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1
Liu, Jinbiao. "Earthquake analysis of steel moment resisting frame structures". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ27000.pdf.
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2
Metin, Asli. "Inelastic Deformation Demands On Moment-resisting Frame Structures". Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607423/index.pdf.
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Interstory drift ratio is an important parameter for the determination of the structural performance under strong ground motions. A probabilistic procedure is proposed in this study to estimate the inelastic maximum interstory drift ratio. The procedure considers the uncertainties associated with the strong ground motions and structural behavior. Elastic and inelastic response history analyses of reinforced-concrete, moment-resisting frames are used together with a near-fault strong ground motion data set to derive the probabilistic procedure. The elastic and inelastic response history analysis results are evaluated in a statistical manner to present the probabilistic approach proposed here. The method presented basically makes use of the fundamental mode properties of the frame systems and modifies the elastic maximum interstory drift ratio by a modifying factor that is determined from the idealized lateral strength capacity (pushover analysis) of the structure. As a part of this thesis, the performance of recently improved nonlinear static procedures that are used in estimating the deformation demands on structural systems are also evaluated using the single- and multi-degree-of-freedom response history analyses results obtained during the conduct of the study.
3
Parsa, Amanullah. "EFFECT OF BUILDING ORIENTATION ON STRUCTURAL RESPONSE OF REINFORCED CONCRETE MOMENT RESISTING FRAME STRUCTURES". OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2698.
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In time history analysis of structures, the geometric mean of two orthogonal horizontal components of ground motion in the as-recorded direction of sensors, have been used as measure of ground motion intensity prior to the 2009 NEHRP provision. The 2009 NEHRP Provisions and accordingly the seismic design provisions of the ASCE/SEI 7-10, modified the definition of ground motion intensity measure from geometric mean to the maximum direction ground motion, corresponding to the direction that results in peak response of the oscillator. Maximum direction response spectra are assumed to envelope the range of maximum possible responses over all nonredundant rotation angles. Two assumptions are made in the use maximum ground motion as the intensity measure: (1) the structure’s strength and stiffness properties are identical in all directions and (2) azimuth of the maximum spectral acceleration coincides with the one of the principal axes of the structure. The implications of these assumptions are examined in this study, using 3D computer models of multi-story structures having symmetric and asymmetric layouts and elastic vibration period of 0.2 second and 1.0 second subjected to a set of 25 ground-motion pairs recorded at a distance of more than 20 km from the fault. The influence of the ground-motion rotation angle on structural response (here lateral displacement and story drift) is examined to form benchmarks for evaluating the use of the maximum direction (MD) ground motions. The results of this study suggest that while MD ground motions do not always result in largest structural response, they tend to produce larger response than the as-recorded ground motions. On the other hand, more research on non-linear seismic time history analysis is recommended, especially for asymmetric layout plan buildings.
4
梁少江 i Siu-kong Leung. "Analysis of shear/core wall structures using a linear moment beam-typeelement". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31213352.
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5
Leung, Siu-kong. "Analysis of shear/core wall structures using a linear moment beam-type element /". Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18155376.
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6
Emidio, Fernando. "Analysis of multidimensional radiating structures by the spatial Fourier transform and computational electromagnetics". Thesis, Saint-Etienne, 2013. http://www.theses.fr/2013STET4011.
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Ce manuscrit présente les travaux de recherche qui concernent l'analyse et la synthèse de structures rayonnantes multidimensionnelles en utilisant une approche qui combine méthode des moments et la transformée de Fourier spatiale. La distribution source (courant électrique) et le diagramme de rayonnement sont liées par la transformée de Fourier spatiale - la théorie de la Relation de Fourier (FR). La distribution des courants est déterminée en utilisant une méthode d'analyse en électromagnétisme (EM), à savoir la Méthode des Moments (MoM). Des travaux antérieurs utilisant la théorie FR ont été réalisés par d'autres auteurs sur des réseaux linéaires - uniformément espacés ou non uniformes. Les sources radiantes élémentaires des dipoles électriques filaires. Les travaux actuels se développent en utilisant la théorie FR à deux et trois dimensions sur des structures réelles. En utilisant la méthode MoM nous pouvons prendre en compte le rayon du fil, sur n'importe quel point d'excitation (générateur de tension ou onde incidente) et le couplage mutuel entre les éléments, créant ainsi un modèle électromagnétique réaliste pour la structure d'antenneThis manuscript presents the research work in the analysis and synthesis of multidimensional radiating structures using an approach that combines Method of Moments and Spatial Fourier Transform. The source distribution (electric current) and radiation pattern are related by the spatial Fourier Transform - Fourier Relation theory (FR). Current distribution is determined using Computational Electromagnetics (CEM), namely Method of Moments (MoM). Previous work using FR theory was done by other authors on linear arrays – uniformly or nonuniformly spaced elemental radiators laid on a straight line. Present work expands FR theory to two and three dimensions on real-world structures. By using MoM we can take into account wire radius, excitation on any point (voltage generator or incident wave) and mutual coupling between elements, thus creating a realistic electromagnetic model for the antenna structure
7
Liu, Jinbiao Carleton University Dissertation Engineering Civil and Environmental. "Earthquake analysis of steel moment resisting frame structure". Ottawa, 1997.
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8
Kruep, Stephanie Jean. "Using Incremental Dynamic Analysis to Visualize the Effects of Viscous Fluid Dampers on Steel Moment Frame Drift". Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/34122.
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This thesis presents the details of a study regarding both the use of linear viscous fluid dampers in controlling the interstory drift in steel moment frames, and the use of incremental dynamic analysis as a method of visualizing the behavior of these moment frames when subjected to seismic load effects. Models of three story and nine story steel moment frames were designed to meet typical strength requirements for office buildings in Seattle, Washington. These models were intentionally designed to violate seismic interstory drift restrictions to test the ability of the linear viscous fluid dampers to reduce these drifts to the point of code compliance. Dampers were included in one bay of every story in each model. These devices were used to produce total structural damping ratios of 5%, 10%, 20%, and 30% of critical. Undamped, traditional stiffness controlled models of both three stories and nine stories were also created for comparison purposes. Incremental dynamic analysis was used to subject these models to ten ground motions, each scaled to twenty incremental levels. Two new computer applications were written to facilitate this process. The results of these analyses were studied to determine if the linear viscous fluid dampers were able to cause compliance with codified drift limits. Also, incremental dynamic analysis plots were created to examine the effects of the dampers on structural behavior as damping increased from inherent to 30% of critical. It was found that including linear viscous fluid dampers in steel moment frame design can satisfactorily control interstory drift, and incremental dynamic analysis is a beneficial tool in visualizing dynamic structural behavior.Master of Science
9
Lan, Shuang Wen. "Stochastic finite element analysis of structures with elementary stiffness matrix decomposition method and exponential polynomial moment method". Thesis, University of Macau, 2010. http://umaclib3.umac.mo/record=b2148241.
