It is vital that Turkey keep abreast of developments in the world and build up its technology to become a developed country. Steel construction is one of these areas. In this context, the main purpose of this study was to define, analyze and evaluate the general characteristics of structural steel and steel construction with the purpose of throwing new light on its advantages and disadvantages. Within this framework, a literature survey was conducted on structural steel components and structures / and on steel construction in Turkey. Additionally, a case study was carried out on a steel office building in Ankara. In this, the T&uuml / rkiye Esnaf ve Sanatkar Kredi Kefalet Kooperatifleri Merkez Birligi (TESKOMB) Building was investigated in terms of the design and production criteria for steel structures and to determine problems faced during these processes. As a result of this study, the existing condition of the construction sector and the means to improve use of structural steel in Turkey were discussed more realistically.

The goal of this study is to design and evaluate economic and rapid seismic retrofit strategies for relatively small rehabilitation projects for steel structures consistent with the tenets of sustainable design. The need to retrofit existing structures in earthquake prone regions may arise directly from the problem of aging and deteriorating conditions, recognition of the vulnerability of existing infrastructure, from updates in seismic code requirements, or changes in building performance objectives. Traditional approaches to seismic hazard mitigation have focused reducing the failure probabilities, consequences from failures, and time to recovery. Such paradigms had been established with little regard to the impact of their rehabilitation measures on the environment and disruptions to occupants. The rapid rehabilitation strategies proposed here have sustainability benefits in terms of providing a more resilient building stock for our communities as well as minimizing environmental and economical impacts and social consequences during the rehabilitation project. To achieve these goals, a unique approach to design supplemental systems using tension-only elements is proposed. In this design approach undesirable global and local buckling are eliminated. Two rapid rehabilitation strategies are presented. The first is a bracing system consisting of cables and a central energy dissipating device (CORE Damper). The second is a shear wall system with the combined use of thin steel plate and tension-only bracing. Analytical studies using both advanced and simplified models and proof-of-concept testing were carried out for the two devices. The results demonstrated stable, highly efficient performance of the devices under seismic load. Preliminary applications of the CORE damper to the retrofitting of a braced steel frame showed the ability of the system to minimize soft story failures. Both techniques can be implemented within a sustainability framework, as these interventions reduce the seismic vulnerability of infrastructure, are low cost, utilize materials and fabrication processes widely available throughout the world, can be handled by unskilled labor and carried out with minimal disruptions to the environment. The approach taken in this study can provide a road map for future development of sustainability-based rehabilitation strategies.

Metal building frames are typically designed using welded prismatic and web-tapered members with doubly-symmetric and/or singly-symmetric cross sections. Until recently, the base U.S. provisions for design of frames with web-tapered members were provided in the AISC ASD (1989) and LRFD (1999) Specifications. Unfortunately, these previous AISC provisions address only a small range of practical designs. As a result, metal building manufacturers have tended to develop their own methods for design of the wide range of nonprismatic member geometries and configurations encountered in practice. This research develops new design procedures for design of frames using general prismatic members and web-tapered members. An equivalent prismatic member concept utilized in prior research and the prior AISC provisions is generalized to accommodate the broad range of member types and configurations commonly used in metal building industry. Furthermore, the new design procedures incorporate many of the improvements achieved in the AISC (2005&2010) Specifications to metal building frame design. These improvements include a new stability design method, the direct analysis method, more complete considerations of different column buckling limit states (flexural, torsional and flexural-torsional buckling), and improved axial load and flexural resistance provisions. This research develops practical design-based procedures for simplified calculation of the elastic buckling resistances of prismatic and web-tapered members to facilitate the application of the proposed design methods. In addition, this research performs a relatively comprehensive assessment of beam lateral torsional buckling (LTB) behavior and strength of prismatic and web-tapered members using refined virtual test simulation. It is demonstrated that web-tapered members behave in a comparable fashion to prismatic members. Based on the virtual simulation study, recommendations for potential improvement of the AISC LTB resistance equations are provided. Lastly, the strength behavior of several representative metal building frames is studied in detail using the same virtual test simulation capabilities developed and applied for the assessment of the beam LTB resistances.

