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Alanazi, Abdulaziz Manqal. "The Use of Core and Outrigger Systems for High-Rise Steel Structures." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1576180826759645.
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Cook, Jason A. (Jason Andrew). "Structural steel framing options for mid- and high rise buildings." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/34634.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2006.Includes bibliographical references.
Selecting a structural system for a building is a complex, multidisciplinary process. No design project is the same; however, there are certain criteria that are commonly true in the initial phase of evaluating different structural schemes. These criteria encompass all aspects of a full, functioning building, forcing the design team to be creative in their approach of satisfying all facets. An investigation was carried out for several structural steel framing options available to designers. The schemes describe how each successfully resist lateral loads explaining the advantages and disadvantages of each. Many of the structural design tools available for initial structural system evaluation are strength based. The demand for cheaper, more efficient and taller structures has paved the way for performance based design. A simple cantilever beam performance based analysis was utilized to evaluate three common structural framing schemes in order to gain a better understanding of the performance of each. Results give recommendations for efficient structural solutions for proposed buildings as a function of height.
by Jason A. Cook.
M.Eng.
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Lin, Xuchuan. "Development of Low-to Mid-rise Building Structures Using Weld-free Built-up Columns Made of Ultra-high Strength Steel." 京都大学 (Kyoto University), 2012. http://hdl.handle.net/2433/161010.
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Marcus, Micheal, and Kuang Zhao. "En studie av höghusbyggande med avseende på stomsystem och lastpåverkan." Thesis, KTH, Byggteknik och design, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149557.
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Vi har valt att undersöka vilka möjligheter och eventuella risker det finns att bygga högt i Stockholm. Undersökningen utgick på att jämföra olika byggtekniska lösningar för stomsystem. Hur tar stomsystemen hand om vertikala och horisontella laster? Vilket stomsystemen är lämpligast vid en viss höjd? Dessa är några av de frågor som besvaras i arbetet. De vertikala och horisontella lasterna är de faktorer som främst försvårar höghusbyggandet. Med en större belastning av laster ju högre det byggs måste stomsystemen dimensioneras med allt större noggrannhet för att lasterna ska nedföras till grundläggningen på ett säkert sätt. Stomsystemen måste även dimensioneras för de svajningar och stabilitetsproblem som uppstår av de transversella lasterna. Genom inläsning av litteratur och intervjuer angående ämnet så har vi kommit fram till att den största orsaken att det finns så få höghus i Sverige beror på den politiska inställningen i landet och efter Turning Torsos kostnad dubblerades så har många dragit sig undan höghusprojekt. Byggtekniskt har vi i Sverige erfarenheter att bygga upp till 100-150m.We have in this thesis decided to examine the possibilities and the possible hazards of high-rise buildings in Stockholm. We compared the different structural systems to determine how the systems handle the vertical and transversal loads and which system is to recommend to a certain height. The vertical and transversal loads are the main factors that make high-rise buildings harder to dimension than normal buildings. The higher the building is the more vertical and transversal loads that needs to be accounted in the dimensioning of the structural systems. This needs to be done accurately to secure the safety of the building. The sway and stability problems that occurs from the transversal loads need to be taking into account when designing the structural system. By reading literature and conducting interviews about the subject we can come to the conclusion that the reason why Sweden is behind with recent high-rise development is because of political reasons rather than lack of knowledge. We in Sweden have the experience to successfully build high-rise buildings up to 100-150m.
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Lubke, Christopher D. (Christopher David) 1980. "Trends and innovations in high-rise structures." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/85380.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003.Includes bibliographical references (leaves 47-48).
by Christopher D. Lubke.
M.Eng.
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Batista, Yolanda Maria Baez. "Financial Feasibility of High Performance Low Rise Steel Buildings." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/4343.
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Comparative performance evaluation including life cycle cost is currently being conducted on a series of conventional and base-isolated case study buildings. Alternative design approaches and their influence in cost were to be evaluated . This investigation is intended to contribute in the development of isolated structures by allowing engineers to communicate the cost of higher performance systems to their clients. The reported effort is part of a larger cost-benefit study for isolated steel buildings, and the purpose of this thesis is to compare initial investment of 3-story conventional and isolated steel buildings and determine how isolation affects the cost of the structure.
The relative cost of seismic isolation, as a percentage of the total cost, may be higher in this study than for typical U.S. isolation applications because the relative premium is greater for a short building than a tall building. The cost of isolation layer for this building is in the order of 11.7% to 12.4% of the total cost. Such a large cost premium may be a huge restraint for most owners; therefore, strategies to reduce the isolation premium cost need to be investigated in detail.
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Zhang, Xiaoyue. "Seismic design of timber steel hybrid high-rise buildings." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/61985.
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Timber-steel hybrid systems utilize timber as main construction material, but also take advantage of the ductility and stiffness that steel provides. For a novel hybrid system to gain recognition, experimental data must be supported by numerical analysis to predict its structural performance. “Finding the Forest Through the Trees” (FFTT) is one proposal for a timber-steel hybrid system using mass-timber panels as shear walls and floor slabs connected with steel header beams.
This thesis presents research to evaluate the seismic performance of the FFTT hybrid system using experimental methods, numerical modeling, and reliability analysis. The FFTT system was investigated on two levels: i) component design, and ii) system design. On the component level, the strength, stiffness, ductility, and failure mechanisms of the two key connections were evaluated experimentally. CLT (Cross Laminated Timber) wall to steel beam connection tests results demonstrated that appropriate connection layouts can lead to the desired failure mechanism while avoiding crushing of the mass-timber panels. For the hold-down connection, a modified HSK (Holz-Stahl-Komposit) assembly with high force and stiffness capacity together with ductile behaviour was proposed. On the system level, the seismic response of the FFTT system with different ductility values was investigated using nonlinear 2D and 3D models subjected to a number of ground motion acceleration records. The seismic reliability with various uncertainties was analysed in order to investigate the FFTT system from a performance based approach. Based on the results, an appropriate seismic force reduction factor specific to the FFTT system was proposed. Finally, a feasibility study confirmed the possibility of the practical application of this system. This thesis can serve as a precursor for developing design guidelines for tall wood-hybrid building systems in seismic regions.Forestry, Faculty of
Graduate
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Surampudi, Bala Anjani Vasudha. "High-Resolution Modeling of Steel Structures." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504787210175847.
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Assefa, Dereje 1974. "Controlling wind induced motion in high-rise structures." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/80639.
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Melhem, George Nadim Materials Science & Engineering Faculty of Science UNSW. "Design variables for steel and aluminium in high-rise rooftops." Publisher:University of New South Wales. Materials Science & Engineering, 2008. http://handle.unsw.edu.au/1959.4/43010.
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This dissertation reports a case study in the design and construction solutions for a major corrosion failure of the aluminium louvres and steel brackets on the roof and fa??ade of levels 26-29 of the Westfield Tower 2, Bondi Junction. This work was undertaken during early 2005. Aims: ?? Consideration of the roles and responsibilities of designer and engineer working on metallurgical corrosion issues in high-rise buildings ?? Undertaking of a literature survey of corrosion issues involving riveting and welding of aluminium and galvanising of steel ?? Undertaking of stress calculations for all components to ensure compliance with the requirements of design principles ?? Confirmation of the stress calculations through finite element modelling ?? Examination of all materials issues in order to prevent re-occurrence of structural degradation and corrosion ?? Consideration of relevant environmental effects on the materials ?? Implementation of these design solutions using novel aerospace materials and methods ?? Prediction of future performance through factorial and matrix method approaches Outcomes: ?? It is hoped that the text provides a documentary basis for future guidance of designers and engineers working in areas related to the subject of the present work. ?? It also is hoped that the work on aerospace technologies will broaden the scope of designers and engineers in the potential that these materials and processes have in building considerations. ?? The manual stress calculations and finite element modelling confirm that the implemented designs are consistently within design specification and that, from the mechanical perspective, no problems are anticipated. ?? Further, since considerable care was taken to ensure that galvanic and other forms of corrosion were avoided through the appropriate use of design, materials, and implementation approaches, no further corrosion has been observed at the site. ?? The development of a generic factorial approach and a specific matrix method, applied to corrosion and welding considerations, was informative but these still are at speculative stages owing to the difficulty of obtaining relevant meaningful data and the problem of assigning weighting factors on what is viewed as a fairly subjective basis.
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Fast, Tobias. "Design considerations for mid-rise steel frame structures using wood-based flooring systems." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/50818.
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This thesis discusses design considerations for mid-rise steel frame structures using wood-based flooring systems. Gravity load design aspects including composite behaviour, structural weight, floor vibration and lateral bracing are considered for joisted and panel floors in steel building structures. The influence of joisted wood-based flooring systems on the seismic response of concentrically braced steel frame buildings is assessed based on linear dynamic analyses and the strength and stiffness demands are compared with capacities provided by the Canadian Wood Design Manual.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Wang, Jie. "Behaviour and design of high strength steel structures." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/43758.