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10
Gudu, Tamer. "Analysis And Design Of Microstrip Printed Structures On Electromagnetic Bandgap Substrates". Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609417/index.pdf.
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In the first part of the thesis, the 2-D structures in stratified media are analyzed using an efficient MoM technique. The method is used to optimize transmitted or reflected electric fields from the 2-D structures. The genetic algorithm is used in the optimization process. In the second part a 3-D MoM technique is implemented to analyze multilayered structures with periodically implanted material blocks. Using the method, the dispersion and reflection characteristics of the structure are calculated for different configurations. The results are compared with the results found in the literature and it is seen that they are in good agreement. Asymptotic Waveform Evaluation (AWE) technique is utilized to obtain the Pade approximation of the solution in terms of frequency. The high order derivatives that are required by the AWE technique are calculated through Automatic Differentiation technique. Using the AWE method, the dispersion diagram and reflection characteristics of the periodic structures are obtained in a shorter time. The results are compared with the ones obtained through direct calculation and it is seen that they are in perfect agreement. The reflection coefficients that are obtained from the 3-D MoM procedure are used to calculate Green&rsquos functions that approximate electric field of an infinitesimal dipole on the periodically implanted substrate. Using the calculated Green&rsquo
s functions and the spectral domain MoM procedure, dispersion characteristics of a microstrip line on the periodically implanted substrate are obtained.
11
Beck, Paul. "Quantitative damage assessment of concrete structures using Acoustic Emission". Thesis, Cardiff University, 2004. http://orca.cf.ac.uk/54656/.
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This thesis examines the role of Acoustic Emission (AE) as a non-destructive testing technique for concrete structures. The work focuses on the development of experimental techniques and data analysis methods for the detection, location and assessment of AE from the failure of plain and reinforced concrete specimens. Four key topics are investigated:
12
Olmez, Harun Deniz. "A Numerical Study On Special Truss Moment Frames". Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12611322/index.pdf.
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A three-phase numerical study was undertaken to address some design issues related with special truss moment frames (STMFs). In the first phase, the design approaches for distribution of shear strength among stories were examined. Multistory STMFs sized based on elastic and inelastic behavior were evaluated from a performance point of view. A set of time history analysis was conducted to investigate performance parameters such as the interstory drift ratio and the plastic rotation at chord member ends. The results of the analysis reveal that the maximum interstory drifts are not significantly influenced by the adopted design philosophy while considerable differences are observed for plastic rotations. In the second phase, the expected shear strength at vierendeel openings was studied through three dimensional finite element modeling. The results from finite element analysis reveal that the expected shear strength formulation presented in the AISC Seismic Provisions for Structural Steel Buildings is overly conservative. Based on the analysis results, an expected shear strength formula was developed and is presented herein. In the third phase, the effects of the load share and slenderness of X-diagonals in the special segment on the performance of the system were evaluated. Lateral drift, curvature at chord member ends, axial strain at X-diagonals and base shear were the investigated parameters obtained from a set of time history analysis. The results illustrate that as the load share of X-diagonals increases, the deformations decreases. Moreover, the slenderness of X-diagonals is not significantly effective on
the system performance.
13
Haselton, Curt B. Deierlein Gregory G. "Assessing seismic collapse safety of modern reinforced concrete moment-frame buildings". Berkeley, Calif. : Pacific Earthquake Engineering Research Center, 2008. http://nisee.berkeley.edu/elibrary/Text/200803261.
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14
Hotz, Carl. "MOMENT REDUCTION ANALYSIS OF BUILT-UP I-SECTION EXPOSED TO UNIFORM CORROSION". University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1525293365942438.
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15
Tuna, Mehmet. "Inelastic Panel Zone Deformation Demands In Steel Moment Resisting Frames". Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614329/index.pdf.
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Panel zone is one of the significant parts of beam-column connections in steel structures. Until the 1994 Northridge Earthquake, a few experimental research and parametric studies had been carried out to understand the behavior of the panel zones. However, after the Northridge Earthquake, it was observed that beam-column connections were unable to show presumed seismic performance. Therefore, current design codes needed to be revised to improve seismic performance of connections in general and panel zones in particular. In this research, panel zone deformation demands are examined using explicit three dimensional finite element models and considering different parameters. For this purpose, a frame model with two different beam-column configurations was developed in order to observe the effects of beam depth, the axial load level and the level of seismicity. The frame models were analyzed under twenty different ground motion records. Local strain demands at the panel zones as well as the global frame deformation demands are evaluated. Analysis results revealed that AISC Specification designs allowed panel zone yieldinghowever, panel zones designed according to FEMA 355D showed minimal yielding for both shallow and deep beam configurations. Based on the analysis results, local shear strain demands in panel zones were expressed as a function of interstory drifts and normalized panel zone thicknesses.
16
Williamson, Conner F. F. "SEISMIC PERFORMANCE OF SYMMETRIC STEEL MOMENT FRAMES WITH RANDOM REACTIVE WEIGHT DISTRIBUTIONS". DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/890.
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When a structure undergoes seismic excitation, the intensities and spatial distributions of the reactive weights on the structure may not be the same as those assumed in original design. Such a difference is inevitable due to many facts with the random nature (e.g., redistribution of live load), resulting in accidental eccentricity and consequently torsional response in the system. The added torsion can cause excessive deformation and premature failure of the lateral force resisting system and its detrimental effect is typically accounted for in most building design codes with an arbitrarily specified accidental eccentricity value. While it tends to amplify drift response of buildings under earthquake excitations, it is unclear whether the code specified accidental eccentricity is quantitatively adequate or not in seismic fragility assessment of steel moment frames (including low-rise, mid-rise and high-rise frames) with random reactive weight distributions. This thesis applies surveyed dead and live load intensities and distributions to three representative steel moment resisting frame structures that have been widely investigated in a series of projects under the collaboration of the Structural Engineers Association of California (SEAOC), the Applied Technology Council (ATC), and Consortium of Universities for Research in Earthquake Engineering (CUREE), known as SAC. Based on an extensive parametric study and incremental nonlinear dynamic analyses, it is found that variable load intensity and eccentricity had negligible impacts on the inter-story drifts of the low- and high-rise steel moment frames. However, they affect to a higher degree the performance of the mid-rise steel moment frames. Moreover, it is found that under the maximum considered earthquake (MCE) event, the actual drifts in steel moment frames with random reactive weight distributions can be conservatively captured through consideration of the code specified accidental eccentricities.
17
Maurya, Abhilasha. "Experimental and Computational Investigation of a Self-Centering Beam Moment Frame (SCB-MF)". Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/70866.
