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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.
81

Olivier Messiaen und die französische Harmonik: Eine Studie zur Verwandtschaft zwischen der französisch-romantischen Orgelschule und dem Frühwerk Olivier Messiaens

Mooiman, Bert 22 September 2023 (has links)
Untersucht wird der Einfluss der französisch-romantischen Orgelschule auf das Frühwerk Olivier Messiaens. Aus methodologischen Gründen – mit Blick auf das Spannungsverhältnis zwischen musikhistorischen, -analytischen und ästhetischen Urteilen – wird sich diversen Traktaten der Harmonie- und Improvisationslehre (Durand, Dupré, Koechelin) sowie Messiaens eigenen musiktheoretischen Schriften zugewendet. Erörtert werden die dort dargelegten Akkordtypen und deren unterschiedliche Kombinationsmöglichkeiten, die sich durch eine Fokussierung auf den Einzelklang und das Entbinden von den Erfordernissen einer funktionalen Harmonik auszeichnen. Sie eignen sich dadurch in besonderem Maße für die Improvisation, die insofern als der Urgrund für alle stilistischen Affinitäten gelten kann. Überlegungen zur Verwandtschaft zwischen der französisch-romantischen Orgelschule auf dem Frühwerk Olivier Messiaens auf dem Gebiet des Rhythmus, der Setzweise und dem theologischer Implikationen runden die Untersuchung ab. / This article examines the influence of the French-Romantic organ school on the early works of Olivier Messiaen. For methodological reasons having to do with the tension between music-historical, analytical, and aesthetic judgements, emphasis will be placed both on various harmony and improvisation treatises (Durand, Dupré, Koechelin) and Messiaen’s own music-theoretical writings. The types of chords described therein and their various possibilities for combination, which are distinguished by a focus on the single chord and the exoneration of the requirements of functional harmony, will be discussed. Such chords are particularly appropriate for improvisation, which may be taken as the ultimate basis for all stylistic affinities. This examination concludes with reflections on the relationship between the French-Romantic organ school and Messiaen’s early works in regard to rhythm, manner of composition, and theological implications.
82

Opernhafte Momente in Konzeptalben von The Who und Marillion: Ein Beitrag zur semiotischen Analyse von Popmusik

Niedermüller, Peter 22 September 2023 (has links)
Der Beitrag präsentiert eine Fallstudie, nicht ohne dabei das nach gängiger Meinung grundsätzlich herrschende Spannungsverhältnis von Popularmusik und musikalischer Analyse zu reflektieren. Das vorgestellte Beispiel belegt, dass musikalische Gestalten in der Popmusik eine komplizierte Zeichenfunktion erfüllen können, für die melodische Wendungen und Chord changes nur einen unter mehreren Ansatzpunkten bieten. Gezeigt wird, dass auch Zitate und Intertextrelationen den Charakter der Konstituenten durchaus mitbestimmen können. Dabei treibt die musikalische Analyse von Popmusik einen Selbstauslegungsprozess voran, der in der Popkultur selbst angelegt ist. Diese Position des ›teilnehmenden Beobachters‹ kann zwar einen Mangel an Objektivität evozieren, indiziert aber nicht deren wissenschaftliche Untauglichkeit. / This article presents a case study in order to reflect upon the supposedly foundational and ever-present tension between pop music and musical analysis. The example shown illustrates that musical gestures in pop music can fulfill a complicated design function (Zeichenfunktion) in which melodic turns and chord changes offer only one of many starting points. It will be demonstrated that quotations and intertextual relations can also influence the character of constituents. Thus the musical analysis of pop music promotes a process of self-interpretation that is present in pop music itself. Admittedly this position of “participating observer” can evoke a lack of objectivity, but this does not indicate its scientific unsuitability.
83

Wagners Tristan im Blickfeld der neuen Tonalität: Eine Betrachtung der V. Szene im Ersten Aufzug mit einer Anmerkung zur Semantik und Konnotation des Tristanakkordes