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High strength steels (HSS), which are generally considered to be those with yield strengths over 460 MPa, are being increasingly utilised in construction, particularly in high rise structural applications and where long and column-free spans are an important design requirement. In place of ordinary carbon steels, the use of HSS can enable structural elements with smaller cross-sections, resulting in significant material savings. However, compared to normal strength steels, the structural use of HSS is still quite rare. The European design code EN 1993-1-12 provides design rules for HSS up to S700, but was conceived as a simple extension of the rules in EN 1993-1-1 for normal strength steels. In order to contribute to the existing limited HSS data pool and to verify and develop the current Eurocode 3 design rules, a comprehensive experimental programme on hot-finished S460 and S690 square and rectangular hollow sections has been carried out. The testing programme covered different structural aspects at the material, cross-section and member levels and consisted of 40 tensile coupon tests, 11 compressive coupon tests, 11 stub column tests, 11 full section tensile tests, 22 in-plane bending tests, 12 eccentrically loaded stub column tests, 30 long column tests, as well as measurements of geometrical imperfections and residual stresses. Numerical models, validated against the test results, were also developed to examine the cross-section and member behaviour, and subsequently employed in a comprehensive parametric study in order to generate further data. Based on the combined test and numerical data set, as well as experimental results reported in the literature, the current HSS design rules in Eurocode 3, including the slenderness limits for cross-section classification, effective width equation, N-M interaction curves and column buckling curves, were assessed by means of reliability analyses in accordance with Annex D of EN 1990. To realise the potential of HSS in long span structures, a novel structural form was also examined, namely an HSS truss with prestressing cables housed within the tubular bottom chord. A total of 4 prestressed trusses, made of S460 square hollow sections with different prestress levels, were tested under static downward loading. The truss test results showed the enhanced structural efficiency brought about by the addition of prestressing cables and by the application of prestress. Additionally, 12 tensile and 10 compressive member tests with cables, representing the bottom chord of the truss under gravity and uplift loading, respectively, were carried out to investigate the behaviour of individual prestressed cable-in-tube members. Analytical models and numerical models were also established to compare with the test behaviour and to contribute to the development of design rules for prestressed cable-in-tube systems.
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Kafetsis, Nikolas K. "Applicability of undermatched welds for high strentgh steel structures." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/37813.
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Thesis (Nav.E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1995.Includes bibliographical references (leaves 182-184).
This study presents experimental and numerical results for the strength of welded joints, made on high strength steels with different degrees of strength matching. The steels involved are the HY-100 and HY-130 U.S. Navy, quenched and tempered steels. The test methods are the self restraint cracking test, the tensile test and the fatigue test. The investigated parameters are the strength of the weld metal and the preheat temperature. The self restraint cracking test does not show clearly the expected results, that the required preheat temperature to avoid cold cracking can be reduced by applying undermatched welds at the root of the welding. This conclusion was reached in a similar experiment that was performed on HT-80 high strength steel. The tensile test and the numerical analysis show that the strength properties of the undermatched weld are not the typical properties of the unrestrained weld material. They are greatly elevated due to the restraint effect provided by both the base metal and the stronger surrounding weld metal. Results from the fatigue test show that the degree of strength undermatching, does not affect significantly the crack propagation rate at the joint.
by Nikolas K. Kafetsis.
S.M.
Nav.E.
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Rimal, Sujan Kumar, and Levi Grennvall. "Analysis of Tripod shaped high rise building using Tubed Mega Frame structures." Thesis, KTH, Betongbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209677.
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Most of the tall buildings that are built today have a straight and vertical shape, because vertical buildings are more stable and easily built than slanted ones. In the case of vertical building, bending moments in the base only exists from horizontal loads such as wind and seismic loads, but in slanted buildings there will also be bending moments from dead and live loads. In addition, transportation inside the building is also a challenge when it comes to slanted buildings. However, a new elevator system that ThyssenKrupp has developed will solve that problem. This new elevator has an ability to move in all direction both vertically and horizontally. The new structural system, Tube Mega Frame (TMF), has been studied and proved to have better efficiency than the central core with outriggers. Moving the bearing structure to the perimeter of the building, gives smaller overturning moment and better stability due to longer lever arm from the center. This thesis focuses on applying the Tube Mega Frame system to a slanted building which has a tripod structure. Different types of TMFs were used to compare the efficiency of the buildings performance. The TMF contains perimeter frame and mega columns with different binding systems such as belt walls and bracings. A pre-study has been carried out in order to see the overall behavior of the tripod shape. Different heights and inclinations have been analyzed with stick models. The analysis has been performed in the finite element software SAP2000 and deflections due to dead load was compared. The buildings with least deflection considering maximum height and maximum inclination was chosen for further model analysis in finite element software ETABS. Furthermore, a short study of different bracings system has been performed for the lateral loads and it concluded that X-bracing have better performance. The main study of this thesis focused on the two building models of 450 m with 7° inclination and 270 and 15° inclination. For each model, five different TMF systems were applied and analyzed. The TMF includes perimeter frame, perimeter frame with belt wall, mega columns, mega columns with belt wall and mega columns with bracings. Deformations due to wind load, seismic load and modal vibration has been compared. It concluded that the least deformation is achieved by the TMF mega columns with bracings for both models with two different heights. The periods of the building are comparatively lower than other systems. The deflection from TMF mega columns with belt walls did not differ much from the TMF mega columns with bracings. For the 270 m high building, the top story displacement was remarkably small because of the three legs, making it stiffer and stable. Even with the p delta effect, there were only millimeters of difference in top story displacement. TMF perimeter frame had a lower deflection than with belt wall, which should have been exact opposite. The reason was while making the total volume of buildings equal, the addition of belt walls led to thinner columns in the perimeter and lower stiffness.
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Narang, Vikas A. "Heat Transfer Analysis In Steel Structures." Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-050405-133533/.
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Gundersen, Håkon A. Holm. "High Temperature Cathodic Disbondin of Organic Coatings on Submerged Steel Structures." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-16335.
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There are currently no standard test methods for testing the cathodic disbonding properties of organic coatings at temperatures above 100 C. There are several subsea oil and gas reservoirs with high temperatures, some as high as 200 C. The main goal of this work was the development of a new apparatus and testing procedure for high temperature cathodic disbonding, hereby referred to as HTCD (High Temperature Cathodic Disbonding).A test method for the cathodic disbonding of organic coatings from submerged steel subjected to high temperatures was studied. The test method requires the use of a specialized HTCD apparatus. In this test method, sample plates were mounted between two channels, one containing a hot (150 C) oil flow and the other containing a pressurized, cold, salt (3.5 % NaCl) water flow. Accelerated conditions made it possible to test the cathodic disbonding properties of several coatings in four weeks. Four weeks is a typical duration for coating prequalification tests. Several commercial coating products of different generic types provided by different manufacturers were tested. The results indicate that adequate coating products for high temperature underwater exposure are available.The required cathodic protection current for the samples tested in the HTCD apparatus was continuously monitored. No correlation between the required cathodic protection current and the extent of cathodic disbonding was observed.A long term test with more field like conditions and a duration of 400 days was performed. Low levels of disbonding for most of the tested products in the 400 day test made comparison to the accelerated tests difficult.An attempt was made to determine the oxygen diffusion coefficient of five coating products. The attempt was unsuccessful. The same method had previously been used to study coatings with a thickness of up to 300 micro m, the coatings studied in this work were between 600 micro-metres and 1200 micro-metres. It remains uncertain whether the chosen method can be used for coatings this thick.Results from electrochemical impedance spectroscopy, performed in a pressurized vessel, showed a large reduction in the ionic resistance of a submerged organic coating upon heating from 30 C to 150 C. This showed that elevated temperatures throughout the coating can reduce the ionic resistance to a level where even an intact coating is incapable of protecting the substrate. Studies of coating samples at ambient temperatures after exposure to higher temperatures showed that exposure to heat causes a lasting reduction in impedance. High impedances correlated with good performance in the HTCD tests.Investigation with a scanning electron microscope (SEM) provided images where the extent of the cathodic disbonding was clearly visible. Electron-dispersive X-ray spectroscopy (EDS) enabled the identification of oxides discovered at the holiday and beneath the disbonded coating. Zinc and calcium oxides were identified at and near the holiday; iron oxide was identified beneath the disbonded coating.
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Lui, Wing Man. "Design of cold-formed high strength stainless steel tubular columns and beam-columns /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20LUI.
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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 149-154). Also available in electronic version. Access restricted to campus users.
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Demetriou, Demetris. "Enhancing the practical applicability of smart tuned mass dampers in high-rise civil engineering structures." Thesis, University of Leeds, 2017. http://etheses.whiterose.ac.uk/19285/.
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The ability of bones to concentrate material where the body needs most of its strength and the ability of trees to spread roots in search of moisture rich locations are only a few amongst the many examples of nature’s way of building adaptive “structures”. Even though civil engineering structures often appear inefficient, static and cumbersome, a new era of structural design aims to alter the status quo by mimicking nature’s way. This suggested adaptation process in civil structures often takes the form of passive, active and semi- active control. Through direct comparison of these methods, semi-active control is shown to combine the benefits of both active and passive systems and can be arguably considered the next step in improving dynamic structural performance; however the applicability of this exciting and novel for the structural engineering field technology, is not all-embracing. In order to enhance the development of this promising technology and contribute on the creation of a new era of “smart & thinking” structures that encompass an unconventional form of performance based design, this study aimed to develop enabling technologies and tools that enhance the selling strengths of semi-active and smart control using tuned-mass dampers. The original contributions to knowledge in this work are divided in three aspects. Firstly, the investigation of the influence of control algorithms on smart tuned-mass damper equipped high-rise structures, for which practical limitations have been taken into account. Leading to conclusion on the conditions for which each algorithm exhibits superior performance over the other. Secondly, the development of a fail-safe novel semi-active hybrid device configuration that enables performance gains similar to the active mass damper at considerably lower actuation and power demands. Finally, the development of a simple and robust at all gains control algorithm based on the modification of one of the most widely used controller in the engineering industry, namely the proportional-integral-derivative controller.