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In the past two decades, there have been significant advances in the development of self-centering (SC) seismic force resisting systems. However, examples of SC systems used in practice are limited due to unusual field construction practices, high initial cost premiums and deformation incompatibility with the gravity framing. A self-centering beam moment frame (SCB-MF) has been developed that virtually eliminates residual drifts and concentrates the majority of structural damage in replaceable fuse elements. The SCB consists of a I-shaped steel beam augmented with a restoring force mechanism attached to the bottom flange and can be shop fabricated. Additionally, the SCB has been designed to eliminate the deformation incompatibility associated with the self-centering mechanism.
The SCB-MF system is investigated and developed through analytical, computational, and experimental means. The first phase of the work involves the development of the SCB concepts and the experimental program on five two-thirds scale SCB specimens. Key parameters were varied to investigate their effect on global system hysteretic response and their effect on system components. These large-scale experiments validated the performance of the system, allowed the investigation of detailing and construction methods, provided information on the behavior of the individual components of the system. The experimental results also provided data to confirm and calibrate computational models that can capable of capturing the salient features of the SCB-MF response on global and component level.
As a part of the second phase, a set of archetype buildings was designed using the self-centering beam moment frame (SCB-MF) to conduct a non-linear response history study. The study was conducted on a set of 9 archetype buildings. Four, twelve and twenty story frames, each with three levels of self-centering ratios representing partial and fully self-centering systems, were subjected to 44 ground motions scaled to two hazard levels. This study evaluated the performance of SCB-MFs in multi-story structures and investigated the probabilities of reaching limit states for earthquake events with varying recurrence period.
The experimental and computational studies described in this dissertation demonstrate that the SCB-MF for steel-framed buildings can satisfy the performance goals of virtually eliminating residual drift and concentrating structural damage in replaceable fuses even during large earthquakes.Ph. D.
18
O'Connor, Mark Anthony. "The prediction of moment-rotation curves of extended endplate connections for use in semi-rigid analysis of steel frameworks". Thesis, City University London, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304590.
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19
Jacobucci, Cody. "Automating structural stress analysis : beam deflection, shear, and moment diagram generator for single and multi-span beams". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112575.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (page 87).
A new tool has been developed with Aurora Flight Sciences to automate stress analysis of beams under loading. It is a Microsoft Excel based tool to be consistent with Aurora's other analysis tools and analyst preference, and is coded in Visual Basic. The tool can generate the shear, moment, and deflection diagram of a single span or multi-span beam in less than 10 seconds for any combination of edge constraints and applied loads, as well as output the reaction force at each support. The tool can also analyze beams that change material or shape after reaching a support to account for changes in longer beams across the airframe.
by Cody Jacobucci.
S.B.
20
Hu, Jong Wan. "Seismic performance evaluations and analyses for composite moment frames with smart SMA PR-CFT connections". Diss., Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22655.
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This thesis investigates the performance of composite frame structures with smart
partially-restrained (PR) concrete filled tube (CFT) column connections through
simplified 2D and advanced 3D computational simulations. It also provides a design
methodology for new types of innovative connections based on achieving a beam hinging
mechanism. These types of connections intend to utilize the recentering properties of
super-elastic SMA tension bars, the energy dissipation capacity of low-carbon steel bars,
and the robustness of CFT columns.
In the first part of this study, three different PR-CFT connection prototypes were
designed based on a hierarchy of strength models for each connection component.
Numerical simulations with refined three dimensional (3D) solid elements were
conducted on full scale PR-CFT connection models in order to verify the strength models
and evaluate the system performance under static loading. Based on system information
obtained from these analyses, simplified connection models were formulated by replacing
the individual connection components with spring elements and condensing their
contributions. Connection behavior under cyclic loads was extrapolated and then
compared with the monotonic behavior.
In the second part of this study, the application of these connections to low-rise
composite frames was illustrated by designing both 2D and 3D, 4 and 6 story buildings
for the Los Angeles region. A total of 36 frames were studied. Pushover curves plotted
as the normalized shear force versus inter story drift ratio (ISDR) showed significant
transition points: elastic range or proportional limit, full yielding of the cross-section,
strength hardening, ultimate strength, and strength degradation or stability limit. Based
on the transition points in the monotonic pushover curves, three performance levels were
defined: Design Point, Yield Point, and Ultimate Point. All frames were stable up to the
yield point level. For all fames, after reaching the ultimate point, plastic rotation
increased significantly and concentrated on the lower levels. These observations were
quantified through the use of elastic strength ratios and inelastic curvature ductility ratios.
The composite frames showed superior performance over traditional welded ones in
terms of ductility and stability, and validated the premises of this research.
21
Lau, S. M. "3D hydrodynamic analysis of first and second order forces on free floating structures with forward speed". Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378314.
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22
Kurniawan, Cyrilus Winatama. "Flexural behaviour and design of the new LiteSteel beams". Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16674/1/Cyrilus_Kurniawan_Thesis.pdf.
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The flexural capacity of the new hollow flange steel section known as LiteSteel beam (LSB) is limited by lateral distortional buckling for intermediate spans, which is characterised by simultaneous lateral deflection, twist and web distortion. Recent research based on finite element analysis and testing has developed design rules for the member capacity of LiteSteel beams subject to this unique lateral distortional buckling. These design rules are limited to a uniform bending moment distribution. However, uniform bending moment conditions rarely exist in practice despite being considered as the worst case due to uniform yielding across the span. Loading position or load height is also known to have significant effects on the lateral buckling strength of beams. Therefore it is important to include the effects of these loading conditions in the assessment of LSB member capacities.
Many steel design codes have adopted equivalent uniform moment distribution and load height factors for this purpose. But they were derived mostly based on data for conventional hot-rolled, doubly symmetric I-beams subject to lateral torsional buckling. In contrast LSBs are made of high strength steel and have a unique crosssection with specific residual stresses and geometrical imperfections along with a unique lateral distortional buckling mode. The moment distribution and load height effects for LSBs, and the suitability of the current steel design code methods to accommodate these effects for LSBs are not yet known. The research study presented in this thesis was therefore undertaken to investigate the effects of nonuniform moment distribution and load height on the lateral buckling strength of simply supported and cantilever LSBs.
Finite element analyses of LSBs subject to lateral buckling formed the main component of this study. As the first step the original finite element model used to develop the current LSB design rules for uniform moment was improved to eliminate some of the modelling inaccuracies. The modified finite element model was validated using the elastic buckling analysis results from well established finite strip analysis programs. It was used to review the current LSB design curve for uniform moment distribution, based on which appropriate recommendations were made.
The modified finite element model was further modified to simulate various loading and support configurations and used to investigate the effects of many commonly used moment distributions and load height for both simply supported and cantilever LSBs. The results were compared with the predictions based on the current steel code design rules. Based on these comparisons, appropriate recommendations were made on the suitability of the current steel code design methods. New design recommendations were made for LSBs subjected to non-uniform moment distributions and varying load positions. A number of LSB experiments was also undertaken to confirm the results of finite element analysis study.
