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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.
21

Dynamická analýza konstrukce zatížená seismickým zatížením / Dynamic analysis of structure loaded seismic loads

Šulerová, Zdeňka January 2014 (has links)
This thesis deals with the calculation of response of reinforced concrete construction on the effect of seismic tension. Time and spectral analysis were made. They are mentioned as possible ways of calculation in EN 1998 - 1:2004 norm. Final figures of global deformations and stress on selected beam from the time and spectral analysis were firstly compared for the horizontal components of seismic stress affecting only in one direction. Subsequently comparison of time progress to combination of these effects mentioned in relevant norm was made. In the conclusion the results of used analysis are appraised.
22

Nelineární dynamická analýza konstrukce zatížena seismickými účinky / Nonlinear dynamic analysis of structures with seismic loads

Navrátilová, Martina January 2015 (has links)
Diploma thesis compares the methods for the calculation of the response of structures with seismic loads. Linear and nonlinear analyses are used for the calculations. In the case of linear analysis response spectrum method is applied. For nonlinear analysis pushover method is used. These two methods are compared in programs AxisVM and RFEM on the examples of high-rise building and space frame.
23

Dynamická analýza lehké mostní konstrukce / Dynamic analysis of lightweight bridge construction

Krzywoň, Filip January 2016 (has links)
The thesis compares the dynamic response of lightweight footbridge structure. Two finite element models were made. One in Ansys 15.0 software, and another in RFEM 5.05 structural software. The results of the models were compared to each other. The response to dynamic excitation from pedestrians was evaluated in accordance to ČSN EN 1990/A2.
24

Prüfung von Flexitanksystemen mittels Bahnauflaufversuchen unter Berücksichtigung des Schockantwortspektrums

Hartwig, Peter 11 November 2013 (has links)
Die vorliegende Arbeit befasst sich mit der Weiterentwicklung eines Prüfregelwerks für Flexitanksysteme hinsichtlich des durchzuführenden Bahnauflaufstoßes. Während eines solchen Versuchs wird das Flexitanksystem, bestehend aus einem herkömmlichen Seefrachtcontainer und beladen mit einem wassergefüllten Folientank sowie einiger Zusatzeinrichtungen, auf einem Tragwagen verankert und anschließend einer intensiven Stoßbelastung ausgesetzt. Der Nachweis der Dichtigkeit des Tanks und die Einhaltung diverser Verformungsgrenzwerte am Container entscheiden über den Ausgang des Versuchs. Während die Arbeit auch diese Punkte aufgreift, liegt der eigentliche Schwerpunkt in der Auseinandersetzung mit derjenigen Beurteilungsgröße, welche die Erfüllung der Prüfanforderungen bestimmt. Derzeit wird dieses Prüfkriterium über eine Beschleunigungsamplitude definiert, was allerdings eine gewisse Unschärfe mit sich bringt. Die Prüfmethodik und ihre Entwicklungsgeschichte, sowie die damit einhergehenden Nachteile werden im Detail erläutert und eine Möglichkeit der Erweiterung des Kriteriums mithilfe des Schockantwortspektrums geboten. Als Beurteilungsgröße für die dynamische Prüfung von Tankcontainern bereits fest etabliert, wird dieses mathematische Analysewerkzeug in allen Einzelheiten vorgestellt und dessen Eignung für die Anwendung im Bahnauflaufstoß für Flexitanksysteme untersucht. Zu diesem Zweck wird ein Simulationsmodell entwickelt, mit dessen Hilfe eine ausführliche Parameteranalyse durchgeführt und deren Ergebnisse Versuchsmessungen gegenübergestellt werden. Die Schlussfolgerungen münden in einem dem Flexitanksystem angepassten Prüfkriterium auf Basis des Schockantwort-spektrums, welches in Form eines Regelwerksentwurfs den entscheidungsberechtigten Gremien vorgeschlagen wird. Die Inhalte der drei Hauptkapitel der Dissertation können in folgenden Punkten zusammengefasst werden: Das Flexitanksystem wird vorgestellt, der Auflaufversuch erläutert und diskutiert sowie Versuchsergebnisse präsentiert und nach verschiedenen Gesichtspunkten analysiert. Das Schockantwortspektrum wird hergeleitet, dessen Charakteristika herausgestellt und deren Anwendung an praktischen Beispielen demonstriert. Die Eignung des Schockantwortspektrums zur Beurteilung von Auflaufstößen mit Flexitanksystem wird überprüft, die Einflussfaktoren in einer Parameteranalyse durchleuchtet und die Ergebnisse in die Definition eines neuen Prüfkriteriums eingeflochten. Die Dissertation entstand im Rahmen eines Fördermittelprojekts des Europäischen Sozialfonds und in Kooperation mit der Prüfanlage der TÜV SÜD Rail GmbH in Görlitz.
25

