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Kernen, Ulrica. "Airborne sound insulation of floating floors." Licentiate thesis, KTH, Byggnader och installationer, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1036.
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Cambridge, Jason Esan. "The Sound Insulation of Cavity Walls." Thesis, University of Canterbury. Mechanical Engineering, 2012. http://hdl.handle.net/10092/7332.
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Lightweight building materials are now commonly employed in many countries in preference to heavyweight materials. This has lead to extensive research into the sound transmission loss of double leaf wall systems. These studies have shown that the wall cavity and sound absorption material placed within the cavity play a crucial role in the sound transmission through these systems. However, the influence of the wall cavity on the sound transmission loss is not fully understood.
The purpose of this research is to obtain a comprehensive understanding of the role played by the wall cavity and any associated sound absorption material on the sound transmission loss through double leaf wall systems. The research was justified by the fact that some of the existing prediction models do not agree with some observed experimental trends.
Gösele’s theory is expanded and used in the creation of an infinite and finite vibrating strip model in order to acquire the desired understanding. The sound transmission loss, radiated sound pressure and directivity of double leaf systems composed of gypsum boards and glass have been calculated using the developed model. A method for calculating the forced radiation efficiency has also been proposed. Predictions are compared to well established theories and to reported experimental results.
This work also provides a physical explanation for the under-prediction of the sound transmission loss in London’s model; explains why Sharp’s model corresponds to Davy’s with a limiting angle of 61° and gives an explanation for Rindel’s directivity and sound transmission loss measurements through double glazed windows. The investigation also revealed that a wide variety of conclusions were obtained by different researchers concerning the role of the cavity and the properties of any associated sound absorption material on the sound transmission loss through double wall systems. Consequently recommendations about the ways in which sound transmission through cavity systems can be improved should always be qualified with regard to the specific frequency range of interest, type of sound absorption material, wall panel and stud characteristics.
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Maluski, Sophie. "Low frequencies sound insulation in dwellings." Thesis, Sheffield Hallam University, 1999. http://shura.shu.ac.uk/3136/.
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Low frequency noise transmission between dwellings is an increasing problem due to home entertainment systems with enhanced bass responses. The problem is exacerbated since there are not presently available methods of measurement, rating and prediction appropriate for low frequency sound in rooms. A review of the classical theory of sound insulation and room acoustics has shown that both theories are not applicable. In fact, the sound insulation of party walls at low frequencies is strongly dependent on the modal characteristics of the sound fields of the two separated rooms, and of the party wall. Therefore methods originally developed for measurement conditions where the sound field was considered diffuse, may not be appropriate for room configurations with volumes smaller than 50m3 and for frequencies where sound wavelengths are large. An alternative approach is proposed using a Finite Element Method (FEM) to study the sound transmission between rooms. Its reliability depends on the definition of the model, which requires validating measurement. FEM therefore does not replace field or laboratory measurements, but provides complementary parametric surveys not easily obtainable by measurements. The method involves modelling the acoustic field of the two rooms as an Acoustic Finite Element model and the displacement field of the party wall as a Structural Finite Element model. The number of elements for each model was selected by comparing the numerical eigenfrequencies with theoretical values within an acceptable processing time and error. The simulation of a single room and of two coupled rooms, defined by linking the acoustic model with the structural model, were validated by comparing the predicted frequency response with measured response of a 1:4 scale model. The effect of three types of party wall edge condition on sound insulation was investigated: simply supported, clamped, and a combination of clamped and simply supported. It is shown that the frequency trends still can be explained in terms of the classical mechanisms. A thin masonry wall is likely to be mass controlled above 50Hz. A thick wall is stiffness controlled, below 100Hz. A clamped thin wall provides a lower sound insulation than a simply supported, whereas a clamped masonry wall provides greater sound level difference at low frequencies than a simply supported. The sound insulation of masonry walls are shown to be strongly dependent on the acoustical modal characteristics of the connected rooms and of the structural modal characteristics of the party wall. The sound pressure level difference displays a sequence of alternating maxima and minima about a trend, dictated by the properties of the party wall. The sound insulation is lower in equal room than in unequal rooms, whatever the edge conditions and smaller wall areas provide higher sound insulation than large areas. A correction factor is proposed as a function of room configuration and wall area and edge conditions. Attempts to quantify the factor were made using statistical and deterministic analyse, but further work is required.
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Sullivan, Rory Daniel. "Sound insulation of brick diaphragm walls." Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318231.
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Toyoda, Masahiro. "Sound insulation strategies for building constructions." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/143996.
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Kyoto University (京都大学)0048
新制・課程博士
博士(工学)
甲第12306号
工博第2635号
新制||工||1372(附属図書館)
24142
UT51-2006-J298
京都大学大学院工学研究科都市環境工学専攻
(主査)教授 髙橋 大弐, 教授 鉾井 修一, 助教授 伊勢 史郎
学位規則第4条第1項該当
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Öqvist, Rikard. "Variations in sound insulation in lightweight timber constructions." Licentiate thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26446.
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This licentiate thesis deals with the topic of variations and uncertainties in building acoustic parameters for lightweight timber constructions. A higher safety margin to the legal requirements is needed to compensate for acoustical uncertainties, which leads to higher costs. Building costs can be reduced if the variations can be identified and controlled. The project was limited to industrially prefabricated timber frame based volumes and massive timber based plate elements. This thesis is based on the work reported in three papers (A, B and C). In paper A, the variations in impact and airborne sound insulation were assessed and quantified in 30 nominally identical volume built apartments in a four-storey building. Large variations were found and the underlying causes were investigated. A statistically significant difference between floor numbers was found as the highest floor achieved better sound insulation. This difference was assumed to be caused by the higher static load on lower floors affecting the elastic layer used to structurally connect the apartments. In paper B, three room volumes were followed and measured at different stages of completion throughout the construction process. The objective was to test if acoustical deviations in the field can be identified at earlier construction stages. An ISO tapping machine was used to excite the floors and the response was measured at 20 positions. The airborne and impact sound insulation were measured in the finished building. Deviations were found, but these could not be traced to earlier stages of completion. In Paper C, the variations in sound insulation of a cross-laminated timber (CLT) building system was investigated. The construction was based on prefabricated wall and floor plate elements which were mounted at the building site. A number of acoustical uncertainties related to the measurement procedure were also investigated. The measurement uncertainty was small in comparison to the total variations. The degree of prefabrication for the CLT system was lower compared to the volume system, which indicated a greater scope for poor workmanship. All papers indicate a higher sound insulation on the upper floors in a building. It is therefore important to carefully design the elastic layer between floor numbers. The measurement uncertainty has been continuously considered in this thesis. In order to properly identify and quantify variations, the measurement uncertainty should be minimised. Advantages and drawbacks with different measurement methods and directions for future research are discussed in the concluding chapters.Godkänd; 2010; 20101110 (ricokv); LICENTIATSEMINARIUM Ämnesområde: Teknisk akustik/Engineering Acoustics Examinator: Professor Anders Ågren, Luleå tekniska universitet Diskutant: Teknologie doktor Christian Simmons, Simmons akustik & utveckling AB, Göteborg Tid: Torsdag den 16 december 2010 kl 13.00 Plats: F719 Taylor, Luleå tekniska universitet
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Forsman, Jimmy. "Game engine based auralization of airborne sound insulation." Thesis, Umeå universitet, Institutionen för fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149498.
