Dissertations / Theses on the topic 'Plate coupling'
To see the other types of publications on this topic, follow the link: Plate coupling.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Plate coupling.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Zanfir, Monica. "Catalytic plate reactors for endothermic-exothermic reaction coupling." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270199.
Full text
2
Lam, Wai-yin. "Plate-reinforced composite coupling beams experimental and numerical studies /." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37311797.
Full text
3
Lam, Wai-yin, and 林慧賢. "Experimental study on embedded steel plate composite coupling beams." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B26643352.
Full text
4
Lam, Wai-yin, and 林慧賢. "Plate-reinforced composite coupling beams: experimental and numerical studies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B37311797.
Full text
5
Cheng, Pak Cheung. "Shear capacity of steel-plate reinforced concrete coupling beams /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20CHENG.
Full textAbstract:
Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 241-245). Also available in electronic version. Access restricted to campus users.
6
FORTNEY, PATRICK JOSEPH. "THE NEXT GENERATION OF COUPLING BEAMS." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1115837131.
Full text
7
Arapan, Lilia. "Thin Film Plate Acoustic Resonators for Frequency Control and Sensing Applications." Doctoral thesis, Uppsala universitet, Fasta tillståndets elektronik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-178592.
Full textAbstract:
The recent development of the commercially viable thin film electro-acoustic technology has triggered a growing interest in the research of plate guided wave or Lamb wave components owing to their unique characteristics. In the present thesis i) an experimental study of the thin film plate resonators (FPAR) performance operating on the lowest symmetrical Lamb wave (S0) propagating in highly textured AlN membranes versus a variety of design parameters has been performed. The S0 mode is excited through an Interdigital Transducer and confined within the structure by means of reflection from metal strip gratings. Devices operating in the vicinity of the stop-band center exhibiting a Q-value of up to 3000 at a frequency around 900MHz have been demonstrated. Temperature compensation of this type of devices has been studied theoretically and successfully realized experimentally for the first time. Further, integrated circuit-compatible S0 Lamb based two-port FPAR stabilized oscillators exhibiting phase noise of -92 dBc/Hz at 1 kHz frequency offset with feasible thermal noise floor below -180 dBc/Hz have been tested under high power for a couple of weeks. More specifically, the FPARs under test have been running without any performance degradation at up to 27 dBm loop power. Further, the S0 mode was experimentally demonstrated to be highly mass and pressure sensitive as well as suitable for in-liquid operation, which together with low phase noise and high Q makes it very suitable for sensor applications; ii) research in view of FPARs operating on other types of Lamb waves as well as novel operation principles has been initiated. In this work, first results on the design, fabrication and characterization of two novel type resonators: The Zero Group Velocity Resonators (ZGVR) and The Intermode-Coupled Thin Film Plate Acoustic Resonators (IC-FPAR), exploiting new principles of operation have been successfully demonstrated. The former exploits the intrinsic zero group velocity feature of the S1 Lamb mode for certain combination of design parameters while the latter takes advantage of the intermode interaction (involving scattering) between S0 and A1 Lamb modes through specially designed metal strip gratings (couplers). Thus both type of resonators operate on principles of confining energy under IDT other than reflection.
8
Yilmazel, Canan. "Analysis Of High Frequency Behavior Of Plate And Beam Structures By Statistical Energy Analysis Method." Phd thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605133/index.pdf.
Full textAbstract:
Statistical Energy Analysis (SEA) is one of the methods in literature to estimate high frequency vibrations. The inputs required for the SEA power balance equations are damping and coupling loss factors, input powers to the subsystems. In this study, the coupling loss factors are derived for two and three plates joined with a stiffener system. Simple formulas given in the literature for coupling loss factors of basic junctions are not used and the factors are calculated from the expressions derived in this study. The stiffener is modelled as line mass, Euler beam, and open section channel having double and triple coupling. Plate is modelled as Kirchoff plate. In the classical SEA approach the joint beam is modelled as another subsystem. In this study, the beam is not a separate subsystem but is used as the characteristics of the joint and to calculate the coupling loss factor between coupled plates. Sensitivity of coupling loss factors to system parameters is studied for different beam approaches.
The derived coupling loss factors and input powers are used to calculate the subsystem energies by SEA. The last plate is joined to the first one to simulate the fuselage structure. A plate representing floor structure and acoustic volume are also added. The different modelling types are assessed by applying pressure wave excitation. It is shown that deriving the parameters as given in this study increases the efficiency of the SEA method.
9
Richart, Nicolas. "Conception et mise en oeuvre d'une plate-forme de pilotage de simltions numériques parallèles et distribuées." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR13991/document.
Full textAbstract:
Le domaine de la simulation numérique évolue vers des simulations de phénomènes physiques toujours plus complexes. Cela se traduit typiquement par le couplage de plusieurs codes de simulation, où chaque code va gérer une physique (simulations multi-physiques) ou une échelle particulière (simulations multi-échelles). Dans ce cadre, l'analyse des résultats des simulations est un point clé, que ce soit en phase de développement pour valider les codes ou détecter des erreurs, ou en phase de production pour confronter les résultats à la réalité expérimentale. Dans tous les cas, le pilotage de simulations peut aider durant ce processus d'analyse des résultats. L'objectif de cette thèse est de concevoir et de réaliser une plate-forme logicielle permettant de piloter de telles simulations. Plus précisément, il s'agit à partir d'un client de pilotage distant d'accéder ou de modifier les données de la simulation de manière cohérente, afin par exemple de visualiser "en-ligne" les résultats intermédiaires. Pour ce faire, nous avons proposé un modèle de pilotage permettant de représenter des simulations couplées et d'interagir avec elles efficacement et de manière cohérente. Ces travaux ont été validés sur une simulation multi-échelles en physique des matériauxThe numerical simulations evolve more and more to simulations of complex physical phenomena through multi-scale or multi-physics codes. For these kind of simulations data analysis is a main issue for many reasons, as detecting bugs during the development phase or to understand the dynamic of the physical phenomena simulated during the production phase. The computational steering is a technique well suited to do all this kind of data analysis. The goal of this thesis is to design and develop a computational steering framework that take into account the complexity of coupled simulations. So, through a computational steering client we want to interact coherently with data generated in coupled simulations. This afford for example to visualize on-line the intermediate results of simulations. In order to make this possible we will introduce an abstract model that enables to represent coupled simulations and to know when we can interact coherently with them. These works have been validated on a legacy multi-scale simulation of material physics
10
Chee, Clinton Yat Kuan. "STATIC SHAPE CONTROL OF LAMINATED COMPOSITE PLATE SMART STRUCTURE USING PIEZOELECTRIC ACTUATORS �." University of Sydney. Aeronautical Engineering, 2000. http://hdl.handle.net/2123/709.
Full textAbstract:
The application of static shape control was investigated in this thesis particularly for a composite plate configuration using piezoelectric actuators. A new electro-mechanically coupled mathematical model was developed for the analysis and is based on a third order displacement field coupled with a layerwise electric potential concept. This formulation, TODL, is then implemented into a finite element program. The mathematical model represents an improvement over existing formulations used to model intelligent structures using piezoelectric materials as actuators and sensors. The reason is TODL does not only account for the electro-mechanical coupling within the adaptive material, it also accounts for the full structural coupling in the entire structure due to the piezoelectric material being attached to the host structure. The other significant improvement of TODL is that it is applicable to structures which are relatively thick whereas existing models are based on thin beam / plate theories. Consequently, transverse shearing effects are automatically accounted for in TODL and unlike first order shear deformation theories, shear correction factors are not required. The second major section of this thesis uses the TODL formulation in static shape control. Shape control is defined here as the determination of shape control parameters, including actuation voltage and actuator orientation configuration, such that the structure that is activated using these parameters will conform as close as possible to the desired shape. Several shape control strategies and consequently algorithms were developed here. Initial investigations in shape control has revealed many interesting issues which have been used in later investigations to improve shape controllability and also led to the development of improved algorithms. For instance, the use of discrete actuator patches has led to greater shape controllability and the use of slopes and curvatures as additional control criteria have resulted in significant reduction in internal stresses. The significance of optimizing actuator orientation and its relation to piezoelectric anisotropy in improving shape controllability has also been presented. Thus the major facets of shape control has been brought together and the algorithms developed here represent a comprehensive strategy to perform static shape control.
11
Osei, Tutu Anthony [Verfasser], Michael [Akademischer Betreuer] Weber, Bernhard [Akademischer Betreuer] Steinberger, and Irina [Akademischer Betreuer] Rogozhina. "Linking global mantle dynamics with lithosphere dynamics using the geoid, plate velocities and lithosphere stress state as constraints : lithosphere and mantle dynamics coupling / Anthony Osei Tutu ; Michael H. Weber, Bernhard Steinberger, Irina Rogozhina." Potsdam : Universität Potsdam, 2018. http://d-nb.info/1218403330/34.