In summary the research reported in this thesis has developed an improved finite element model that can be used to investigate the buckling behaviour of LSBs for the purpose of developing design rules. It has increased the understanding and knowledge of simply supported and cantilever LSBs subject to non-uniform moment distributions and load height effects. Finally it has proposed suitable design rules for LSBs in the form of equations and factors within the current steel code design provisions. All of these advances have thus further enhanced the economical and safe design of LSBs.
23
Kurniawan, Cyrilus Winatama. "Flexural behaviour and design of the new LiteSteel beams". Queensland University of Technology, 2007. http://eprints.qut.edu.au/16674/.
Pełny tekst źródłaStreszczenie:
The flexural capacity of the new hollow flange steel section known as LiteSteel beam (LSB) is limited by lateral distortional buckling for intermediate spans, which is characterised by simultaneous lateral deflection, twist and web distortion. Recent research based on finite element analysis and testing has developed design rules for the member capacity of LiteSteel beams subject to this unique lateral distortional buckling. These design rules are limited to a uniform bending moment distribution. However, uniform bending moment conditions rarely exist in practice despite being considered as the worst case due to uniform yielding across the span. Loading position or load height is also known to have significant effects on the lateral buckling strength of beams. Therefore it is important to include the effects of these loading conditions in the assessment of LSB member capacities. Many steel design codes have adopted equivalent uniform moment distribution and load height factors for this purpose. But they were derived mostly based on data for conventional hot-rolled, doubly symmetric I-beams subject to lateral torsional buckling. In contrast LSBs are made of high strength steel and have a unique crosssection with specific residual stresses and geometrical imperfections along with a unique lateral distortional buckling mode. The moment distribution and load height effects for LSBs, and the suitability of the current steel design code methods to accommodate these effects for LSBs are not yet known. The research study presented in this thesis was therefore undertaken to investigate the effects of nonuniform moment distribution and load height on the lateral buckling strength of simply supported and cantilever LSBs. Finite element analyses of LSBs subject to lateral buckling formed the main component of this study. As the first step the original finite element model used to develop the current LSB design rules for uniform moment was improved to eliminate some of the modelling inaccuracies. The modified finite element model was validated using the elastic buckling analysis results from well established finite strip analysis programs. It was used to review the current LSB design curve for uniform moment distribution, based on which appropriate recommendations were made. The modified finite element model was further modified to simulate various loading and support configurations and used to investigate the effects of many commonly used moment distributions and load height for both simply supported and cantilever LSBs. The results were compared with the predictions based on the current steel code design rules. Based on these comparisons, appropriate recommendations were made on the suitability of the current steel code design methods. New design recommendations were made for LSBs subjected to non-uniform moment distributions and varying load positions. A number of LSB experiments was also undertaken to confirm the results of finite element analysis study. In summary the research reported in this thesis has developed an improved finite element model that can be used to investigate the buckling behaviour of LSBs for the purpose of developing design rules. It has increased the understanding and knowledge of simply supported and cantilever LSBs subject to non-uniform moment distributions and load height effects. Finally it has proposed suitable design rules for LSBs in the form of equations and factors within the current steel code design provisions. All of these advances have thus further enhanced the economical and safe design of LSBs.
24
Judd, Johnn P. "Multi-hazard performance of steel moment frame buildings with collapse prevention systems in the central and eastern United States". Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/73509.
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This dissertation discusses the potential for using a conventional main lateral-force resisting system, combined with the reserve strength in the gravity framing, and or auxiliary collapse-inhibiting mechanisms deployed throughout the building, or enhanced shear tab connections, to provide adequate serviceability performance and collapse safety for seismic and wind hazards in the central and eastern United States. While the proposed concept is likely applicable to building structures of all materials, the focus of this study is on structural steel-frame buildings using either non-ductile moment frames with fully-restrained flange welded connections not specifically detailed for seismic resistance, or ductile moment frames with reduced beam section connections designed for moderate seismic demands.
The research shows that collapse prevention systems were effective at reducing the conditional probability of seismic collapse during Maximum Considered Earthquake (MCE) level ground motions, and at lowering the seismic and wind collapse risk of a building with moment frames not specifically detailed for seismic resistance. Reserve lateral strength in gravity framing, including the shear tab connections was a significant factor. The pattern of collapse prevention component failure depended on the type of loading, archetype building, and type of collapse prevention system, but most story collapse mechanisms formed in the lower stories of the building. Collapse prevention devices usually did not change the story failure mechanism of the building. Collapse prevention systems with energy dissipation devices contributed to a significant reduction in both repair cost and downtime. Resilience contour plots showed that reserve lateral strength in the gravity framing was effective at reducing recovery time, but less effective at reducing the associated economic losses. A conventional lateral force resisting system or a collapse prevention system with a highly ductile moment frame would be required for regions of higher seismicity or exposed to high hurricane wind speeds, but buildings with collapse prevention systems were adequate for many regions in the central and eastern United States.Ph. D.
25
Fontes, Fernando Fernandes. "Análise estrutural de elementos lineares segundo a NBR 6118:2003". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-14072006-110932/.
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O objetivo da análise estrutural é determinar os efeitos das ações em uma estrutura, com a finalidade de efetuar verificações de estados limites últimos e de serviço (NBR 6118:2003 Projeto de estruturas de concreto). A análise estrutural consiste numa das principais etapas do projeto estrutural de um edifício, pois compreende a escolha dos modelos teóricos, que devem representar adequadamente a estrutura real, e do tipo de análise, com relação ao comportamento dos materiais. Visa-se, com este trabalho, aproximar o meio técnico do acadêmico, e tornar mais acessível a parte da NBR 6118:2003 que trata da análise estrutural. Neste trabalho consideram-se os modelos estruturais mais utilizados, no cálculo de edifícios, e os principais conceitos relativos aos diferentes tipos de análise permitidos pela norma. Em seguida são realizados exemplos de elementos lineares, pelos diferentes tipos de análise, com ênfase na redistribuição de esforços, empregando-se análise linear com redistribuição ou análise plástica. Ressalta-se a importância da consideração de seção T nas vigas e os ajustes necessários quando da consideração de uma envoltória de carregamentos. Tem-se ainda um exemplo de um edifício de oito pavimentos, que visa demonstrar as diferenças nos esforços ou nos deslocamentos obtidos com modelos estruturais distintosThe structural analysis objective is to determine the actions effects in a structure, with the purpose of verifying the ultimate limit states and serviceability (brazilian code NBR 6118:2003 - Design of concrete structures). The structural analysis is one of the main parts of a building structural design, since it involves the choice of theoretical models that represent appropriately the real structure, and the type of analysis due to the materials behavior. This work intends to shorten the distance between design engineers and the academic world, providing a clearer vision of the NBR 6118:2003 structural analysis approach. This work considers the most common structural models used for buildings, and the theory concerning the different types of analysis permitted by the brazilian code. It presents simple examples of linear elements computed by different types of analysis, emphasizing the moment redistribution possibility, either with the linear analysis with redistribution or the plastic analysis. The importance of considering T-beam with moment redistribution is made clear, and lines of direction to consider alternate position of live loads are given. The last example presents an eight store building, and its differences relative to efforts and displacements, obtained by distinct structural models
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Cakir, Emre. "The Use Of Wavelet Type Basis Functions In The Mom Analysis Of Microstrip Structures". Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605639/index.pdf.