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Describing planned acoustic design by single number ratings yields a weak link to the subjective event, especially when the single number ratings are interpreted by others than experienced acousticians. When developing infrastructure, tools for decision making needs to address visual and aural perception. Visual perception can be addressed using game engines and this has enabled the establishment of tools for visualizations of planned constructions in virtual reality. Audio engines accounting for sound propagation in the game engine environment are steadily developing and have recently been made available. The aim of this project is to simulate airborne sound insulation by extending the support of recently developed audio engines directed towards virtual reality applications. The case studied was airborne sound insulation between two adjacent rooms in a building, the sound transmitted to the receiving room through the building structure resulting from sound pressure exciting the structural elements in the adjacent source room into vibration. The receiving room composed modelled space in the game engine Unreal Engine and Steam Audio was the considered audio engine. Sound transmission was modelled by filtering based on calculations of transmission loss via direct and flanking paths using the model included in the standard EN 12354-1. It was verified that the filtering technique for modelling sound transmission reproduced attenuations in correspondence with the predicted transmission loss. Methodology was established to quantify the quality of the audio engine room acoustics simulations. A room acoustics simulation was evaluated by comparing the reverberation time derived from simulation with theoretical predictions and the simulated reverberation time showed fair agreement with Eyring’s formula above its frequency threshold. The quality of the simulation of airborne sound insulation was evaluated relating the sound field in simulation to insulation classification by the standardized level difference. The spectrum of the simulated standardized level difference was compared with the corresponding sound transmission calculation for a modelled scenario. The simulated data displayed noticeable deviations from the transmission calculation, caused by the audio engine room acoustics simulation. However, the simulated data exhibited cancellation of favourable and unfavourable deviations from the transmission calculation resulting in a mean difference across the spectrum below the just noticeable difference of about 1 dB. Single number ratings was compared and the simulated single number rating was within the standard deviation of how the transmission model calculates predictions for a corresponding practical scenario measured in situ. Thus, the simulated data shows potential and comparisons between simulated data, established room acoustics simulation software and in situ measurements should further be made to deduce whether the deviations entails defects in the airborne sound insulation prediction or is an error imposed by the audio engine room acoustics simulation.
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Kernen, Ulrica. "Airborne sound insulation of single and double plate constructions." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-182.
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Shi, Wanqing. "Assessing and modelling impact sound insulation of wooden joist constructions." Licentiate thesis, Luleå tekniska universitet, 1995. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26012.
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Impact sound insulation is one of the most important aspects when assessing sound insulation of floor constructions in buildings. For assessing the impact sound insulation of aconstruction, a standard tapping machine is used as a sound source. However, the use of the current standard tapping machine has been criticised, especially with regard to measurement of wooden joist floors since the noise spectrum generated by a tapping machine differs from the spectrum generated by actual footfall. There are insufficient low frequency components in the noise spectrum produced by the tapping machine and it does not, therefore, accurately reflect low frequency noise from the construction.Reduce impact sound level from wooden joist floors are the main object of our study. It is important to be able to predict the sound insulation properties of wooden joist constructions at the design stage. To reduce the noise level in the receiving room, the input power transmitted through the construction must be estimated where the appropriate sound- and vibration-insulation can be designed.This study has investigated the waveform and frequency spectra of human footfall (walking, rum- ingand jumping); of the dropping of sand balls, sand bags and tires; and of the standard tapping machine. The impact sound power radiation from a wooden joist construction while applying different impact sources, such as actual footfall and the standard tapping machine, have also been studied.Research was also carried out regarding the development of a practical impact sound insulation calculation method for wooden joist floor constructions. The characteristics with regard to mechanical properties of floor construction was calculated using the impedance method. The impact sound level inside the sound receiving room was determined. The method developed can predict the basic performance of the wooden floor structure when excited by impact sounds.Godkänd; 1995; 20070108 (biem)
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Mu, Rui Lin. "Improvement of Sound Insulation Performance of Multi-layer Structures in Buildings." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/174914.
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Yan, Feng. "The use of passive damping to increase sound insulation in buildings." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/31643/.
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This thesis examined the potential sound insulation benefit by using damping material to absorb vibrational energy along its transmission path. Statistical Energy Analysis (SEA) was used to evaluate the effect on system performance of adding damping globally, as well as its influence on individual transmission paths. Nine different theoretical models were studied using both bending only and three-wave SEA models to predict the system behaviour in different frequency regions. The results suggest that global damping treatment generally increases the sound insulation in buildings. Initial increases in the internal loss factor (a term used in SEA to describe material damping properties) were found to provide significant initial improvements in sound insulation and flanking paths as opposed to direct paths were found to benefit more from damping treatment. A simple approximation was proposed to predict the damping benefit of paths of specific order without the need to run a full SEA model. In the presence of heavily damped structural element, where SEA is less likely to provide accurate prediction, a forward ray tracing algorithm was proposed as a supplement. It enables one to predict the energy transmission through a heavily damped component coupling two or more lightly damped components (or SEA subsystems). The energy distribution along the edges of the damped component was studied. The contribution from the direct field was found to dominate the incident energy and resulting transmission, especially in areas close to the source when damping is high. Different passive damping treatment techniques were reviewed as well as the theoretical damping level that is achievable as a guidance for theoretical and experimental validation. Several damping measurement techniques were studied and experimental validation of the ray tracing code was undertaken.
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Öqvist, Rikard. "Measurement and perception of sound insulation from 20 Hz between dwellings." Doctoral thesis, Luleå tekniska universitet, Drift, underhåll och akustik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-62843.
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Population growth and urbanization are projected by the United Nations to add 2,5 billionpeople to the world’s urban population by 2050. We need to construct buildings in anunprecedented scale to meet global housing demand. Sustainable development is critical.Compared to traditional heavy constructions, lightweight wooden constructions are moreenvironmentally friendly and will play a key role in meeting future demands. However, thereare two major problems with lightweight constructions that need to be addressed: 1) Limitedlow frequency sound insulation and 2) Variations in sound insulation.Annoyance from walking sound tend to be higher in lightweight than in heavy constructionseven with the same measured sound insulation. The Swedish research program AkuLiteindicated that the correlation between measured sound insulation and annoyance wassignificantly improved by extending current evaluation methods from 50 Hz down to 20 Hz.Secondly, large variations in sound insulation between nominally identical lightweightconstructions are common, which leads to larger safety margins. By identifying and quantifyingunderlying causes, production costs can be minimized and the performance can be improved.The aim of the thesis is to develop a new evaluation method for impact sound insulation thatbetter correspond to rated annoyance, and to identify and control underlying causes forvariations in sound insulation. The thesis contains six papers.In Paper I and II, sound insulation measurements were carried out in a large number ofnominally identical rooms of two different industrially prefabricated lightweight woodenconstructions. The purpose was to assess and quantify the variations in impact and airbornesound insulation. In Paper I, 30 nominally identical apartments of a volume based system wasevaluated. The apartments on the highest floor achieved significantly better sound insulationdue to the extra weight on lower floors affecting the elastic connections between stories. InPaper II, 18 rooms of a cross-laminated timber system of plate elements were evaluated.Additionally, several potential parameters related to measurement uncertainty wereinvestigated.Paper III deals with measurement uncertainty. An empirical study of reverberation timemeasurements showed that current methods need to be improved, if sound insulationrequirements are to be extended to 20 Hz.Paper IV and V verified that the frequency range 20-50 Hz is important for walking soundannoyance, and that alternative frequency adaptation terms can improve the correlation betweenmeasured impact sound insulation and annoyance ratings. In Paper IV, the methodology was toperform extensive field measurements in apartment buildings of various construction types andto perform questionnaire surveys among the residents. In Paper V, the methodology was toevaluate annoyance based on binaural recordings of walking sound in a two-part listening test.In Paper VI, 70 measurements in a lightweight wooden system were evaluated to quantify thetotal variations in impact and airborne sound insulation from 20 and 50 Hz, respectively. It wasconcluded that the proposed metrics of impact sound insulation were primarily determined bythe impact sound level 20-40 Hz and that the measurement methods must be evaluatedthoroughly to avoid excessive safety margins. A new evaluation method for impact sound insulation from 25 Hz, that correspond to the ratedannoyance for both heavy and lightweight constructions is proposed. By using the proposedmethod and attending the specific causes for variations, the lightweight industry will be able todevelop improved multi-story dwellings with higher perceived acoustic quality.Forskningsfinansiärer:
Sven Tyréns Stiftelse
Formas
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Bull, John Ivan. "Measurement of the airborne sound insulation of traffic noise barriers using impulse response techniques." Thesis, University of Canterbury. Mechanical Engineering, 2014. http://hdl.handle.net/10092/8962.
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This research thesis involves the measurement of the airborne sound insulation of road traffic noise barriers, with the goal of gaining a more in depth understanding of the factors that influence noise barrier performance. A measurement system is developed, based on EN 1793-6:2012, to quantify the airborne sound insulation of a noise barrier in situ. Validation testing is performed to ensure that the system meets the requirements of EN 1793-6:2012. MATLAB code is developed, incorporating all of the signal processing tasks into a single graphical user interface. The measurement system is then used to measure the airborne sound insulation of eight existing traffic noise barriers located around Auckland, New Zealand.