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Chung, YuLin. "Existing Performance and Effect of Retrofit of High-Rise Steel Buildings Subjected to Long-Period Ground Motions." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120856.
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Schnerch, David. "Strengthening of Steel Structures with High Modulus Carbon Fiber Reinforced Polymer (CFRP) Materials." NCSU, 2005. http://www.lib.ncsu.edu/theses/available/etd-06152005-090112/.
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Transportation departments and the telecommunications industry are currently demanding cost-effective rehabilitation and/or strengthening techniques for steel structures, including bridges and monopole towers. Rehabilitation is often required due to cross-section losses resulting from corrosion damage and strengthening may be required due to changes in the use of a structure. Current strengthening techniques, have several disadvantages including their cost, need to match the surface configuration of the existing structure, poor fatigue performance and the need for ongoing maintenance due to continued corrosion attack. The current research program makes use of new high modulus types of carbon fiber for strengthening steel structures. The experimental program was developed in four phases. These phases included the selection of suitable resins and adhesives for bonding the CFRP sheets and strips to the steel, characterization the bond to the steel through testing of the development length, performing large-scale tests on strengthened steel monopole towers and also determining the behavior of strengthened steel-concrete composite beams that are typical of bridge structures. The result of the experimental program was the demonstration of sizeable strength and stiffness increases for the steel structures, strengthened with the developed system. Analytical work has also been completed to predict these strength and stiffness increases as well as to determine the bond stresses to ensure the avoidance of a debonding failure, which is detrimental to the effective use of the high modulus CFRP material.
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Keating, Elspeth. "Lightweighting of stiffness critical advanced high strength steel structures using fibre reinforced plastics." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/89185/.
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In the drive for lightweighting in many industries, optimum material selection is at the forefront of research. Many solutions are being investigated, including the fabrication of multi-material components. Following a state of the art review of the literature, it has been shown that there is an opportunity to improve basic knowledge and understanding of the characteristics of hybrid steel-FRP materials for lightweight applications. This dissertation explores the potential for designing lightweight automotive steel structures through novel use of lower gauges combined with local reinforcement by fibre-reinforced plastics to achieve desired stiffness performances. The main focus of the work is to provide underpinning research to enable the further understanding of the stiffness performance of hybrid steel-FRP materials, both experimentally and in simulation. This thesis focuses on the characterisation of high strength automotive grade steel (DP600) reinforced with a fibre reinforced polyamide (PA6 GF60) laminate, however, the results are readily applicable for other combinations. The project was achieved through two main phases; each phase consisting of an iteration loop between experimentation and simulation validations. Initial characterisation was achieved using coupon samples in quasi-static three-point bend, cross-validated in simulation providing a trusted material model. Correlating experimental and simulated results showed a potential lightweighting of up to 30 % of a hybrid DP600-GFRP over a DP600 counterpart with a matched stiffness performance. Further characterisation was performed using an idealised automotive component in flexure, confirming a potential lightweighting of up to 30 %. The simulation investigation demonstrated the effect of localised hybrid reinforcements, and identified difficulties in predicting the local geometrical effects of plastic hinging. For an overall application to an automotive body-in-white, these would require further investigating. This thesis has proven that downgauging steel whilst locally reinforcing (intelligent deployment) with FRP patches provides a significant lightweight solution with a matched stiffness performance. A hybrid material model has been validated and the application to an automotive component investigated. This work provides the basic understanding for a direct application in lightweight automotive designs using computer aided engineering (CAE).
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Homaioon, Ebrahimi Amir. "The investigation of the effect of plan irregularities on the progressive collapse response of low to medium rise steel structures." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8094/.
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This research examines the effect of plan irregularities on the progressive collapse of steel structures. Firstly, 2, 3 and 5-storey steel structures, regular and irregular, located in regions with different seismic activity designed in accordance with AISC (20 I 0) and ASCE7 (20 I 0). Secondly, the effect of the four plan irregularities on the progressive collapse of braced and unbraced steel structures located in regions with different seismic activity assessed. The collapse patterns of the I4 buildings is analysed and compared under seven loading scenarios using nonlinear dynamic and static analyses. In the nonlinear dynamic analyses, node displacements above the removed columns and the additional force on the columns adjacent to them are discussed. Furthermore, the capacity of the columns is compared to determine their susceptibility to collapse. ln the nonlinear static analyses, the pushdown curve and yield load factor of the structures are obtained after column removal. The results indicate that an irregular structure designed in site class C seismic zone collapses in most of the column removal scenarios. Moreover, when comparing regular and irregular structures designed in site class E seismic zone, the demand force to capacity ratio (D/C) of the columns in the irregular structures is on average between I.5 and 2 times that of the regular ones has been discussed by Homaioon Ebrahimi et.al (20 I7). The lack of 2-storey building bearing capacity to withstand the removal of the column is lower than that of the 5-storey structure, which is due to the level of redundancy that characterises in the 5-storey structure.
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Viano, David Michael. "The influence of alloying additions on the microstructure and mechanical properties in high current GTA welding of structural steel /." Title page, abstract and contents only, 1998. http://web4.library.adelaide.edu.au/theses/09ENS/09ensv617.pdf.
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Gkantou, Michaela. "Response and design of high strength steel structures employing square and rectangular hollow sections." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7522/.
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The application of high strength steels (HSS) in the construction industry can lead to more economic design and profound sustainability benefits. To facilitate their use in modern practice, most international structural design codes have included HSS within their contents. Due to limited test data at the time of publishing, HSS design provisions are largely based on those for mild steel, with some restrictions, due to HSS’s inferior ductility and strain-hardening characteristics. Hence, further investigation on the applicability of such design specifications to HSS is required. To this end, within the present research work the structural performance of high strength steel structures employing square and rectangular hot-finished hollow sections is rigorously investigated. Meticulously generated finite element models of individual structural components are validated against test data and subsequently used for the generation of additional structural performance data through the execution of parametric studies. Implementing the aforementioned methodology, focus is also placed upon the structural performance of HSS trusses, whilst the possibility of applying prestress to them to enhance their behaviour is examined. Based on the obtained results, the suitability of current codified design methods to HSS is assessed and appropriate design recommendations are made.
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Khurshid, Mansoor. "Static and fatigue analyses of welded steel structures : some aspects towards lightweight design." Doctoral thesis, KTH, Lättkonstruktioner, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-200829.
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The objectives of this thesis comprise of overcoming the challenges in designing lightweight welded structures such as material selection, choice of fatigue design methods, and increased performance by using improvement techniques. Material selection of welded joints is dependent on the filler and base material strengths. Partially and fully penetrated cruciform and butt welded joints were designed in under-matching, matching, and over-matching filler materials. Base material steel grades were S600MC, S700MC, and S960. Current design rules are developed for welds in steel up to yield strength of 700MPa. Therefore, design rules in Eurocode3, AWS d1.1, and BSK 07 were verified and recommendations for developing design rules for designing welded joints in S960 were concluded. Numerical methodology for estimating static strength of welded joints by simulating heat affected zone was also developed. Another objective of the thesis work was to overcome the challenges in selection of fatigue design methods. The available design curves in standards are developed for uniaxial stress states, however, in real life the welds in mechanical structures are subjected to complex multiaxial stress states. Furthermore; weld toe failures are frequently investigated, weld root failures are seldom investigated. Therefore, in this work the multiaxial fatigue strength of welded joints failing at the weld root was assessed using experiments and various nominal and local stress based approaches. Butt welded joints with different weld seam inclinations with respect to applied uniaxial loading were designed to assess the root fatigue strength in higher multiaxial stress ratio regime. The fatigue strength of multi-pass tube-to-plate welded joints subjected to internal pressure only and combined internal pressure and torsion in and 90° out of phase loading was also investigated. Test data generated in this thesis was evaluated together with the test data collected from literature. Last objective of the thesis included investigation of the increased performance in fatigue strength by post weld treatment methods such as HFMI. The behavior of residual stresses induced due to HFMI treatment during fatigue loading is studied. Numerical residual stress estimations and residual stress relaxation models are developed and the effect of various HFMI treatment process parameters and steel grade on the induced residual stress state is investigated. Specimens studied were non load carrying longitudinal attachments and simple plates. Residual stresses in both test specimens were measured using X-ray diffraction technique.QC 20170206
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Meyer, Arnold Matthys. "Intersitial diffusion from the weld metal into the high temperature heat affected zone in 11-12% chromium steel welded joints." Pretoria : [s.n.], 2000. http://upetd.up.ac.za/thesis/available/etd-09292008-100709/.
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Tudor, Kerry. "Life cycle assessment of materials and automotive structures." Thesis, Swansea University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.587511.
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Jiao, Hui 1963. "The behaviour of very high strength (VHS) members and welded connections." Monash University, Dept. of Civil Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/9417.
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Brahmachari, Koushik, of Western Sydney Hawkesbury University, of Science Technology and Agriculture Faculty, and School of Construction and Building Sciences. "Connection and flexural behaviour of steel RHS filled with high strength concrete." THESIS_FTA_CBS_BRAHMACHARI_K.xml, 1997. http://handle.uws.edu.au:8081/1959.7/526.