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The Method of Moments (MoM) has been used extensively to solve electromagnetic problems. Its popularity is largely attributed to its adaptability to structures with various shapes and success in predicting the equivalent induced currents accurately. However, due to its dense matrix, especially for large structures, the MoM suffers from long matrix solution time and large storage requirement. In this thesis it is shown that use of wavelet basis functions result in a MoM matrix which is sparser than the one obtained by using traditional basis functions. A new wavelet system, different from the ones found in literature, is proposed. Stabilized Bi-Conjugate Gradient Method which is an iterative matrix solution method is utilized to solve the resulting sparse matrix equation. Both a one-dimensional problem with a microstrip line example and a two-dimensional problem with a rectangular patch antenna example are studied and the results are compared.
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Tournier-Lasserve, Catherine. "Modeles d'analyse et de synthese de textures homogenes et inhomogenes". Paris 6, 1987. http://www.theses.fr/1987PA066649.
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Ce travail presente quelques modeles d'analyse et de synthese de textures planes. On analyse tout d'abord une modelisation statistique par un ensemble restreint des moyennes d'espace du second ordre efficace pour les textures homogenes. Pour les textures inhomogenes, il a fallu envisage une autre modelisation basee sur les moments tripolaires, utile pour retrouver les structures de telles textures. Les modeles ont ete etendus aux textures couleur apres les avoir codees. Enfin, ces modeles ont ete enrichi afin de realiser des syntheses au niveau macroscopique sur des textures fortement structurees
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Siahaan, Ropalin. "Structural behaviour and design of rivet fastened rectangular hollow flange channel beams". Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/106913/1/Ropalin_Siahaan_Thesis.pdf.
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This thesis presents a study into the structural behaviour and design of the innovative rivet fastened Rectangular Hollow Flange Channel Beams (RHFCB). The RHFCB utilizes the inexpensive self-pierce rivet fastening in its fabrication, providing cost effective structural solutions in floor systems. The first part of the thesis focuses on the section moment capacities of the beams subject to local buckling effects while the second part investigates the member moment capacities of intermediate span beams subject to the unique lateral distortional buckling effects. Each part involves experimental investigations, advanced finite element analyses, parametric studies and design recommendations.
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Dysart, Paul S. "Moment-radius-stress drop relations and temporal changes in the regional stress from the analysis of small earthquakes in the Matsushiro region, southwest Honshu, Japan". Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/53873.
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Moment-radius-stress drop relations and composite focal mechanisms were determined for 33 small, shallow, strike slip earthquakes (1.7$MLS4.3) in the Matsushiro region of southwest Honshu, Japan during the period August 1971 through September 1974. Estimates of the scalar moment derived from deconvolved SH displacement amplitude spectra range from 1018 to 1022 dyne-cm. The apparent stress ranges from 0.001 to 3.00 bars and the relationship between apparent stress and moment is approximately linear with a slope of 1.Ph. D.
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Sivaprakasam, Thananjayan. "Structural behaviour and design of aluminium facade mullions under wind actions". Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/135457/1/Thananjayan_Sivaprakasam_Thesis.pdf.
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This research has significantly advanced the knowledge and understanding of the structural behaviour and design of vertical load bearing members of aluminium facades subject to wind actions, based on full-scale wind pressure tests and extensive advanced numerical simulations. It has shown that the design approaches used in the industry may result in either conservative or unsafe designs of vertical load bearing members, and thus developed improved design guidelines. Further, it has demonstrated that advanced numerical simulations can be used for economical designs of these facade members.
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LOMBARDI, Guido. "Singular high-order complete vector functions for the analysis and design of electromagnetic structures with Finite Methods". Doctoral thesis, Politecnico di Torino, 2004. http://hdl.handle.net/11583/2504599.
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This dissertation presents new singular curl- and divergence- conforming vector bases that incorporate the edge conditions.
Singular bases complete to arbitrarily high order are described in a unified and consistent manner for curved triangular and quadrilateral elements. The higher order basis functions are obtained as the product of lowest order functions and Silvester–Lagrange interpolatory polynomials with specially arranged arrays of interpolation points. The completeness properties are discussed and these bases are proved to be fully compatible with the standard, high-order regular vector bases used in adjacent elements. The curl (divergence) conforming singular bases guarantee tangential (normal) continuity along the edges of the elements allowing for the discontinuity of normal (tangential) components, adequate modeling of the curl (divergence), and removal of spurious modes (solutions). These singular high-order bases should provide more accurate and efficient numerical solutions of both surface integral and differential problems. Sample numerical results confirm the faster convergence of these bases on wedge problems.
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Slanina, Bohumil. "Rámová konstrukce atypického půdorysu". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240204.
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The thesis describes the analysis and design part of reinforced concrete frame structure. Calculation was made by program SCIA Engineer and verified by manual calculations using simplified methods. Static solution includes an assessment of floor slabs, columns and stairs. The output is then individual drawings of reinforcement. The thesis also includes a study determining the effective width for single rib.
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Yaqoob, Saima. "BRIDGE EDGE BEAM : NON-LINEAR ANALYSIS OF REINFORCEDCONCRETE OVERHANG SLAB BY FINITEELEMENT METHOD". Thesis, KTH, Bro- och stålbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-222806.
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Bridge edge beam system is an increasing concern in Sweden. Because it is the mostvisible part of the structure which is subjected to harsh weather. The edge beamcontributes to the stiffness of overhang slab and helps to distribute the concentratedload. The design of edge beam is not only affected by the structural members, but it isalso affected by non-structural members.The aim of the thesis is to investigate the influence of edge beam on the structuralbehavior of reinforced concrete overhang slab. A three-dimensional (3D) non-linearfinite element model is developed by using the commercial software ABAQUS version6.1.14. The load displacement curves and failure modes were observed. The bendingmoment and shear capacity of the cantilever slab is studied.The validated model from non-linear analysis of reinforced concrete slab gives morestiffer result and leads to the high value of load capacity when comparing with theexperimental test. The presence of the edge beam in the overhang slab of length 2.4 mslightly increases the load capacity and shows ductile behavior due to the self-weightof the edge beam. The non-linear FE-analysis of overhang slab of length 10 m leads tomuch higher load capacity and gives stiffer response as compare to the overhang slabof 2.4 m. The presence of the edge beam in the overhang slab of length 10 m giveshigher load capacity and shows stiffer response when comparing with the overhangslab of length 10 m. This might be due to the self-weight of the edge beam and theoverhang slab is restrained at the right side of the slab.
