Les panneaux passifs, en particulier les doubles-cloisons, permettent d’obtenir de bonnes performances en isolation acoustique pour éliminer les bruits indésirables en moyennes et hautes fréquences. Ils ont été largement utilisés dans les domaines du bâtiment ou encore de l’industrie du transport. Un panneau hybride actif/passif est ici étudié, afin d’obtenir de bonnes performances en absorption et en isolation sur une gamme incluant des basses fréquences. La source secondaire est réalisée par une plaque active composée de deux céramiques piézo-électriques collées sur une plaque en acier. Le coeur du double panneau peut inclure un matériau poreux pour améliorer les performances de l’ensemble. Les résultats numériques et les données de mesure montrent que ces panneaux présentent sur une large bande de fréquences de bonnes performances avec contrôle actif. / Passive structures such as double walls are effective at reducing noise transmission at medium and high frequencies. They are widely used in building and transport applications. In this thesis, a hybrid passive/active acoustic panel concept is developped, with the aim of allowing high levels of absorption and insulation over a wide range of frecuencies. The secondary source is realized by an active plate consiting of two piezoelectric patches bonded to an elastic thin plate. The use of porous material as the core of the double-panel improves the acoustic efficiency of the structure. Numerical and experimental results show that this structure presents good absorption and transmission properties thanks to active control.

Ce travail de thèse porte sur l'étude de l'influence des micro-perforations sur la réponse vibratoire d'une structure cellulaire de type panneau sandwich NIDA (nid d'abeille). Les réflecteurs d'antenne de satellites placés sur les satellites de télécommunication, comme beaucoup d'autres éléments, sont fabriqués avec ce type de matériaux. Lors du décollage du lanceur pour la mise en orbite du satellite, les sollicitations mécaniques appliquées au système sont de nature acoustique et solidienne. La sollicitation acoustique liée au champ acoustique diffus et de très fort niveau présent dans la coiffe du lanceur est la plus importante. Elle joue un rôle important dans le dimensionnement et la conception du réflecteur d'antenne. L'enjeu de la thèse est d'évaluer le potentiel d'un traitement de ce panneau par micro-perforations pour en réduire les vibrations. L'effet des micro-perforations sur la réponse vibratoire du réflecteur d'antenne est double. D'une part, le chargement acoustique que constitue la pression excitatrice est réduit par un mécanisme d'absorption du à la présence des micro-perforations, couplées aux cavités formées par les cellules NIDA du matériau. Cet effet, connu dans la littérature est décrit notamment par le modèle d'impédance acoustique de D.-Y. Maa, couplé à un modèle d'impédance de la cavité NIDA et prenant en compte les rayonnements interne et externe à la micro-perforation. D'autre part, un effet, de nature vibro-acoustique est induit par le couplage entre les vibrations du panneau et les mouvements acoustiques dans les micro-perforations. La modélisation de cet effet, mal décrit dans la littérature constitue un élément original du travail : un modèle discret construit à partir de l'impédance acoustique d'un orifice permet le calcul d'une force d'amortissement élémentaire, puis, après homogénéisation, à une estimation de l'amortissement modal du panneau micro-perforé. Les modélisations proposées pour la réduction de chargement acoustique et de l'amortissement ajouté par micro-perforation montrent que la réponse vibratoire du panneau est faiblement réduite dans la plage de fréquence d'intérêt, ce que confirment plusieurs tests expérimentaux : comparaison de réponse de panneau micro-perforé ou non en chambre réverbérante et en chambre à bruit. La modification de chargement acoustique apportée par la micro-perforation des deux faces du panneau sandwich NIDA est modélisée dans le dernier chapitre et donne lieu à une augmentation de l'effet dans la gamme de fréquence visée. / This thesis work is about the study of the microperforations influence on the vibratory response of a cellular structure as a honeycomb sandwich panel. Satellites' antenna's reflectors placed on telecommunication satellites, as many satellites' elements, are manufactured in this kind of materials. During the launcher take-off for putting satellite into orbit, the mechanical stresses applied to the system are acoustical and vibration borne stress. The acoustic stress, linked to the high level diffuse acoustic field inside the launcher fairing is the most important. It plays a part in the antenna's reflector size and conception. The issue of the thesis is to evaluate the potential of a treatment using microperforations on this panel in order to reduce its vibration. The microperforations effect on the vibration response of the antenna's reflector is double. On one hand, the acoustic loading applied by the exciter pressure is reduced by an absorption mechanism due to the presence of microperforations, coupled to cavities formed by honeycomb cells. This effect, well known in the litterature, is for instance described by the acoustic impedance model developped by D.