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Steel hollow section members filled with concrete have been frequently used in recent construction industry as columns and beams and beam-columns because of their superior performance and constructability. Previous research demonstrated that such system has large energy absorption capacity which is critical in the event of an earthquake. By filling steel RHS with concrete, the failure of the steel shell due to local buckling can be delayed and the ductility of the concrete core can be improved as a result of the confinement of the steel shell. This type of composite section may be used in various structures including frames of high rise buildings, bridges, offshore structures, cast-in-situ piles in foundation etc. Design methods for concrete-filled steel tubular sections are recommended in a number of code of practices. Due to the significant differences in the material properties between normal strength concrete and high strength concrete, there is a need to study the behaviour of composite sections with higher strength concretes. The study emphasises ultimate strength, ductility, post-failure strength reserve and interface bond. It also emphasises ductility and post-failure strength of the composite beams due to the brittle behaviour of higher strength concretes when compared to normal strength concrete. Spreadsheet graph were used to present the results such as load versus strains, load versus deflections etc. In this thesis analytical study is presented on the calculation of ultimate moment of resistance of the concrete-filled RHS beams. Among the main considerations of the derivation, the steel portion was assumed either elastic-perfectly plastic or perfectly plastic and concrete carries no strength in the tensile zone. At the interface both full bond and partial bond were assumed for comparison. Efforts were also made to calculate the midspan deflections of the composite beams. Simple analytical expressions derived from this study can be coded to a prgrammable calculator or in a small spreadsheet program for design use. Finite element studies were carried out by using a proprietorship software package ANSYS. In the analysis of concrete-filled, three types of elements with large deformation and nonlinear capabilities were used. A plastic shell element, a solid concrete element with cracking and crushing capabilities, and a nonlinear spring contact element were used to model the steel shell, the concrete core and the interface respectively.Doctor of Philosophy (PhD)
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Choi, Joonho. "Concurrent fire dynamic models and thermomechanical analysis of steel and concrete structures." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26679.
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Al-Nassrawi, Hamzah, and Grigorios Tsamis. "Global Analysis and design of a complex slanted High-Rise Building with Tube Mega Frame." Thesis, KTH, Betongbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215950.
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The need for tall buildings will increase in the future and new building techniques will emerge to full fill that need. Tyrénshas developed a new structural system called Tube Mega Frame where the major loads are transferred to the ground through big columns located in the perimeter of the building. The new concept has the advantage of eliminating the core inside the heart of the building but furthermore gives countless possibilities and flexibility for a designer. The elimination of the central core, plus the multiformity the Tube Mega Frame, can result new building shapes if combined with new inventions like the Multi elevator Thussenkrupp developed. Multi is a new elevator system with the ability to move in all directions apart from vertically. In this thesis research of the possible combinations between TMF and Multi was conducted. The building shaped resulted is only one of the many possible outcomes which the mix of Multi and TMF can have. The building was constructed in a way so the TMF would be the main structural system, the building would have inclinations so the multi elevator would be the only elevator appropriate for the structure and the height would be significantly large. The pre-study focused on the inclination and its particularities. The inclination played a significant role on how the inner forces were distributed in a structure. Under special circumstances the inclination could be even beneficial although inclination could result in axial forces on the slabs so the horizontal elements should be designed thoroughly not only for bending or shear but also for axial loading. The next phase was experimenting on different simple shaped buildings and combinations of them. The conclusions on the simple buildings formed the idea on how the main building would be. The main building was modeled using four different structural systems and their subcategories with seven models in total. Totally seven systems were compared in load combinations for wind, dead, live, and seismic loads and the global behavior was studied. The model comparison included maximum deformations and modes of vibrations. This way the best structural systems were discovered for the specific building shape and conclusions on inclination into a structure were made. The best structural systems and more reliable in terms of results but also in simplicity of construction were chosen to be designed in ETABS. The 50m belt system, the outside braces system and the diagrid system were designed. The design of the buildings was conducted using the American code ASCE /SEI 7-10. In the design two different mega columns were used to study how a solid or hollow cross section can affect the global behavior. Depending on the structural system the mega column had a major or minor effect on the stiffness of the structure. The design of the cross sections was divided in many groups since the complex geometry had an impact on how and where forces arised in the structure. The outside brace system had the best results in terms of less weight and global stiffness proving that in inclined building and columns with the correct bracing and triangulation of elements could extinguish the negative effects of inclination and even perform better compared to conventional buildings. The 50-belt system was furthermore studied in buckling since it was one of the best structural systems but with the least bracing, but also the least complex in terms of construction method. The automated buckling through ETABS was conducted and a more conservative approach where the user is defining the buckling length and support factors was used. In addition, a comparison between the user defined factors and global buckling was conducted.Behovet av höga byggnader kommer att öka i framtiden och ny byggteknik kommer att uppfylla detta behov. Tyréns har utvecklat ett nytt konstruktionssystem som kallas Tube Mega Frame där de stora lasterna överförs till marken genom stora pelare i byggnadens omkrets. Det nya konceptet har fördelen att eliminera kärnan inuti byggnadens hjärta, men ger dessutom otaliga möjligheter och flexibilitet för en konstruktör. Avlägsnandet av den centrala kärnan, plus mångfalden av Tube Mega Frame, kan resultera i nya byggnadsformer i kombination med nya uppfinningar som Multi Lift ThyssenKrupphar utvecklat. Multi är ett nytt hissystem med möjlighet att röra sig i alla riktningar bortsett från vertikalt. I denna uppsats genomfördes forskning om möjliga kombinationer med TMF och Multi. Den formgivna byggnaden är bara ett av de många möjliga resultaten som blandningen av Multi och TMF kan ha. Byggnaden byggdes på ett sätt att TMF skulle vara det huvudsakliga struktursystemet, byggnaden skulle ha lutningar så att Multi skulle vara den enda lösning som är lämplig för konstruktionen och höjden skulle vara betydligt stor. Förstudien fokuserade på lutningen och dess särdrag. Lutningen spelar en viktig roll för hur de inre krafterna fördelas i en struktur. Under speciella förhållanden kan lutningen vara till och med fördelaktig, även om lutning kan resultera i axiella krafter på plattorna så att de horisontella elementen måste utformas noggrant, inte bara för böjning eller skjuvning. Nästa fas var att experimentera på olika enkla lutande bygg former och kombinationer av dem. Slutsatserna från dessa enkla byggnaderna bildade tanken på hur huvudbyggnaden skulle vara. Huvudbyggnaden modellerades med fyra olika strukturella system och deras underkategorier med totalt sju modeller. Hela sju system jämfördes i lastkombinationer med vind last, seismisk last, egenvikt, nyttig last och det globala beteendet studerades. Modellens jämförelse inkluderade maximala deformationer och vibrationer. På detta sätt upptäcktes de bästa strukturella systemen för den specifika byggformen och slutsatser om lutning i en struktur gjordes. De bästa strukturella systemen och mer tillförlitliga vad gäller resultat men också avseende enkel konstruktion valdes att utformas i ETABS. 50 m Bältessystemet, det yttre Bäcksystemet och Diagridsystemet konstruerades. Utformningen av byggnaderna utfördes med användning av den amerikanska normen ASCE / SEI 7–10. I designen användes två olika megapelare för att studera hur en solid eller ihålig tvärsektion kunde påverka det globala beteendet. Beroende på konstruktionssystemet kunde megapelaren ha en större eller mindre effekt på strukturens styvhet. Tvärsnittens konstruktion var uppdelad i många grupper eftersom komplexa geometrin har en inverkan på hur och där krafter uppstår i strukturen. Utvändiga stödsystem hade de bästa resultaten när det gäller mindre vikt och global styvhet, vilket viste att i lutande byggnader och pelare kunde den korrekta förstärkningen och trianguleringen av element skilja de negativa effekterna av lutning och till och med fungera bättre jämfört med konventionella byggnader. 50-bältesystemet studerades vidare förknäckning, eftersom det var ett av de bästa konstruktionssystemen, men med minst fackverk, men också det minst komplexa med avseende på konstruktionsmetod. Den automatiska knäckning analysgenom ETABS genomfördes och ett mer konservativt tillvägagångssätt där användaren definierar knäcklängden och stödfaktorerna. Dessutom genomfördes en jämförelse mellan de användardefinierade faktorerna och global knäckning.
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Stanford, Kirk Alan. "STRENGTHENING OF STEEL STRUCTURES WITH HIGH MODULUS CARBON FIBER REINFORCED POLYMERS (CFRP) MATERIALS: BOND AND DEVELOPMENT LENGTH STUDY." NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-12202008-112409/.
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Cost-effective solutions for the rehabilitation and strengthening of steel structures, such as steel bridges and steel monopole towers used for cellular phone antennas, are greatly needed by government transportation departments and industry. Rehabilitation is often required due to loss of cross-section from corrosion and/or changes of the demand or use of a structure. Current techniques for strengthening steel structures have several drawbacks including requiring heavy equipment for installation, their fatigue performance, in addition to the need for ongoing maintenance due to continued corrosion attack. The current research program proposed the use of a new high modulus carbon fiber reinforced polymer (CFRP) for strengthening of steel structures. This program includes extensive research to select the resin for wet lay-up of carbon fiber sheets and the adhesives for bonding of pre-cured laminate strips. The bond behavior of FRP materials to steel structures is quite different from that of concrete structures. Preliminary test results showed the occurrence of very high bond stresses for most strengthening applications due to the amount of strengthening required for developing the material for steel structures and bridges.
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AYME, CARRIE NATHALIE. "Analyse des effets du vent sur les structures baties : constructions basses et structures elancees." Nantes, 1987. http://www.theses.fr/1987NANT2051.