Full text
12
Osei, Tutu Anthony [Verfasser], Michael H. [Akademischer Betreuer] Weber, Bernhard [Akademischer Betreuer] Steinberger, and Irina [Akademischer Betreuer] Rogozhina. "Linking global mantle dynamics with lithosphere dynamics using the geoid, plate velocities and lithosphere stress state as constraints : lithosphere and mantle dynamics coupling / Anthony Osei Tutu ; Michael H. Weber, Bernhard Steinberger, Irina Rogozhina." Potsdam : Universität Potsdam, 2018. http://d-nb.info/1218403330/34.
Full text
13
Fuchs, Lukas. "Strain quantifications in different tectonic scales using numerical modelling." Doctoral thesis, Uppsala universitet, Mineralogi, petrologi och tektonik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-280759.
Full textAbstract:
This thesis focuses on calculation of finite and progressive deformation in different tectonic scales using 2D numerical models with application to natural cases. Essentially, two major tectonic areas have been covered: a) salt tectonics and b) upper mantle deformation due to interaction between the lithosphere and asthenosphere. The focus in salt tectonics lies on deformation within down-built diapirs consisting of a source layer feeding a vertical stem. Three deformation regimes have been identified within the salt: (I) a squeezing channel flow underneath the overburden, (II) a corner flow underneath the stem, and (III) a pure channel flow within the stem. The results of the model show that the deformation pattern within the stem of a diapir (e.g. symmetric or asymmetric) can reveal information on different rates of salt supplies from the source layer (e.g. observed in Klodowa-diapir, Poland). Composite rock salt rheology results in strong localization and amplification of the strain along the salt layer boundaries in comparison to Newtonian rock salt. Flow and fold structures of passive marker lines are directly correlated to natural folds within a salt diapir. In case of the upper mantle, focus lies on deformation and resulting lattice preferred orientation (LPO) underneath an oceanic plate. Sensitivity of deformation and seismic anisotropy on rheology, grain size (d), temperature (T), and kinematics (v) has been investigated. The results of the model show that the mechanical lithosphere-asthenosphere boundary is strongly controlled by T and less so by v or d. A higher strain concentration within the asthenosphere (e.g. for smaller potential mantle temperatures, higher plate velocities, or smaller d) indicates a weaker coupling between the plate and the underlying mantle, which becomes stronger with the age of the plate. A Poiseuille flow within the asthenosphere, significantly affects the deformation and LPO in the upper mantle. The results of the model show, that deformation in the upper mantle at a certain distance away from the ridge depends on the absolute velocity in the asthenosphere. However, only in cases of a driving upper mantle base does the seismic anisotropy and delay times reach values within the range of natural data.
14
Bonnet, Guillaume. "Seamount subduction in the Zagros Suture Zone : structural and petrologic characterization and implications for seismogenesis." Electronic Thesis or Diss., Sorbonne université, 2018. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2018SORUS526.pdf.
Full textAbstract:
Les monts sous-marins subductés jouent un rôle majeur dans le comportement mécanique et sismogénique des zones de subduction: sont-ils des barrières à la propagation des séismes ou bien des aspérités permettant leur nucléation ? Les rares exemples naturels arrachés de la plaque plongeante le long de l'interface de subduction et préservés de la subduction représentent donc des témoins précieux des processus profonds. Cette thèse de doctorat reporte l'existence d'un mont sous-marin dans la zone de suture du Zagros (l'unité de Siah Kuh). Cette unité de 20x12 km de large et d'un minimum de 1.5 km de hauteur est composée de basaltes en coussins couverts de calcaire récifal et s'est formée au sein d'un arc volcanique au Crétacé supérieur. La présence de minéraux de HP-BT dans l'ensemble de la structure et dans des zones de déformation compressive localisée montrent qu'elle a été subductée jusqu' à environ 30 km. La déformation synchrone de la subduction, liée à l'écaillage interne du mont sous-marin, est assistée par des décollements enracinés dans la serpentinite ou dans des sédiments, ce qui limite possiblement l'essentiel de l'activité sismique, étant donné qu'une unique pseudotachylite a été observée, témoignant d'un séisme de magnitude Mw2-3.Nous discutons des processus océaniques de déstabilisation de pente et de subsidence, et des processus de subduction comme le couplage mécanique, les surpressions de fluide et/ou tectoniques ainsi que la nature des fluides de subduction. Nous finissons en proposant un modèles d'évolution de cette unité en relation avec les autres unités océaniques héritées de la NéotethysEamounts are for the most part subducted with the downgoing oceanic plate. They are expected to critically impact the mechanical and seismogenic behavior of subduction zones, but their exact role is strongly debated (i.e. as to whether they represent barriers to propagation or asperities promoting nucleation). Rare natural examples of metamorphosed seamounts, that got sliced off the slab along the plate interface are therefore precious witnesses to document processes operating at depth.This PhD thesis reports the existence of a former seamount in the Zagros suture zone (the Siah Kuh unit).This 20x12 kilometer-large, minimum 1.5 km-high unit composed of pillow basalts capped by reef limestone was formed in an arc environment during the Late Cretaceous.HP-LT minerals (lawsonite, aragonite veins, blue amphibole) found across the whole structure, particularly in zones of localized compressive deformation, indicate that this seamount was shallowly subducted at 30 km. Syn-subduction deformation is assisted by dŽcollement rooting in serpentinite and/or oceanic sediments and is related to the internal slicing of the seamount. The presence of soft layers may prevent most of the seismic activity, since only one pseudotachylite, recording a Mw2-3 earthquake has been found. The Siah Kuh unit is also a perfect target to investigate oceanic processes such as slope destabilization and subsidence, and subduction processes such as mechanical coupling, fluid/tectonic overpressure and the nature of subduction fluids. We finally build a model for the tectonic evolution of the Siah Kuh unit and its relationship with other ophiolites
15
Shim, Kar Wei. "Mixed dimensional coupling for laminated structures in finite element analysis." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269169.
Full text
16
Hoon, K. H. "Buckling behaviour of intermediately stiffened plate elements." Thesis, University of Strathclyde, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372102.
Full text
17
Park, Woo Sun. "The sources of variability in the statistical energy analysis of two rectangular plates." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271652.
Full text
18
Cheng, Bei, and 程蓓. "Retrofitting of deep concrete coupling beams by laterally restrained side plates." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B45791132.
Full text
19
LOPES, STEFANE RODRIGUES XAVIER. "THE INFLUENCE OF THE MODAL COUPLING IN THE STABILITY OF PLATES." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1999. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=1267@1.
Full textAbstract:
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORNessa dissertação, são avaliados os comportamentos crítico e pós-crítico de uma placa retangular fina, simplesmente apoiada, sob compressão. Um modelo não-linear para placas perfeitas e com imperfeições é desenvolvido com base na teoria não-linear de placas proposta por Marguerre. O modelo discretizado possui dois graus de liberdade que são caracterizados pela flambagem em m e (m+1) meia-ondas senoidais na direção do carregamento. Obtém-se analiticamente soluções desacopladas e acopladas através de programas de álgebra simbólica (Maple V Realese 4). Realiza- se um detalhado estudo paramétrico visando identificar todas as possíveis configurações de equilíbrio e, para cada configuração determinada, analisa-se sua estabilidade. É também estudada a influência de imperfeições geométricas iniciais, tanto na superfície de energia quanto no número e estabilidade das soluções. Os resultados mostram que o acoplamento modal tem uma grande influência sobre o comportamento pós-crítico destas placas, podendo provocar mudanças bruscas dos modos de flambagem. Finalmente, é analisada a influência das imperfeições e tensões de compressão inicias nas freqüências naturais da placa, mostrando como estas freqüências podem ser utilizadas para determinar cargas críticas sem a necessidade de execução de ensaios destrutivos.
The buckling and post buckling behavior of simply supported thin rectangular plates in axial compression is considered in this dissertation. A non- linear model for perfect and imperfect plates is developed based on Marguerre non-linear plate theory. The discretized model is considered as having two degrees of freedom characterized by buckling in m and (m+1) halfsinewaves axially and uncoupled and coupled solutions are obtained analytically by the use of symbolic algebra software. A detailed parametric study is conducted to identify all possible equilibrium solutions and establish their stability. The influence of initial geometric imperfections on the energy surface, number and stability of solutions is taken into account as an indispensable part of the analysis. The results shown that modal coupling has a strong influence on the post-buckling behavior of these plates and may explain abrupt changes of waveform of plates in the post-buckling range. Also, the influence of imperfections and initial compressive stress on the natural frequencies of the plate is analyzed and it is shown how these frequencies can be used to estimate safe buckling loads of rectangular plates non-destructively.