Pütz, Elisabeth 22 October 2023 (has links)
No description available.
84

Lávka pro chodce / Pedestrian bridge

Štelcl, Jan January 2013 (has links)
Master thesis is focused to design the timber pedestrian bridge over the track. The load-bearing construction is composed from the truss girder and cross laminated tiber plates. Bridge is coveder. Layout dimensions of the bridge are 49.0 m x 4.8 m
85

Um passeio pelo pensamento musical de Leonhard Euler: a leitura do mestre e seu uso em sala de aula / A journey through Leonhards Euler musical thought: reading the master and its use in the classroom

Lima, Guilherme Augusto Vaz de 21 February 2018 (has links)
Este estudo se dedica a uma parte pouco conhecida dos trabalhos de Leonhard Euler (1707 - 1783) relacionado à música enquanto uma ciência matemática. Tais trabalhos mostram, em certo sentido, um lado pitagórico do pensador e também algumas contribuições do mesmo à teoria musical. O interesse deste matemático pelo assunto permeia várias obras e épocas de sua vida, mas neste trabalho focamos em três delas: um conjunto de nove cartas que compõem a obra Lettres a une princesse dAllemagne sur divers sujets de physique e de philosophie (1768) e dois artigos, Conjecture sur la raison de quelques dissonances generalement reçues dans la musique (1766) e De harmoniae veris principiis per speculum musicum repraesentatis (1774). Para possibilitar uma melhor compreensão desses textos, faremos uma revisão histórica do tratamento aritmético dado à música desde os tempos clássicos até o Renascimento com enfoque nas principais contribuições que levam à construção da escala da entonação pura ou justa, trabalhada por Euler nos originais estudados. Após a apresentação e análise desses trabalhos eulerianos, especialmente seus diagramas para representar sons e acordes e do seu expoente de um acorde para medir consonâncias, terminaremos essa dissertação refletindo sobre as implicações pedagógicas e históricas, bem como as potencialidades e limitações do uso de fontes originais de determinados mestres do pensamento matemático ocidental, nomeadamente o próprio Euler, na formação de matemáticos, professores e licenciados. / This present research takes a journey into a little know part of Leonhard Eulers works about music as a mathematical science. Those works show, at certain level, his Pythagorean thoughts and also his contributions to music theory. Eulers interest for this subject permeates many of his works through his lifetime (1707 - 1783), but here we focus on three of them: a set of nine letters from the book Lettres a une princesse dAllemagne sur divers sujets de physique e de philosophie (1768), and two articles, Conjecture sur la raison de quelques dissonances generalement reçues dans la musique (1766) and De harmoniae veris principiis per speculum musicum repraesentatis (1774). To allow a better understanding of his ideas, first we put on a historical review of the arithmetic treatment of music since the ancient Greece to the Renaissance Era pointing out the main contributions to the development of the pure just intonation scale, the one used by Euler on the works just mentioned. After presenting and analyzing these Eulers contributions, specially his diagrams to represent sounds and chords to the eyes and the concept of exponent of a chord to measure consonances, we conclude this dissertation thinking about the pedagogical and historical impact, and also the potential and limitations concerning the use of historical sources of the masters of mathematics, to the training of future mathematics and teachers.
86

Analytical and experimental assessment of steel truss bridge gusset plate connections

Mentes, Yavuz 25 August 2011 (has links)
The I-35W Bridge over the Mississippi River in Minneapolis, MN had a catastrophic failure in the main span of the deck truss in 2007. This collapse has brought significant attention on the gusset plate connections in steel truss bridges throughout the U.S. Steel truss bridge gusset plate design has not received much focus in the past 40 years, and there is a lack of consensus within the design profession on the procedures to evaluate, design, and rate these critical elements. In the short term, based on the best available information on the gusset plate design, the Federal Highway Administration (FHWA) has issued preliminary guidance. Although some experimental research has been conducted on the ultimate strength of gusset plates, much of this work has been directed toward the performance of tension members and their connections. There has been limited experimental work on the compression capacity and stability of gusset plates, but most of this work is relevant primarily to bracing connections common in building structures. This research focuses on comprehensive experimental and analytical studies on steel truss bridge gusset plate behavior. The studies include comparisons of advanced analytical models with the responses from large-scale experimental tests using discrete and innovative full-field measurements. The calibrated finite element analysis models are then utilized to study a variety of gusset plate configurations. Improved mechanistic idealizations that better capture the observed behavior in the experiments and analytical studies are proposed as the result of this work. The design checks recommended in this thesis present a comprehensive methodology for determining the ultimate gusset plate resistance. This research provides a large database of original results that will be useful for future similar studies. In addition, this research provides modeling procedures that permit the study of steel truss bridge connections and their adjacent framing members using truss bridge sub-assemblies. Based on the comprehensive analytical studies, simple and accurate design calculation procedures to assess the nominal ultimate strength of steel truss gusset plate connections are recommended for steel truss bridge gusset plate connections.
87