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Anapayan, Tharmarajah. "Flexural behaviour and design of hollow flange steel beams". Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/36210/1/Tharmarajah_Anapayan_Thesis.pdf.
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The LiteSteel Beam (LSB) is a new hollow flange channel section developed by OneSteel Australian Tube Mills using a patented Dual Electric Resistance Welding technique. The LSB has a unique geometry consisting of torsionally rigid rectangular hollow flanges and a relatively slender web. It is commonly used as rafters, floor joists and bearers and roof beams in residential, industrial and commercial buildings. It is on average 40% lighter than traditional hot-rolled steel beams of equivalent performance. The LSB flexural members are subjected to a relatively new Lateral Distortional Buckling mode, which reduces the member moment capacity. Unlike the commonly observed lateral torsional buckling of steel beams, lateral distortional buckling of LSBs is characterised by simultaneous lateral deflection, twist and web distortion. Current member moment capacity design rules for lateral distortional buckling in AS/NZS 4600 (SA, 2005) do not include the effect of section geometry of hollow flange beams although its effect is considered to be important. Therefore detailed experimental and finite element analyses (FEA) were carried out to investigate the lateral distortional buckling behaviour of LSBs including the effect of section geometry. The results showed that the current design rules in AS/NZS 4600 (SA, 2005) are over-conservative in the inelastic lateral buckling region. New improved design rules were therefore developed for LSBs based on both FEA and experimental results. A geometrical parameter (K) defined as the ratio of the flange torsional rigidity to the major axis flexural rigidity of the web (GJf/EIxweb) was identified as the critical parameter affecting the lateral distortional buckling of hollow flange beams. The effect of section geometry was then included in the new design rules using the new parameter (K). The new design rule developed by including this parameter was found to be accurate in calculating the member moment capacities of not only LSBs, but also other types of hollow flange steel beams such as Hollow Flange Beams (HFBs), Monosymmetric Hollow Flange Beams (MHFBs) and Rectangular Hollow Flange Beams (RHFBs). The inelastic reserve bending capacity of LSBs has not been investigated yet although the section moment capacity tests of LSBs in the past revealed that inelastic reserve bending capacity is present in LSBs. However, the Australian and American cold-formed steel design codes limit them to the first yield moment. Therefore both experimental and FEA were carried out to investigate the section moment capacity behaviour of LSBs. A comparison of the section moment capacity results from FEA, experiments and current cold-formed steel design codes showed that compact and non-compact LSB sections classified based on AS 4100 (SA, 1998) have some inelastic reserve capacity while slender LSBs do not have any inelastic reserve capacity beyond their first yield moment. It was found that Shifferaw and Schafer’s (2008) proposed equations and Eurocode 3 Part 1.3 (ECS, 2006) design equations can be used to include the inelastic bending capacities of compact and non-compact LSBs in design. As a simple design approach, the section moment capacity of compact LSB sections can be taken as 1.10 times their first yield moment while it is the first yield moment for non-compact sections. For slender LSB sections, current cold-formed steel codes can be used to predict their section moment capacities. It was believed that the use of transverse web stiffeners could improve the lateral distortional buckling moment capacities of LSBs. However, currently there are no design equations to predict the elastic lateral distortional buckling and member moment capacities of LSBs with web stiffeners under uniform moment conditions. Therefore, a detailed study was conducted using FEA to simulate both experimental and ideal conditions of LSB flexural members. It was shown that the use of 3 to 5 mm steel plate stiffeners welded or screwed to the inner faces of the top and bottom flanges of LSBs at third span points and supports provided an optimum web stiffener arrangement. Suitable design rules were developed to calculate the improved elastic buckling and ultimate moment capacities of LSBs with these optimum web stiffeners. A design rule using the geometrical parameter K was also developed to improve the accuracy of ultimate moment capacity predictions. This thesis presents the details and results of the experimental and numerical studies of the section and member moment capacities of LSBs conducted in this research. It includes the recommendations made regarding the accuracy of current design rules as well as the new design rules for lateral distortional buckling. The new design rules include the effects of section geometry of hollow flange steel beams. This thesis also developed a method of using web stiffeners to reduce the lateral distortional buckling effects, and associated design rules to calculate the improved moment capacities.
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Mahdi, Ali Abdulkarim. "Moment-rotation behaviour of connections in precast concrete structures". Thesis, University of Nottingham, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387185.
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Garcia, Edgard Enrique Mulford. "Procedimento para determinação experimental de carregamentos externos para o projeto estrutural de uma plataforma semi-submersível". Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3135/tde-28082015-103925/.
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Um dos aspectos fundamentais do projeto estrutural de plataformas flutuantes para produção de petróleo no mar é a determinação dos carregamentos externos globais provenientes da ação das ondas sobre a estrutura da plataforma. A presente dissertação de mestrado apresenta uma proposta de procedimento destinado à determinação experimental, em tanque de provas, dos carregamentos estruturais globais atuantes em uma plataforma de exploração e produção de petróleo do tipo semi-submersível. O procedimento proposto envolve as seguintes etapas: especificação do tipo de esforço que se pretende medir; definição das condições de ensaio; definição da escala dos modelos; escolha do processo construtivo dos modelos; especificação do processo de medida dos esforços; definição dos equipamentos e instrumentos de medida experimental; especificação da matriz de ensaios; definição dos procedimentos de análise de resultados. Como exemplo de aplicação, o procedimento proposto foi empregado na avaliação dos esforços de Momento Fletor no Convés e Força de Separação nos Flutuadores de uma Plataforma Semi-submersível padrão, empregada para validação de resultados em tanques de prova. Os resultados obtidos foram comparados com os da literatura, mostrando uma boa aderência qualitativa e quantitativa.One of the fundamental aspects in the structural design of floating platforms for oil production in the sea is the determination of the global structural loads induced by the wave-platform structure interaction. This master degree thesis proposes a procedure destined to the experimental determination, in a wave tank, of the global structural loads acting in an exploration and production semi-submersible oil platform. The proposed procedure involve the following stages: Specifying the kind of stress to be measured; definition of the test conditions; model scale definition; choosing the model building process; stress measurement process specification; definition of resources and instrumentation for experimental measurement; test matrix specification; results analysis procedure definition. As an application example, the proposed procedure was used in the bending moment stress evaluation on deck and split force on the pontoons of a standard semi-submersible oil platform, used for the results evaluation in wave tanks. The results obtained were compared with the literature, showing a good qualitative and quantitative adhesion.