Development of Computational Tools for Characterization, Evaluation, and Modification of Strong Ground Motions within a Performance-Based Seismic Design Framework

Syed, Riaz 27 January 2004 (has links)
One of the most difficult tasks towards designing earthquake resistant structures is the determination of critical earthquakes. Conceptually, these are the ground motions that would induce the critical response in the structures being designed. The quantification of this concept, however, is not easy. Unlike the linear response of a structure, which can often be obtained by using a single spectrally modified ground acceleration history, the nonlinear response is strongly dependent on the phasing of ground motion and the detailed shape of its spectrum. This necessitates the use of a suite (bin) of ground acceleration histories having phasing and spectral shapes appropriate for the characteristics of the earthquake source, wave propagation path, and site conditions that control the design spectrum. Further, these suites of records may have to be scaled to match the design spectrum over a period range of interest, rotated into strike-normal and strike-parallel directions for near-fault effects, and modified for local site conditions before they can be input into time-domain nonlinear analysis of structures. The generation of these acceleration histories is cumbersome and daunting. This is especially so due to the sheer magnitude of the data processing involved. The purpose of this thesis is the development and documentation of PC-based computational tools (hereinafter called EQTools) to provide a rapid and consistent means towards systematic assembly of representative strong ground motions and their characterization, evaluation, and modification within a performance-based seismic design framework. The application is graphics-intensive and every effort has been made to make it as user-friendly as possible. The application seeks to provide processed data which will help the user address the problem of determination of the critical earthquakes. The various computational tools developed in EQTools facilitate the identification of severity and damage potential of more than 700 components of recorded earthquake ground motions. The application also includes computational tools to estimate the ground motion parameters for different geographical and tectonic environments, and perform one-dimensional linear/nonlinear site response analysis as a means to predict ground surface motions at sites where soft soils overlay the bedrock. While EQTools may be used for professional practice or academic research, the fundamental purpose behind the development of the software is to make available a classroom/laboratory tool that provides a visual basis for learning the principles behind the selection of ground motion histories and their scaling/modification for input into time domain nonlinear (or linear) analysis of structures. EQTools, in association with NONLIN, a Microsoft Windows based application for the dynamic analysis of single- and multi-degree-of-freedom structural systems (Charney, 2003), may be used for learning the concepts of earthquake engineering, particularly as related to structural dynamics, damping, ductility, and energy dissipation. / Master of Science
26

The Influence of the Recommended LRFD Guidelines for the Seismic Design of Highway Bridges on Virginia Bridges

Widjaja, Matius Andy 26 August 2003 (has links)
The influence of the recommended LRFD Guidelines for the seismic design of highway bridges in Virginia was investigated by analyzing two existing bridges. The first bridge has prestressed concrete girders and is located in the Richmond area. The second bridge has steel girders and is located in the Bristol area. The analysis procedure for both bridges is similar. First the material and section properties were calculated. Then the bridge was modeled in RISA 3D. Live and dead load were imposed on the bridge to calculate the cracked section properties of the bridge. The period of vibration of the bridge was also calculated. After the soil class of the bridge was determined, the design response spectrum curve of the bridge was drawn. The spectral acceleration obtained from the design spectrum curve was used to calculate the equivalent earthquake loads, which were applied to the superstructure of the bridge to obtain the earthquake load effects. Live and dead loads were also applied to get the live and dead load effects. The combined effects of the dead, live and earthquake loads were compared to the interaction diagram of the columns and moment strength of the columns. The details of the bridge design were also checked with the corresponding seismic design requirement.A parametric study was performed to explore the effects of different column heights and superstructure heights in different parts of Virginia. The column longitudinal reinforcing was increased to satisfy the bridge axial loads and moments that are not within the column interaction diagram. / Master of Science
27