Este trabajo presenta un análisis experimental de cinco vigas de concreto, simplemente apoyadas, protendidas con cables sintéticos externos, con el objetivo de estudiar la influencia de la resistencia del concreto en la variación de la fuerza de los cables de protensión y en la resistencia a la flexión de las vigas. La protensión de las vigas fue hecha con cables sintéticos conocidos como Parafil, con resistenciaa la tracción de 1950MPa y módulo de elasticidad de 126000MPa. La única variable considerada fue la resistencia del concreto, cuyos valores fueron 36, 57, 73, 74 y 104MPa. El concreto de las vigas con resistencia de 57, 73, 74 y 104MPa fueron construidos con el uso de la microsílica y aditivo superplastificante, con excepción de la viga con resistencia de 36MPa que fue construida con concreto común. Los resultados mostraron que la influencia de la resistencia del concreto sobre la resistencia a la flexión de las vigas no es grande. Para el aumento de 189% en la resistencia del concreto, se produjo un aumento en la variación de la fuerza en el cable de apenas 13.6% y un aumento de 33% en el momento de ruptura. Comparando los resultados experimentales con los resultados de las principales normas y modelos propuestos se verificó que todos ofrecen buenos resultados y subestiman los valores experimentales. Comparando los resultados experimentales con el modelo de Campos (1993) se observó que los valores de la variación en la fuerza en el cable superestiman los valores experimentales. 1267 En esta disertación, se evalúan los comportamientos crítico y poscrítico de una placa rectangular fina, simplemente apoyada, bajo compresión. Se desarrolla un modelo no lineal para placas perfectas y con imperfecciones teniendo como base la teoría no lineal de placas propuesta por Marguerre. El modelo discretizado posee dos grados de libertad que son caracterizados al flamear en m y (m+1) medias-ondas senoidales en la dirección de sobrepeso. Se obtienen analíticamente soluciones desacopladas y acopladas a través de programas de álgebra simbólica (Maple V Realese 4). Se realiza un detallado estudio paronétrico tratando de identificar todas las posibles configuraciones de equilibrio y, para cada configuración determinada se analisa la estabilidad. También se estudia la influencia de imperfecciones geométricas iniciales, tanto en la superfície de energía como en el número y estabilidad de las soluciones. Los resultados muestran que el acoplamiento modal tiene una gran influencia sobre el comportamiento poscrítico de estas placas, lo que puede provocar cambios bruscos de los modos de flamear. Finalmente, se analiza la influencia de las imperfecciones y tensiones de compresión iniciales en las frecuencias naturales de la placa, mostrando como estas frecuencias pueden ser utilizadas para determinar cargas críticas sin necesidad de ejecución de ensayos destructivos.
20
Almitani, Khalid H. "Minimizing the acoustic coupling of fluid loaded plates using topology optimization." College Park, Md.: University of Maryland, 2009. http://hdl.handle.net/1903/9206.
Full textAbstract:
Thesis (Ph.D.) -- University of Maryland, College Park, 2009.Thesis research directed by: Dept. of Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
21
Hartmann, Nicolai. "Coupling of emitters to surface plasmons investigated by back focal plane microscopy." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-164238.
Full textAbstract:
Current efforts in the field of plasmonics towards device integration and miniaturization require detailed knowledge about the coupling between surface plasmons and emitters. In this work coupling between surface plasmon polaritons and different emitter systems has been investigated by the technique of back focal plane imaging. To develop a deeper understanding of the interaction phenomena the studies focused on single emitters in elementary plasmonic configurations that allow for an analytical description.
The first part of the thesis reports on the successful demonstration of surface plasmon polaritons launched by a single dipolar carbon nanotube emitter on a metal thin film after local optical excitation. Leakage radiation microscopy images, recorded in the back focal plane of a microscope objective, could be modeled successfully and contained the propagation length and direction of surface plasmon polaritons. Corresponding real-space images revealed plasmon propagation away from the single dipolar plasmon source. The polarization behavior of surface plasmon polaritons launched by single carbon nanotubes was found to be radial as predicted by theoretical calculations.
Remote excitation of single walled carbon nanotube excitons via propagating surface plasmons is demonstrated in the second part. A scanning aperture probe was used as source for propagating surface plasmons with fine controllability over excitation position and propagation direction. It was raster scanned in close proximity over a single carbon nanotube located on a metal film while recording the emission response from the nanotube. The carbon nanotube showed an emission response while the aperture plasmon source was still far away from the nanotube position. Theoretical modeling of the excited surface plasmon fields confirmed that the nanotube maps the surface plasmons locally with sub-diffraction resolution.
In the last part, radiation channels in the vicinity of a plasmonic nanowire were investigated. Radiation patterns of a coupled system of rare earth nanocrystals and silver nanowires in the back focal plane revealed that the emission in the vicinity of a nanowire can be approximately described by two emission channels that can be calculated analytically: Dipolar emission, also observed in the absence of the nanowire, and leakage radiation from the nanowire. The latter can be calculated using an antenna-resonator model that considers the air-dielectric interface on which the nanowire is deposited and the position of excitation along the nanowire. Fitting of the experimentally observed patterns provides estimates for the branching ratio between the two emission channels and further enable the determination of the plasmon wave-vector supported by the nanowires.
22
Villanueva, Robles Fernando. "The role of the Investigator Fracture Zone in the Sumatra subduction zone process using high-resolution bathymetry, seismic data, and numerical geodynamic models." Thesis, Sorbonne Paris Cité, 2019. http://www.theses.fr/2019USPCC074.
Full textAbstract:
La plupart des grands séismes se produit sur les frontières de plaques tectoniques en subduction mais la segmentation sismique au long des zones de subduction reste encore mal comprise. Pour mieux comprendre cette segmentation sismique, j’ai traité, analysé et interprété des données de bathymétrie multifaisceaux et de sismique réflexion de haute résolution. Ces données ont été acquises durant la campagne géophysique MegaTera. Celle-ci a levé la région où la Zone de Fracture Investigator (IFZ en anglais), constituée de longues rides sous-marines, rentre dans la zone de subduction de Sumatra central. Les résultats de l’interprétation montrent que la subduction de ce groupe de quatre rides a un impact considérable sur la morphologie du prisme d’accrétion, notamment des failles normales et décrochantes, ainsi que des chevauchements, conduisant sous l’effet de l’érosion au développement de systèmes de canaux et de bassins complexes. Le relief des rides IFZ a soulevé les sédiments de l’avant-arc, produisant aussi de la subsidence à la suite de la subduction des rides. Les parties frontales des rides en subduction ont favorisé le maintien des chevauchements sur de longues durées, alors que le décollement passe horizontalement par les sédiments situés au-dessus des deux rides voisines. J’ai également réalisé des modèles 3D géodynamiques numériques afin d’étudier les effets de la subduction oblique de rides sur l’évolution de la contrainte persistante et les types de déformation permanente de l’avant-arc. Finalement, J’ai analysé et comparé les résultats des modèles numériques avec l’interprétation du plancher océanique et les structures situées sous la surface du fond marin. Les résultats intégrés indiquent que les rides IFZ en subduction ont généré une déformation du prisme d’accrétion et un comportement de la contrainte qui sont hétérogènes au long du prisme. Par conséquent, la subduction des rides IFZ pourrait favoriser l’hétérogénéité du couplage interplaque, agissant comme une frontière de segmentation sismique et représentant donc un candidat plausible pour arrêter la propagation du grand tremblement de terre de 2005 Nias-Simeulue, Mw 8.7Major earthquakes occur mainly on subduction plate boundaries, but what causes the along strike earthquake segmentation remains poorly understood. To understand earthquake segmentation, I have processed, analysed and interpreted high-resolution seismic reflection and multibeam bathymetry data acquired during the MegaTera experiment of 2015. The MegaTera survey covered an area where the Investigator Fracture Zone (IFZ), a linear group of long ridges, impinges the trench along the central Sumatra subduction zone. The interpretation results show the subduction of these four groups of ridges has a considerable impact on the accretionary wedge morphology, including strike-slip and normal faulting, along with thrusts, leading to the development of complex channel systems and basins, and hence erosion. The relief of IFZ ridges has uplifted the forearc sediments, creating subsidence in the wake of subducting ridges. Frontal parts of the subducting ridges have created long-lived thrusts, whereas the décollement horizontally passes through the sedimentary sequences on the top of two neighbouring ridges. Additionally, I have performed 3-D numerical geodynamic models to study the effects of oblique subduction of ridges on the persistent stress evolution and the permanent forearc deformation patterns. Finally, I have analysed and compared the numerical experiments to the interpretation of the seafloor and subsurface features. The overall results indicate the subducting IFZ create heterogeneous wedge deformation and stress behaviour along the accretionary prism. Hence, the subduction of the IFZ might promote a heterogeneous inter-plate coupling, acting as a segment boundary and being a proper candidate for having stopped the south-eastward propagation of the 2005 Mw 8.7 Nias-Simeulue earthquake
23
Fu, Bin. "Advanced fracture mechanics analysis of shallow surface cracks in fillet welded T-butt plate joints." Thesis, University of Newcastle Upon Tyne, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363860.
Full text
24
Waksmanski, Natalie P. "Static and Dynamic Analyses of Layered Composite Plates with Multiphase Coupling and Nonlocal Effects." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1478775596863257.