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Methode de calcul d'une force statique equivalente pour representer l'action du vent sur une structure basse type (halle industrielle), avec determination de coefficients de pression dans une approche reglementaire. Pour les structures elevees, ou l'aspect dynamique est preponderant, developpement d'un logiciel a partir du modele vickery-basu (structure elancee a section circulaire); determination des parametres aerodynamiques a partir de donnees experimentales
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Chang, Lei. "Experimental Data on Fire-Resistance Behavior of Reinforced Concrete Structures with Example Calculations." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3003/.
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This thesis selects concrete, steel and their relation as research subjects, mainly commentary and discusses the property changes of steel and concrete materials under and after high temperature.The differences and comparisons of reasearch methods and ways between different researchers and different papers,particularly for chinese researches and chinese papers,and partly for comparison between chinese papers methods and Euro-Amercian papers methods about Fire Resistance Behavior of Reinforced Concrete will be summarized and analyzed.The researches on fire-resistance behavior of reinforced concrete become more and more important all over the world. And I would find differences between Chinese researches results, between Chinese researches results and other countries researches results.
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Lu, Jian. "Microstructure Evolution in 304L Stainless Steel Subjected to Hot Torsion at Elevated Temperature." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2854.
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The current study focus on investigating a relationship between processing variables and microstructure evolution mechanism in 304L stainless steel subjected to hot torsion. The Gleeble 3800 with Mobile Torsion Unit (MTU) is utilized in the current study to conduct hot torsion test of 304L stainless steel. Samples are rotated at 1100℃ in the shear strain rate range of 0.02s-1 to 4.70s-1 and the shear strain range of 0.5 to 4. Orientation imaging microscopy (OIM) technique is used to collect and analyze the microstructure. At low strains (≤1) and strain rate (0.02s-1), average grain size remains relatively constant, but the lengths of DSs and LABs increase within grains. These are characteristics of the dynamic recovery (DRV). With increasing strain and strain rate, the lengths of DSs, LABs and HABs increase, accompanied by the decrease of average grain size. Subgrains with HAB segments are observed. These are characteristics of continuous dynamic recrystallization (CDRX). At strain rates greater than or equal to 0.94s-1, the fraction of deformation texture is about 3 times higher than that of rotated cube texture. The average grain size increases relative to that at a strain rate of 0.20s-1, accompanied by the increase of twin length per area. This indicates that grain growth take place after CDRX. Sigma phase is not observed in the current study due to the lack of static recrystallization (SRX) and the higher cooling rate.
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Lopez, Samuel. "Définition de nouvelles structures de circuits magnétiques de machines AC utilisant des tôles à grains orientés." Thesis, Artois, 2011. http://www.theses.fr/2011ARTO0202/document.
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Le travail présenté porte sur la définition et le développement d’un circuit magnétique pour moteurs à haut rendement de faible et moyenne puissances. Il est réalisé avec des tôles à Grains Orientés (GO) non-segmentées. Des expérimentations réalisées en champ unidirectionnel, destinées à comparer les caractéristiques globales de la structure GO à celles obtenues sur un assemblage classique composé de tôles à grains Non-Orientés (NO), permettent de conclure quant à l’efficacité de l’association proposée en termes de pertes fer. Des investigations au niveau local, accompagnées d’une modélisation numérique, conduisent à une analyse de la répartition interne du flux magnétique dans la structure, permettant de l’optimiser. Cette technique d’assemblage est ensuite testée en champ tournant sur des moteurs statiques. Les performances obtenues, sont de nouveau comparées à celles relevées sur une maquette NO. L’étape finale consiste à tester le principe développé sur des moteurs à induction réalisés avec la configuration GO. Diverses caractéristiques sont relevées ou estimées (norme CEI) et comparées à celles de la machine NO d’origine. L’efficacité de la structure GOse traduit par une réduction notable des pertes fer, notamment statiques, conduisant à accroître sensiblement le rendement global de la machineThe work presented is focused on the design and development of a magnetic circuit for high efficiency motors of medium and small powers. It is built with non-segmented laminations of Grain Oriented (GO) steel. Experimentations on magnetic circuits excited under unidirectional magnetic field are performed. Such tests aim the comparison of the GO structure global characteristics with those of a classic one composed of Non-Oriented (NO) steel, allowing seeing the superiority of the GO structure in terms of iron losses. Local experimentations, followed by a numerical model, allow the analysis of the local distribution of the magnetic flux within the structure, leading to its optimisation. Such technique of assembly is then tested under rotational magnetic field. In that context, several experimentations are performed and its performance is compared with the one of a NO prototype. The final stage consists in testing the developed structure in induction motors built withthis GO assembly. Several characteristics are measured or estimated (IEC standard) and compared with those obtained on the initial NO motor. The GO structure efficiency leads to a remarkable reduction of the static losses, allowing the increase of the global efficiency of the motor
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Bernardi, Douglas Francescatto. "Um modelo computacional para a análise global tridimensional da estrutura de edifícios altos de concreto armado com a presença de paredes estruturais." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/25435.
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A crescente valorização das áreas disponíveis para a construção de edifícios nas grandes cidades tem constantemente elevado a altura das edificações. Nos edifícios altos, a consideração das ações horizontais na verificação da estabilidade da construção passa a ter um caráter essencial. As ações horizontais podem ser absorvidas, basicamente, por dois sistemas estruturais: por uma estrutura composta por pórticos de grande rigidez ou pela combinação de pórticos e paredes estruturais. Dentro deste contexto, esta dissertação trata da análise tridimensional de estruturas de edifícios altos de concreto armado, considerando a presença de paredes estruturais. Ao longo do trabalho é desenvolvido um modelo computacional em linguagem FORTRAN 90, baseado no Método dos Elementos Finitos, para realizar este tipo de análise. O modelo segue as recomendações da NBR6118 (ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS, 2007). Conforme esta norma, a não linearidade física é considerada de forma simplificada pela redução da rigidez dos elementos através de um fator fixo, função do nível de fissuração esperado A não linearidade geométrica, por outro lado, pode ser considerada de maneira simplificada ou de forma exata a partir de uma formulação desenvolvida por Argyris et al. (1979). No modelo analisado, foram implementados elementos de pórtico espacial para a representação de vigas e pilares, e de casca poliédrica para as paredes e lajes. Com o objetivo de se obter um sistema computacional eficiente, são utilizados recursos como a hipótese de diafragma rígido nos pavimentos e a subestruturação. Tais recursos permitem diminuir o tamanho do problema a ser resolvido, sem, no entanto, perder precisão nos resultados. O desenvolvimento do modelo computacional permitiu uma análise crítica de casos, confrontando as duas alternativas de sistemas para edifícios altos, ou seja, de pórticos com e sem paredes estruturais.The on going increase in value of available construction sites in big cities has steadily pushing up the height of new buildings. In high-rise buildings, the consideration of lateral loads when stability is verified gains an essential role. Basically, lateral loads can be carried out by two types of structural systems: by a structure composed of high-stiffness frames or by a combination of these frames and shear walls. In this context, this work focuses on 3D analyses of high-rise reinforced concrete buildings with the consideration of shear walls. A computational model based on the Finite Element Method is developed for the analyses, being the model described in detail in the text. The model follows the recommendations given in the Brazilian code NBR6118:2007. According to this code, physical nonlinearities are considered in a simplified manner by decreasing stiffnesses by a fixed factor, which depends on the expected level of cracking. Geometrical nonlinearities, on the other hand, could be considered either in a simplified manner or in an exact approach from the formulation developed by Argyris et al. (1979). In the developed model, spatial frame elements were implemented to represent beams and columns, while polyedric shells would represent shear walls and slabs. Targeting an efficient computational system, the rigid diaphragm hypothesis for the slabs as well as substructuring procedures were demanded strategies. Such means allowed smaller problem sizes to be solved without putting in jeopardy the results’ precision. It is also presented an analysis confronting the two alternatives of systems for high-rise building structures, i.e., frames with and without shear walls.
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Bradaric, Matea, and David Desimons. "Design and Analysis of a Slanted Cable-stayed Building." Thesis, KTH, Bro- och stålbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209912.