Seismic analysis of concrete structures within nuclear industry / Dimensionering av nukleära betongkonstruktioner med avseende på seismisk påverkan

Tabatabaei Araghi, Pedram January 2014 (has links)
Earthquake has always been a hazard for civil structures and keeping the structures integrity during and after an earthquake is of vital importance. This phenomenon’s impact is sudden and there is little or no warning to make the preparations for this natural disaster. Much damage has been done on structures which have led to major collapses and loss of many lives. Civil structures such as nuclear power plants are designed to withstand earthquakes and in the event of a major seismic event, to shut down safely. The aim of this thesis is to present the seismic design procedures for concrete structures, in basic and detailed design, according to Eurocode 8. Also to describe and understand the difference between Eurocode 8 and the DNB in seismic analysis of nuclear power plants. To evaluate the use of DNB instead of Eurocode 8 with Swedish seismic conditions is also another aim in this thesis.  Loads and actions which apply on a structure in a seismic design and corresponding load combinations are presented for Eurocode 8 and the DNB. An example is also given to clarify the design of primary seismic beams and columns with high ductility class (DCH). A case study of a nuclear structure from a test project named SMART2013 has been made by analyzing and comparing the results from Eurocode 8 and the DNB with a finite element model in FEM-Design software. Natural frequencies of the model are compared with the tested model in SMART2013-project to evaluate the finite element modeling. The model is seismically analyzed with load combinations from Eurocode 8 and the DNB with Swedish elastic ground response spectrum with the probability of 10-5. Results obtained from the primary seismic beams and columns are compared and analyzed.  Being on the safe and conservative side of the design values is always preferred in seismic analysis of a vital and sensitive structure such as nuclear power plants. The results from this thesis shows that, purely structural, combination of Swedish elastic ground response spectrum with the Eurocode 8 load combination will give more conservative values than the DNB. / I stora delar av världen har jordbävningar alltid varit ett hot för byggnaders integritet. Karaktären av en jordbävning är plötslig och föranleds av små eller inga varningar. Om jordbävningen medför att byggnader kollapsar sker ofta stora förluster av människoliv direkt eller indirekt. Kärnkraftsverk är anläggningar som dimensioneras för att klara jordbävningar och ska kunna gå till säker avställning vid en sådan händelse. Syftet med föreliggande rapport är att presentera hur betongkonstruktioner dimensioneras för jordbävning enligt Eurokod 8. Rapporten redogör även för skillnader mellan att dimensionera enligt Eurokod 8 och DNB (Dimensionering av nukleära byggnadskonstruktioner) samt hur det slår att använda Eurokod med svenska seismiska förhållanden. Laster och lastkombinationer som används vid jordbävningsdimensionering av betongbyggnader är presenterad enligt både Eurokod och DNB. Ett exempel presenteras för att visa hur primära balkar och pelare med hög duktilitetsklass (DCH) dimensioneras för seismisk påverkan. En fallstudie av en nukleär byggnad från ett internationellt projekt, SMART2013, har använts för att analysera och utvärdera resultaten från Eurokod och DNB. Byggnaden har analyserats med finita element med programvaran FEM Design. Modellens riktighet har verifierats genom att jämföra bland annat egenfrekvenser med de från officiella rapporter från SMART2013. Byggnaden är analyserad för seismisk last enligt svenska förhållanden med markresponsspektra 10-5, och primära balkar och pelare har analyserats och utvärderats enligt både Eurokod och DNB.
28

Berechnung von Schockspektren und praktische Anwendung der dynamischen Stoßanalyse in Creo Elements / Pro Mechanica / Shock spectra analysis and practical application of dynamic shock analysis in Creo Elements / Pro Mechanica