Full text
25
Leray, Cedric. "Etude du comportement thermique et thermomécanique des récepteurs solaires sous haut flux radiatif." Thesis, Perpignan, 2017. http://www.theses.fr/2017PERP0003/document.
Full textAbstract:
Dans le contexte énergétique qui se profile, la production d’électricité par voie solaire thermodynamique s’avère une solution prometteuse, que ce soit pour des considérations économiques, d’échelle de production ou environnementales. Une voie d’amélioration du rendement des centrales solaires à tour consiste à utiliser des cycles thermodynamiques à haut rendement type cycles combinés. Cela nécessite de pouvoir fournir un fluide de travail pressurisé à très haute température (10bar et 1000°C minimum). Ce manuscrit présente les travaux menés afin de développer et de viabiliser un concept d’absorbeur solaire surfacique modulaire en céramique (carbure de silicium) capable de répondre à ces exigences. Le choix du carbure de silicium s’est imposé pour sa résistance aux hautes températures et aux problèmes d’oxydation. Cependant, l’utilisation d’une céramique comme matériau implique un risque de casse des modules. Les céramiques sont en effet fragiles lorsqu’elles sont soumises à des contraintes de traction. C’est la connaissance et la maitrise de ce risque qui fait l’objet de cette étude. L’approche adoptée combine le développement d’outils numériques et d’études expérimentales réalisées sur le site de la centrale solaire Thémis (Targassonne, 66, France). La méthodologie desimulation développée permet de prédire le comportement thermique et le comportement mécanique de l’absorbeur. Ceci permet de réduire les risques encourus par l’absorbeur et d’en connaitre les performances. Cette méthodologie a été éprouvée à l’aide des résultats expérimentauxFor the future, using thermodynamical solar power plant seems to be a good solution to ensure electrical production. Solar tower plants are able to produce electricity in significant amount, are environmentally friendly and economically competitive. One way to increase the yield of these plants is using high efficiency thermodynamical cycles, like combined cycle. That requires to providing a working fluid at high temperature and high pressure (10bar and 1000°C at least). This PHD thesis presents the works performed to develop and enhance a concept of modular plate solar ceramic absorber that can ensure the required air production. We chose the silicon carbide as material due to its resistance to high temperatures and oxidation problems. The drawback is ceramic modules are weak to traction stresses. The study focuses on the knowledge and the control of this phenomenon. This work combines the developments of numerical tools and experimental studies performed at Thémis power plant (Targassonne, 66, FRANCE). The numerical method permits simulations to predict the thermal behavior and the mechanical behavior of a solar module absorber. It allows the reduction of the mechanical stresses undergone by solar receiver and the prediction of its performances. This methodology was tested using experimental results
26
Van, der Merwe Jacki. "The effect of mutual coupling on the noise performance of large antenna arrays." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4277.
Full textAbstract:
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: Worldwide, more large antenna arrays are being deployed in areas of science previously dominated by other antenna geometries. Applications for large arrays include Radar, Satellite Communications and Radio Astronomy. Even though the use of large arrays solve some of the difficulties posed by more traditional antennas, new challenges are also faced. One of these challenges is the problem of noise coupling, and how the overall system performance is affected by it. The Focal Plane Array (FPA), which is a new example of a large antenna array, is currently being researched at a number of institutions worldwide for use in Radio Astronomy. As a result, FPA’s were used as an example element to demonstrate the practical importance of this research. In this study, the effect of mutual coupling on the noise performance of FPA’s was illustrated. This was done by calculating the mutual coupling between the elements of the array, and then calculating the noise power received by each element as a result of the mutual coupling. Next, the Active Noise Figure and Active Noise Temperature were calculated. These parameters were introduced to visualise the effect of mutual coupling on the overall noise performance of the array. Since FPA’s are by definition large, conventional brute-force analysis techniques are very resource intensive. Solving the coupling terms using these methods therefore requires the use of computer clusters even during the design phase of the antenna, which is very expensive. A method was therefore developed to calculate the coupling terms of a large array using Periodic Boundary Conditions. The method uses infinite array analysis, which resulted in an improvement in memory usage in orders of magnitude. This improvement comfortably places the memory requirements for the analysis of large arrays within the range of current personal computers. The results also displayed a reasonable amount of accuracy for use during the design phase of an array. The additional noise power on each element as a result of mutual coupling were also calculated. This was achieved by developing an equivalent circuit diagram that represents the system in terms of the noise and transmission parameters of the LNA of each receiver channel, and the coupling terms of the antenna array. Lastly, the active noise temperature and active noise figure are calculated. The theory was implemented by means of a script with a graphical user interface, to provide easy-to-use access to the theory. A quick reference table of estimated noise coupling penalty versus first term coupling and LNA noise temperature was also compiled. The results of an example calculation showed a significant amount of noise coupling in an 8×8 Vivaldi array. The noise coupling resulted in an increase in system noise temperature, Tsys, in the order of 9% of the LNA noise temperature, TLNA. According to the SKA Tsys budget, this results in an approximate Tsys increase of 1.3 Kelvin. In the context of Radio Astronomy, this additional source of noise cannot be ignored, as it can greatly affect the usebility of the telescope for certain areas of research.
AFRIKAANSE OPSOMMING: Groot antennaskikkings word deesdae al hoe meer ingespan in plek van ander tradisionele antennamodelle. Toepassings vir groot antennaskikkings sluit Radar, Satellietkommunikasie en Radioastronomie in. Alhoewel die gebruik van groot antennaskikkings baie van die probleme wat deur ander tradisionele antennamodelle veroorsaak word oplos, word nuwe uitdagings terselfdertyd geskep. Een van hierdie nuwe uitdagins is ruiskoppelling en hoe dit die ruisgedrag van die stelsel as ’n geheel affekteer. ’n Beeldvlakskikking (FPA), is ’n opwindende nuwe voorbeeld van ’n groot antennaskikking en die moontlikheid vir die gebruik daarvan in radioastronomie word tans wêreldwyd nagevors. Om hierdie rede is die FPA gekies as voorbeeldelement om die bruikbaarheid van hierdie navorsing in die praktyk te beklemtoon. In hierdie studie word die effek van wedersydse koppelling op die ruisgedrag van FPA’s geïllustreer. Dit word gedoen deur eers die wedersydse koppelling tussen die elemente van die antennaskikking te bereken en dan die ruisdrywing wat deur elke element ontvang word as gevolg van wedersydse koppelling. Daarna word die Aktiewe Ruistal en die Aktiewe Ruistemperatuur bereken. Hierdie nuwe parameters word bekendgestel om die gevolge van wedersydse koppelling op die ruisgedrag van die stelsel as ’n geheel te visualiseer. Omdat FPA’s per definisie groot is, vereis die analise daarvan deur middel van konvensionele metodes baie rekenaar hulpbronne. Hierdie metodes vereis dus die gebruik van rekenaarbondels of superrekenaars selfs gedurende die ontwerpfase van die antenna, wat baie duur en onprakties is. Daar is dus ’n metode ontwikkel wat gebruik maak van periodiese randvoorwaardes om groot antennaskikkings te analiseer. Die metode benader ’n groot antennaskikking as ’n eindig-opgewekte oneindige skikking van antennas. As gevolg hiervan, word die geheueverbruik met ordegroottes verbeter. Hierdie verbetering plaas dus die analise van groot antennaskikkings binne die vermoëns van huidige persoonlike rekenaars. Die resultate wys ook ’n aanvaarbare graad van akkuraatheid vir gebruik gedurende die ontwerpfase van die skikking. Die bykomende ruisdrwying op elke element as gevolg van wedersydse koppelling is ook bereken. Om dit te vermag, is daar ’n ekwivalente stroombaandiagram ontwikkel wat die gekoppelde stelsel in terme van die ruis- en transmissieparameters van die laeruisversterker (LNA) aan elke ontvangerkanaal en die koppelterme van die antenna skikking voorstel. Laastens word die aktiewe ruistal en die aktiewe ruistermperatuur ook bereken. Die teorie is geïmplimenteer deur gebruik te maak van ’n grafiesegebruikerskoppelvlak (GUI). Die GUI verskaf aan die gebruiker maklike toegang tot die teorie wat onwikkel is in hierdie navorsing. Daar is ook ’n snelnaslaantabel geskep met benaderde waardes van ruiskoppelling vir ’n verskeidenheid waardes van LNA ruistemperature en eerste element koppelling. Die resultate van ’n 8×8 Vivaldiskikking voorbeeld, het ’n beduidende hoeveelheid ruiskoppelling getoon. Die ruiskoppelling het ’n maksimum toename in stelsel ruistemperatuur, Tsys, van ongeveer 9% van die LNA ruistemperatuur tot gevolg gehad. Volgens die huidige Tsys begroting van die SKA, kom dit neer op ’n Tsys toename van byna 1.3 Kelvin. In die konteks van die radioastronomie, kan hierdie toename in ruistemperatuur nie geïgnoreer word nie aangesien dit die bruikbaarheid van die teleskoop vir sekere velde van navorsing nadelig kan beïnvloed.