The results from the Auckland field tests show that consistent single number ratings of airborne sound insulation can be achieved on different samples of the same noise barrier. The presence of air gaps and hidden defects will degrade the acoustic performance of a noise barrier, most significantly at the high frequencies. The comparison of single number ratings calculated with differing measurement frequency ranges is discussed, and some comments are made on the measurement standard itself.
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Balilah, Y. A. "The use of impulse techniques in the measurement of sound insulation in buildings." Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234843.
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Pavasovic, Vladimir, and vpavasovic@wmgacoustics com au. "The radiation of Sound from Surfaces at Grazing Angles of Incidence." RMIT University. Applied Sciences, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20060911.115939.
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It is difficult to predict the sound radiation from large factory roofs. The existing infinite panel theories of sound insulation are not sufficient when the sound radiates at grazing angles. It has been shown that the reason for the collapse of the theory is the well known result for the radiation efficiency. This research will present a simple analytic strip theory, which agrees reasonably well with numerical calculations for a rectangular panel. Simple analytic strip theory has lead to the conclusion that it is mainly the length of the panel in the direction of radiation, rather than its width that is important in determining its radiation efficiency. The findings of the current research also indicated that apart from the effect due to coincidence, a panel was non-directional compared to an opening.
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Hall, Robin. "Impact sound insulation of flooring systems with polyurethane foam on concrete floors." Thesis, Sheffield Hallam University, 1999. http://shura.shu.ac.uk/3135/.
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The problem of unwanted noise in buildings has grown continuously over the last twenty years and impact noise through separating floors has been identified as a particularly important problem. One accepted method for improving impact sound insulation is to use floating floors in which the walking surfaces are isolated from the supporting structure by a resilient layer. Traditionally the resilient layers comprise mineral or glass fibre quilts but other materials such as flooring grade polystyrene are increasingly used. Recently, shallow profile floating floors comprising flexible open cell polyurethane foam resilient layers have been developed. These systems are attractive for refurbishment projects since they can simply be placed on existing floors in order to improve their impact sound insulation whilst raising the existing floor level less than systems comprising fibre quilts. Shallow profile floating floors with thin layers of flexible open cell polyurethane foam are the subject of investigation as part of this research work. This thesis reviews the previous research on polyurethane foams and evaluates the usefulness of the Standard Tests on these materials for assisting in the selection of foam for use as resilient layers under lightweight floors. Both the static and dynamic behaviour of flexible open cell polyurethane foam are investigated and recycled polyurethane foam is shown to be particularly useful for use under floating floors Its characteristic behaviour under compressive strain is described for the first time. This thesis shows that by modifying the Standard Method for the determinaf on of the dynamic stiffness of resilient layers under floating floors (BS EN 29052-1), the effect of the air contained in the open cell foam specimens can be included in the Standard laboratory test. The modification makes it possible to evaluate the dynamic stiffness of low airflow resistivity resilient polyurethane resilient layers using the apparatus described in BS EN 29052-1 for the first time. Field measurements of impact sound pressure level conducted using sections of lightweight shallow profile floating floor on a concrete supporting floor are described. The measured improvements in impact sound insulation achieved by using the sections of floating floor are compared with the improvements predicted using the results from the modified Standard laboratory tests on the foams used as resilient layers. It is shown that by compensating for the mass impedance of the Standard tapping machine hammers good correlation between predicted and measured data is achieved. A simple method for predicting the weighted standardised impact sound pressure level (L'nT,w) in the receiving room is proposed which shows excellent correlation with L'nT,w obtained from the measured data. The work shows that BS EN 29052-1 is more widely applicable than the Standard itself states and for the first time identifies a method of predicting the performance of lightweight shallow profile floating floors with polyurethane foam resilient layers. Finally the use of the ISO tapping machine for assessing the impact sound insulation of the very lightweight floating floors of interest to this research is considered. Different methods of correlating perceived and measured the impact sound insulation of floors are reviewed. Experimental results conducted in this research programme, along with searches of the literature confirm that the tapping machine is a suitable source for measuring the impact sound insulation of these floors.
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Anani, John Kodjo. "A subjective and objective assessment of sound insulation in newly converted dwellings." Thesis, Open University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316964.
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Whitfield, William. "Uncertainty associated with the measurement of airborne sound insulation in the field." Thesis, University of Liverpool, 2013. http://livrepository.liverpool.ac.uk/14517/.
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Understanding uncertainty is an important part of any scientific measurement process and the ability to evaluate and understand uncertainty is a requirement of the International Standards for quality control. The basic uncertainties relating to the measurement of airborne sound insulation in the field can be assessed using the methods in BS5725. However, identifying the components that contribute to the total variability is beyond the scope of the standard and more detailed information requires a more advanced approach. Recent developments in the “Guide to the expression of uncertainty in measurement” (GUM) suggest an approach can be used where identification of the input variables and their likely contribution will result in a solution that can be modelled providing enough information is available. However, recent research on uncertainty in sound insulation using GUM has identified problems involving the correlation between frequency bands, which leads to an overestimate of uncertainty. An empirical approach is used in this thesis, which incorporates advanced analysis of variance (ANOVA) and a specific model called Gauge Repeatability and Reproducibility (GRR). It enables the components of variance in the measurement system to be partitioned and provides an estimate of their contribution. In addition, ANOVA highlights any interaction between factors. In the GRR, carried out on a lightweight timber floor and a heavyweight concrete floor, significant interaction was detected between the operator and part. Good agreement is obtained in the repeatability and reproducibility calculated for each construction and the samples are combined with measurements of test elements that provide a wider range of sound insulation performance. The uncertainty associated with the instrumentation, operator, interaction and part are calculated in each case. It is shown that the interaction component is important and should be contained in any approach evaluating uncertainty. Further evidence reveals that the total uncertainty in the measurement process is dependent on the construction being measured.
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Lester, Martin Richard. "Selective intensimetry for the measurement of sound radiation from building elements." Thesis, Liverpool John Moores University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294022.
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Morgan, Julian Rees. "Selective estimation of sound pressure and intensity in determinations of transmission loss." Thesis, Liverpool John Moores University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253702.
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Mason, James Meredith. "A reciprocity technique for the characterisation of sound transmission into aircraft fuselages." Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254602.
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Shimizu, Takafumi. "Study on improvement of sound insulation performance for multi-layer windowpanes and gaps." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215221.
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Massaglia, J. F. "Modelling the sound insulation of corrugated roof structures : an extended transfer matrix approach." Thesis, University of Salford, 2017. http://usir.salford.ac.uk/43778/.
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Over the course of this work, the transfer matrix method (TMM) was implemented and studied for its potential in predicting the sound insulation characteristics of corrugated dual leaf roof structures. A model of periodically connected plates, using Fourier expansions, was derived independently and extended in this work to include the stiffness of connectors and orthotropic plates, and intermediate beams in the framework of the structure. The same principles were applied in deriving the transmission loss through periodically stiffened plates, as a proxy for corrugated panels. At the same time, corrugated plates were modelled as equivalent orthotropic panels, a process which is compatible with the TMM without particular modifications. Infill materials were modelled using simple fluid representations and more complex poroelastic behaviour. The point-connected plate models were combined with the TMM to enable multiple layers of infill materials between the two plates, by using an effective fluid approach. The stiffness of typical roof connectors was obtained with numerical simulations, and used in predicting transmission loss. Corrections were introduced to simulate diffuse laboratory conditions and enable meaningful comparisons to available data. The limitations of a simple orthotropic plate model compared to laboratory measurements and the ribbed plate model were identified. A number of measurements of dual leaf partitions and full roof systems were compared to the TMM and point-connected plate models, finding typically good agreement at low to mid-frequency, and a strong dependence of high frequency transmission loss on connector stiffness.
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McKell, Bernadette. "The development of a screening test to determine the impact sound insulation of floors." Thesis, Heriot-Watt University, 1991. http://hdl.handle.net/10399/823.
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Chitela, Yuvaraj R. "Sustainable Ecofriendly Insulation Foams for Disaster Relief Housing." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984180/.