Στην παρούσα διατριβή παρουσιάζεται μια μέθοδος αντισεισμικού σχεδιασμού μεταλλικών κατασκευών με βάση τη χρήση λόγων ιδιομορφικής ιξώδους απόσβεσης. Η μέθοδος αυτή βρίσκει τη μέγιστη σεισμική απόκριση μιας κατασκευής με φασματική ανάλυση και χρήση των λόγων ιδιομορφικής ιξώδους απόσβεσης αντί του χονδροειδούς συντελεστή συμπεριφοράς. Η βασική ιδέα της μεθόδου είναι η κατασκευή μιας ισοδύναμης γραμμικής πολυβάθμιας κατασκευής η οποία να μπορεί να αναπαράξει τη σεισμική απόκριση μιας πραγματικής μη γραμμικής. Συγκεκριμένα, αυτή η ισοδύναμη γραμμική κατασκευή έχει την ίδια μάζα και αρχική δυσκαμψία με την πραγματική μη γραμμική κατασκευή και λόγους ιδιομορφικής ιξώδους απόσβεσης οι οποίοι ποσοτικοποιούν το έργο όλων των μη γραμμικών παραμορφώσεων. Αυτοί οι λόγοι ισοδύναμης ιξώδους απόσβεσης για τις πρώτες σημαντικές ιδιομορφές υπολογίζονται συναρτήσει της παραμόρφωσης και της βλάβης της κατασκευής αρχικά σχηματίζοντας επαναληπτικά μια συνάρτηση μεταφοράς στο πεδίο των συχνοτήτων, μέχρις ότου αυτή να ικανοποιήσει συγκεκριμένα κριτήρια ομαλότητας, και μετά επιλύοντας ένα σύστημα μη γραμμικών αλγεβρικών εξισώσεων. Αφού κατασκευαστούν εξισώσεις σχεδιασμού που παρέχουν τους λόγους ιδιομορφικής ιξώδους απόσβεσης, γίνεται χρήση φασμάτων σχεδιασμού τροποποιημένων για μεγάλη απόσβεση και ιδιομορφικής σύνθεσης για τον υπολογισμό των σεισμικών δυνάμεων σχεδιασμού. Μέσω των ελαστικών φασμάτων για διάφορες τιμές απόσβεσης υπολογίζεται ο ιδιομορφικός συντελεστής συμπεριφοράς ο οποίος επίσης δίνεται για τις πρώτες σημαντικές ιδιομορφές συναρτήσει της παραμόρφωσης και της βλάβης της κατασκευής. Τέλος, πραγματοποιείται ο αντισεισμικός σχεδιασμός μιας μεταλλικής πλαισιωτής κατασκευής με ελαστική φασματική ανάλυση τόσο με βάση τους λόγους της ισοδύναμης ιξώδους ιδιομορφικής απόσβεσης όσο και με βάση τους ιδιομορφικούς συντελεστές συμπεριφοράς. Και οι δυο τρόποι σχεδιασμού ελέγχονται χρησιμοποιώντας μη γραμμικές ανελαστικές δυναμικές αναλύσεις και συγκρίνονται με την συνηθισμένη μέθοδο των αντισεισμικών κανονισμών η οποία χρησιμοποιεί μια κοινή τιμή του συντελεστή συμπεριφοράς για όλες τις ιδιομορφές. Συμπεραίνεται ότι η προτεινόμενη μέθοδος αντισεισμικού σχεδιασμού οδηγεί σε ορθολογικότερα και ακριβέστερα αποτελέσματα σε σχέση με τη συνηθισμένη μέθοδο. / A rational method for seismic design of plane building frames based on the use of equivalent modal damping ratios is developed. The method determines the maximum seismic structural response through spectrum analysis using rationally obtained equivalent modal damping ratios instead of the crude strength reduction (behavior) factor. This is materialized in the second part of this work. In this first part, all theoretical aspects regarding equivalent modal damping ratios are developed and described in detail. The basic idea is the establishment of an equivalent linear multi-degree-of-freedom (MDOF) structure which can reproduce the seismic response of a MDOF geometrically and materially non – linear structure. More specifically, this equivalent linear structure retains the mass and stiffness of the original non – linear structure and takes into account geometrical non – linearity and inelasticity in the form of equivalent, time – invariant, modal damping ratios. The equivalent damping ratios for the first few significant modes are numerically computed by first iteratively forming a frequency response transfer function until it satisfies some specific smoothness criteria and then by solving a set of non – linear algebraic equations. Moreover, it is shown that these equivalent modal damping ratios can be computed in such a way so as to be deformation and damage dependent, which can lead to a better design in a direct manner. The concept of equivalent modal damping ratios developed is then employed for the seismic design of plane steel moment resisting frames. The goal is the determination of the maximum seismic structural response through spectrum analysis using rationally obtained equivalent modal damping ratios instead of the crude strength reduction factor. Therefore, design equations providing equivalent damping ratios as functions of period and allowable deformation and damage for the first few significant modes are constructed using extensive numerical data coming from a representative number of plane steel moment resisting frames excited by various seismic motions. These equations can be used in conjunction with a design spectrum, appropriately modified for high damping values, and modal synthesis tools to calculate the seismic design forces of the structure. The proposed method is illustrated by performing the seismic design of a steel moment resisting framed structure. It is concluded that unlike the usual code – based approach, which employs a single and crude strength reduction factor value for all modes, the proposed approach works with deformation and damage dependent equivalent modal damping ratios and thus leads to more accurate and deformation and damage controlled results in a direct and more rational way. Moreover, it is shown that by using equivalent modal dampiing one may define modal strength reduction factors. Thus, alternatively, maximum seismic response may be obtained by spectrum analysis and modal strength reduction factors.