27
Sun, Liecheng. "ANALYTICAL STRIP METHOD TO ANTISYMMETRIC LAMINATED PLATES." UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_diss/715.
Full textAbstract:
An Analytical Strip Method (ASM) for the analysis of stiffened and non-stiffened antisymmetric laminated composite plates is derived by considering the bending-extension coupling effect for bending, free vibration and buckling. A system of three equations of equilibrium, governing the general response of arbitrarily laminated composite plates, is reduced to a single eighth order partial differential equation in terms of a displacement function. The displacement function is solved in a single series form to determine the displacement, fundamental frequency, and buckling load of antisymmetric cross-ply and angle-ply laminated composite plates. The solution is applicable to rectangular plates with two opposite edges simply supported, while the other edges are simply supported, clamped, free, beam supported, or any combinations of these boundary conditions.
This method overcomes the limitations of other analytical methods (Navier’s and Lévy’s), and provides an alternative to numerical, semi-numerical, and approximate methods of analysis. Numerical examples of bending, free vibration, and buckling of antisymmetric laminated composite plates are presented in tabular and graphical form. Whenever possible, the results of the present study are compared with those published in the literature and/or ANSYS solutions. The comparison firmly establishes that this method could be used for the analysis of antisymmetric laminated composite plates. Future research needs are identified for the aspects that have not been reached by the present study and others.
28
Papastefanakis, Dimitrios. "Orthoptere : etude aerodynamique d'une eolienne a axe vertical et sa regulation energetique par microprocesseur." Paris 6, 1986. http://www.theses.fr/1986PA066517.
Full textAbstract:
L'orthoptere est une eolienne non conventionnelle, a axe vertical, constituee de deux palmes type plaque plane qui restent constamment perpendiculaires entre elles. Etude experimentale et numerique de l'influence de divers parametres: grandeur de corde, calage, presence d'un axe central, et rayon de courbure des bords d'attaque, sur les performances globales de l'eolienne. Conception d'un systeme de regulation par microprocesseur. Etude theorique de couplage direct avec une pompe a chaleur
29
Zhu, Yong. "Retrofitting of reinforced concrete coupling beams by bolted side steel plates for strength and deformability." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36434048.
Full text
30
Zhu, Yong, and 朱勇. "Retrofitting of reinforced concrete coupling beams by bolted side steel plates for strength and deformability." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B36434048.
Full text
31
Wenzel, Christian. "Local FEM Analysis of Composite Beams and Plates : free-Edge effect and Incompatible Kinematics Coupling." Thesis, Paris 10, 2014. http://www.theses.fr/2014PA100107/document.
Full textAbstract:
Cette thèse traite des problèmes des concentrations de contraintes locales, en particularité des effets des bords libres dans des structures stratifiés. À l'interface entre deux couches avec des propriétés élastiques différentes, les contraintes ont un comportement singulier dans le voisinage du bord libre en supposant un comportement de matériau élastique linéaire. Par conséquent, ils sont essentiels pour promouvoir le délaminage. Via Formulation unifiée de la Carrera (CUF) différents modèles cinématiques sont testés dans le but de capter les concentrations de contraintes. Dans la première partie de ce travail, les approches de modélisation dimensionnelle réduits sont comparées. Deux classe principale sont présentés: la couche équivalent (ESL) et l'approche par couche, LW. Par la suite leurs capacités à capter les singularités sont comparées. En utilisant une fonction a priori singulière, via une expression exponentielle, une mesure des contraintes singulières est introduite. Seulement deux paramètres décrivent pleinement les composantes des contraintes singulières au voisinage du bord libre. Sur la base des paramètres obtenus les modèles sont comparés et aussi les effets sous des charges d'extension et de flexion et pour différents stratifiés. Les résultats montrent une nécessité des modèles complexes dans le voisinage du bord libre. Cependant loin des bords libres, dans le centre de plaques composite, aucune différence significative ne peut être noté pour les modèles plutôt simples. La deuxième partie de ce travail est donc dédiée au couplage de modèles cinématique incompatibles. Modèles complexes et coûteux sont utilisés seulement dans des domaines locaux d'intérêt, tandis que les modèles économiques simples seront modéliser le domaine global. La eXtended Variational Formulation (XVF) est utilisé pour coupler les modèles de dimensionnalité homogènes mais de cinématique hétérogènes. Ici pas de recouvrement de domaine est présent. En outre, le XVF offre la possibilité d'adapter les conditions imposées à l'interface en utilisant un paramètre scalaire unique. On montre que, pour le problème de dimensionnalité homogène, que deux conditions différentes peuvent être imposées par ce paramètre. Un correspondant à des conditions fortes des Multi Point Constraints (MPC) et un second fournir des conditions faibles. La dernière offre la possibilité de réduire extrêmement le domaine qui utilise le modèle cinématique complexe, sans perte de précision locale. Comme il s'agit de la première application de la XVF vers les structures composites, le besoin d'un nouvel opérateur de couplage a été identifié. Un nouveau formulaire est proposé, testé et sa robustesse sera évaluéeThis work considers local stress concentrations, especially the free-Edge effects of multilayered structures. At the interface of two adjacent layers with different elastic properties, the stresses can become singular in the intermediate vicinity of the free edge. This is valid while assuming a linear elastic material behaviour. As a consequence this zones are an essential delamination trigger. Via the Carrera Unified Formulation (CUF), different kinematical models are testes in order to obtain the correct local stress concentration. In the first part of this work, the reduced dimensional modelling approaches are compared. Two main class are presented: Equivalent Single Layer (ESL) models treating the layered structure like one homogenous plate of equal mechanical proper- ties, and the Layer Wise approach, treating each layer independently. Subsequently their capabilities to capture the appearing singularities are compared. In order to have a comparable measurement of those singularities, the obtained stress distributions will be expressed via a power law function, which has a priori a singular behaviour. Only two parameters fully describe therefore the singular stress components in the vicinity of the free edge. With the help of these two parameters not only the different models capabilities will be compared, but also the free edge effect itself will be measured and compared for different symmetrical laminates and the case of extensional and uniform bending load. The results for all laminates under both load cases confirm the before stated need for rather complex models in the vicinity of the free edge. However far from the free edges, in the composite plates centre, no significant difference can be noted for rather simple models. The second part of this work is therefore dedicated to the coupling of kinematically incompatible models. The use of costly expensive complex models is restricted to local domains of interest, while economic simple models will model the global do- main. The Extended Variational Formulation (XVF) is identified as the most suitable way to couple the kinematically heterogenous but dimensional homogenous models. As it uses a configuration with one common interface without domain overlap, the additional efforts for establishing the coupling are limited. Further the XVF offers the possibility to adapt the conditions imposed at the interface using a single scalar parameter. It will be shown that for the homogenous dimensional problem under consideration only two different conditions can be imposed by this parameter. One matching the strong conditions imposed by the classical Multi Point Constrains (MPC) and a second one providing a weak condition. The last one is shown to provide the possibility to reduce further the domain using the complex kinematical model, without the loss of local precision. As this is the first application of the XVF towards composite structures, the need for a new coupling operator was identified. A new form is proposed, tested and its robustness will be evaluated
32
Hawkins, Guy Lawrence. "The behaviour of bonded out-of-plane joints in fibre reinforced plastic structures." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261750.
Full text
33
Han, Chao. "3D state space analysis and free-edge effect of piezoelectric laminated thick plates." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/3d-state-space-analysis-and-freeedge-effect-of-piezoelectric-laminated-thick-plates(13cf01e1-8c3a-419e-aaf0-31b818b9c069).html.
Full textAbstract:
The accurate evaluation of interlaminar stresses is of great significance in the analysis and design of laminated and piezoelectric laminated structures because complex behaviours of these stresses near free edges initiate edge delamination that raises concerns about the structural integrity and reliability. This thesis presented 3D hybrid analyses on the interlaminar stresses to investigate the electromechanical coupling and free edge effects of piezoelectric laminated plates with an emphasis on the realistic distributions of the 3D stress and electric fields near free edges. In this research, the state space equations for simply-supported and free-edge piezoelectric laminates under transverse loads and infinite long free-edge piezoelectric laminates under uniaxial extension were obtained in the framework of 3D piezoelasticity by considering all the independent elastic and piezoelectric constants. The equations satisfy the traction-free and open-circuit boundary conditions at free edges and the continuity conditions across all interfaces. On the basis of the transfer matrix and recursive solution approaches, 3D exact solutions were sought by a novel non-uniform layer refinement technique to evaluate the accuracy of the finite element method (FEM), and realistic gradients of interlaminar stresses and electric fields were captured. The FEM results were in good agreement with those from the present solutions except for the regions near free edges. For simply-supported and free-edge laminates, stress variations with material properties, geometries and stacking sequences were obtained. The interlaminar stress τxz was dominant at corners and τyz also tended to contribute to delamination. In the infinite long free-edge laminates, σz, τyz, Ey and Ez exhibited significant gradients near free edges. Furthermore, the considerable influence of the electromechanical coupling effect on interlaminar stresses revealed that piezoelectric laminates were more susceptible to edge delamination and the application of closed-circuited surface conditions might prevent such edge delamination. The present analytical solution demonstrated an improvement in precision over other 2D analytical and numerical solutions and could serve as a benchmark for the determination of interlaminar stresses and electric fields near the free edges of the piezoelectric laminates.