-Y. Maa, coupled to an impedance model of honeycomb cavity and taking into account the inner and outer radiations of the microperforation. On the other hand, a vibro-acoustical effect is induced by the coupling between panel vibrations and acoustic movements inside microperforations. The modelling of this effect, not well described in the litterature, constitutes an original element of the thesis work: a discrete model constructed using the acoustic impedance of an orifice, allows the computation of an elementary damping force and then leads, after an homogenisation, to an estimation of the modal damping of the microperforated panel. Both modellings proposed for the acoustic loading reduction and the damping added by microperforations, show that the panel vibration response is weakly reduced in the frequency band of interest, which confirms experimental tests like: response comparison of non microperforated and microperforated panels placed in reverberant room and noise chamber. The acoustic loading modification induced by the microperforation of both sides of the honeycomb sandwich panel is modelling in the thesis last chapter and allows an increase of the effect on the frequency band aimed.

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. / Ministry of Science and Technology of Thailand; Naresuan University, Phitsanulok, Thailand,

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Road transport is extremely important for the development of Brazil and the increasing vehicular traffic in the transport of people gives an excessive dependence on roads. The quality of the road network of the country requires improvements to both structural aspects (resilience to the efforts required by traffic) as the functional in driving the vehicle, especially in terms of safety and acoustics, requiring the construction of increasingly discerning pavement and improved. Among the various types of asphalt blends, the asphalt blends of open type graded friction course (OGFC), presents some characteristics that serve as an alternative to the functional improvement of a pavement. In the present study verified the mechanical and functional behavior of five types of blends of OGFC to be used in construction of federal highways in Rio Grande do Sul, comparing with data from two Asphalt Concrete blends (AC) - (Range B and C). To determine the mechanical properties were used the tests resilient modulus (RM), tensile strength (RT) and testing Cântabro abrasion (PM), to investigate the functional properties were used sound absorption testing and hydraulic conductivity and finally to evaluate the structural contribution of the OGFC in flexible pavements a mechanistic analysis was carried out. The five OGFC mixtures were designated OGFC1, OGFC2, OGFC3, OGFC4 (with lime) and OGFC5 (with lime) and the mixtures of AC designated in ACB (Range B) and ACC (Range C). Samples OGFC and AC was determined the density parameters along with the volumetric properties, voids, empty bitumen ratio and other properties, being prepared with asphalt cements oil (CAP) 60/85 and CAP 55/75 respectively. In the test PM Cantabro it was observed that increasing the binder content leads to a consequent improvement in wear resistance. In RT assays, it was found that no peak maximum variable resistance trends in different amounts of binders, blends OGFC. In the RT assays, it was found that there are variable maximum strength values, in the different binder contents, in the OGFC mixtures. The RM test showed that the deformability of the blends increases as the amount of binder increases, and consequently decreases the value of RM, it being understood that the asphalt binder decreases the rigidity of the blends. The increase of temperature and decrease of charging frequency increases the deformability for all mixes for making a termosusceptivel behavior. In the sound absorption assay, the five OGFC blends exhibited fairly high absorption values with variations in peak absorption values between 0.90 and 0.98 between the 500 and 800 Hz frequency band. OGFC presented values of sound absorption higher than the values of dense asphalt mixtures found in the literature. The hydraulic conductivity test showed that the