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Dolamune, Kankanamge Nirosha. "Structural behaviour and design of cold-formed steel beams at elevated temperatures". Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/33221/1/Nirosha_Dolamune_Kankanamge_Thesis.pdf.
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Cold-formed steel members are extensively used in the building construction industry, especially in residential, commercial and industrial buildings. In recent times, fire safety has become important in structural design due to increased fire damage to properties and loss of lives. However, past research into the fire performance of cold-formed steel members has been limited, and was confined to compression members. Therefore a research project was undertaken to investigate the structural behaviour of compact cold-formed steel lipped channel beams subject to inelastic local buckling and yielding, and lateral-torsional buckling effects under simulated fire conditions and associated section and member moment capacities. In the first phase of this research, an experimental study based on tensile coupon tests was undertaken to obtain the mechanical properties of elastic modulus and yield strength and the stress-strain relationship of cold-formed steels at uniform ambient and elevated temperatures up to 700oC. The mechanical properties deteriorated with increasing temperature and are likely to reduce the strength of cold-formed beams under fire conditions. Predictive equations were developed for yield strength and elastic modulus reduction factors while a modification was proposed for the stressstrain model at elevated temperatures. These results were used in the numerical modelling phases investigating the section and member moment capacities. The second phase of this research involved the development and validation of two finite element models to simulate the behaviour of compact cold-formed steel lipped channel beams subject to local buckling and yielding, and lateral-torsional buckling effects. Both models were first validated for elastic buckling. Lateral-torsional buckling tests of compact lipped channel beams were conducted at ambient temperature in order to validate the finite element model in predicting the non-linear ultimate strength behaviour. The results from this experimental study did not agree well with those from the developed experimental finite element model due to some unavoidable problems with testing. However, it highlighted the importance of magnitude and direction of initial geometric imperfection as well as the failure direction, and thus led to further enhancement of the finite element model. The finite element model for lateral-torsional buckling was then validated using the available experimental and numerical ultimate moment capacity results from past research. The third phase based on the validated finite element models included detailed parametric studies of section and member moment capacities of compact lipped channel beams at ambient temperature, and provided the basis for similar studies at elevated temperatures. The results showed the existence of inelastic reserve capacity for compact cold-formed steel beams at ambient temperature. However, full plastic capacity was not achieved by the mono-symmetric cold-formed steel beams. Suitable recommendations were made in relation to the accuracy and suitability of current design rules for section moment capacity. Comparison of member capacity results from finite element analyses with current design rules showed that they do not give accurate predictions of lateral-torsional buckling capacities at ambient temperature and hence new design rules were developed. The fourth phase of this research investigated the section and member moment capacities of compact lipped channel beams at uniform elevated temperatures based on detailed parametric studies using the validated finite element models. The results showed the existence of inelastic reserve capacity at elevated temperatures. Suitable recommendations were made in relation to the accuracy and suitability of current design rules for section moment capacity in fire design codes, ambient temperature design codes as well as those proposed by other researchers. The results showed that lateral-torsional buckling capacities are dependent on the ratio of yield strength and elasticity modulus reduction factors and the level of non-linearity in the stress-strain curves at elevated temperatures in addition to the temperature. Current design rules do not include the effects of non-linear stress-strain relationship and therefore their predictions were found to be inaccurate. Therefore a new design rule that uses a nonlinearity factor, which is defined as the ratio of the limit of proportionality to the yield stress at a given temperature, was developed for cold-formed steel beams subject to lateral-torsional buckling at elevated temperatures. This thesis presents the details and results of the experimental and numerical studies conducted in this research including a comparison of results with predictions using available design rules. It also presents the recommendations made regarding the accuracy of current design rules as well as the new developed design rules for coldformed steel beams both at ambient and elevated temperatures.
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Matthews, James Christopher Gordon. "Patch moment method modelling of wire fed vehicular structures as adaptive antennas". Thesis, University of Sheffield, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412702.
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Kossack, Wilhelm. "Infrared Transition Moment Orientational Analysis on polymeric systems". Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-189315.
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In dieser Arbeit wird ein Verfahren entwickelt (Infrared Transition Moment Orientational Analysis, IR-TMOA) um die dreidimensionale Ordnung auf molekularer Ebene in infrarot-durchlässigen Systemen zu quantifizieren. Es beruht auf der Messung zahlreicher Infrarotspektren, die unter systematisch variierender Polarisation des einfallenden Lichts und Ausrichtung der Probe relativ zur optischen Achse aufgenommen werden. So wird ein repräsentativer Ausschnitt des dreidimensionalen Absorptionsellipsoids gemessen. Die Tensordarstellung dieses Ellipsoids ist äquivalent zum quadratischen Mittel der Verteilungsfunktion der Orientierung der Übergangsmomente, was wiederum dem Ordnungsparameter entspricht. Von zentraler Bedeutung ist ebenfalls, dass die Ordnung (und Orientierung) spezifisch für verschiedene molekulare Untereinheiten angegeben werden kann, da im mittleren Infrarot die Übergangsdipolmomente definierten, lokalen Schwingungen zugeordnet sind. Im zweiten Teil der Arbeit wird IR-TMOA angewendet um die molekulare Ordnung von verschiedenen amorphen und kristallinen Untereinheiten in teil-kristallinen Polymeren (Polycaprolacton, PCL und Polyethylen, PE) zu bestimmen. So kann der Einfluss der Grenzflächen und der geometrischen Einschränkungen in PCL-Filmen auf Substraten in seiner Temperaturabhängigkeit charakterisiert werden. Ebenso wird erstmalig in freitragenden PCL-Filmen in durch mechanische Streckung plastisch deformierten Bereichen die stark biaxiale molekulare Ordnung quantifiziert. In industriell produzierten PE-Filmen, die unter dem Einfluss von äußerer mechanischer Spannung kristallisieren, wird die biaxiale Ordnung und Orientierung vollständig charakterisiert und in Abhängigkeit der Präparationsbedingungen analysiert. Des weiteren wird die Ordnung in einem System aus zwei Phasen untersucht: einer ferroelektrischen Polymermatrix mit mikrometer-großen Flüssigkristalleinschlüssen (Polymer Dispersed Liquid Crystals). Dies erlaubt es, den Einfluss eines äußeren elektrischen Feldes und des remanenten Feldes der Matrix auf die Flüssigkristalle zu quantifizieren. Durch IR-TMOA wird für alle Systeme, die infrarot aktive Vibrationen aufweisen, eine dreidimensionale molekulare Beschreibung der Orientierung und Ordnung ermöglicht. Dies stellt wiederum einen unverzichtbaren Beitrag zum Verständnis der unterliegenden strukturbildenden Prozesse dar und deren Beitrag zur resultierenden makroskopischen Struktur.