34
Hartmann, Nicolai [Verfasser], and Achim [Akademischer Betreuer] Hartschuh. "Coupling of emitters to surface plasmons investigated by back focal plane microscopy / Nicolai Hartmann. Betreuer: Achim Hartschuh." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2013. http://d-nb.info/1046503197/34.
Full text
35
Newman, Michael Geoffery. "Mathematical modelling of creep in weldments using the Cosserat theory of plates and shells." Thesis, University of Southampton, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239654.
Full text
36
Sanchis, Kilders Pablo. "Coupling techniques between dielectric waveguides and planar photonic crystals." Doctoral thesis, Universitat Politècnica de València, 2008. http://hdl.handle.net/10251/1854.
Full textAbstract:
El objetivo de esta tesis es la investigación de estructuras y técnicas de acoplo para minimizar las pérdidas de acoplo entre guías dieléctricas y cristales fotónicos planares. En primer lugar se ha estudiado el modelado del acoplo entre guías dieléctricas y guías en cristal fotónico así como la influencia de los principales parámetros del cristal en la eficiencia de acoplo. Se han obtenido expresiones cerradas para las matrices de reflexión y transmisión que caracterizan totalmente el scattering que ocurre en el interfaz formado entre una guía dieléctrica y una guía en cristal fotónico. A continuación y con el fin de mejorar la eficiencia de acoplo desde guías dieléctrica de anchura arbitraria, se ha propuesto como contribución original una técnica de acoplo basada en la introducción de defectos puntuales en el interior de una estructura de acoplo tipo cuña realizada en el cristal fotónico. Diferentes soluciones, incluida los algoritmos genéticos, han sido propuestas con el objetivo de conseguir el diseño óptimo de la configuración de defectos. Una vez conseguido un acoplo eficiente desde guías dieléctricas a guías en cristal fotónico, se ha investigado el acoplo en guías de cavidades acopladas. Como contribución original se ha propuesto una técnica de acoplo basada en la variación gradual del radio de los defectos situados entre cavidades adyacentes. Además, se ha realizado un riguroso análisis en el dominio del tiempo y la frecuencia de la propagación de pulsos en guías acopladas de longitud finita. Dicho estudio ha tenido como objetivo la caracterización de la influencia de la eficiencia del acoplo en los parámetros del pulso. Finalmente, se han presentado los procesos de fabricación y resultados experimentales de las estructuras de acoplo propuestas.Sanchis Kilders, P. (2005). Coupling techniques between dielectric waveguides and planar photonic crystals [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1854
Palancia
37
Dutta, Maitreya. "Hysteresis in the Conductance of Quantum Point Contacts with In-Plane Side Gates." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1396530257.
Full text
38
Kokkinos, Filis-Triantaphyllos T. "Three-dimensional layerwise modeling of layered media with boundary integral equations." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-02132009-170805/.
Full text
39
Gonneau, Vincent. "Modélisation du transfert thermique par marcheurs browniens dans des milieux hétérogènes." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST022.
Full textAbstract:
Ce travail porte sur la modélisation par marcheurs browniens du transfert conductif instationnaire au sein d’un milieu hétérogène. Le milieu est représenté par une structure voxélisée 3D. Chaque marcheur transporte une enthalpie élémentaire au cours de son déplacement. Ce mouvement d’enthalpie représente le flux conductif et permet de simuler la conduction en régime transitoire de façon quantitative. Une étude a montré l’importance du choix du pas de temps du calcul. Une valeur empirique de ce paramètre, dépendant du pas spatial et de la diffusivité des constituants, a été établie, permettant de modéliser correctement la conduction dans chacun des régimes de transfert. Plusieurs problèmes liés au comportement des marcheurs ont dû être résolus pour pouvoir modéliser deux techniques expérimentales de caractérisation thermique bien connues : la technique dite de la plaque chaude gardée et la méthode flash. Une condition de température imposée est modélisée par un réservoir dont le nombre de marcheurs est régulé. Une condition de paroi adiabatique impose une réflexion spéculaire aux marcheurs. Un critère stochastique de transmission basé sur les effusivités a été établi pour traiter la rencontre d’un marcheur avec une interface entre deux constituants d’un milieu hétérogène. La gestion des pertes convectives aux frontières du domaine de calcul se base également sur un critère de transmission faisant intervenir l’effusivité du constituant, le pas de temps et le coefficient d’échange convectif. Une condition de flux imposé, de profil temporel quelconque, se traduit par une injection de marcheurs à travers la frontière concernée. L’association complexe de ces briques a permis de modéliser le transfert thermique instationnaire dans des structures hétérogènes voxélisées. La comparaison de nos résultats à ceux issus d’approches plus classiques a permis de valider la capacité de notre modèle à caractériser les propriétés thermiques phoniques de structures virtuelles ou réelles. On conclut ce travail en posant les bases d’une stratégie de simulation du couplage conducto-radiatif à l’échelle locale de la structure voxélisée : l’apport énergétique du rayonnement est modélisé par un terme source de puissance volumique dans les voxelsThis work deals with the modeling of transient conduction heat transfer by brownian walkers within a heterogenous medium. The medium is described by a 3D voxelised structure. Each walker carries an elementary enthalpy during its movement. This enthalpy motion represents the thermal flux and allows to solve quantitatively the transient thermal conduction. A study demonstrates the importance of the time step chosen in the simulations. An empirical value of this parameter, based on the spatial resolution and the thermal diffusivities of the constituents, has been established to model accurately the conduction at each step of the heat transfer. Several problems related to the behavior of the walkers had to be solved to model two well-known experimental thermal characterization techniques: the hot guarded plate technique and the flash method. An imposed temperature condition is modeled by a reservoir where the number of walkers is regulated. An adiabatic wall condition imposes a specular reflection to the walkers. A stochastic transmission criterion, based on the thermal effusivities, was established to treat the behavior of a walker at voxel-voxel interface between two different constituents. Convective losses at a boundary of the numerical structure are represented by an analogous stochastic transmission criterion involving the effusivity, the convective exchange coefficient and the time step. An imposed thermal flux condition, of any temporal profile, is modeled by an injection of walkers through the boundary. The complex combination of these computing blocks allowed to model transient heat transfer within voxelised heterogeneous structures. The comparison between our results and those issued from more classical approaches allowed to validate the ability of our model to characterize the phonic thermal properties of virtual and real structures. We conclude this PhD work with preliminary activities aiming at the simulation of conduction-radiation coupling at the voxel scale of the structure: the radiative contribution is modeled by an internal power source term within the voxels
40
Elagiri, Ramalingam Rajkumar. "Development of a hybrid method for investigating near-field radiated couplings on electric cables above the GND plane." Rouen, 2012. http://www.theses.fr/2012ROUES035.
Full textAbstract:
This thesis is aimed to the development of a global methodology of computational electromagnetic (CEM) for predicting the coupling effects caused by the electromagnetic (EM) near-field (NF) radiated by electrical/electronic devices in wide frequency band on the electric cables. The method proposed is based on the association of the EM NF data from the simulations, modelling or measurements to the semi-analytical models for evaluating the coupling voltage across the cable. The originality of the hybrid method investigated in this PhD thesis lies on its flexibility for different types of electrical/electronic structures as the positions between the perturbation sources and the victim cables and also its validity in very wide frequency band and also its validity with EM aggressions including the evanescent waves. Different flow diagrams of guidelines for the application of the hybrid method proposed in function of the context of the considered structures were proposed. Analytical results showing the relevance of the method by considering NF radiated by elementary dipoles are first introduced. Then, experimental investigations from NF scanned data are presented for the radiations in low frequency and radio frequency electronic circuit enabling the predictions of coupling voltages across the cable with lengths in order of mm to m and by considering radiations of patch antennas from 0. 5 GHz to 4 GHz are presented. Finally, numerical investigations showing the effectiveness of the hybrid method by considering various complex forms of the victim wires were also performed and validated. The method developed in this PhD thesis is particularly useful for predicting the coupling between complex structures in frequency bands from some kHz to several GHzCe travail de thèse a pour objectif de développer une méthodologie globale pour l’analyse des effets électriques de couplage causés par les champs proches ElectroMagnétiques (EM) rayonnées par des dispositifs électriques et électroniques dans une bande de fréquence ultra large sur des câbles électriques. La méthode proposée est basée sur l’association des champs EM définis à partir des simulations, modélisations ou des mesures avec des modèles semi-analytiques pour évaluer la tension de couplage à travers le câble. L’originalité de la méthode de calcul hybride étudiée pour cette thèse repose sur son adaptabilité aux agressions incluant les ondes évanescentes et aux différents types de structures électriques et électroniques pour divers positions entre les sources de perturbation et les câbles victime et aussi sa validité sur une bande de fréquence ultra large. Des méthodologies indiquant de lignes directrices pour l’application de la méthode hybride proposée en fonction des types de structures considérées ont été proposées. Les résultats analytiques mettant en évidence la pertinence de la méthode en considérant les champs proches rayonnés par un réseau des dipôles élémentaires sont d’abord introduits. Ensuite, des études expérimentales de l’analyse des champs proches basse fréquence et radiofréquences émis par des circuits électroniques permettant les prédictions des tensions de couplage à travers les câbles électriques de longueur de l’ordre de quelques mm à quelques m en considérant le rayonnement des antennes patch à partir de 0,5 GHz à 4 GHz sont présentés. Enfin, les analyses numériques montrant l’efficacité de la méthode hybride en considérant diverses formes réalistes complexes des fils électriques victimes des agressions des champs EM ont également été réalisées et validées. La méthode développée dans cette thèse est particulièrement utile pour prédire le couplage entre les structures complexes dans des bandes de fréquences de quelques kHz à plusieurs GHz
41
Sprouse, Garrett William. "Coupling fluvial-hydraulic models to study the effects of vegetation on sediment transport and flow dynamics in the South Platte River, Colorado." Thesis, University of Colorado at Boulder, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10162882.