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The Tubed Mega Frame (TMF) is a structural system for high-rise building developed by Tyréns AB. Compared to conventional structural systems, the TMF is a coreless system that transfers the loads through the perimeter of the building instead and in turn enables ability to support new architectural shapes and forms of buildings. This thesis covers an initial study of a high-rise building with an unconventional shape implementing the TMF system, the Cable-stayed Building, which consists of a slanted tower with a cable-supported cantilever. The study of the building was divided in to a geometrical study and a cable study. The geometrical study was carried out to gain an initial understanding of the global structural behavior by altering specific geometrical parameters. The cable efficiency in terms of total vertical forces was investigated in the cable study by comparing different cable arrangements, cable diameters and prestressing forces for a fixed global geometry. The studies were performed under linear and nonlinear static conditions using the finite element software SAP2000 and ETABS. The results from the geometrical study showed that the cable efficiency increases in terms of larger vertical cable forces with a less inclined building and longer cantilever length. In addition, the results showed significant effects of geometric nonlinearities considering P-delta for different geometric cases. Furthermore, a study of the axial forces in the mega columns indicated that the most inclined building in which no uplifting forces and barely any tension occur along the mega columns, is the 7° incline with cantilever length 73.4 m. As abovementioned, the efficiency of the cables was compared for different arrangements, cable diameter and prestressing forces. The results indicated that as the prestressing force increases, the efficiency of cables rises more for smaller cable diameter than for larger. Furthermore, the comparison of fan- and harp-shape cable arrangements showed that the latter, including three pairs of cables, gives the highest cable efficiency relative to the amount of steel required of the cantilever bracing system. Nevertheless, the study indicates that the cable forces are inherently dependent on many parameters, such as the sag effect considered in the modulus of elasticity and the stress inducing temperature, which in turn depends on cable diameter, prestressing force and cable arrangement. To conclude the study, a modal analysis showed that the Cable-stayed Building is classified as a stiff building according to the guidelines from Council on Tall Buildings and Urban Habitat. Further research on the structure could be carried out within different areas, as this thesis is only an initial study of the structure. For instance, material nonlinearities, dynamic responses of the building as well as soil structure interaction, should be investigated further.Tubed Mega Frame (TMF) är ett bärande system för höghus utvecklat av Tyréns AB. TMF är, till skillnad från nuvarande konstruktioner, ett system utan en bärande kärna som överför laster via byggnadens perimeter istället, vilket skapar nya förutsättningar gällande arkitektoniska former på höghus. I detta projektarbete genomförs en förstudie på en byggnad med en ovanlig design, Snedkabel Byggnaden, bestående av ett lutande torn och en konsol som bärs upp av kablar. Studien är uppdelad i en geometrisk analys och en kabel analys. Den geometriska studien syftar till att få en uppfattning om hur det globala bärande systemet beter sig genom att variera vissa geometriska parametrar. Syftet med kabel studiens är att undersöka kablarnas effektivitet genom att jämföra den totala vertikala kabelkraften med olika kabelsystem, kabeldiametrar och förspänningar för en fastställd geometri av byggnaden. Statiskt linjära och ickelinjära strukturanalyser genomfördes för båda studier i finita element programmen SAP2000 och ETABS. Resultaten från den geometriska studien visade att kabel effektiviteten ökar för en mindre lutad byggnad och en längre konsol, då kabelkrafterna ökar. Dessutom indikerar resultaten anmärkningsvärda effekter vid beaktandet av ickelinjäritet med P-delta för olika globala geometrier. En undersökning av axialkrafter i pelarna visar att den mest lutade byggnaden som inte ger upphov till upplyftande krafter och knappt några dragkrafter längs pelarna är byggnaden med 7° lutning och konsollängd på 73.4 m. Som tidigare nämnt undersöktes kablarna effektivitet genom att jämföra olika kabelsystem, kabeldiametrar och förspänningar. Resultaten påvisade att med högre förspänningar, desto mer ökar kabeleffektiviteten för mindre kabeldiameter än större. Dessutom visade jämförelsen mellan solfjäder- och harp-systemet att harp-systemet med tre kabelpar ger stört kabeleffektivitet i relation till stålmassan för stagningen i konsolen. Krafterna i kablarna beror i sig till stor del av exempelvis elasticitets modulen med hänsyn till kablarnas nedböjning och den spänningsinducerande temperaturen, som i sin tur beror på kabeldiameter, förspänning och kabelsystem. Avslutningsvis utfördes en modalanalys som visade på att Snedkabel Byggnaden klassificeras som en styv byggnad enligt riktlinjer från Council on Tall Buildings and Urban Habitat. Ytterligare studier på strukturen kan genomföras inom olika områden, då detta är en förstudie på byggnaden. Exempelvis på vidare forskning är att ta hänsyn till materialens ickelinjäriteter, byggnadens dynamiska respons samt samverkan mellan byggnad och grund.
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Sheng, Risheng. "Application de l’approche de simulation des grandes échelles à l’évaluation des charges de vent sur les structures." Thesis, Ecole centrale de Nantes, 2017. http://www.theses.fr/2017ECDN0030/document.
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Des bâtiments de grande hauteur sont construits avec un poids et un amortissement structurel de plus en plus faibles en lien avec l'évolution des techniques de construction et des matériaux. La connaissance des charges de vent dynamiques est un enjeu important pour la conception des grands bâtiments afin de garantir leur sécurité structurelle. L'objectif de cette thèse est d’évaluer la capacité de la simulation numérique des grandes échelles (LES) à prédire les charges de vent sur les structures et d’étudier l'influence des conditions d’entrée d’une simulation LES sur ces charges. Des expériences ont été menées à échelle réduite dans la soufflerie atmosphérique NSA du CSTB afin de documenter l’écoulement atmosphérique modélisé, de caractériser son interaction avec un bâtiment et les charges de vent statiques et dynamiques résultantes. Le sillage du bâtiment a été caractérisé grâce à des mesures PIV. Les efforts globaux et les pressions locales ont été mesurés par une balance et des prises de pression à haute fréquence. Ces expériences en soufflerie ont permis de développer un générateur de conditions amont (GCA) pour la simulation LES, visant à reproduire les principales caractéristiques de la turbulence dans la couche limite. La base de données constituée a également permis de qualifier les résultats des simulations LES réalisées avec le code OpenFOAM dans la configuration de l’expérience. L’utilisation du nouveau GCA et d’un générateur dégradé qui ne respecte pas toutes les caractéristiques de l'écoulement a permis de montrer la nécessité de bien reproduire les caractéristiques du vent incident pour accéder aux charges dynamiques sur le bâtimentHigh-rise buildings are built with increasingly low weight and structural damping in relation to the evolution of construction techniques and materials. The understanding of dynamic wind loads is an important issue for the design of high-rise buildings in order to guarantee their structural safety. The objective of the present work is to assess the ability of large eddy simulation (LES) to predict wind loads on structures and to investigate the influence of the inflow boundary conditions of a LES simulation on these loads. Experiments were carried out at a small scale in the NSA atmospheric wind tunnel of CSTB to document the modeled atmospheric boundary layer, to characterize its interaction with a building and the resulting static and dynamic wind loads. The wake flow around the building has been characterized by PIV measurements. Global and local wind loads were measured by a high frequency force balance and high frequency pressure taps. These wind tunnel experiments allowed for the development of an inflow turbulence generator for the LES simulation,which was aimed at reproducing the main characteristics of turbulence in the boundary layer. The database also made it possible to assess the quality of the results of the LES simulations carried out with the OpenFOAM code in the same configuration as the experiment. The use of both the new turbulence generator and a degraded one that does not account for all the characteristics of the flow has made it possible to show the necessity to reproduce the characteristics of the upstream wind flow in order to access the dynamic wind loads on the building
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Lee, Trevor J. "Investigation of ASTM E 238 Bearing Pin Properties for Various Aerospace Alloys." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1074.
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Aircraft are often designed with numbers determined by testing in a lab, rather than by repeatedly building prototypes. These lab tests conform to testing specifications so that the numbers can be compared between manufacturers, suppliers, and lab technicians. One such specification is ASTM specification E238 – 84(08), and it is used to determine important properties of a bearing pin joint like hinges, bolt holes, and rivet joints. The properties determined from this fastener-through-plate method are bearing strength, bearing yield strength, and bearing stiffness.
Adhering to the methods outlined in ASTM E238, a study was performed, looking at the effects that plate material, fastener used, fastener lubrication, and plate hole preparation method (whether drilled and reamed or just drilled) have on the three bearing joint properties. The plate materials used were Al 7050 – T7451, Ti – 6Al – 4V (mill annealed), and PH13 – 8Mo – H1000. The fasteners were Ti – 6Al – 4V screws, coated A286 screws, and high speed steel (HSS) pins used as a control. Lubrication was tested using a corrosion inhibitor, PR – 1776M B – 2 from PRC – DeSoto, on the fastener or leaving the fastener uncoated. The HSS pins were always tested in the uncoated condition. 54 runs were performed, as outlined by a D-optimal design of experiment.
It was discovered from the statistical analysis of the results via ANOVA that both the plate material used and the pin material, whether a screw or a pin, had a significant effect on the bearing strength, bearing yield strength, and bearing stiffness. The interaction between the two factors was also significant on all responses but the bearing stiffness. PH13 – 8Mo – H1000 plates seemed to perform best on average, followed by Ti – 6Al – 4V plates, then Al 7050 – T7451 plates. PH13 – 8Mo – H1000 and Ti – 6Al – 4V plates had similar bearing strength and bearing yield strength averages with the HSS control pins being used, which had the highest mean values for a given plate and fastener. The Ti – 6Al – 4V and A286 screws behaved and performed statistically similar in most cases, except when hole preparation method was take into account. The Ti – 6Al – 4V screws performed better when the hole was drilled and reamed, while the coated A286 screws performed better when the hole was drilled only. All screws had lower resulting bearing properties than the HSS control pins.
It was also found that ASTM specification E238 – 84(08) is a precise test method, since the method could be performed repeatably and reliably with no missing data points. Therefore, this ASTM testing method is reasonable for determining bearing properties, which can then be used to design aircraft.
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Kalinsky, Ray. "Urban microcosm." Thesis, Virginia Polytechnic Institute and State University, 1990. http://hdl.handle.net/10919/77736.
Full textAbstract:
Over the course of time, the built environment has been a manifestation of human ideals and aspirations. Although these ideals, diverse and varied in each case, are only present in a small few of the buildings that are actually constructed, it ls my belief that they are the givers of meaning and identity to human culture and history. ln this thesis, l have created, at least on an embryonic level, an expression of my vision and dream of the coming together of human, urban life and nature.Master of Architecture
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Neal, Douglas A. "Between the experiential and intellectual." Thesis, Virginia Polytechnic Institute and State University, 1990. http://hdl.handle.net/10919/53269.