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Natural disasters are affecting a significant number of people around the world. Sheltering is the first step in post-disaster activities towards the normalization of the affected people's lives. Temporary housing is being used in these cases until the construction of permanent houses are done. Disposal of temporary housing after use is leading to a significant environmental impact because most of them are filled with thermally insulative polymer foams that do not degrade in a short period. To reduce these problems this work proposes to use foams made with compostable thermoplastic polylactic acid (PLA) and degradable kenaf core as filler materials; these foams are made using CO2 as blowing agent for insulation purposes.
Foams with PLA and 5%, 10% and 15% kenaf core were tested. Different properties and their relations were examined using differential scanning calorimetry (DSC), thermal conductivity, mechanical properties, scanning electron microscopy (SEM), x-ray μ-computed tomography (μ-CT) and building energy simulations were done using Energy Plus by NREL. The results show that mechanical properties are reduced with the introduction of kenaf core reinforcement while thermal conductivity display a noticeable improvement.
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Peyvandi, A. "A study of the causes of variation of the sound insulation properties of party floors in newly converted dwellings." Thesis, London South Bank University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.618630.
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Mahasaranon, Sararat. "Acoustic and thermal properties of recycled porous media." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5516.
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This thesis is concerned with developing porous materials from tyre shred residue and polyurethane binder for acoustic absorption and thermal insulation applications. The resultant materials contains a high proportion of open, interconnected cells that are able to absorb incident sound waves through viscous friction, inertia effects and thermal energy exchanges. The materials developed are also able to insulate against heat by suppressing the convection of heat and reduced conductivity of the fluid locked in the large proportion of close-cell pores. The acoustic absorption performance of a porous media is controlled by the number of open cells and pore size distribution. Therefore, this work also investigates the use of catalysts and surfactants to modify the pore structure and studies the influence of the various components in the chemical formulations used to produce these porous materials. An optimum type and amounts of catalyst are selected to obtain a high chemical conversion and a short expanding time for the bubble growth phase. The surfactant is used to reduce the surface tension and achieve a homogenous mixing between the solid particulates tyre shred residue, the water, the catalyst and the binder. It is found that all of the components significantly affect the resultant materials structure and its morphology. The results show that the catalyst has a particularly strong effect on the pore structure and the ensuing thermal and acoustical properties. In this research, the properties of the porous materials developed are characterized using standard experimental techniques and the acoustic and thermal insulation performance underpinned using theoretical models. The important observation from this research is that a new class of recycled materials with pore stratification has been developed. It is shown that the pore stratification can have a positive effect on the acoustic absorption in a broadband frequency range. The control of reaction time in the foaming process is a key function that leads to a gradual change in the pore size distribution, porosity, flow resistivity and tortuosity which vary as a function of sample depth. It is shown that the Pade approximation is a suitable model to study the acoustic behaviour of these materials. A good agreement between the measured data and the model was attained.
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Lane, Jeremy David. "Active Control of Noise Through Windows." Thesis, University of Canterbury. Mechanical Engineering dept, 2013. http://hdl.handle.net/10092/10523.
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Windows are a weakness in building facade sound transmission loss (STL). This coupled with the detrimental effects of excessive noise exposure on human health including: annoyance, sleep deprivation, hearing impairment and heart disease, is the motivation for this investigation of the STL improvements active noise control (ANC) of windows can provide.
Window speaker development, ANC window experiments and analytical modelling of ANC windows were investigated. Five different window speaker constructions were characterised then compared with a previously developed window speaker. ANC window testing used three different ANC configurations and was performed in two different
environments, one with a reverberant receiving room, and the other with an anechoic receiving room. Optimisation of ANC systems with particular control source locations was the aim of the modelling. This enabled comparison with the ANC window tests and would aid in further development of ANC windows.
Window speaker constructions were characterised by sound pressure level (SPL) measurements performed in an anechoic room. These measurements were made in a way that enabled comparison with the previously developed window speaker.
Total sound energy reduction calculations were used to determine the relative performance of the tested ANC windows.
An STL model, based on a modal panel vibration model, was initially created and verified against published STL data before it was expanded to include ANC control sources. The model was used to simulate the performed anechoic environment tests and an ideal ANC case.
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Ba, Abdoulaye Sidiki. "Étude de la transmission acoustique de métaplaques localement résonantes." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0228/document.
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Les matériaux acoustiques super absorbants, sub-longueur d’ondes et large bande, ouvrent de nouvelles perspectives prometteuses pour l’isolation sonore. Dans ce contexte, nous avons conçu et synthétisé des structures hétérogènes comportant des microbilles sphériques de silicone poreux « ultra-lentes », distribuées dans des matrices aqueuses ou élastomériques. Dans un premier temps, nous avons démontré pourquoi la vitesse du son est aussi basse dans les silicones poreux (<100 m/s) comparativement à celle de milieux homogènes (~1000 m/s). Ce fort contraste de propriétés acoustiques entre phases étant susceptible d’induire des propriétés extrêmement diffusantes des microbilles, nous avons étudié l’impact de la nature de la matrice et de l’arrangement (aléatoire ou périodique) des microbilles sur les propriétés acoustiques d’échantillons se présentant sous forme de plaques sub-longueurs d’ondes à faces parallèles. Nous avons montré que la présence de minima prononcés dans le coefficient de transmission de ces métaplaques était pilotée par la résonance monopolaire des microbilles, et était fortement conditionnée par la nature de la matrice environnante. Enfin, toutes les mesures ultrasonores de l’étude ont été confrontées avec succès à des prédictions issues de modèles de diffusion multipleAcoustic metamaterials may behave like sub-wavelength and broadband sound-absorbers, opening thus new promising routes for sound insulation. In this context, we have designed and achieved heterogeneous structures composed of soft porous silicone rubber microbeads with ultra-low sound speeds, dispersed in various aqueous or elastomeric matrices. First, we show why the sound speed is so low in soft porous silicone rubber materials (<100m/s) in comparison with soft homogeneous materials (~1000m/s). Such a large sound-speed contrast resulting in strongly scattering properties of the microbeads, we have studied the influence of the matrix characteristics as well as the arrangement of microbeads (random or ordered) on the acoustic properties of the samples in form of sub-wavelength slabs. We have evidenced deep and wide minima of acoustic transmission due to the strong monopolar resonances of the microbeads, which strongly depend on the properties of the surrounding matrix. All our ultrasonic measurements have been compared with theoretical predictions based on various Multiple Scattering Theories, revealing an excellent quantitative agreement
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Al-Hilo, Naeem A. "Novel Sound Absorbing Materials Made From Elastomeric Waste: Compounding And Structuring Of Elastomeric Waste Crumb And Fibers With Binders Into Innovative Noise Insulation Materials." Thesis, University of Bradford, 2018. http://hdl.handle.net/10454/17383.
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Elastomeric wastes plague our time, polluting our environment and requiring urgent upcycling solutions. This research contributes to this agenda using an important source of waste, car tyre shred fibre residue (TSFR). It is demonstrated how using binders, non-foaming (SBR) and foaming (PU), we can transform these TSFR into structured porous acoustic-thermal insulation materials, suitable as underlay, cavity wall and pipe insulation. These structures were fabricated in purpose designed moulds and characterised for their porosity, tortuosity, flow resistivity and density. Their acoustic absorption performance was measured using industrial standards and the measurement underpinned with the Johnson-Champoux-Allard (JCA) model. With the under-layer materials, thermal insulation was also measured.
The results were as follows: (i) 40%/60% SBR/TSFR was an optimal composition for the underlay with the addition of 15% w/w bumper crumb of size > 1mm enhancing both impact sound and thermal insulation, (ii) PU was found to produce well performing wall cavity insulation, particularly when vacuum pressure was applied, allowing micro and macro pores to be formed; (iii) PU applied with controlled amount of water to control foaming CO2 formation produced super-performing (compared with Armacell System B) stratified pipe cladding insulation, optimal at porosity stratification of 90%, 83%, and 70%; (iv) Very good agreement was observed with predictions using JCA model, allowing further research to be carried out with these now well characterised sound insulations.
In addition to the developing materials, a novel technique for measuring sound absorption of pipe cladding was developed that could replace the expensive standard using a reverberation chamber.
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Джур, Ярослав Володимирович. "Акустична модернізація конференц-залу." Bachelor's thesis, КПІ ім. Ігоря Сікорського, 2021. https://ela.kpi.ua/handle/123456789/43159.