In this study two dimensional steel frames, reinforced with un-stiffened thin steel panels, are investigated. In the first part of the study, the strip model, a method for analyzing un-stiffened thin steel plate shear walls, was investigated. Sensitivity studies to investigate the influence of the number of strip members to be used to in the strip model and their angle of inclination were conducted. In the second part, responses of various un-stiffened steel plate shear wall systems to lateral loads were investigated. The influences of three major parameters were studied. These are the beam-to-column connection type, the boundary frame stiffness and the plate slenderness ratio (the ratio of the centerline column spacing to the thickness of the plate). In both parts nonlinear pushover analysis were performed with SAP2000 structural analysis program. In this study, the history of development, theory and advantages of un-stiffened thin steel plate shear walls and recommendations for this lateral load resisting system are presented.

Thesis (Ph.D.)--University of Western Sydney, 2000. / Bibliography : leaves 197-204.

O sistema construtivo Light Steel Framing, que já é bastante desenvolvido e utilizado no exterior, vem sendo cada vez mais empregado no Brasil. Esse sistema apresenta diversas vantagens, tanto em relação ao uso de madeira quanto às construções tradicionais em alvenaria, destacando-se pela redução no prazo de execução, maior durabilidade das construções e redução de desperdício e perda de materiais. Contudo, verificam-se carências de informações no que diz respeito, principalmente, ao método de dimensionamento dessas estruturas. No âmbito nacional, a principal referência é a norma NBR 14762, mas ela não atende a algumas especificações correspondentes às soluções empregadas no Light Steel Framing. Os perfis metálicos utilizados para compor o esqueleto estrutural autoportante são de vários tipos, como as vigas, guias e os montantes, que são utilizados verticalmente para a composição de paredes, sujeitos, portanto, a esforços de compressão. Para que seja possível a passagem de instalações elétricas e hidráulicas, são empregados furos nas almas desses montantes, sendo desconhecidos os efeitos de perda da resistência gerada nos perfis devido a tais furos. O trabalho pretende contribuir com uma indicação normativa para a adequada utilização de montantes através de um estudo desenvolvido sobre as consequências dos furos empregados. O trabalho desenvolve-se em três frentes: revisão bibliográfica, desenvolvimento de um modelo numérico através do método de elementos finitos e ensaio experimental dos montantes com e sem furos, com a posterior comparação dos resultados obtidos pelas abordagens. / The Light Steel Framing construction system, which is already well developed and used abroad, has been increasingly used in Brazil. This system has several advantages, both in relation to the use of wood and traditional masonry structures, especially in terms of reduced execution time, longer structure durability and reduction of waste and loss of materials. However, there is a lack of information regarding, mainly, the method of designing these structures. At the national level, the main reference is the standard NBR 14762, but it doesn’t meet some specifications corresponding to the solutions used in Light Steel Framing. The metal profiles used to form the self-supporting structural skeleton are of various types, such as beams, guides and wall studs, which are used vertically for the composition of walls, therefore subjected to compression forces. In order to allow the passage of electrical and hydraulic installations, holes are used in the webs of these wall studs, however, the loss of resistance effects caused by holes in the profiles are unknown. This work aims to contribute with a normative indication for the adequate use of wall studs through a study developed on the consequences of the holes used. The work is carried out on three fronts: bibliographic review, development of a numerical model using the finite element method and experimental testing of the wall studs with and without holes, with the subsequent comparison of the results obtained by the approaches.

