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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Dynamique des structures à interfaces non linéaires : Extension des techniques de balance harmonique

Jaumouillé, Vincent 22 March 2011 (has links)
Cette étude porte sur la simulation dynamique de structures présentant des interfaces non linéaires et plus particulièrement sur le développement de diverses extensions à la méthode de balance harmonique. Cette méthode, qui permet le calcul de réponses vibratoires stationnaires, est basée sur l’approximation en série de Fourier tronquée de la réponse. En fonction de caractère plus ou moins non linéaire de la réponse, le nombre d’harmoniques à retenir pour approcher de façon satisfaisante la réponse peut être important et varier fortement sur l’ensemble de la plage de fréquence de simulation. Un des objectifs principaux de cette recherche a été de proposer une stratégie de calcul qui permette d’adapter le nombre d’harmoniques à chaque fréquence. Dans l’optique d’approcher le mouvement global de la structure, la méthodologie proposée se base sur le suivi de l’énergie de déformation du système en fonction de la richesse du contenu fréquentiel. La formulation développée reste simple à calculer et compatible avec les étapes de condensation interne à la méthode de balance harmonique. L’extension de cette technique au calcul de réponses quasi-stationnaires est en outre possible en redéfinissant les stratégies de choix des harmoniques à retenir. Parallèlement à ce but principal, la présence de variables internes dans les modèles non linéaires d’interface (modèle de frottement par exemple) a été prise en compte dans la formulation des équations de la balance harmonique adaptative. Ces méthodes spécifiques ont ensuite été mises en oeuvre sur des modèles numériques de structures aéronautiques. Un isolateur d’équipement utilisant un matériau viscoélastique non linéaire a ainsi pu être simulé. Ensuite, la méthode de balance harmonique adaptative a pu être appliquée à l’étude des effets dynamiques non linéaires observée sur les structures boulonnées. Enfin, le calcul de réponses quasi périodiques s’est effectué sur un tronçon de lanceur intégrant des amortisseurs à frottement sec. / The study deals with the dynamic simulation of structures with non linear interfaces and particularly with the development of various extensions of the harmonic balance method. This method, applied for steady state vibrations, is based on the response approximation with a truncated Fourier series. Depending on the more or less pronounced non linear response behavior, the number of harmonics to retain to correctly approach the response may be important and may strongly vary over all the frequency band. One of the main objectives of this research work has been to propose a calculation strategy which allows adapting the number of harmonics for each frequency. In order to globally approach the structure vibration, the proposed methodology basics is to observe the strain energy evolution functions of frequency contents. The developed formulation is easy to calculate and may be employed with internal reduction steps of the harmonic balance method. Moreover, an extension of this technique for quasi-periodic vibrations is possible by redefining harmonic choice strategies. In conjunction with this main objective, internal variables in non linear interface models (friction models for example) have been considered in a specific adaptive harmonic balance method formulation. Then, these specific methods have been applied on numerical aeronautical structure models. An equipment isolator integrating a non linear viscoelastic material has been simulated. Secondly, adaptive harmonic balance method has been employed for the study of non linear dynamic effects of bolted structures. Finally, quasi periodic vibration calculation has been carried out on a launcher stage integrating dry friction dampers.
162

Obchodní a nákupní centrum v Brně / Trade House in Brno

Serbousková, Kateřina January 2018 (has links)
The final thesis deals with the design of the steel loadbearing structure of the shopping center situated in Brno. The built-up floor area is 1973 m2 (L-shaped ground plan with dimensions 48 m x 50 m). The construction consists of three parts. Building A has four above-ground floors and reaches a height of 25.5 m. The steel structure of mono-pitched roof is designed in two options. Both options consist of full-length purlins and truss girders. Building B is a single-storey building with a mono-pitched roof top reaching 8.1 m high. Building C is three-storey with a flat roof. The first floor has a construction height of 4.5 m and the remaining two floors reach height of 3.6 m, which coincide with building A. The steel structure is made of steel-concrete composite ceilings and pin-supported columns. In the case of bracings, pressure was eliminated by means of non-linearities.The work includes proposal, assessment of the supporting structure and calculation of the directional details. Internal forces were determined based on a static analysis in the SCIA Engineer calculation program.
163

Administrativní budova / Office Building

Poláček, Petr January 2019 (has links)
Master's thesis is follow up with the disign of the load bearing structure of a office building. The building is designed for the area of Svitavy. The plan's dimension are 54,0 x 54,0 m. The objects has 10 floors. Load-bearing structure is disigned in two variants. In the variant A is centre to centre spacing 6m, in variant the B it si 9m. The coulomns and floor structure are composite steel-concrete. Thesis includes drawings.
164

Zastřešení zimního stadionu / Ice Hockey stadium

Chalupa, Vojtěch January 2014 (has links)
The aim of this diploma thesis is the design of the roofing of an ice hockey stadium situated in Žďár nad Sázavou. Plan view dimensions are 55 m x 77 m. The structural height of the roof varies from 10 to 17 m. The roof itself consists of pipe truss girders with a span of 55 m, which are supported by columns on each side. The girders are suspended by a load-carrying arch with a span of 96 m and a camber of 29 m through a system of pre-stressed cables. To determine the internal forces, structural analysis software Scia Engineer was used. Individual elements were then manually designed.
165

