-1628","url":null,"abstract":"\u0000 This paper presents the results of an ongoing investigation into the use of broadband vibration data to monitor the structural integrity and health of an all-composite road bridge. Bridge 1-351 on Business Route 896 in Glasgow, Delaware, was replaced with one of the first state-owned all-composite bridges in the nation in the fall of 1998. The bridge consists of two E-Glass/vinyl ester sandwich core sections (13-ft × 32 ft) joined by a longitudinal joint in the traffic direction. Each sandwich core section consists of a 28-inch deep core and 0.4-0.7-inch thick facesheets.\u0000 Vibration data were obtained from the upper and lower surfaces of the bridge using a mesh of 1050 test points. From the modal information and the visualization of the data, several aspects of the structural behavior of the bridge were obtained. These characteristics include the interactions between the bridge and abutments; the effectiveness of the longitudinal joint to couple the deck sections; the effectiveness of the core to couple the face sheets; and the structural integrity and dynamic consistency of the entire structure. Mode shapes and natural frequencies were determined and are correlated with theoretical calculations and vibration analyses conducted for this bridge.\u0000 A novel algorithm using the vibration data is being developed that enables local perturbations sensitive to the state of the material (e.g. manufacturing defects, material degradation or service damage) to be detected and spatially located in the bridge. This technique has been successfully validated for locating damage in 1-D beam structures and is being extended to the 3-D sandwich configuration of the bridge. By coupling this damage detection algorithm with the more conventional modal technique, the quality assurance/quality control and health monitoring of large composite bridge can be obtained.","PeriodicalId":387882,"journal":{"name":"Noise Control and Acoustics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129532872","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: 2

Ultra-Pure Viscoelastic Damping Polymers and Associated Low Outgassing Materials 超纯粘弹性阻尼聚合物及相关低放气材料

Noise Control and Acoustics Pub Date : 2000-11-05 DOI: 10.1115/imece2000-1636

Jeff W. McCutcheon

{"title":"Ultra-Pure Viscoelastic Damping Polymers and Associated Low Outgassing Materials","authors":"Jeff W. McCutcheon","doi":"10.1115/imece2000-1636","DOIUrl":"https://doi.org/10.1115/imece2000-1636","url":null,"abstract":"\u0000 The key to successful multifunctional materials applications for vibration, shock and acoustic control is often the proper selection of materials, geometric design and optimum application. Much work has been done in the areas of geometric designs and optimum application of the multi-functional materials. The next step is improvements in the passive damping materials themselves.\u0000 The improvement in the passive materials in the past has often focused on the areas of improved damping performance (loss factor, storage modulus), material performance (acrylics, silicones, etc.) and enhanced features (thermally conductive, electrically conductive, etc). One of the newest requirements for passive damping polymers is in the area of ultra-pure viscoelastic damping polymers. This new generation of materials is finding growing use because the sensitive environment where the passive material is used require a material that will not negatively impact the components in that environment. This new generation of passive materials needs to be ultra-pure with respect to organic material outgassing, anions, catalysts and siloxanes.\u0000 In addition to the viscoelastic damping polymer requirements for high purity, the associated polymeric materials (epoxies, laminating adhesives and tapes) used in the same environment must also be of a similar low outgassing, ultra-pure, ultra-clean, electronics grade or clean room performance designation. If this is not done, the environment could become contaminated and negate a portion of the benefit of using the clean damping material. This also requires an understanding of the test method used to determine each product’s cleanliness performance, as all test methods are not equal and can give significantly different test results. An example is comparing a polymer sample tested for organic outgassing and using a static headspace gas chromatography/mass spectroscopy (GC/MS) and a dynamic headspace GC/MS.","PeriodicalId":387882,"journal":{"name":"Noise Control and Acoustics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115980353","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