Made available in DSpace on 2014-06-11T19:25:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-05-19Bitstream added on 2014-06-13T19:32:22Z : No. of bitstreams: 1 pinto_el_me_ilha.pdf: 1624906 bytes, checksum: 5bc2d5cfa5a9fecd4b7df0008cf99be3 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Fundação de Ensino Pesquisa e Extensão de Ilha Solteira (FEPISA) / O desenvolvimento da presente pesquisa tem a finalidade de estudar um dos efeitos principais de restrição de telhas conectadas nas terças, que é a rigidez ao cisalhamento. O valor da rigidez ao cisalhamento é determinado pela influência da restrição da telha no deslocamento lateral da terça sobre o seu eixo longitudinal, em função do espaçamento dos parafusos de conexão. Para a determinação da rigidez ao cisalhamento foi utilizado um procedimento experimental, semelhante ao modelo numérico, referido como DOUBLE BEAM SHEAR TEST - DBST, que permite avaliar a restrição dada pela telha à terça ao cisalhamento. Para os testes do modelo DBST foi utilizado o Laboratório de Engenharia Civil, onde foram ensaiadas séries desse conjunto para a determinação da rigidez ao cisalhamento. As terças são constituídas de perfil formado a frio. As distâncias entre as terças são compreendidas entre os valores de 1000 a 2300 mm. As telhas são do tipo ondulada com altura de 17 mm e trapezoidal com altura compreendida entre 25 mm e 100 mm. As espessuras das telhas estão entre os valores de 0,43 mm e 0,80 mm. / The development of the present research has the purpose to study one of the main effect of restriction of the sheeting connected in purlin, that it is the rigidity to the shear. The value of the rigidity to the shear is determined by the influence of the restriction of the sheeting in the lateral displacement of purlin on its longitudinal axis, in function of the spacing of the connection screws. For the determination of the rigidity to the shear an experimental procedure was used, similar to the numerical model, related as DOUBLE BEAM SHEAR TEST - DBST, that allows to evaluate the restriction given for the sheeting to purlin to the shear. For the tests of model DBST the Laboratory of Civil Engineering was used, where had been assayed series of this set for the determination of the rigidity to the shear. Purlins are constituted of the cold formed profile. The distances between purlins are understood between the values of 1000 the 2300 mm. The sheeting are of the type wavy with height of 17 mm and trapezoidal with height understood between 25 mm and 100 mm. The thicknesses of the sheeting are between the values of 0,43 mm and 0,80 mm.