Sportovní hala v Prostějově / The Sport Hall in Prostějov

Houška, Daniel January 2015 (has links)
The goal of the submitted thesis is a design and assessment of a steel load-bearing structure of a multipurpose sports hall situated in Prostějov. The floor plan measurements of the object are 38x54 m with the maximum ceiling height of 9,5 m. Final design variant was chosen on the basis of two preliminary drafts, both processed according to standard ČSN EN. The structure is designed with respect to ultimate and serviceability limit states. The construction consists of 10 cross-links spaced by 6,0 m. The spatial rigidity of the structure’s main load-bearing system is provided by spatial elliptic trussed girders, longitudinal and sway bracings. Roof cladding is carried by purlins placed on trusses. Steel columns are designed as a part of gable walls. The project was carried out in Scia Engineer 2014 software. Some particular elements were subsequently assessed by means of manual calculation. The thesis also includes assessment of joints, construction details and drawing documentation.
166

Realizace edukační úlohy na experimentální stanici pro modelování předepjatých šroubových spojů / Realization of educational problem based on preloaded bolted joint apparatus

Žaba, Tomáš January 2011 (has links)
In the master’s thesis an educational task concerning an experimental apparatus for quantity measurement in preloaded bolted joint is realised. In terms of its preparation an innovation of the apparatus leading to an easier and faster pretension realisation was implemented. The educational task for students and also teaching material were produced. The educational task itself consists in experimental confirmation of the relation between the tightening torque and the caused pretension. An FEM model simulating an apparatus flange deformation by given pretension was designed to verify the experiment. The thesis also contains information about the preloaded bolts, pretension elicitation methods and pretension control methods.
167

Srovnávací studie únosnosti a tuhosti vybraných spojů kovové a kompozitní části konstrukce / A comparative study of ultimate load and stiffness of metal-to-composite joints

Tchír, Michal January 2016 (has links)
V současnosti jedna z metod spojování zejména tlustých a vysoce zatížených kompozitních komponent je šroubový spoj, který je možné rozebrat pro případ opravy na rozdíl od lepeného spoje. Kompozitní konstrukce se tradičně dimenzují tak, aby během provozu nedošlo k porušení první vrstvy laminátu, nicméně důležité je taky poznat chování laminátu po porušení první vrstvy. Pro strukturální analýzu nejenom spojů, ale také dalších komponent se používá metoda konečných prvků a protože moderní nelineání řešiče jsou schopné modelovat chování laminátu po porušení první vrstvy, tato schopnost jednoho z nich byla využita v této práci při zkoumaní chování sklolaminátu spojeného s hliníkovou částí šrouby. Konečno-prvkové modely dvou spojů kovové a kompozitní části konstrukce schopné popsat progresivní porušování laminátu byly postaveny s využitím tří různých poruchových kritérií – kritéria maximálního napětí, kritéria Hill a kritéria Tsai-Wu. Problém byl řešen s využitím řešiče Nastran. Křivky síla-posuv, tuhost-posuv a hodnoty zatížení při hraničním posuvu byly porov-nány s výsledky experimentů. Jelikož faktor zbytkové tuhosti ovlivňuje výsledky ana-lýzy progresivního porušování, byly provedeny citlivostní studie zkoumajíci vliv faktoru na přesnost a stabilitu výpočtu. Shoda výpočtu s experimentem v případe prvního šroubového spoje je méně uspokojivá, nicméně shoda v případě druhého spoje, který má zesilující tenkou ocelovou destičku na spodní straně, je podstatně lepší. Vý-borná shoda je zejména při použití interaktivních kritérií Hill a Tsai-Wu.
168

Přístřešek restaurace s tanečním parketem / Restaurant dance floor shelter

Horský, Vojtěch January 2017 (has links)
In my diploma thesis I designed 2 options for an arch roofing of place for dancing next to the restaurant in Dolní Jablonná. The first solution was designed as a timber structure with internal supporting arch from glue laminated timber. The second solution was designed as a two pin-supported steel beam. These variants were predesigned and as the final solution was chosen the timber structure. I designed a rafter, a glue laminated arch, a purlin, an anchorage and field joints. The thesis is including drawings of the layout design, details and anchorage plans.
169

Studie styčníků rámových ocelových konstrukcí / Study of joints of frame steel structures

Cikánek, Ondřej January 2017 (has links)
Master's thesis „Study of joints of frame steel structures“ examine certain analysis types of frame steal joints, which are analysed both by component method and by specialized software IDEA RS. Obtained results are compared by both methods, in terms of load-bearing capacity and in terms of stiffness. Theoretical joints stiffness calculation according to standard ČSN EN 1993-1-8 is included in the introductory part of the thesis. In the second part, joints are designed to bear inner forces and moments, which were created by load combination effects and then analysed.
170

Rozhledna / Lookout tower

Jedzoková, Patricie January 2022 (has links)
The object of the diploma thesis is design and assessment of a steel lookout tower situated in Beskydy mountains. Two different variants were designed. The first variant is of square shaped plan and the second one is of hexagonal shaped plan. Both variants are spatial truss structures. They are shaped as hourglass. The variants were compared and the first one was chosen to be further developed. The lookout tower is 36 meters high and it is divided by floors. One floor is 3,6 meters high. The widest section is 8 meters, the narrowest section is 5 meters wide. The structure is pin-supported into concrete foundation. The concrete is class C25/30. The roof covering is made of trapezoidal sheet of class S280GD. Each steel element is made of steel of class S355.

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