asphalt content directly influences the value of the hydraulic conductivity coefficient. With regard to the determination of the design content of the CPA blends, the only content that met all the specifications of the DNER-ES-386/99 standard was the 4% binder content. The OGFC1 mixture presented the best mechanical performance and the OGFC5 blend presented the best results from a functional point of view, but did not achieve good results from the mechanical point of view, presenting limit values required by standard DNER-ES-386/99. In relation to the values of deflection, horizontal deformation of traction and vertical deformation of compression, the OGFC caused a small contribution to the structure of the pavement generating a small decrease of these parameters. For the N of fatigue, a small contribution of the OGFC in the results of N of fatigue in the pavement was realized which took into consideration its use. / O transporte rodoviário é de extrema importância para o desenvolvimento do Brasil e pelo crescente aumento do tráfego de veículos no trasporte de pessoas confere-se uma dependência excessiva em relação às rodovias. A qualidade da malha viária do país requer melhorias, tanto aos aspectos estruturais (capacidade de resistência aos esforços solicitados pelo tráfego) quanto aos funcionais na condução do veículo, especialmente em termos de segurança e acústica, exigindo a construção de pavimentos cada vez mais criteriosos e aprimorados. Entre os diversos tipos de misturas asfálticas, a mistura asfáltica do tipo Camada Porosa de Atrito (CPA), apresenta algumas características que servem como uma alternativa para a melhoria funcional de um pavimento. No presente trabalho verificado o comportamento mecânico e funcional de cinco tipos de misturas de CPA que serão utilizadas em obras de rodovias federais do Rio Grande do Sul BR 158 e BR 285, confrontando com dados de duas misturas de Concreto Asfáltico (CA) - (Faixa B e C). Para investigar as propriedades mecânicas foram usados os ensaios mecânicos Módulo de Resiliência (MR), Resistência a Tração (RT) e o ensaio de Perda de Massa Cântabro (PM), para avaliar as propriedades funcionais foram usados os ensaios de absorção sonora e de condutibilidade hidráulica e por fim para avaliar a contribuição estrutural da CPA em pavimentos flexíveis realizou-se uma análise mecanística. As cinco misturas de CPA foram designadas em CPA1, CPA2, CPA3, CPA4 (com cal) e CPA5 (com cal) e as misturas de CA designadas em CAB (Faixa B) e CAC (Faixa C). Nas amostras de CPA e CA determinou-se os parâmetros de densidade juntamente com as propriedades volumétricas, volume de vazios, relação betume vazio e outras propriedades, sendo preparadas com ligante CAP 60/85 e CAP 55/75, respectivamente. No ensaio de PM Cântabro observouse, que um aumento no teor de ligante leva a uma consequente melhoria da resistência ao desgaste. Nos ensaios de RT constatou-se que há valores de resistência máxima variáveis, nos diferentes teores de ligantes, nas misturas de CPA. O ensaio de MR demonstrou que a deformabilidade das misturas aumenta ao passo que a quantidade de ligante aumenta, e consequentemente o valor de MR diminui, ficando claro que o ligante asfáltico diminui a rigidez das misturas. O aumento da temperatura e redução da frequência de carregamento aumenta a deformabilidade para todas as misturas por apresentarem um comportamento termosusceptível. No ensaio de absorção sonora, as cinco misturas de CPA apresentaram valores de absorção bastante elevado, com variações de valores do pico de absorção entre 0,90 a 0,98, entre a faixa de frequência de 500 a 800 Hz. As misturas de CPA apresentaram valores de absorção sonora maior que os valores de misturas asfálticas densas encontradas nas literatura. O ensaio de condutividade hidráulica demonstrou que o teor de asfalto e o volume de vazios influenciam diretamente no valor do coeficiente de condutividade hidráulica. Com respeito à determinação do teor de projeto das misturas de CPA, o único teor que satisfez todas as especificações da norma DNER 386/99 foi o teor de ligante de 4%. A mistura de CPA1 apresentou o melhor desempenho mecânico e a mistura de CPA5 apresentou os melhores resultados no ponto de vista funcional, porém não atingiu bons resultados no ponto de vista mecânico, apresentando valores limites exigido pela norma DNER-ES- 386/99. Em relação aos valores de deflexão, deformação horizontal de tração e deformação vertical de compressão, a CPA originou uma pequena contribuição para a estrutura do pavimento gerando uma pequena diminuição desses parâmetros. Para o N de fadiga, percebeu-se uma pequena contribuição da CPA nos resultados encontrados de N de fadiga nos pavimento os quais levou-se em consideração sua utilização.