Full textAbstract:
Об’єктом дослідження в даній роботі є методи розрахунку акустичних параметрів конференц-залів.
Метою дослідження роботи є проектування та модернізація акустичних умов конференц-залів та захист приміщень від шумів.
Актуальність дослідження заключається у високому попиті на багатоцільові зали з хорошими акустичними параметри серед бізнесу та освіти.
Методом дослідження є теоретичне проектування залу та покращення його акустичних параметрів за допомогою опрацювання та аналізу літури по архітектурній акустиці.
Предметом дослідження є методи та засоби покращення акустичних характеристик приміщень.
Практичним значенням роботи є застосування результатів аналізу в проектуванні та побудові конференц-залів з оптимальними характеристиками.The object of research in this paper are the methods of calculating the acoustic parameters of conference rooms. The purpose of the study is to design and upgrade the acoustic conditions of conference rooms and protect the premises from noise. The relevance of the study lies in the high demand for multi-purpose halls with good acoustic parameters among business and education. The research method is the theoretical design of the hall and the improvement of its acoustic parameters through the processing and analysis of literature on architectural acoustics. The subject of research is methods and means of improving the acoustic characteristics of the premises. The practical significance of the work is the application of the results of the analysis in the design and construction of conference rooms with optimal characteristics.
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Oliveira, Marco Aurélio de. "ESTUDO DA EFICIÊNCIA DA DUPLICAÇÃO DE JANELAS NA MELHORIA DO ISOLAMENTO ACÚSTICO DESTES COMPONENTES." Universidade Federal de Santa Maria, 2007. http://repositorio.ufsm.br/handle/1/7923.
Full textAbstract:
The aim of this research is to evaluate sound insulation behavior of double windows, when a second window is placed upon a previous one, keeping an air layer between them. This was done through standard tests carried out at the reverberation chambers of the Thermo Acoustics Laboratory, of Universidade Federal de Santa Maria in accordance with ISO 140-III, ISO 717-I international norms and the Brazilian Norm Project 02:135.01-001. First, low air hermetic windows were duplicated, each one having Rw = 18 dB. Second, good air hermetic windows were duplicated. The objective, through this technique, was to find out sound insulation improvement of double windows under the two mentioned circumstances.
Observing the test results, it was verified that low air hermetic double window obtained Rw = 26 dB, with an increase of 8 dB in relation to just one window of the same typology. Insulation gain, in this case, occurred mainly in medium and high frequencies. In relation to good air hermetic double window, a Rw final of 37 dB was obtained, considering that the increase in sound insulation depends on the initial performance of the fist installed window. The gain in insulation in the second instance was between 4 to 8 dB, mainly in relation to low and medium frequencies. Therefore, it was possible to quantify which sound insulation
improvement could be done on façades employing the technique of double windows in order to contribute to the betterment and quality of buildings in BrazilA proposta deste trabalho é avaliar o comportamento da isolação sonora de janelas duplas, em que uma segunda janela é sobreposta a outra já existente, havendo entre ambas uma camada de ar. Tal determinação é feita mediante ensaios normalizados nas câmaras reverberantes do Laboratório de Termo Acústica da Universidade Federal de Santa Maria, de acordo com as normas internacionais ISO 140-III, ISO 717-I e Projeto de Norma Brasileira 02:135.01-001. Inicialmente foram duplicadas janelas com baixa estanqüeidade ao ar, tendo Rw = 18 dB cada uma, e a seguir, janelas com boa estanqüeidade. Buscou-se, através dessa técnica, conhecer o desempenho sonoro da duplicação de janelas nestas duas situações consideradas. A partir dos resultados dos ensaios, verificou-se que a duplicação de janelas com baixa estanqüeidade ao ar atingiu um Rw = 26 dB, com acréscimo de 8 dB em relação à uma única janela de mesma tipologia. O ganho de isolamento, nesse caso, ocorreu principalmente nas médias e altas freqüências. Em relação à duplicação de janelas com boa estanqüeidade, atingiu-se um Rw final de 37 dB, sendo o acréscimo no isolamento acústico dependente do desempenho inicial da primeira janela. O ganho em isolamento nesta segunda situação foi de 4 a 8 dB, com incidência sobretudo nas baixas e médias freqüências. Dessa maneira, pôde-se quantificar qual a melhoria do isolamento sonoro em fachadas, a partir da duplicação de janelas, de forma a contribuir para o aperfeiçoamento e qualidade das construções em nosso país
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Sjöberg, Andrea. "Utvärdering av standard EN 1793–6:2012 för att undersöka bullerskyddsskärmars effektivitet in-situ." Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-347175.
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Bullerskyddsskärmar används för att reducera buller från väg- och spårtrafik. Syftet med examensarbetet var att utvärdera standard EN 1793–6:2012, en mätmetod för att undersöka bullerskyddsskärmars effektivitet in-situ med avseende på ljudisoleringen. I nuläget bestäms bullerskyddsskärmars effektivitet med laborationsmätningar i ett diffust ljudfält, som inte överensstämmer med det direkta ljudfält och den komplexitet som är in-situ. Till följd av det blir ofta laborationsmätningarna missvisande. Det finns även en okunskap kring håligheter/ läckage och hur det påverkar den akustiska prestandan, vilket gör att det emellanåt leder till brister i installationen av bullerskyddsskärmar och att enhetens ljudreducering inte stämmer överens med förväntningarna. Det finns således ett behov av att bestämma en bullerskyddsskärms befintliga prestanda in-situ för att säkerställa de krav som ställs i specifikationerna. EN 1793–6:2012 ansågs vara lämplig för ändamålet men fler mätningar behövs utföras för att kunna säkerställa resultaten och för att verifiera mätsystemet. Ljudisoleringen bestämdes som en funktion av frekvenser i tersband och var giltiga i frekvensområdet mellan 200 Hz till 5 kHz respektive 400 Hz till 5 kHz. De undersökta bullerskyddsskärmar var: en i laminerat och härdat glas med aluminiumpelare, en icke-homogen vegetationsskärm i stålram och en kombinerad bullerskyddsskärm i akrylglas med aluminiumprofiler. Resultaten jämfördes med laborationsmätningar och/eller simuleringar i Insul. Bullerskyddsskärmarna i glas gav högre värden på ljudisoleringen än i laborationsmätning, ett resultat som kan bero på skillnaderna mellan diffust ljudfält och direkt ljudfält. Komplexiteten i vegetationsskärmen gjorde resultaten svåra att analysera, men läckage förekom i de högre frekvenserna. Adrienne-fönstren behövde bli specifikt beräknade för samtliga impulssvar eftersom dimensionerna för bullerskyddsskärmarna inte överensstämde med vad som definieras i EN 1793–6:2012 för certifieringsändamål. I EN 1793–6:2012 omnämns inte heller markreflektion, som påverkar den filtrerade signalen. Vidare studier behövs för att filtrera bort dessa oönskade komponenter.Road traffic noise devices, for example noise barriers, are used to reduce the noise from road traffic and trams. The purpose of this master thesis is to evaluate the standard EN 1793-6:2012, a test method for determining noise barriers efficiency in-situ. Currently, noise barriers efficiency is determined with laboratory measurements in a diffuse sound field, which does not reflect the direct sound field and the complexity that are in-situ. As a result, laboratory measurements are often misleading. Due to a lack of knowledge about leakage, there are sometimes defects caused in the installation of the noise barriers that adversely affect the acoustic properties. There is thus a need to determine the intrinsic parameters of a noise barrier in-situ to ensure the requirements set in the specifications. The new method described in EN 1793-6:2012 was considered useful for the purpose but it was found that more measurements need to be performed to ensure results and to verify the measurement system. The sound insulation was determined for three noise barriers where results are expressed as a function of frequency in one third octave band and were valid in the frequency range between 200 Hz to 5 kHz respective 400 Hz to 5 kHz. The noise barriers tested were: a barrier in laminated glass with metal posts, a non-homogeneous vegetation barrier in a steel frame and a combined barrier with acrylic glass and metal. The results were compared with laboratory measurements and/or simulations in Insul. The glass barriers showed higher values of the sound insulation index than the laboratory measurements, perhaps due to the different sound fields. The complexity of the vegetation barrier made the results difficult to analyze, but leakage occurred in the higher frequencies. The Adrienne temporal windows were specifically calculated for all impulse responses, since the dimensions of the noise barriers differed from the one defined in EN 1793-6: 2012 for certification purposes. Also, in EN 1793-6: 2012, ground reflection, which affects the filtered signal, is not mentioned. Further studies are needed to filter out these unwanted components.