Full textAbstract:
Great architecture exists by creating an equilibrium between the experiential world and the intellectual world. On one hand these two worlds operate at polar opposites, while on the other hand these two worlds are totally dependent on one another’s existence. Through the conscious pursuit of reconciling these differences, the creation process is open to its fullest realm of possibilities and complexities. Le Corbusier used the intellectual world to gain the experiential. Although, in his later years, this process began to reverse itself. Alvaro Siza uses the experiential world to gain the intellectual. While these processes are pursued from opposite extremes, the final works reach a common goal. That goal being a complete fusion of the experiential and intellectual worlds which allows these works to procure a vital new spirit. One other case needs to be mentioned here. This being the case of Alvar Aalto. Aalto was pure genius in his understanding the significance and consequences of unifying the experiential and intellectual worlds. As a result, I believe Aalto's starting point was where the reconciliation of these two worlds occurs. By starting at this point, Aalto allowed himself the enormous freedom of reaching out simultaneously to both the experiential and intellectual worlds, extracting whatever components were necessary to create his wonderful works of art. A major objective for me is to simultaneously reconcile the experiential and intellectual worlds into a harmonious equilibrium. The moment this harmonious equilibrium occurs is the point where architecture is on the threshold of beautyMaster of Architecture
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Nilforoush, Rasoul. "Anchorage in Concrete Structures : Numerical and Experimental Evaluations of Load-Carrying Capacity of Cast-in-Place Headed Anchors and Post-Installed Adhesive Anchors." Doctoral thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-66333.
Full textAbstract:
Various anchorage systems including both cast-in-place and post-installed anchors have been developed for fastening both non-structural and structural components to concrete structures. The need for increased flexibility in the design of new structures and strengthening of existing concrete structures has led to increased use of various metallic anchors in practice. Although millions of fasteners are used each year in the construction industry around the world, knowledge of the fastening technology remains poor. In a sustainable society, buildings and structures must, from time to time, be adjusted to meet new demands. Loads on structures must, in general, be increased to comply with new demands, and the structural components and the structural connections must also be upgraded. From the structural connection point of view, the adequacy of the current fastenings for the intended increased load must be determined, and inadequate fastenings must either be replaced or upgraded. The current design models are generally believed to be conservative, although the extent of this behavior is not very clear. To address these issues, the current models must be refined to allow the design of new fastenings and also the assessment of current anchorage systems in practice. The research presented in this thesis consists of numerical and experimental studies of the load-carrying capacity of anchors in concrete structures. Two different types of anchors were studied: (I) cast-in-place headed anchors, and (II) post-installed adhesive anchors. This research focused particularly on the tensile load-carrying capacity of cast-in-place headed anchors and also on the sustained tension loading performance of post-installed adhesive anchors. The overall objective of this research was to provide knowledge for the development of improved methods of designing new fastening systems and assessing the current anchorage systems in practice. For the cast-in-place headed anchors (I), the influence of various parameters including the size of anchor head, thickness of concrete member, amount of orthogonal surface reinforcement, presence of concrete cracks, concrete compressive strength, and addition of steel fibers to concrete were studied. Among these parameters, the influence of the anchor head size, member thickness, surface reinforcement, and cracked concrete was initially evaluated via numerical analysis of headed anchors at various embedment depths. Although these parameters have considerable influence on the anchorage capacity and performance, this influence is not explicitly considered by the current design models. The numerical results showed that the tensile breakout capacity of headed anchors increases with increasing member thickness and/or increasing size of the anchor head or the use of orthogonal surface reinforcement. However, their capacity decreased considerably in cracked concrete. Based on the numerical results, the current theoretical model for the tensile breakout capacity of headed anchors was extended by incorporating several modification factors that take the influence of the investigated parameters into account. In addition, a supplementary experimental study was performed to verify the numerically obtained findings and the proposed refined model. The experimental results corresponded closely to the numerical results, both in terms of failure load and failure pattern, thereby confirming the validity of the proposed model. The validity of the model was further confirmed through experimental results reported in the literature. Additional experiments were performed to determine the influence of the concrete compressive strength and the addition of steel fiber to concrete on the anchorage capacity and performance. These experiments showed that the anchorage capacity and stiffness increase considerably with increasing concrete compressive strength, but the ductility of the anchor decreases. However, the anchorage capacity and ductility increased significantly with the addition of steel fibers to the concrete mixture. The test results also revealed that the tensile breakout capacity of headed anchors in steel fiber-reinforced concrete is significantly underestimated by the current design model. The long-term performance and creep behavior of the post-installed headed anchors (II) was evaluated from the results of long-time tests on adhesive anchors under sustained loads. In this experimental study, adhesive anchors of various sizes were subjected to various sustained load levels for up to 28 years. The anchors were also exposed to several in-service conditions including indoor temperature, variations in the outdoor temperature and humidity, wetness (i.e., water on the surface of concrete), and the presence of salt (setting accelerant) additives in the concrete. Among the tested in-service conditions, variations in the outdoor temperature and humidity had the most adverse effect on the long-term sustained loading performance of the anchors. Based on the test results, recommendations were proposed for maximum sustained load levels under various conditions. The anchors tested under indoor conditions could carry sustained loads of up to 47% of their mean ultimate short-term capacities. However, compared with these anchors, the anchors tested under outdoor conditions exhibited larger creep deformation and failure occurred at sustained loads higher than 23% of their mean ultimate short-term capacities. Salt additives in concrete and wet conditions had negligible influence on the long-term performance of the anchors, although the wet condition resulted in progressive corrosion of the steel. Based on the experimental results, the suitability of the current testing and approval provisions for qualifying adhesive anchors subjected to long-term sustained tensile loads was evaluated. The evaluations revealed that the current approval provisions are not necessarily reliable for qualifying adhesive anchors for long-term sustained loading applications. Recommendations were given for modifying the current provisions to ensure safe long-term performance of adhesive anchors under sustained loads.
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Skuhravý, František. "Železobetonová konstrukce vysoké administrativní budovy." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372283.
Full textAbstract:
Aim of The Diploma Thesis was to design load-bearing structure of a multi-storey reinforced concrete building, to realize structural analysis in Dlubal-RFEM software and dimension its selected parts. Designed structure is based on already erected building in office edifices campus in Brno-Slatina district. Its original number of storeys was increased from ten to nineteen, so the specific problems connected to high-rise building designing could be solved. Time dependent deformations of vertical structures were analysed in detail, so the changes in load of horizontal elements could be described more precisely, because of its direct dependence on compression of the columns. Within the paper, foundation structure dimensions were designed, assessment and design of composite columns assembly were made, as well of floor slab in 2nd floor with column deformations impact check on the 17th floor. Also, the external walls, pillars and shear core walls were designed and assessed. Formwork drawing of designed structure parts and detailed drawing of reinforcement of assessed elements were elaborated. Based on Diploma Thesis results it can be stated, that if influence of nonuniform load of vertical structures within the high-rise building designing is neglected, consequent project would presumably be uneconomic, or dangerous after an optimization attempts.
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Májek, Jan. "Kompaktní formy bydlení." Doctoral thesis, Vysoké učení technické v Brně. Fakulta architektury, 2012. http://www.nusl.cz/ntk/nusl-233240.
Full textAbstract:
"The compact forms of housing" is a term with which the Czech interior design yet do not often occur. This concept densely built low-rise residential files yet carries a strong potential not only in matters of mere living, but also offers one of the progressive alternative ways of living environment in general. Examined form of residential buildings is becoming increasingly important especially in specific situations where conventional housing is failing and instead generates other social problems. This thesis is primarily seeking the maximum extent available to document the issue of a compact housing, describe its basic form and point out the historical roots of this typology. The acquired knowledge was then subjected to an in-depth analysis, the output of which is to be the most comprehensive characterization researched the topic and its inclusion in the context of the standard forms of housing. The result is a set of research information, assumptions and typological bases that determine the primary urban, architectural, or social limits of the residential category. This work attempts to take into account the specified topic in the broader context of housing as a basic human need. As a result of findings would be its contribution to the culture scene in our home and create a theoretical material that would become an essential information base for creating compact residential files. The conclusions of this research can be further developed, tested and refined in the educational process at the faculties of architecture or in the practice. The results of research could stimulate interest in this type of housing and contribute to the enrichment of Czech housing scene of a synthetic form, which will form the connecting link between the typological family house and an apartment building. Low-rise housing complexes with a high population density can also create an effective counterbalance to the typical suburban development of part-time family home and offer method, respectively one of the alternative ways to be with this dilapidated urban housing estate deal.
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Rekik, Mahmoud. "Mesure et modélisation du comportement magnéto-mécanique dissipatif des matériaux ferromagnétiques à haute limite élastique sous chargement multiaxial." Thesis, Cachan, Ecole normale supérieure, 2014. http://www.theses.fr/2014DENS0019/document.