Επιλογή στρατηγικής ενίσχυσης σε υφιστάμενες κατασκευές απο οπλισμένο σκυρόδεμα με χρήση ανελαστικών αναλύσεων / Selection of retrofit strategy for existing reinforced concrete structures using non-linear analysis

Μπάρος, Δημήτριος 27 August 2007 (has links)
Βασικός σκοπός της παρούσης διατριβής είναι η ανάπτυξη μιας διαδικασίας προσδιορισμού της βέλτιστης στρατηγικής ενίσχυσης ενός υφιστάμενου ανεπαρκούς κτιρίου, αξιοποιώντας τα δεδομένα που προκύπτουν από την αποτίμησή του με χρήση της ανελαστικής στατικής ανάλυσης και συνεκτιμώντας τις καμπύλες που αντιστοιχούν σε εναλλακτικές λύσεις επέμβασης και προσδιορίζονται προσεγγιστικά. Επειδή η καμπύλη αντίστασης του αρχικού φορέα αποτελεί τη σημαντικότερη πληροφορία που αξιολογείται στα πλαίσια της διαδικασίας που αναπτύχθηκε, ένας έμμεσος στόχος της παρούσης διατριβής είναι η αξιολόγηση των προσομοιωμάτων συμπεριφοράς στοιχείων οπλισμένου σκυροδέματος που συμπεριλαμβάνονται στο σχέδιο του Ελληνικού Κανονισμού Επεμβάσεων (ΚΑΝ.ΕΠΕ.), τα οποία χρησιμοποιήθηκαν στα πλαίσια των αναλύσεων που πραγματοποιήθηκαν. Για τις ανάγκες της διερεύνησης των προσομοιώματων του ΚΑΝ.ΕΠΕ. και την ανάπτυξη της μεθόδου επιλογής στρατηγικής επέμβασης διενεργήθηκαν ανελαστικές αναλύσεις σε κτίρια που τα οποία είχαν μορφωθεί και διαστασιολογηθεί με βάση της επικρατούσες πριν το 1985 αντιλήψεις. Στο πρώτο κεφάλαιο της εργασίας γίνεται μια εισαγωγή στο θέμα αποτίμησης και ενίσχυσης υφιστάμενων κατασκευών. Εντοπίζονται οι δυσκολίες και οι απαιτήσεις του προβλήματος της μελέτης υφιστάμενων κτιρίων και σχολιάζονται σύντομα τα υπάρχοντα κανονιστικά σχέδια για την αποτίμηση υφιστάμενων κατασκευών. Στο δεύτερο κεφάλαιο παρουσιάζονται οι μέθοδοι που χρησιμοποιούνται για την αποτίμηση υφιστάμενων κτιρίων. Οι μέθοδοι διακρίνονται σε ελαστικές και ανελαστικές. Η στατική ανελαστική ανάλυση παρουσιάζεται εκτενέστερα, καθώς χρησιμοποιείται για τις αναλύσεις που πραγματοποιούνται. Συγκεκριμένα αναφέρονται οι παραδοχές στις οποίες βασίζεται και παρουσιάζονται τρεις διαφορετικές διαδικασίες για τον προσδιορισμό της στοχευόμενης μετατόπισης. Ιδιαίτερη αναφορά γίνεται στη μέθοδο των ανελαστικών φασμάτων απαίτησης, στην οποία βασίζεται η διαδικασία επιλογής στρατηγικής επέμβασης που αναπτύχθηκε. Το τρίτο κεφάλαιο αφορά τα προσομοιώματα συμπεριφοράς στοιχείων Ο/Σ που χρησιμοποιούνται σε ανελαστικές αναλύσεις. Συγκεκριμένα παρουσιάζεται αναλυτικά το προσομοίωμα του ΚΑΝ.ΕΠΕ. που υιοθετείται στη συνέχεια για τις ανάγκες της προσομοίωσης των κτιρίων που αναλύονται. Σύντομη αναφορά γίνεται και σε άλλα προσομοιώματα, τα οποία προτείνονται σε σχέδια κανονισμών ή ερευνητικές εργασίες. Στο τέταρτο κεφάλαιο εξετάζονται αναλυτικά τα προτεινόμενα από τον ΚΑΝ.ΕΠΕ. προσομοιώματα συμπεριφοράς των δομικών στοιχείων και η χρήση τους για την σεισμική αποτίμηση με χρήση της μη-γραμμικής στατικής ανάλυσης. Οι προτεινόμενες σχέσεις χρησιμοποιούνται για την προσομοίωση των μελών δύο ιδεατών κτιρίων και ενός πραγματικού. Εξετάζονται πιθανές αποκλίσεις μεταξύ των διατιθέμενων σχέσεων, καθώς και η επιρροή διαφορετικών παραδοχών για τις τιμές του μήκους διάτμησης και του ανηγμένου αξονικού φορτίου στα προσδιοριζόμενα μεγέθη. Τέλος ελέγχεται η επίδραση των ίδιων παραμέτρων στην τελική μορφή της καμπύλης τέμνουσας βάσης – μετατόπισης και στα συμπεράσματα της διαδικασίας αποτίμησης. Το πέμπτο κεφάλαιο αναφέρεται στις στρατηγικές ενίσχυσης υφιστάμενων κτιρίων. Συγκεκριμένα αρχικά γίνεται η διάκριση μεταξύ στρατηγικής και τεχνικής επέμβασης. Στη συνέχεια αναφέρονται και σχολιάζονται διαδικασίες για την επιλογή της κατάλληλης στρατηγικής επέμβασης που αναπτύχθηκαν παλαιότερα. Ακολούθως παρουσιάζεται η προτεινόμενη διαδικασία για την επιλογή της κατάλληλης στρατηγικής επέμβασης. Αναφέρονται