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Dahlström, Hannes, and Alexander Dyk-Strömberg. "Lätta väggar, högt buller." Thesis, Malmö universitet, Fakulteten för teknik och samhälle (TS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-44434.
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En av modern tids största miljöproblem anses vara buller. Bland annat kan nedsatt fysisk hälsaoch mental stress förekomma för människor som utsätts för bullerexponering. Ökande önskan om god akustisk miljö är idag i konflikt med att pågående urbanisering gör att vi utsätts för ökad bullerexponering i våra bostadsmiljöer. Urbaniseringen har lett till framställningen av en förordning som är fördelaktig för mer expansivt bostadsbyggande i bullerutsatta miljöer.Förordningen möjliggör byggnation vid högre trafikbullernivåer än tidigare tillåtet. Med avseende på tidigare kravnivåer har fasadväggar generellt ansetts ha mer än tillräcklig ljudisoleringsförmåga att klara trafikbullernivåerna. Till följd av nu gällande förordning är det nu inte lika entydigt att fasader med lättbyggnadsteknik har tillräckligt god ljudreduktionsförmåga. Av dessa anledningar är det aktuellt att studera hur bra fasader av lättbyggnadsteknik klarar att reducera bullret för att erfordra en kravställning på ekvivalentljudtrycksnivå inomhus som motsvarar ljudklass C eller B.Studien syftar till att undersöka om lättbyggnadsteknik är lämpligt i bullerutsatta områden som tillåts av dagens bullerkravställning. Målet är att erhålla en konstruktion i lättbyggnadsteknik som lämpas att byggas i denna höga bullerexponering. Frågeställningar ämnar att reda ut hur resultaten på väggarnas ljudisoleringsförmåga förhåller sig mellan de olika empiriska insamlingarna och dessutom hur de presterar gentemot dagens kravställningar.I rapporten genomförs akustiska fältmätningar av reduktionstalet (ljudisoleringen) enligt svenskstandard på tre fasadväggar av lättbyggnadsteknik. Fasadväggskonstruktionerna modelleras även i programvaran Insul 8 för att genom detta erhålla väggarnas beräknade reduktionstal. På en av fasadväggarna undersöks även det modellerade reduktionstalets variation följandemodifieringar av väggkonstruktionens uppbyggnad. Väggarna jämförs även med riktvärden förtre referensväggar redovisade i litteratur.Genom det teoretiska underlaget har resultaten från mätningarna, modelleringarna och litteratur-riktvärden utvärderats i förhållande till om de uppnår kravnivåer på ekvivalent ljudtryck inomhus. Resultaten för rådande fallundersökningar visar att alla undersökta väggar har erforderlig ljudreduktionsförmåga för att uppnå samhällets minimikrav (ljudklass C) då ljudreduktionen dimensioneras med väggen som dimensionerande fasadelement. Med avseende på fönster som dimensionerande fasadelement klarar två av sex väggar ej att uppnå inomhusnivåer för ljudklass C. Då kravnivåerna avser att upprätta en ännu bättre ljudmiljö (ljudklass B) än minimikraven så erhåller fyra av sex väggar denna erforderliga ljudisolering med vägg som dimensionerande element. För att uppnå ljudklass B då fönstrets ljudreduktion är dimensionerande så har en fältmätning, en referensvägg och två väggmodelleringar (utan modifieringar) erforderlig ljudisolering.Slutsatserna påvisar att ljudisoleringen är generellt sett erforderlig för väggarna i lättbyggnadsteknik, även i bullerutsatta områden som tillåts av dagens kravställning. Att kunnauppnå en god ljudmiljö (ljudklass B) avseende ekvivalent ljudtryck inomhus är däremot ej självklart då väggar i lättbyggnadsteknik byggs på bullerexponerad plats. Möjligheten att förbättra reduktionstalet är möjligt och tillämpbart genom att öka massan eller minska styvheten på väggen om reduktionstal är undermåliga.This thesis evaluates whether walls with light-frame construction are suitable to build in areas with high sound pressure levels, allowed by Sweden’s law regarding loud traffic noise nearbuildings. Previous consensus has been that exterior walls have sufficient sound insulation,regarding sound pressure levels by the residence-façade generated from traffic noise, to achieverequired indoor sound pressure levels. Due to the ongoing urbanization in Sweden, a law haspassed that increased the allowed levels of equivalent sound pressure by a residence-façade. Therefore, it has become relevant to examine if light-frame construction façades really do have sufficient sound insulation.In the study, field measurements are made on three façade walls to determine their noise reduction properties. The values from the measurements are compared to the sound insulation capacity of software-built wall-models with the same wall constructions as the field measured walls. Both the measured and the modelled walls sound insulation is also compared parallel to insulation values for light-frame construction walls found in literature. The values of the walls sound insultation are also evaluated regarding high but occurring sound pressure levels by facades and demanded levels of sound pressure indoors. Modifications are made to the construction of one modelled wall to quantify the improvement in sound insulation of the walls derived from the investigated construction-modifications.The results conclude that the examined light-frame construction walls are indeed sufficient in the aspect of sound insulation to merely satisfy the laws. The walls sound insulation is not as unambiguously sufficient when establishing what is considered a good indoor acoustic environment, instead of only achieving minimum levels required by law.
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LIN, FANG-MING, and 林芳銘. "Research on the sound insulation capability of walls in buildings:measurement and evaluation of sound insulation of walls by sound intensity Method." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/56259341963059847004.
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Chen, Ping-Chung, and 陳炳全. "An airborne sound insulation and sound absorption analysis in situ measurements." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/50644816306294052938.
Full textAbstract:
碩士國立臺灣海洋大學
系統工程暨造船學系
99
This thesis is to study the sound insulation and sound absorption of acoustic materials which is used to buildings and roadway engineering. In order to understanding the acoustic insulation materials property, the acoustic measurement experiments must be carried out in the standard laboratory . The measurement values are sound transmission loss and the sound absorption coefficients with a reverberation room method or the impedance tube method. Also, in this thesis quote the norm prCEN/TS 1793 Road Traffic Noise Reducing Devices-Test Method for determining the acoustic performance-Part 5:Intrinsic characteristics-In situ values of sound reflection and airborne sound insulation , we can confer the material effect which is installed actually . The in-situ measurement is an analysis that produce an impulse response with the temporal signal, use a maximum-length sequence (MLS) as the standard test signal , we also join the Adrienne temporal window and signal subtraction technique to calculate the values of sound insulation index and sound absorption. The comparison and discussion are finished with the results of experimentation in laboratory . We can understand the effects of reducing noise that the materials is at the scene and the laboratory, and also can get the relative relation between the both results.
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Tarng, Ming-Jhih, and 唐明志. "Sound Insulation Characteristics of Honeycomb Sandwich Panels." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/62847748383507787574.
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碩士國立臺灣大學
工程科學及海洋工程學研究所
93
The purpose of this research is to discuss the sound insulation characteristics of honeycomb sandwich panel. At first, the sandwich panel is made of layered media and the center core was regarded as an elastic porous material. Thus, the Biot theory could be employed to analyze the waves propagated in fluid saturated porous material. The transfer matrix for waves propagated between two ends of the sandwich panel was established. The combination of these related matrices can be applied to evaluate the transmission loss. To order to verify the present method, four sandwich panels which were measured by Moore are analyzed. The comparison of the transmission loss between experimental data and numerical predictions is reliable except the Panel D. In the case of Panel D, the fundamental settings are different from present method in this thesis. Using the present method, several cases are set up to investigate related parameters of cores, such as thickness, density and cell size. The numerical results show that the coincident frequency will change with different thickness of the core and this variance in frequency will influence the sound insulation of the panel. In addition, the effect of core density is similar to the effect of core thickness. The coincident frequency will decrease with the increase of the core density until the core density increase to exceed certain limit. At the time, the coincidence will occur in the same frequency. Finally, cell size of the core doesn’t influence the transmission loss of sandwich panels.
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Li, Yuan-Wei, and 李芫維. "Sound insulation performance of double-leaf panel." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/gh6hme.