Full textAbstract:
Les travaux de recherche discutés dans ce manuscrit concernent la conception des générateurs de puissance électrique pour l'aéronautique. L’augmentation de la puissance massique de ces équipements passe par une augmentation des vitesses de rotation, donc une augmentation des contraintes. Un premier point est de s'assurer de la bonne tenue mécanique des matériaux. Un deuxième point est de pouvoir prendre en compte les modifications du comportement magnétique (et donc in fine du couple) lorsqu'ils sont soumis à un état de contraintes multiaxial. L’étude présentée vise en particulier à illustrer l’influence d'états de contraintes biaxiaux sur le comportement magnétique des matériaux constitutifs du rotor. Le défi repose sur la mise en place de méthodes de caractérisation du comportement magnéto-mécanique dissipatif uniaxial et multiaxial des nuances développées par Aperam et utilisées par Thales Avionics pour leurs applications aéronautiques (en FeCo-2V et Fe-3%Si à grains non orientés). Des essais non conventionnels seront effectués sur des échantillons en forme de croix de manière à s'approcher des contraintes réellement subies par le rotor. Les essais sont effectués sur la machine d'essai triaxiale Astrée du LMT-Cachan. L'état de contraintes est estimé par corrélation d'images et par diffraction des rayons X. Des mesures magnétiques anhystérétiques et de pertes d'énergie sous contraintes sont reportées. D'autre part, un modèle multi-échelle multiaxial, décrivant le comportement d’un VER à partir de l'équilibre énergétique à l'échelle microscopique sera présenté. L’approche est fondée sur la comparaison des énergies libres de chaque domaine. Une comparaison probabiliste est faite pour déterminer les variables internes que sont les fractions volumiques des domaines. Différentes stratégies envisageables pour modéliser la dissipation statique seront discutées. Puis nous présentons l’approche magnéto-élastique que nous avons retenue visant à une meilleure considération de l’effet de la contrainte sur le comportement des matériaux ferromagnétiquesThe research presented in this thesis is motivated by the design of rotors for high speed rotating machines. The increased power density of these devices requires a higher rotation speed, leading to higher levels of centrifugal forces and stress in the rotor. A first point is to ensure good mechanical strength of the materials. A second point is to take into account changes in the magnetic behavior (and ultimately torque) when they are subjected to a multiaxial stress state. The present study aims at exploring the influence of biaxial stress states on the magnetic behavior of the materials of the rotor. The challenge lies in the development of methods for the characterization of the magneto-mechanical dissipative uniaxial and multiaxial behavior of metal sheets developed by Aperam Alloy and used by Thales Avionics for their aeronautical applications (in FeCo-2V and non-oriented Fe-3%Si). Non conventional experiments are performed on cross-shaped samples in order to apply biaxial stress representative of the loadings experienced by rotors of rotating machines. These experiments are performed on a multiaxial testing machine, Astrée. Stress level is estimated thanks to digital image correlation and X-ray diffraction Both anhysteretic and dissipative magnetic responses to magneto-mechanical loadings have been recorded. On the other hand, a multi-scale multiaxial model describing the behavior of a RVE from the energy balance at the microscopic scale is presented. The approach is based on a comparison of the free energy of each domain. A probabilistic comparison is made to determine the volume fraction of domains used as internal variables. Different strategies for modeling the static dissipation are discussed. Then we present the chosen magneto-elastic approach, improving the description of the effect of stress on ferromagnetic materials behavior
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Stephen, D., J. Ye, and Dennis Lam. "Progressive Collapse Evaluation of High Rise Steel Structures due to Sudden Loss of Structural Members." 2012. http://hdl.handle.net/10454/5602.
Full textAbstract:
NoDamage or instantaneous loss of critical structural members due to unforeseen events like impact, blast and natural disasters often propagates progressive collapse as a result of complex redistribution of stresses within the structural system. In severe conditions, in which the structure lacks the ability to absorb the stresses in seeking a new equilibrium state, it could result in partial or total collapse of the building. Current design guidelines such as GSA 2003 recommend single removal of load bearing member for progressive collapse assessment. However, triggering events may affect one or more structural member resulting in partial or total collapse of the structure. This paper presents the various effect of sudden column loss on the redistribution of forces in structural members that determine the equilibrium state of the structure.
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Tseng, Wei-Hsuan, and 曾暐琁. "Load Ratio of Concrete-filled Steel Box Columns in Medium- and High-rise Building Structures." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/88615972863118101642.
Full textAbstract:
碩士國立交通大學
土木工程系所
104
This study aims to investigate the axial load ratio, moment ratio, and load ratio of concrete-filled steel box columns in service conditions while the columns were designed to satisfy domestic seismic design specifications. Moreover, the fire resistance of the concrete-filled steel box columns was also studied based on their load ratios. Axial load ratio, moment ratio, and load ratio were the ratios of service axial compression, service moment, and the interaction of axial compression and moment to column’s ultimate strengths, respectively. With concrete-filled steel box columns, two steel reinforced concrete (SRC) medium- and high-rise buildings, 12- and 21-story, were modeled using commercial structural analysis software. Based on their locations, columns can be classified into corner column, long edge column, short edge column and interior column. Analysis results demonstrated that, in service conditions, all axial load ratios of concrete-filled steel box columns in both buildings were less than 0.3. The higher floor the columns located at, the lower the axial load ratios were. Generally, the axial load ratio of long edge and interior columns were higher than those of short edge and corner columns. Literature showed that the fire resistance of concrete-filled steel box columns mainly influenced by the axial load but not moment. Neglecting the effect of the moment and without fireproofing, the concrete-filled steel box columns can satisfy the one hour fire-rated requirement of Building Technical Regulations. Nevertheless, only short edge columns could achieve the two hours fire-rated requirement. The span of the buildings is the main cause to affect the moment ratio of the concrete-filled steel box columns. The load ratios of concrete-filled steel box columns were not larger than 0.4 in the 12-story building and less than 0.3 in the 21-story building. The analysis of the two buildings indicated that the ratios of service load to ultimate strength of concrete-filled steel box columns are small due to the consideration of seismic design.
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Chou, Chien-Lung, and 周建龍. "Structural Analysis and Design of Irregular High Rise Steel Building." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/23336940436112601479.
Full textAbstract:
碩士淡江大學
土木工程學系
87
Since land cost in city is expensive today owing to the population concentration in the urban area, more high-rise buildings are developed recently. In order to reduce the weight of structure and the construction period, those buildings higher than 20 stories are usually built by steel structure. Moreover, with the characteristics of high safety, construction convenience and well development of construction and design related regulations, the high-rise buildings thereby turn out to be the main trend currently. In general, the analysis and the design of irregular structure are more difficult since they always embody complicated characteristics. The main purpose of this paper is to investigate those characteristics and to analyze the main and sub-building structures of these irregular high-rise buildings by following those methods applied traditionally by engineers. The framework of this study is as below: (1)introduce the classifications of structure systems and their layout restrictions, and check the layout, height-to-width ratio and foundation depth of example structure, (2)develop the ETABS model, and execute quasi-static and spectrum analysis according to the building code, and check the lateral story drift and rigidity ratio due to seismic and wind loading, (3) design the beam, column, brace, and connections of semi-rigid moment resistant frame (SMRF) and eccentrically braced frame for the buildings, (4)design the beam and column of reinforced concrete (RC) and steel reinforced concrete (SRC) for the underground structures, (5)propose the reasonable design procedures after comparing the natural frequencies, story shear, and member forces of different types of modeling such as brace, rigidity ratio, secondary moment, rigidity zone reduction or flexible diaphragm.
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林豪. "Study on managing the engineering quality and quality cost under the most advantageous tender:lllustrated by steel frame structure in high-rise steek buildings." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/70290628504340502418.
Full textAbstract:
碩士國立臺灣科技大學
營建工程系
90
ABSTRACT This master’s thesis is a study on managing the engineering quality and quality cost under the most advantageous tender with an illustration of steel frame structures in high-rise buildings. The topics of discussion include the historical process in the awarding of contracts, the lowest tender, the reasonable tender and the most advantageous tender (the advantages and disadvantages of these three types of awarding of contracts), the mechanism for the most advantageous tender to assess the best bidder among contractors, construction quality assessment system (CONQUAS), engineering quality management system, engineering cost and quality cost control, etc. This study also presents the critical items for the engineering quality and cost control in steel structure buildings. By using three completed high-rise steel buildings for case studies, this study analyzes the critical items for cost control, and the task, control, inspecting items and standard of control operation. Finally, by using an on-going high-rise steel building construction with the most advantageous tender as an example, and using the questionnaires for obtaining the quality control, inspecting items and their costs, this study makes a very detailed analysis for the quality and quality cost in steel frame structures. The most cost-efficient items for quality control are then selected and formulated with a table of detailed items for steel frame structures. The conclusions of this study are: 1. This study concludes the frame work and implementation procedure for the most advantageous tender to achieve the management of engineering quality and quality cost, which, in turn, can be utilized as a reference for the assessment stage of bidding with the most advantage tender and the construction stage for the quality control operation. 2. Among the three types of awarding of contracts, the most advantageous tender is the best way to achieve the engineering quality and quality cost managements in the steel frame structure of high-rise steel buildings. 3. The steel frame structure is the most important issue among the various subjects related to the management of engineering quality and quality cost for high-rise steel buildings. 4. The costs of material of the steel frame and steel manufacturing process are two of the six main items in the management of quality cost for steel frame structures. 5. Among 59 management items in steel frame structures, seven most cost-efficient items for quality cost are the tensile test and hardness test for the anchor bolt and the high-strength bolt, the material property test of steel decking, the tests of density, adhesion and compressive strength for the adhesive fire-resistive materials, etc. 6. The table of detailed items for assessing quality cost in steel frame structures can be served as a basis for search members to assess the most advantageous tender. It also can be used as a reference for the client and construction supervisor to evaluate the engineering quality of steel frame structures for contractors during the construction stage with regular inspection, measurement and calculation of construction fee on these items for quality control.