οι βασικές παραδοχές που λαμβάνονται και τα βήματα υπολογισμών που πραγματοποιούνται. Τέλος η προτεινόμενη διαδικασία εφαρμόζεται σε δύο ιδεατά κτίρια και παρουσιάζονται αναλυτικά τα αποτελέσματα και τα συμπεράσματα που αφορούν τις απαιτούμενες ενισχύσεις στα κτίρια που αναλύονται. Στο έκτο κεφάλαιο επιχειρείται η σύνδεση των εκτιμώμενων καμπυλών συμπεριφοράς για τα ενισχυμένα κτίρια, οι οποίες προκύπτουν από τη διαδικασία επιλογής στρατηγικής επέμβασης που αναπτύχθηκε, με τις απαιτούμενες επεμβάσεις στα μέλη. Σκοπός είναι να προκύψει μια διαδικασία προδιαστασιολόγησης των ενισχύσεων. Ορίζονται αδιάστατες παράμετροι που συσχετίζουν τα χαρακτηριστικά του φορέα με αυτά των μελών. Αναλύονται φορείς που προκύπτουν από υλοποίηση εναλλακτικών ενισχύσεων στα κτίρια στα οποία εφαρμόστηκε η προτεινόμενη διαδικασία και εξετάζεται πως μεταβάλλεται η τιμή των παραμέτρων που ορίστηκαν. Με βάση τα αποτελέσματα των ανελαστικών αναλύσεων και των υπολογισμών που παρουσιάζονται, διατυπώνονται απλοί κανόνες για την αρχική διαστασιολόγηση των επεμβάσεων στα μέλη. Στο τελευταίο κεφάλαιο γίνεται μια προσπάθεια ερμηνείας των αποτελεσμάτων των διερευνήσεων που παρουσιάσθηκαν ώστε να προκύψουν γενικότερα συμπεράσματα για τη διαδικασία επιλογής στρατηγικής επέμβασης που αναπτύχθηκε. Από τη διερεύνηση που πραγματοποιήθηκε προκύπτει πως με χρήση της προτεινόμενης μεθόδου εκτιμώνται με ικανοποιητική ακρίβεια οι καμπύλες συμπεριφοράς των ενισχυμένων κατασκευών για δύο ακραίες περιπτώσεις επέμβασης (αύξηση αντοχής - δυσκαμψίας και αύξηση πλαστιμότητας), η αξιολόγηση των οποίων μπορεί να οδηγήσει σε μια αξιόπιστη επιλογή της βέλτιστης στρατηγικής ενίσχυσης, χωρίς να απαιτούνται εμπειρικού χαρακτήρα εκτιμήσεις. Τέλος είναι δυνατόν να γίνει μια συντηρητική εκτίμηση των απαιτούμενων επεμβάσεων στα μέλη, η οποία κατευθύνει σε μεγάλο βαθμό την τελική επιλογή λύσης. / The main aim of the present thesis is the development of a procedure to determine the optimum retrofit strategy for an existing building, using the results obtained from the assessment of the building via non-linear static analysis and evaluating the capacity curves that correspond to the application of different strengthening solutions for the building under consideration. The latter curves are approximated without further analysis. Because of the significance of the capacity curve of the original building which is taken into consideration in the proposed strategy selection procedure, a second aim of this thesis is the evaluation of the analytical models for the behavior of Reinforced Concrete (R/C) members which are included in the first and second draft versions of the Greek Retrofitting Code (GRECO). These were used to create the numerical models of the buildings that have been analyzed. In order to develop the proposed procedure for the selection of the optimum retrofit strategy, as well as to evaluate the proposed models that are referred above, three buildings have been analyzed via non-linear static analysis (pushover analysis). The dimensioning of members of these buildings complies with the regulatory demands of the prior to 1985 Greek building Codes. In the first chapter of the present thesis, a brief introduction to the topic of assessment and strengthening of existing buildings is conducted. The basic difficulties of the problem of analyzing existing structures are pointed. Finally, draft codes that have been developed for the assessment and rehabilitation of existing buildings are reviewed briefly. In the second chapter, the basic analysis procedures that are used for the assessment of existing buildings are presented. The available procedures are separated into linear and non-linear. Non-linear static (pushover) analysis is presented thoroughly since it is used for the analyses of the buildings referred above. The basic assumptions of this analysis procedure are described as well as three different methods to determine the target displacement (or performance point). The capacity spectrum method is presented in detail, since it is the basis for the development of the proposed strategy selection procedure. The third chapter refers to the analytical models for the behavior of R/C members that are used in non-linear analyses. The models proposed in GRECO, which have been used in terms of the analyses of the buildings that were examined in this thesis, are presented thoroughly. Other models included in draft codes (such as FEMA 356) or proposed by researchers are briefly reviewed. In the fourth chapter, the analytical models for the behavior of R/C members that are included in GRECO are presented in detail. Moreover, the application of the above models in the assessment of existing buildings using pushover analysis is examined. The proposed equations are applied to model the behavior of the members of three buildings, in order to examine whether the use of different equations leads to significantly different results for the inelastic deformation capacities of the members. Furthermore, the impact of different assumptions for parameters, such as the non-constant axial load, to the results of the above equations is discussed. Finally, the effect of the above parameters in the capacity curve of the building, which is being analyzed, is examined. In the fifth chapter, the strategies for the retrofit of existing buildings are discussed. The difference between retrofit techniques and retrofit strategies is stated. Available procedures for the selection of the optimum retrofit strategy are reviewed and commented. Furthermore, the procedure proposed in this thesis is presented. The basic assumptions and the required calculations are stated. Finally, the procedure is applied for the selection of the optimum retrofit strategy of two of the buildings analyzed earlier in the present thesis. The results and main conclusions are referred briefly. In the sixth chapter, the estimated capacity curves of the strengthened buildings, which arise from the strategy selection procedure that has been developed, are correlated with the required rehabilitation measures for the members. The buildings under consideration are analyzed taking into account the application of different rehabilitation scenarios and several parameters such as the strength or ductility of the retrofitted members in regard with that of the entire building are evaluated. Finally a simplified procedure for the estimation of the needed rehabilitation measures for the members in order to achieve the targeted capacity curve for the structure is proposed. In the final chapter, the results concerning the proposed procedure for the estimation of the optimum retrofit strategy for an existing building are reviewed and the main conclusions are presented. The use of the proposed procedure results in the estimation of the capacity curve of the rehabilitated building with acceptable accuracy, considering two “extreme” retrofit scenarios (system strengthening and stiffening or increasing the ductility of the building). The evaluation of these two curves leads to the selection of the optimum retrofit strategy for a building, which usually combines the effects of the above scenarios. Finally, it is possible to estimate the required retrofit measures for the members of the structure under consideration, although the results are conservative and can be used only for the needs of the initial evaluation discussed in this thesis.
88