Jakel, Roland 12 May 2011 (has links) (PDF)
Der Vortrag stellt Idee und Grundlagen der Berechnung von Schockantwortspektren dar. Er zeigt, wie man exemplarisch für einen Halbsinusstoß das Schockantwortspektrum in der PTC FEM-Software Creo Elements / Pro Mechanica berechnen kann. Die Schockantworten eines Ein- und Zweimassenschwingers werden sowohl zeitaufgelöst als auch über die dynamische Stoßanalyse berechnet. Die modalen Superpositionsmethoden "Absolute Summe" und "SRSS" (Square Root of the Sum of the Squares - geometrischer Mittelwert) werden vorgestellt. Als reales Beispiel werden Schockanalysen für verschiedene Halbsinusimpulse mit einem Wärmebildgerät der Firma Carl Zeiss Optronics GmbH durchgeführt und mit einer zeitaufgelösten Analyse verglichen. Abschließend wird auf die Erzeugung von Antwortspektren für die Substrukturauslegung eingegangen. / The presentation explains idea and fundamentals of shock response spectra analysis. With help of the PTC FEM-software Creo Elements / Pro Mechanica the shock response spectra (SRS) for an exemplary half sine shock is calculated. The shock response of a one-mass and a two-mass oscillator are analyzed per dynamic time as well as per dynamic shock analysis. The modal superposition methods "absolute sum" and "SRSS" (Square Root of the Sum of the Squares) are explained. The method is applied for different half sine shocks on a realistic example: A thermal imaging system of the company Carl Zeiss Optronics GmbH. Finally, the creation of response spectra for global-local analysis is explained.
29

Dynamická analýza konstrukce zatížené seismickým zatížením / Dynamic analysis of structure loaded seismic loads

Janošková, Lenka January 2013 (has links)
In this diploma thesis the seismic load on two different models is solved – the first model is a beam hall and the second model is a multistory building. The calculation of seismic load was performed according to standard ČSN EN 1998-1 (Eurocode 8) using the response spectrum analysis and the method of equivalent static forces (substi-tute load). For the combination of seismic responses in different directions are used SRSS and CQC rules. Models and calculations were solved in a student’s version of program RFEM 4.10 (Ing. Software Dlubal, s.r.o.). The comparison of mentioned methods in each models, also the comparison of combinative rules in calculation and the final evaluation of seismic responses on both of models are the subject of this thesis.
30

Berechnung von Schockspektren und praktische Anwendung der dynamischen Stoßanalyse in Creo Elements / Pro Mechanica

Jakel, Roland 12 May 2011 (has links)
Der Vortrag stellt Idee und Grundlagen der Berechnung von Schockantwortspektren dar. Er zeigt, wie man exemplarisch für einen Halbsinusstoß das Schockantwortspektrum in der PTC FEM-Software Creo Elements / Pro Mechanica berechnen kann. Die Schockantworten eines Ein- und Zweimassenschwingers werden sowohl zeitaufgelöst als auch über die dynamische Stoßanalyse berechnet. Die modalen Superpositionsmethoden "Absolute Summe" und "SRSS" (Square Root of the Sum of the Squares - geometrischer Mittelwert) werden vorgestellt. Als reales Beispiel werden Schockanalysen für verschiedene Halbsinusimpulse mit einem Wärmebildgerät der Firma Carl Zeiss Optronics GmbH durchgeführt und mit einer zeitaufgelösten Analyse verglichen. Abschließend wird auf die Erzeugung von Antwortspektren für die Substrukturauslegung eingegangen. / The presentation explains idea and fundamentals of shock response spectra analysis. With help of the PTC FEM-software Creo Elements / Pro Mechanica the shock response spectra (SRS) for an exemplary half sine shock is calculated. The shock response of a one-mass and a two-mass oscillator are analyzed per dynamic time as well as per dynamic shock analysis. The modal superposition methods "absolute sum" and "SRSS" (Square Root of the Sum of the Squares) are explained. The method is applied for different half sine shocks on a realistic example: A thermal imaging system of the company Carl Zeiss Optronics GmbH. Finally, the creation of response spectra for global-local analysis is explained.

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