Full textAbstract:
This study investigated the effects of riparian vegetation on sediment transport rates and flow dynamics in the South Platte River just downstream of Fort Lupton, Colorado. FaSTMECH, a two-dimensional coupled fluvial and hydraulic model, was used to compute flow characteristics (velocity and depth) in addition to sediment mobility characteristics (shear stress and sediment flux) for four discharge levels ranging from 5% of bankfull flow to bankfull flow (Qbf). Estimates of a dimensionless drag coefficient (Cd) representative of the middle-aged bushy willows found on the river banks at the study site were used to create a spatially variable roughness in the model throughout the river reach. Model results show that during average annual flood events, vegetation on the river banks causes increased drag forces on the flow, leading to an increased proportion of flow being diverted into the main channel and resulting in higher velocities. The spatial distribution of shear stresses collapse under these conditions with an order of magnitude decreases over river banks and significant increases throughout the main channel. Sediment fluxes in the reach increase by nearly an order of magnitude with the presence of bank vegetation, however, the greatest differences occur during Qbf when the highest fraction of the sediment is mobile. Further analysis of vegetation effects was conducted by performing a sensitivity analysis by altering the representative non-dimensional vegetation drag coefficient by as much as +/- 400%. These alterations represent differences in vegetation density, height, orientation, leafy/leafless structure, age, rigidity, and vegetation type. Although there is a relationship between sediment fluxes and changes in Cd, there only exists a 14% increase in transport at Qbf between the two exterior limits of Cd.
42
Font, Molins Marc. "Model aryl halide macrocyclic substrates for the elucidation of coinage metal catalysed cross-coupling reaction mechanism." Doctoral thesis, Universitat de Girona, 2015. http://hdl.handle.net/10803/285975.
Full textAbstract:
Aryl-Cu(III) species have been often implicated as the intermediate species that operate Ullmann-type couplings. However, such species have long remained elusive and the fundamental pathways that govern Ullmann-type couplings, first discovered in the beginning of the last century, are still under debate. The first part of this thesis deals with the reactivity of a well-defined aryl-Cu(III) complex in the presence of sulphur, selenium and phosphorus-based nucleophiles. The results obtained demonstrate the plausibility of Cu(I)/Cu(III) redox cycles in copper-catalysed C-S, C-Se and C-P cross-coupling reactions.
An aryl-Ag(III) complex analogous to the aryl-Cu(III) complex was synthesised and its coupling reactions in the presence of a broad range of nucleophile coupling partners of different nature via reductive elimination was shown. The results of this thesis validate for the first time the feasibility of oxidative addition and reductive elimination steps at silver centres and unravels a mechanism based on two-electron redox cycles Ag(I)/Ag(III) in silver-catalysed cross-coupling reactions.Espècies aril-Cu(III) han estat implicades sovint com les espècies a través de les quals operen els acoblaments tipus Ullmann. No obstant, aquestes espècies han restat elusives, així com els processos fonamentals que governen els acoblaments tipus Ullmann, descoberts per primer cop al començament del segle passat, romanen encara objecte de debat. La primera part d’aquesta tesi s’ocupa de la reactivitat d’un complex aril-Cu(III) ben definit, en presència de nucleòfils basats en sofre, seleni i fósfor. Els resultats obtinguts demostren la plausibilitat de cicles redox Cu(I)/Cu(III) en les reaccions d’acoblament creuat per a la formació d’enllaços C-S, C-Se i C-P catalitzades per coure. Un complex aril-Ag(III) anàleg al complex aril-Cu(III) va ser sintetitzat i va ser demostrat que les seves reaccions d’acoblament en presència d’un ampli rang de nucleòfils de diferent naturalesa tenen lloc via eliminació reductiva. Els resultats d’aquesta tesi validen per primer cop la factibilitat de processos d’addició oxidant i eliminació reductiva en centres de plata i revelen un mecanisme basat en cicles redox Ag(I)/Ag(III) de dos electrons en reaccions d’acoblament creuat catalitzades per plata.
43
Neděla, Lukáš. "Zesílení silničního mostu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265570.
Full textAbstract:
This thesis deals with the reconstruction of a road bridge with two simple fields over the river Olše in Třinec. The reconstruction of the bridge structure is designed in two versions, for which there is an executed design and assessment of a supporting structure according to applicable standards. The calculation of internal strenght is carried out by using the Scia Engineer 2016 program. This work contains a static calculation, a drawing documentation , an economical comparison of variants and visualization.
44
Niezgoda, Mathieu. "Modélisation du transfert thermique au sein de matériaux poreux multiconstituants." Phd thesis, Université d'Orléans, 2012. http://tel.archives-ouvertes.fr/tel-00829217.
Full textAbstract:
Le CEA travaille sur des matériaux poreux - alvéolaires, composites, céramiques, etc. - et cherche à optimiser leurs propriétés pour des utilisations spécifiques. Ces matériaux, souvent composés de plusieurs constituants, ont en général une structure complexe avec une taille de pores de quelques dizaines de microns. Ils sont mis en oeuvre dans des systèmes de grande échelle, supérieure à leurs propres échelles caractéristiques, dans lesquels on les considère comme équivalents à des milieux homogènes, sans prendre en compte sa microstructure locale, pour simuler leur comportement dans leur environnement d'utilisation.Nous nous intéressons donc à la caractérisation des propriétés thermiques effectives de matériaux à microstructure hétérogène en cherchant à déterminer par méthode inverse en fonction de la température la diffusivité thermique qu'ils auraient s'ils étaient homogènes.L'identification de la diffusivité de matériaux poreux et/ou semi-transparents est rendue difficile par le couplage conducto-radiatif fort qui peut se développer rapidement dans ces milieux avec une augmentation de la température. Nous avons donc modélisé le transfert de chaleur couplé conducto-radiatif en fonction de la température au sein de matériaux poreux multiconstituants à partir de leur microstructure numérisée en voxels. Notre démarche consiste à nous appuyer sur la microstructure 3D obtenue par tomographie. Ces microstructures servent de support numérique à cette modélisation qui permet d'une part de simuler tout type d'expériences thermiques numériques - en particulier la méthode flash dont les résultats nous permettent de déduire la diffusivité thermique -, et d'autre part de reproduire le comportement thermique de ces échantillons dans leur condition d'utilisation.
45
Ara?jo, Gilmara Linhares Ramos de. "Efeito da inclina??o do plano de terra para antenas de microfita multicamadas com elementos parasitas fractais." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15363.