Tonal description of music audio signals

Gómez Gutiérrez, Emilia 25 July 2006 (has links)
Aquesta tesi doctoral proposa i avalua un enfocament computacional per a la descripció automàtica dels aspectes tonals de la música a partir de l'anàlisi de senyals d'-audio polifòniques. Aquests mètodes es centren en el càlcul de descriptors de distribucions de notes, en l'estimació de tonalitat d'una peça, en la visualització de l'evolució del centre tonal o en la mesura de la similitud tonal entre dues peces diferents. Aquesta tesi contribueix substancialment al camp de la descripció tonal mitjançant mètodes computacionals: a) Proporciona una revisió multidisciplinària dels sistemes d'estimació de la tonalitat; b) Defineix una sèrie de requeriments que han de complir els descriptors tonals de baix nivell; c) Proporciona una avaluació quantitativa i modular dels mètodes proposats; d) Justifica la idea de que per a certes aplicacions es poden fer servir mètodes que treballen amb partitures sense la necessitat de realitzar una transcripció automàtica e) Estén la literatura existent que treballa amb música clàssica a altres generes musicals; f) Demostra la utilitat dels descriptors tonals per a comparar peces musicals; g) Proporciona un algoritme optimitzat que es fa servir dins un sistema real per a visualització, cerca i recomanació musical, que treballa amb més d'un milió de obres musicals. / Esta tesis doctoral propone y evalúa un enfoque computacional para la descripción automática de aspectos tonales de la música a partir del análisis de señales de audio polifónicas. Estos métodos se centran en calcular descriptores de distribución de notas, en estimar la tonalidad de una pieza, en visualizar la evolución del centro tonal o en medir la similitud tonal entre dos piezas diferentes.Esta tesis contribuye sustancialmente al campo de la descripción tonal mediante métodos computacionales: a) Proporciona una revisión multidisciplinar de los sistemas de estimación de la tonalidad; b) Define una serie de requerimientos que deben cumplir los descriptores tonales de bajo nivel; c) Proporciona una evaluación cuantitativa y modular de los métodos propuestos; d) Respalda la idea de que para ciertas aplicaciones no es necesario obtener una transcripción perfecta de la partitura, y que se pueden utilizar métodos que trabajan con partituras sin realizar una transcripción automática; e) Extiende la literatura existente que trabaja con música clásica a otros géneros musicales; f) Demuestra la utilidad de los descriptores tonales para comparar piezas musicales; g) Proporciona un algoritmo optimizado que se utiliza en un sistema real para visualización, búsqueda y recomendación musical, que trabaja con mas de un millón de piezas musicales. / This doctoral dissertation proposes and evaluates a computational approach for the automatic description of tonal aspects of music from the analysis of polyphonic audio signals. These algorithms focus on the computation of pitch class distributions descriptors, the estimation of the key of a piece, the visualization of the evolution of its tonal center or the measurement of the similarity between two different musical pieces.This dissertation substantially contributes to the field of computational tonal description: a) It provides a multidisciplinary review of tonal induction systems; b) It defines a set of requirements for low-level tonal features; c) It provides a quantitative and modular evaluation of the proposed methods; d) It contributes to bridge the gap between audio and symbolic-oriented methods without the need of a perfect transcription; e) It extents current literature dealing with classical music to other musical genres; f) It shows the usefulness of tonal descriptors for music similarity; g) It provides an optimized method which is used in a real system for music visualization and retrieval, working with over a million of musical pieces.
89