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碩士國立臺灣大學
工程科學及海洋工程學研究所
107
The purpose of this research is to discuss the sound insulation of double-leaf panel. In the actual production of panels and experimental measurements, the middle part of the double-leaf panel needs to be connected by studs. Then the way of connection divided of points and line. The sound insulation quantity of different connection methods is not the same. In this thesis, we use the governing equation to simulate the sound insulation performance of double-leaf panel, while the middle structure is simulated by springs. With the difference of the incident frequency, the stiffness of the spring is also different. Based on the literature proposed to distribution of spring stiffness values, into the theoretical calculation to simulate the sound insulation performance of double-leaf panel. To order to verify the present method, citing data measured by NRCC. The comparison of the transmission loss between experimental data and numerical predictions is reliable. Using the present method, several cases are set up to investigate related parameters of double-leaf panel, such as thickness, density, stud spacing, distance between two panels and add some porous between two panels. The numerical results show that the coincident frequency will change with different thickness of the panel. Finally, theoretical analysis show that add porous to the structure can increase the sound insulation by about 5 dB.
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He, Yu-Wei, and 何育蔚. "Research of Resilient Material on Sound Insulation with Residential Floor Impact Sound." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/05694562208148809795.
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碩士國立臺灣海洋大學
系統工程暨造船學系
103
In recent years, people began to pay attention to the quality of the living environment of home. Not just the interference of horizontal neighborhood noise, the concerned about vertical floor impact sound has become upward. The dispute cause by residential floor impact sound often happen. Domestic standard floor impact sound measurement labs are few. In order to improve the interference of impact sound to residential floor, in this study we build a imitate-standard double reverberation chambers without the flanking sound effects. Take the spatial correction and comparison of sound field property with a series of experimental groups test. We make sure the floor impact sound experimental can be used. Since existing floor is not easy to change, we often cover resilient materials over the floor to improve the impact noise. We provided a complete floor impact sound insulation indexes of raised floor and resilient materials through a series of experiments.
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Jan, Shu Hui, and 冉淑慧. "The Study on Sound Insulation of Perforated Facings." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/17369767705381731193.
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碩士國立臺灣大學
造船工程學系
85
This paper is to study the performance sound insulation of perforated facings in passive noise-control method. A simplified theory with reasonable assumptions is presentedfor predicting the acoustic impedance and the transmission loss of perforated facings. Measurements of transmission loss of the perforated facings were worked out using Sound IntensityMethod in a single reverberation room. From the result of study, it shows that the measurements above 630Hz are in good agreement with calculations and the maximum difference, by nearly 2dB, of transmission loss betweenmeasurements and calculations is obtained. It also shows that perforation can avoid the coincidence phenomenon. The influences of different factors such as material, thickness, diameter of perforation and percentage of perforation transmission loss are also discussed in this study.
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Chueh-HsienHuang and 黃覺賢. "A Study on Sound Insulation of Movable Partition." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/90386691974285619324.
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Yan-JhihChen and 陳彥智. "Study of Sound Absorption and Insulation in Porous Materials." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/25512956010079496256.
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碩士國立成功大學
土木工程學系
102
A single material hardly has the abilities in both sound absorption and insulation. However, the recently developed inorganic polymeric foams, which are produced by mixing inorganic binders with foaming agent, have large amount of internal pores. Their high porosity and relatively heavy mass attribute absorption and insulation abilities in experiments. This research uses the poroelastic theory mainly by Biot to predict the acoustic performance of inorganic polymeric foams, and discuss the effects of their physical properties and microstructures. Our results show that the overall trend of analysis is close to that of experimental measurements.
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Juang, Darming, and 莊達明. "The Study on Sound Insulation of Light Weight Wall." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/64194916311600888276.
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碩士國立成功大學
建築研究所
81
For the need of structure and constructing, partitions of high- rise buildings are gradually made of light-weight walls. Its merits of light-weight theoretically cause less property than masonary materials─brick or concrete in the performance of sound insulation. Furthermore, there is lacking sound insulation data of light-weight walls interiorly. The aim of this research is mainly in studying the performances of commonly available partition on the market, the differences between measurement and calculation and the factors of sound transmission loss. The main contents of the thesis are outlined in four parts as follows: (1) Investigation and Sortation─ There are 89 pieces of tests to be distributed into nine types according to the combinations of partitions. (2) Apply "sound intensity method" to measure sound transmission loss of the partitions, and use D-curve system to assess their sound insulation. Among these partitions, the worst one is the formica hollow wall with wood skeleton structure. The best one is the hollow wall filling with glasswool made of double gypsum panels. (3) Sound insulation performances of these partitions can be generalized into four types. They are ①single panel② coincidence with smooth curve ③coincidence with sharp curve ④ double panel. Comparing the laboratory measurement with calculation of mass law , when frequency is higher, the difference is more. For example, at 2KHz, there''s a distance of 20-30dB between them, because the hollow space is filled with glasswool or rockwool. (4) The factors of sound transmission loss,"Surface density" and "Total thickness" of partitions, can be analyzed with STC value in regression. The results of single panels are congruous with the mass law. The same as another two kinds of light-weight walls ,but the other''s coefficient of determination is low. Considering the other factor of transmission loss to find out the important factor helping for sound insulation of partitions.
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Chuan-Ting, Tseng, and 曾傳庭. "The research on sound insulation of windows in apartments." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/87595738218454007868.
Full textAbstract:
碩士高苑科技大學
建築研究所
105
The domestic cities developed in high density makes the environment worse. It causes the noise becomes one of the main factors of environmental deteriorations, so the sound insulation of windows are more important in nowadays. Customers demands soundproof windows and high-level sound insulations. Therefore, this research aims to the window patterns and integration of glass thickness to do a field measurement to investigate the soundproof performance of apartments. The main solutions to the noise problems are more complex, including lower the noise, decrease the residential densities and strengthen the soundproof facilities…etc. This research aims eleven apartments in Tainan and Kaohsiung to investigate the materials which influence the soundproof performance by using equipment. It included glass thickness, material of window frames…to build a better soundproof window pattern to benefit the appliance and designs in the future. Please see the events below. First, The 11 results of the cases have shown the difference and the different value between the full-opened windows and the full-closed windows. The average value of sound insulation in the living room is 7.8 dB(A). The average value of sound insulation in the master bedroom is 10.7dB(A). The average value of sound insulation in the bedroom(1) is 9dB(A). The average value of sound insulation in the bedroom(2) is 10.1dB(A). The average value of sound insulation of bathroom in master bedroom is 12.2dB(A). The average value of sound insulation in public bathroom is 9.3dB(A). The average value of sound insulation in dining room is 7.2dB(A). Second, The 11 results of the cases have shown background noise in the living room would be 43dB(A) when the windows are full-closed. Background noise in the master bedroom would be 40.9dB(A) when the windows are full-closed. Background noise in the bedroom(1) would be 40.8dB(A) when the windows are full-closed. Background noise in the bedroom(2) would be 38.6dB(A) when the windows are full-closed. Background noise in bathroom in master bedroom would be 36.7dB(A) when the windows are full-closed. Background noise in public bathroom would be 39dB(A) when the windows are full-closed. Background noise in the dining room would be 45.6 dB(A) when the windows are full-closed.
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Wang, Tzu-Mei, and 王姿玫. "Sound Insulation Performances of Woody Panels for Wall and Floor." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/13092762838801666089.