This work is concerned with the fluid dynamic processes and the associated loss of acoustic energy produced by circular apertures within noise absorbing perforated walls. Although applicable to a wide range of engineering applications particular emphasis in this work is placed on the use of such features within a gas turbine combustion system. The primary aim for noise absorbers in gas turbine combustion systems is the elimination of thermo-acoustic instabilities, which are characterised by rapidly rising pressure amplitudes which are potentially damaging to the combustion system components. By increasing the amount of acoustic energy being absorbed the occurrence of thermo-acoustic instabilities can be avoided. The fundamental acoustic characteristics relating to linear acoustic absorption are presented. It is shown that changes in orifice geometry, in terms of gas turbine combustion system representative length-to-diameter ratios, result in changes in the measured Rayleigh Conductivity. Furthermore in the linear regime the maximum possible acoustic energy absorption for a given cooling mass flow budget of a conventional combustor wall will be identified. An investigation into current Rayleigh Conductivity and aperture impedance (1D) modelling techniques are assessed and the ranges of validity for these modelling techniques will be identified. Moreover possible improvements to the modelling techniques are discussed. Within a gas turbine system absorption can also occur in the non-linear operating regime. Hence the influence of the orifice geometry upon the optimum non-linear acoustic absorption is also investigated. Furthermore the performance of non-linear acoustic absorption modelling techniques is evaluated against the conducted measurements. As the amplitudes within the combustion system increase the acoustic absorption will transition from the linear to the non-linear regime. This is important for the design of absorbers or cooling geometries for gas turbine combustion systems as the propensity for hot gas ingestion increases. Hence the relevant parameters and phenomena are investigated during the transition process from linear to non-linear acoustic absorption. The unsteady velocity field during linear and non-linear acoustic absorption is captured using particle image velocimetry. A novel analysis technique is developed which enables the identification of the unsteady flow field associated with the acoustic absorption. In this way an investigation into the relevant mechanisms within the unsteady flow fields to describe the acoustic absorption behaviour of the investigated orifice plates is conducted. This methodology will also help in the development and optimisation of future damping systems and provide validation for more sophisticated 3D numerical modelling methods. Finally a set of design tools developed during this work will be discussed which enable a comprehensive preliminary design of non-resonant and resonant acoustic absorbers with multiple perforated liners within a gas turbine combustion system. The tool set is applied to assess the impact of the gas turbine combustion system space envelope, complex swirling flow fields and the propensity to hot gas ingestion in the preliminary design stages.

Presented work deals with the problem of solar glass waste recycling. In theoretical part recent EU regulation regarding waste management is presented. Different ways of PV panels recycling are explained as well as raw materials for glass production are listed. Differences between regular and solar glass is explained. In experimental part different recipes using solar glass waste and polymer binders are presented. Grindability was tested on specimen tiles. Potential of solar glass waste for manufacturing products with acoustic properties was examined.

An adapted building served as a military kitchen with a military club and an accommodation. The building was built in the 1950s. It is partly two storey basement building made of full baked bricks. Carrying and external constructions will be left unchanged. The old kitchen and dining room will be removed and replaced by a kindergarten and a gym on the 1st floor. There will be left in the original accomodation on the 2nd floor. In the cellar, there will be constructed a nightclub. All wooden windows and doors in the facade will be replaced by plastic ones. The building will be additionally insulated.