Full textAbstract:
Made available in DSpace on 2014-12-17T14:55:51Z (GMT). No. of bitstreams: 1
GilmaraLRA_DISSERT.pdf: 1784124 bytes, checksum: 3fa88890e9688357a4f14429c6d94ab0 (MD5)
Previous issue date: 2011-07-29Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
This work presents the analysis of an antenna of fractal microstrip of Koch with dielectric multilayers and inclinations in the ground plane, whose values of the angles are zero degree (without inclinations), three, seven and twelve degrees. This antenna consists of three dielectric layers arranged vertically on each other, using feeding microstrip line in patch 1, of the first layer, which will feed the remaining patches of the upper layers by electromagnetic coupling. The objective of this work is to analyze the effects caused by increase of the angle of inclination of the ground plane in some antenna parameters such as return loss, resonant frequency, bandwidth and radiation pattern. The presented results demonstrate that with the increase of the inclination angle it is possible to get antennas with characteristics multiband, with bigger bandwidth, and improving the impedance matching for each case analyzed, especially the larger angle
Este trabalho apresenta a an?lise de uma antena de microfita fractal de Koch com multicamadas diel?tricas e inclina??es no plano de terra, cujos valores dos ?ngulos s?o zero grau (sem inclina??es), tr?s, sete e doze graus. Esta antena ? constitu?da por tr?s camadas diel?tricas dispostas verticalmente umas sobre as outras, utilizando alimenta??o por linha de microfita no patch 1, da primeira camada, que ir? alimentar os demais patches das camadas superiores por acoplamento eletromagn?tico. O objetivo deste trabalho ? analisar os efeitos causados pelo aumento do ?ngulo de inclina??o do plano de terra em alguns par?metros da antena, tais como perda de retorno, frequ?ncia de resson?ncia, largura de banda e diagrama de radia??o. Os resultados apresentados demonstram que com o aumento do ?ngulo de inclina??o ? poss?vel obter antenas com caracter?sticas multibanda, com maiores larguras de banda, al?m de melhoramento do casamento de imped?ncias para cada caso analisado, sobretudo os de maior ?ngulo de inclina??o
46
Abidin, Z. Z. "Design, modelling and implementation of antennas using electromagnetic bandgap material and defected ground planes. Surface Meshing Analysis and Genetic Algorithm Optimisation on EBG and Defected Ground Structures for Reducing the Mutual Coupling between Radiating Elements of Antenna Array and MIMO Systems." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5385.
Full textAbstract:
The main objective of this research is to design, model and implement several antenna
geometries using electromagnetic band gap (EBG) material and a defected ground
plane. Several antenna applications are addressed with the aim of improving
performance, particularly the mutual coupling between the elements.
The EBG structures have the unique capability to prevent or assist the propagation of
electromagnetic waves in a specific band of frequencies, and have been incorporated
here in antenna structures to improve patterns and reduce mutual coupling in multielement
arrays. A neutralization technique and defected ground plane structures have
also been investigated as alternative approaches, and may be more practical in real
applications.
A new Uni-planar Compact EBG (UC-EBG) formed from a compact unit cell was
presented, giving a stop band in the 2.4 GHz WLAN range. Dual band forms of the
neutralization and defected ground plane techniques have also been developed and
measured. The recorded results for all antenna configurations show good improvement
in terms of the mutual coupling effect.
The MIMO antenna performance with EBG, neutralization and defected ground of
several wireless communication applications were analysed and evaluated. The
correlation coefficient, total active reflection coefficient (TARC), channel capacity and
capacity loss of the array antenna were computed and the results compared to
measurements with good agreement.
In addition, a computational method combining Genetic Algorithm (GA) with surface
meshing code for the analysis of a 2×2 antenna arrays on EBG was developed. Here the
impedance matrix resulting from the meshing analysis is manipulated by the GA
process in order to find the optimal antenna and EBG operated at 2.4 GHz with the goal
of targeting a specific fitness function. Furthermore, an investigation of GA on 2×2
printed slot on DGS was also done.Ministry of Higher Education Malaysia and Universiti Tun Hussein Onn Malaysia (UTHM)
47
Abidin, Zuhairiah Zainal. "Design, modelling and implementation of antennas using electromagnetic bandgap material and defected ground planes : surface meshing analysis and genetic algorithm optimisation on EBG and defected ground structures for reducing the mutual coupling between radiating elements of antenna array MIMO systems." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5385.
Full textAbstract:
The main objective of this research is to design, model and implement several antenna geometries using electromagnetic band gap (EBG) material and a defected ground plane. Several antenna applications are addressed with the aim of improving performance, particularly the mutual coupling between the elements. The EBG structures have the unique capability to prevent or assist the propagation of electromagnetic waves in a specific band of frequencies, and have been incorporated here in antenna structures to improve patterns and reduce mutual coupling in multielement arrays. A neutralization technique and defected ground plane structures have also been investigated as alternative approaches, and may be more practical in real applications. A new Uni-planar Compact EBG (UC-EBG) formed from a compact unit cell was presented, giving a stop band in the 2.4 GHz WLAN range. Dual band forms of the neutralization and defected ground plane techniques have also been developed and measured. The recorded results for all antenna configurations show good improvement in terms of the mutual coupling effect. The MIMO antenna performance with EBG, neutralization and defected ground of several wireless communication applications were analysed and evaluated. The correlation coefficient, total active reflection coefficient (TARC), channel capacity and capacity loss of the array antenna were computed and the results compared to measurements with good agreement. In addition, a computational method combining Genetic Algorithm (GA) with surface meshing code for the analysis of a 2×2 antenna arrays on EBG was developed. Here the impedance matrix resulting from the meshing analysis is manipulated by the GA process in order to find the optimal antenna and EBG operated at 2.4 GHz with the goal of targeting a specific fitness function. Furthermore, an investigation of GA on 2×2 printed slot on DGS was also done.
48
Carmo, Regina Maria dos Santos. "Determinação da rigidez de estruturas de pavimentos através dos métodos dos elementos de contorno e finitos." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-05042016-135834/.
Full textAbstract:
O tema desta pesquisa refere-se ao tratamento numérico de estruturas de pavimentos, dando ênfase à utilização do método dos elementos de contorno - MEC para o tratamento de elementos planos, enquanto os elementos lineares serão tratados através do método dos elementos finitos - MEF. Busca-se contribuir com uma série de trabalhos realizados nesta área, principalmente com a consideração do efeito da excentricidade do eixo neutro das barras em relação à superfície neutra da placa somando-o, portanto, ao fenômeno de flexão desta última. A técnica de acoplamento dos elementos estruturais utilizada foi a técnica das sub-regiões, que facilita a visualização do problema da combinação e viabiliza o uso da técnica de condensação estática na resolução do sistema de equações.This research refers to the numeric analysis of structures, emphasizing the use of the boundary element method - BEM - in the discretization of the plates, while the linear elements wil be formulated through the finite element method - FEM. The aim is to contribute with a number of works related to this subject, specially in the consideration of the effect of the stiffeners eccentricity in relation to the plates neutral surface, in addition to its bending state. The tool adopted to fulfill the coupling among these kinds of structural elements is the well-known sub region or multi-domain technique, which works well with the static condensation technique for solving the sparse system of equation generated.
49
Zhao, Tao. "Investigation of landslide-induced debris flows by the DEM and CFD." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:316cb3fc-dfc6-4e5a-bc0d-298e298c9c5b.
Full textAbstract:
In recent years, the increasing impacts of landslide hazards on human lives and lifeline facilities worldwide has advanced the necessity to find out both economically acceptable and useful techniques to predict the occurrence and destructive power of landslides. Though many projects exist to attain this goal, the current investigation set out to establish an understanding of the initiation and propagation mechanisms of landslides via numerical simulations, so that mitigation strategies to reduce the long-term losses from landslide hazards can be made. In this research, the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) have been used to investigate the mechanical and hydraulic behaviour of granular materials involved in landslides. The main challenge is to provide rational analyses of large scale landslides via small scale numerical simulations. To solve this problem, dimensional analyses have been performed on a simple granular column collapse model. The influence of governing dimensionless groups on the debris runout distance and deposit height has been studied for the terrestrial and submerged granular flows. 3D DEM investigations of granular flows in plane strain conditions have been performed in this research. The input parameters of the DEM model have been calibrated by the numerical triaxial tests, based on which, the relationships between the microscopic variables and the macroscopic soil strength properties are analysed. Using the simple granular column collapse model, the influences of column aspect ratio, characteristic strain, model size ratio and material internal friction angle on the runout distance and deposit height of granular materials have been examined. Additionally, the deformation and energy evolution of dry granular materials are also discussed. The DEM-CFD coupling model has been employed to study the mechanical and hydraulic behaviour of highly mobilized terrestrial / submarine landslides. This model has been validated via numerical simulations of fluid flow through a porous soil sample and grain batch sedimentations. The simulations of granular flows in the submerged environment have led to some meaningful insights into the flow mechanisms, such as the mobilization of sediments, the generation and dissipation of excess pore water pressures and the evolution of effective stresses. Overall, this study shows that the proposed numerical tools are capable of modelling the mechanical and hydraulic behaviour of terrestrial and submarine landslides.
50
Nieweglowski, Krzysztof, and Karlheinz Bock. "Assembly of optical transceivers for board-level optical interconnects." SPIE, 2016. https://tud.qucosa.de/id/qucosa%3A35102.
Full textAbstract:
This paper demonstrates an approach for passive alignment and assembly of link components for board-level very-short range optical interconnects. This interchip optical link is based on planar polymeric multimode waveguides and glassbased electro-optical transceivers. The main aim of the work is the investigation of assembly processes of link components in order to fulfill the tolerance requirements using passive alignment. The optical characterization in regard to the optical coupling between link components will define the tolerances for the alignment process. This optical analysis is based on measurements of spatial coupling characteristics. The influence of assembly tolerances on the coupling efficiency is investigated. Flip-chip assembly of electro-optical devices on the glass interposer and of the glass interposer on optical overlay is presented to prove the implementation of the concept.