Full textAbstract:
碩士國立中興大學
森林學系
83
The purpose of this study was to investigate the sound insulation performances of woody panel walls and floors, and understand the improvement effect by filling with other insulation materials or the different constructure methods. The sound intensity method ( the sound transmission loss (TL) tested on woody walls ) and the measurement of floor impact sound level ( the sound pressure level and vibration acceleration level tested on woody floor ). The important results are summarized as the followings: Regarding the woody panel wall, the panels that were made from higher specific gravity showed better sound insulation performance, the TL values for red oak 39.3 dB and china fir 36.2 dB. The values of sandwich structure panel walls was more excellent than single panel. All of the samples, the improved effect of filling with insulation materials for red oak panel walls showed that the soundproof carpet with glassfiber (7.2 dB) was the best, and the coated metal sheet (4.2 dB) was the worst.With respect to the woody floors, the floor which made from different wood species showed the higher hardness and MOE, this could increase the floor impact vibration characteristics. The floor made of the lumber frame type of the red oak floor panel showed the light-weight impact characteristics,it was better than the flat type. Filling with the glass fiber can improve the resonance of floor panel. All of the samples, the best improvement of sound pressure level (SPL) in light- weight impact panel which filling up the vibration- resistant pad with the glassfiber (9.9 dB), the improved value was 13.1 dB and the improved extent was 14%. The highest improved effects on the SPL in heavy-weight impact was red oak panel filling up the vibration- resistant pad with the vibration-resistant cushion (9.7 dB). Regarding about the VAL, the panel filling up vibration-resistant lining with glassfiber and floating lumber
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Kin-ChongHoi and 許健冲. "Effects of Resilient Materials on Impact Sound Insulation of Floors." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/27713711960138822315.
Full textAbstract:
碩士國立成功大學
土木工程學系碩博士班
101
A numerical model was generated by using ABAQUS to analyze the mechanical and acoustic properties of floors with resilient materials. First, the effects of resilient materials and face panels on the maximum tensile stress of floors subjected to uniform or concentrated loads are studied numerically. Furthermore, the acoustic properties of floors with resilient materials is investigated numerically to give the sound pressure distribution in an interior space, later switched to 1/3 octave SPL frequency domain according to ISO 717-2 standard, and then to propose an optimum arrangement of resilient materials and face panels for floors when their structural and acoustic properties are of concern. Numerical results show that the arrangement of resilient materials and face panels are important to determine the mechanical and acoustic properties of floors. When loads are partially supported by resilient materials, the maximum tensile stress became greater if their span is larger. However, the tensile stress can be significantly reduced when loads are fully supported by resilient materials. Also, the impact sound insulation is enhanced if a compliant resilient material is used, leading to a sound level of 35dB compared to 8dB for a stiff resilient material. But, the effects of density and thickness of resilient materials are insignificant.
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Sun, Chia-Hung, and 孫嘉鴻. "The Semiautomatic Sound Insulation Measuring System and Uncertainty of Measurement." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/65623527465260420400.
Full textAbstract:
碩士國立臺灣海洋大學
系統工程暨造船學系
104
This study is to design and develop a semi-automatic sound insulation measuring system, and analyze this system’s uncertainty of measurement using a uniform signal layer of material. We adapt the semi-automatic and manual placement measuring methods and analyze the repeatability and reproducibility of sound transmission loss data using single layer polycarbonate panels . We also take acoustical software simulation calculation and compare the experimental results using calcium silicate board. Finally, we adapt the semi-automatic measuring system and use scanning and fixed points testing for a series of windows type in the domestic market. The results shown that the measurement procedure with shorter time can be finished and the accuracy of measurement data can be confirmed for the semi-acoustic measuring system.
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Chung, Wen, and 鍾文. "The Automatic Measurement Analysis for Sound Insulation of Acoustic Materials." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/49460939870975383497.
Full textAbstract:
碩士國立臺灣海洋大學
系統工程暨造船學系
100
This thesis is to design an automatic sound insulation measurement system, and compare with artificial intensity set. The design of automatic sound insulation measurement system is use the step motor to drive and PLC(Programmable Logic Controller)for programming and control. Compare with two ways of experiment in same number of measure points and same material, to find out what was the cause of the errors and improve it to achieve completely automatic control.
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Jian, Jhih-ting, and 簡志廷. "The Influence of floor impact sound insulation with ceiling coverings construction." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/65868425407380500555.
Full textAbstract:
碩士雲林科技大學
空間設計系碩士班
96
In recently years, the economy of our country is grown up fast, and our national income is raised. The habitation is becoming high-risingly alone with serious noise problem emerged from high constructionevery. Our people realize to the importance of superior quality life gradually. Because narrow people are thick in our country, the noise problem is becoming more serious from high building. The source of sound about floor impact sound always takes place on the abovestairs. It can not control by oneself, so we can only use interior decoration to achieve to sound insulation. Consequently, using ceiling coverings to improve the performance of floor impact sound is already becoming the best methods of improving the sound environment of the building. The research hopes to proceed the way of practical test by full-scall chamber. This research utilize experimental to discuss characteristics of floor impact sound insulation used to common ceiling covering materials in internal (including ceiling material pack the material). The research utilize to factor analytic method to attempt to found out the most economic and most effective ceiling covering materials, hope to promote quality built at internal and international competitiveness. ■Procedure 1. Collection of theories in the floor impact sound and related experiment. To check a method and assessment for light impact sound in full-scale chamber, and method of use to small-scale test structure. 2. Choose the experiment material is according to survey and literature. This study utilize to factor analytic method to experiment design and measure by small-scale test structure. 3. This study analytic to factor in the effect of impact sound insulation of ceiling covering by the method of frequency analytic；Thereafter, utilizing regeression to approach the predicted model and follow-up suggestion. ■Results 1. Result of analytic：The airspace of ceiling highly increases with the framework material, have improvement trend of impact sound；Different ceiling material have different material characteristic, so the improvement of impact sound will different alone with material characteristic; Using tapping machine obviously surpass on the whole improvement degree than impact ball. 2. This study verification practicable to experimental of the small-scale test structure, Reduction of impact sound because the material characteristic and constructing will be different；The experiment of the ideal structure using tapping machine , the impact sound level of floor to L-70、△Lw-5、IIC-67; the impact sound level of impact ball to L-45、△Lw-12、IIC-79。 3. In this study utilize to method of regression analytical prove to dB(A) changing L value ΔLw and IIC into very effective to use, tapping machine R2 =0.632~0.9387；Impact ball R2 =0.3515~0.7338. ΔLw and IIC value, tapping machine R2= 0.9411; impact ball R2 =0.939.
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Chang, Han-wei, and 張涵瑋. "Experimental Investigation on floor impact sound insulation with floor coverings construction." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/13115193906400251267.
Full textAbstract:
碩士國立雲林科技大學
空間設計系碩士班
93
The habitation condition in Taiwan was high-density gradually with cause of the floor impact sound was becoming obvious to noise question.The amount of the building tends to the saturation gradually nowadays .Life cycle of building products was to end to the beginning that necessary time was long and difficult to meet meiminates-change of demand,While the old-time buildings are mach more than ewly-construct, and the sturctures cannot be changed easily, to substitute coverings will be the best measure to improve sound performance of the most general ways in the living environment. Experimental of the small-scale test structure for predict the floor impact sound and improves the result already complete to develop at present, but it still belongs to minority that such an experiment in internal. Therefore the research to hope to proceed the way of practical test by full-scall chamber. This research utilize experimental to discuss characteristics of floor impact sound insulation used to common floor covering materials in internal. The research utilize to factor analytic method to attempt to found out the most economic and most effective floor covering materials, hope to promote quality built at internal and international competitiveness, moreover to ensur effecttively to control cost of architectural and interior. ■Procedure 1.Collection of theories in the floor impact sound and related experiment. To check a method and assessment for light impact sound in full-scale chamber, and method of use to small-scale test structure. 2.Choose the experiment material is according to survey and literature. This study utilize to factor analytic method to experiment design and measure by small-scale test structure. 3. This study analytic to factor in the effect of impact sound insulation of floor covering by the method of frequency analytic；Thereafter, utilizing regeression to approach the predictied model and follow-up suggestion. ■Results 1.Result of analytic：The wooden floors highly increases with the framework material, have improvement trend of impact sound；Set up the fill materials with relative height of framework material , have the tendency to reduce to L value；Set up the damping materials will be improving impact sound level and having the obvious tendency to whole structure. 2.This study verification practicable to experimental of the small-scale test structure, Reduction of impact sound because the material characteristic and constructing will be different；The experiment of the ideal structure, the impact sound level of floor to L-45、ΔLw-45、IIC-67. 3.In this study utilize to method of regression analytical prove to dB(A) changing L value ΔLw and IIC into very effective to use, R2 =0.8675 ,0.9014,0.9014；It’s not obvious that L value be changed into ΔLw and IIC value,R2= 0.9383. The determine on frequency cf impact sound level relative to L curve, R2=0.737；ISO curve, R2=0.8661. The L curve toward low frequency and the probability of improving to impact sound level increases, ISO curve relatively obvious.