Este documento describe la elaboración de un concreto poroso con fibra de polipropileno (CPF). Se propone este material como una alternativa para reducir la contaminación sonora causada por la interacción entre el neumático y calzada. La propuesta consta de dos etapas de estudio: Elaboración de un concreto poroso y evaluación acústica mediante un modelo matemático microestructural. En la primera etapa, se evaluó dieciséis diseños, los cuales de cada mezcla se realizaron doce muestras para posteriormente ser sometidas al ensayo de resistencia a la compresión. Así se obtuvieron un total de 192 probetas que fueron evaluadas a los 7, 14 y 28 días de tiempo de curado. Los diseños están compuestos con agregados recomendados por el ACI 522R, agregados de HUSO 8 y agregados de HUSO 67, de los cuales se pretende seleccionar un concreto poroso que pueda cumplir las especificaciones mínimas de un pavimento manteniendo un porcentaje de vacíos óptimo para su posterior evaluación acústica. De los diseños obtenidos se estudió la influencia de la porosidad y porcentaje de vacíos en las propiedades mecánicas del concreto. De esta manera, se encontró una dosificación de CPF adecuado para la propuesta con una relación agua cemento de 0.36, fibra tipo I, 0% de aditivo y piedra de HUSO 8, con el cual se obtuvo una resistencia a la compresión de 296.37 kg/cm2, con el cual se cumplía los requisitos mínimos de resistencia del concreto para su aplicación a un pavimento. En la segunda etapa, se pretende obtener resultados del coeficiente de absorción acústica mediante una simulación numérica basados en la teoría microestructural de Neithalath. Este modelo fue aplicado a los diseños de CPF obtenidos en la primera parte, teniendo en cuenta el tamaño, forma de los agregados y la relación de vacíos. El desarrollo de este modelo matemático y su correlación con las mediciones físicas permiten la predicción del coeficiente máximo absorción acústica de un CPF basado en las características geométricas de la estructura de poros. Los diseños óptimos sometidos a la simulación numérica obtuvieron un coeficiente de absorción acústica de 0.79 y 0.63 para agregados de HUSO 8 y HUSO 67 respectivamente. De esta manera, con la investigación y experimentación se llegó a la conclusión que el CPF permite reducir el ruido generado por la interacción del neumático y la calzada, con lo cual se verificó un nuevo beneficio del concreto poroso en la ingeniería de pavimentos. / This document describes the fabrication of a polypropylene fiber (CPF) porous concrete. This material is proposed as an alternative to reduce noise pollution caused by the interaction between the tire and road. The proposal consists of two stages of study: Preparation of a porous concrete and acoustic evaluation using a microstructural mathematical model. In the first stage, sixteen designs were evaluated, of which twelve samples were made from each mixture and subsequently subjected to the compression resistance test. Thus, a total of 192 specimens were obtained, which were evaluated at 7, 14 and 28 days of curing time. The designs are composed of aggregates recommended by ACI 522R, aggregates of HUSO 8 and aggregates of HUSO 67, of which it is intended to select a porous concrete that can meet the minimum specifications of a pavement while maintaining an optimal percentage of voids for its subsequent evaluation. acoustics. The influence of porosity and void percentage on the mechanical properties of concrete was studied from the designs obtained. In this way, a suitable CPF dosage was found for the proposal with a water-cement ratio of 0.36, type I fiber, 0% additive and HUSO 8 stone, with which a compressive strength of 296.37 kg / cm2, with which the minimum strength requirements of concrete for its application to a pavement were met. In the second stage, it is intended to obtain results of the acoustic absorption coefficient by means of a numerical simulation based on the microstructural theory of Neithalath. This model was applied to the CPF designs obtained in the first part, taking into account the size, shape of the aggregates and the ratio of voids. The development of this mathematical model and its correlation with physical measurements allow the prediction of the maximum acoustic absorption coefficient of a CPF based on the geometric characteristics of the pore structure. The optimal designs submitted to the numerical simulation obtained a sound absorption coefficient of 0.79 and 0.63 for aggregates of HUSO 8 and HUSO 67 respectively. In this way, with the investigation and experimentation, it was concluded that the CPF allows to reduce the noise generated by the interaction of the tire and the road, which verified a new benefit of porous concrete in pavement engineering. / Tesis

The Master’s thesis is focused on low-noise asphalt mixtures in general, namely asphalt concrete for very thin layers with low noise (BBTM 8 NH) and stone mastic asphalt with low noise (SMA 8 NH). The first half of the thesis describes basic types of asphalt mixtures with low noise, requirements for raw materials (aggregates and asphalt), noise emissions and their measurement methods. The second part deals the design of BBTM 8 NH and SMA 8 NH so that they have the same voids. Subsequently, their parameters were tested. Acoustic absorption, resistence against permanent deformation and stiffness. Test methods are described and evaluated.