Avaliação da influência do esforço normal no banzo no comportamento de ligações tubulares em aço. / Analysis of the influence of chord normal stresses on the behavior of hollow sections connections.

Adriano Nizer 12 March 2014 (has links)
A demanda pelo uso de perfis tubulares em estruturas na construção civil tem tido grande avanço no Brasil, apesar de ser, há muito tempo, amplamente empregado na Europa e países desenvolvidos. O lançamento de uma norma técnica brasileira específica para dimensionamento de perfis tubulares confirma esta tendência, havendo então a necessidade de uma maior divulgação e execução de estudos e trabalhos de pesquisa para uma melhor compreensão e desenvolvimento desta tecnologia. O presente trabalho apresenta uma análise da influência da aplicação de esforço normal no banzo no comportamento de ligações tubulares do tipo T. No desenvolvimento deste trabalho, foram realizados seis ensaios em laboratório com ligações do tipo T com perfis do tipo RHS para o banzo e SHS para o montante, sendo utilizados perfis conformados a frio para composição das ligações ensaiadas. Do total dos ensaios foram executados dois ensaios sem aplicação de esforço normal no banzo; dois com aplicação de esforço normal de compressão e dois com aplicação de esforço normal de tração. A resistência última das ligações nos ensaios foi obtida por meio do Critério de Deformação Limite proposto por diversos pesquisadores. Estes resultados foram comparados com os resultados obtidos em modelos numéricos em elementos finitos desenvolvidos no programa ANSYS 12.0, sendo considerado nestes modelos as não-linearidades geométricas e de material. Estes resultados também foram comparados com os resultados teóricos obtidos com base nas prescrições constantes nas normas Eurocode 3; norma brasileira NBR 16239 e do CIDECT. Conclui-se com este estudo que os resultados obtidos tanto nos ensaios experimentais quanto nos modelos numéricos ficaram a favor da segurança quando comparados com os valores teóricos obtidos pelas normas Eurocode 3 e NBR 16239:2013 e CIDECT com o banzo sem aplicação de esforço normal e com aplicação de esforço normal de compressão de até 60% e 80 % da carga de plastificação do banzo, respectivamente, para o Eurocode 3/NBR16239:2013 e para o CIDECT. As resistências obtidas para as ligações com a aplicação de esforço normal de tração no banzo foram superiores aos resultados teóricos no caso estudado. / The demand for the use of hollow sections structures in construction has had great progress in Brazil, despite being a long time widely used in Europe and developed countries. The release of a Brazilian Technical Standard specific for design of hollow sections, confirms this trend, and the need for increased dissemination and implementation of studies and research for a better understanding and development of this technology. This paper presents an analysis of the influence of chord normal stresses on the behavior of hollow sections connections, specifically for a T tubular joint. The experimental program consisted of six tests where two experiments were executed without chord axial forces, two were performed with compressive axial forces and two tension axial forces. The tested joints ultimate strengths were determined using deformation limit criteria proposed by several researchers. These results were then compared to the results obtained from a finite element numerical model developed 12.0 ANSYS program that included geometrical and material nonlinearities. These results were also compared to the design provisions present at the Eurocode 3; Brazilian standard NBR 16239:2013 and CIDECT. This assessment indicated that the results obtained in both experimental tests and in the numerical models were in favor of security when compared to the theoretical values obtained by all the investigated standards for chords without axial forces and with compressive axial forces corresponding to 60% and 80% of the chord plastic resistance, respectively, according to Eurocode 3/NBR16239:2013 and CIDECT. The obtained resistances for the joints applying tensile axial force on the chord were superior to the predicted theoretical results in the studied cases.
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Avaliação da influência do esforço normal no banzo no comportamento de ligações tubulares em aço. / Analysis of the influence of chord normal stresses on the behavior of hollow sections connections.