Orientador: Renato Bertolino Junior / Banca: José Antonio Matthiesen / Banca: Francisco Carlos Rodrigues / Resumo: O desenvolvimento da presente pesquisa tem a finalidade de estudar um dos efeitos principais de restrição de telhas conectadas nas terças, que é a rigidez ao cisalhamento. O valor da rigidez ao cisalhamento é determinado pela influência da restrição da telha no deslocamento lateral da terça sobre o seu eixo longitudinal, em função do espaçamento dos parafusos de conexão. Para a determinação da rigidez ao cisalhamento foi utilizado um procedimento experimental, semelhante ao modelo numérico, referido como DOUBLE BEAM SHEAR TEST - DBST, que permite avaliar a restrição dada pela telha à terça ao cisalhamento. Para os testes do modelo DBST foi utilizado o Laboratório de Engenharia Civil, onde foram ensaiadas séries desse conjunto para a determinação da rigidez ao cisalhamento. As terças são constituídas de perfil formado a frio. As distâncias entre as terças são compreendidas entre os valores de 1000 a 2300 mm. As telhas são do tipo ondulada com altura de 17 mm e trapezoidal com altura compreendida entre 25 mm e 100 mm. As espessuras das telhas estão entre os valores de 0,43 mm e 0,80 mm. / Abstract: The development of the present research has the purpose to study one of the main effect of restriction of the sheeting connected in purlin, that it is the rigidity to the shear. The value of the rigidity to the shear is determined by the influence of the restriction of the sheeting in the lateral displacement of purlin on its longitudinal axis, in function of the spacing of the connection screws. For the determination of the rigidity to the shear an experimental procedure was used, similar to the numerical model, related as DOUBLE BEAM SHEAR TEST - DBST, that allows to evaluate the restriction given for the sheeting to purlin to the shear. For the tests of model DBST the Laboratory of Civil Engineering was used, where had been assayed series of this set for the determination of the rigidity to the shear. Purlins are constituted of the cold formed profile. The distances between purlins are understood between the values of 1000 the 2300 mm. The sheeting are of the type wavy with height of 17 mm and trapezoidal with height understood between 25 mm and 100 mm. The thicknesses of the sheeting are between the values of 0,43 mm and 0,80 mm. / Mestre

O sistema construtivo Light Steel Framing, que já é bastante desenvolvido e utilizado no exterior, vem sendo cada vez mais empregado no Brasil. Esse sistema apresenta diversas vantagens, tanto em relação ao uso de madeira quanto às construções tradicionais em alvenaria, destacando-se pela redução no prazo de execução, maior durabilidade das construções e redução de desperdício e perda de materiais. Contudo, verificam-se carências de informações no que diz respeito, principalmente, ao método de dimensionamento dessas estruturas. No âmbito nacional, a principal referência é a norma NBR 14762, mas ela não atende a algumas especificações correspondentes às soluções empregadas no Light Steel Framing. Os perfis metálicos utilizados para compor o esqueleto estrutural autoportante são de vários tipos, como as vigas, guias e os montantes, que são utilizados verticalmente para a composição de paredes, sujeitos, portanto, a esforços de compressão. Para que seja possível a passagem de instalações elétricas e hidráulicas, são empregados furos nas almas desses montantes, sendo desconhecidos os efeitos de perda da resistência gerada nos perfis devido a tais furos. O trabalho pretende contribuir com uma indicação normativa para a adequada utilização de montantes através de um estudo desenvolvido sobre as consequências dos furos empregados. O trabalho desenvolve-se em três frentes: revisão bibliográfica, desenvolvimento de um modelo numérico através do método de elementos finitos e ensaio experimental dos montantes com e sem furos, com a posterior comparação dos resultados obtidos pelas abordagens. / The Light Steel Framing construction system, which is already well developed and used abroad, has been increasingly used in Brazil. This system has several advantages, both in relation to the use of wood and traditional masonry structures, especially in terms of reduced execution time, longer structure durability and reduction of waste and loss of materials. However, there is a lack of information regarding, mainly, the method of designing these structures. At the national level, the main reference is the standard NBR 14762, but it doesn’t meet some specifications corresponding to the solutions used in Light Steel Framing. The metal profiles used to form the self-supporting structural skeleton are of various types, such as beams, guides and wall studs, which are used vertically for the composition of walls, therefore subjected to compression forces. In order to allow the passage of electrical and hydraulic installations, holes are used in the webs of these wall studs, however, the loss of resistance effects caused by holes in the profiles are unknown. This work aims to contribute with a normative indication for the adequate use of wall studs through a study developed on the consequences of the holes used. The work is carried out on three fronts: bibliographic review, development of a numerical model using the finite element method and experimental testing of the wall studs with and without holes, with the subsequent comparison of the results obtained by the approaches.