Adriano Nizer 12 March 2014 (has links)
A demanda pelo uso de perfis tubulares em estruturas na construção civil tem tido grande avanço no Brasil, apesar de ser, há muito tempo, amplamente empregado na Europa e países desenvolvidos. O lançamento de uma norma técnica brasileira específica para dimensionamento de perfis tubulares confirma esta tendência, havendo então a necessidade de uma maior divulgação e execução de estudos e trabalhos de pesquisa para uma melhor compreensão e desenvolvimento desta tecnologia. O presente trabalho apresenta uma análise da influência da aplicação de esforço normal no banzo no comportamento de ligações tubulares do tipo T. No desenvolvimento deste trabalho, foram realizados seis ensaios em laboratório com ligações do tipo T com perfis do tipo RHS para o banzo e SHS para o montante, sendo utilizados perfis conformados a frio para composição das ligações ensaiadas. Do total dos ensaios foram executados dois ensaios sem aplicação de esforço normal no banzo; dois com aplicação de esforço normal de compressão e dois com aplicação de esforço normal de tração. A resistência última das ligações nos ensaios foi obtida por meio do Critério de Deformação Limite proposto por diversos pesquisadores. Estes resultados foram comparados com os resultados obtidos em modelos numéricos em elementos finitos desenvolvidos no programa ANSYS 12.0, sendo considerado nestes modelos as não-linearidades geométricas e de material. Estes resultados também foram comparados com os resultados teóricos obtidos com base nas prescrições constantes nas normas Eurocode 3; norma brasileira NBR 16239 e do CIDECT. Conclui-se com este estudo que os resultados obtidos tanto nos ensaios experimentais quanto nos modelos numéricos ficaram a favor da segurança quando comparados com os valores teóricos obtidos pelas normas Eurocode 3 e NBR 16239:2013 e CIDECT com o banzo sem aplicação de esforço normal e com aplicação de esforço normal de compressão de até 60% e 80 % da carga de plastificação do banzo, respectivamente, para o Eurocode 3/NBR16239:2013 e para o CIDECT. As resistências obtidas para as ligações com a aplicação de esforço normal de tração no banzo foram superiores aos resultados teóricos no caso estudado. / The demand for the use of hollow sections structures in construction has had great progress in Brazil, despite being a long time widely used in Europe and developed countries. The release of a Brazilian Technical Standard specific for design of hollow sections, confirms this trend, and the need for increased dissemination and implementation of studies and research for a better understanding and development of this technology. This paper presents an analysis of the influence of chord normal stresses on the behavior of hollow sections connections, specifically for a T tubular joint. The experimental program consisted of six tests where two experiments were executed without chord axial forces, two were performed with compressive axial forces and two tension axial forces. The tested joints ultimate strengths were determined using deformation limit criteria proposed by several researchers. These results were then compared to the results obtained from a finite element numerical model developed 12.0 ANSYS program that included geometrical and material nonlinearities. These results were also compared to the design provisions present at the Eurocode 3; Brazilian standard NBR 16239:2013 and CIDECT. This assessment indicated that the results obtained in both experimental tests and in the numerical models were in favor of security when compared to the theoretical values obtained by all the investigated standards for chords without axial forces and with compressive axial forces corresponding to 60% and 80% of the chord plastic resistance, respectively, according to Eurocode 3/NBR16239:2013 and CIDECT. The obtained resistances for the joints applying tensile axial force on the chord were superior to the predicted theoretical results in the studied cases.

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