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Carriere, Jean-Michel. "Seismic retrofit of existing reinforced concrete moment resisting frame structures using diagonal prestressing". Thesis, University of Ottawa (Canada), 2007. http://hdl.handle.net/10393/27449.
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The national building code of Canada (NBCC) has been under constant evolution since its first issue in 1941. Over the years, knowledge related to structural engineering and more specifically seismic response has continued to evolve through research and field investigations. Recently, the 2005 NBCC has been made available with a new perspective on seismic design, including uniform hazard spectra provided for each city for static and dynamic analyses.
Due to a greater understanding of seismic response of structures and the Canadian seismicity, the NBCC has increased the values of elastic base shears over the years. Between the 1970 and 2005 editions of NBCC, the elastic design base shear has increased by a factor as high as 2.6. A structure designed in 1970, if subjected to 2005 NBCC compatible design earthquake record would potentially be labeled as seismically deficient and fail under code specified loads. Multiple technologies currently exist to retrofit seismically deficient structures. The purpose of this research is to explore the possibilities of using diagonal prestressing, in various configurations, to increase structural stiffness and decrease lateral drift demands under seismic loading.
Shallouf (2005) successfully demonstrated experimentally that a 1 bay, 1 storey R/C frame with masonry infill panels, designed based on the ACI 318-1963 building code, hence seismically deficient, could be retrofitted with prestressed cables to reduced lateral drift. In addition, analytical modeling of the 1 storey frame and analysis of a 5 storey structure in a high seismic region (i.e. Vancouver) were used to illustrate the effectiveness of the approach. This analytical model was successful in reducing lateral drift under various prestressing patterns.
The objective of this research is to continue investigating the effectiveness of the retrofit methodology for structures in two different seismic zones, such as Vancouver and Ottawa. Also, it is examined for buildings with different heights. Structures varying between five and fifteen storeys are analyzed. The results indicate the effectiveness of high-strength prestressing cables as lateral bracing elements, while the effect of prestressing the cables changing with the dynamic characteristics of the building and their interaction with the frequency of the exciting force, i.e., earthquake record.
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Sankaranarayanan, Ragunath. "Seismic response of acceleration-sensitive nonstructural components mounted on moment-resisting frame structures". College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/6700.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Civil Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Park, Kyungha. "Lateral load patterns for the conceptual seismic design of moment-resisting frame structures". College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7731.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Dept. of Civil and Environmental Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Topkara, Mustafa. "Orthogonal Polynomials And Moment Problem". Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/1109164/index.pdf.
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The generalized moment of order k of a mass distribution sigma for a natural number k is given by integral of lambda to the power k with respect to mass distribution sigma and variable lambda. In extended moment problem, given
a sequence of real numbers, it is required to find a mass distribution whose generalized moment of order k is k'th term of the sequence. The conditions of existence and uniqueness of the solution obtained by Hamburger are studied in this thesis by the use of orthogonal polynomials determined by a measure on real line. A chapter on the study of asymptotic behaviour of orthogonal functions on compact subsets of complex numbers is also included.
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Theis, Charles W. "Moment variations: for orchestra and choir". Thesis, University of North Texas, 1993. https://digital.library.unt.edu/ark:/67531/metadc332702/.
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Moment Variations is a three-movement composition for chamber orchestra and chamber choir of approximately 21 minutes duration. The basis of this piece is compositional unity through variations technique, where the retained element of the theme is its structure or fixed-structure variations.The fixed-structure is a succession of six musical events, called moments, in the order: I II III II IV V III V VI, where moments II, III, and V are internally repeated and I, IV, and VI occur only once.
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Biddah, Aiman Mahmoud Samy. "Evaluation of the seismic level of protection of steel moment resisting frame building structures". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0007/NQ42833.pdf.
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Ng, Bernard. "Novel region based fMRI analysis using invariant moment descriptors". Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31787.
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A new functional magnetic resonance imaging (fMRI) analysis approach based on invariant spatial descriptors was developed for quantitative characterization of brain activation patterns within a region of interest (ROI). In particular, the feasibility of using three dimensional moment invariants (3DMIs) to perform such spatial characterization was examined. The use of spatial descriptors is particularly novel in the field of ROI-based fMRI analysis, since up till now, only magnitude-based features were traditionally employed, which neglect the information encoded by voxel locations within an ROI. The invariance properties of the proposed descriptors to similarity transformations account for inter-subject variability in brain size and subject's orientation within the MR scanner, thus allowing for spatial distributions of activation statistics to be meaningfully compared across subjects. Enhanced sensitivity in detecting task-related activation differences as compared to traditional magnitude-based methods was demonstrated with real fMRI data. To handle the issue of feature selection, a modified linear discriminant analysis (LDA) procedure that incorporates leave-one-out cross-validation was developed. Also, methods to deal with the two main issues in ROI-based fMRI group analysis, namely errors in ROI delineation and inclusions of voxels falsely deemed active, were proposed. One method involves remapping the coordinate space with a Gaussian function, which in effect de-emphasizes voxels near the ROI boundary, thus also accounts for inter-subject variability in brain shapes. The other method detects outlier voxels that exhibit disproportional influence on the proposed invariant spatial descriptors, and deweights or removes those voxels accordingly. Testing these processing methods on real fMRI data showed further increase in discriminability of task-related activation differences compared to the original 3DMIs alone. To fully exploit the spatio-temporal structure inherent in fMRI data, we extended our spatial characterization approach into the spatio-temporal domain. We showed, for the very first time, that the modulation of the spatial distribution of BOLD signals does in fact correlate with the stimulus, and provides greater sensitivity in detecting activated ROIs and in discriminating task-related differences as compared to traditional mean intensity-based methods. The neuroscience implications of our findings are substantial, and might hence provide brain researchers and clinicians a new promising direction to explore.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
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Chiprout, Eli Carleton University Dissertation Engineering Electronics. "Moment-maching analysis of high-speed VLSI interconnect models". Ottawa, 1994.
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Cox, Wilfred. "Nonlinear analysis of reinforced concrete portal frames". Thesis, University of East London, 2001. http://roar.uel.ac.uk/1303/.
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There are considerable difficulties in describing the properties of reinforced concrete materials and their interaction. It is therefore necessary to calibrate the mathematical model by accurate testing of laboratory specimens. It can be shown that momentcurvature relationship varies along the length of a member and at beam-column joints. This behaviour depends critically on the geometry of the joint, reinforcement details and the stress-strain characteristics of concrete and steel. Tests have been carried out on model reinforced concrete portal frames and independent specimens making up the frame to predict their non-linear behaviour. The stiffness of the joint plays an important role in the response of the complete frame structure. The behaviour of the corner joints is of particular interest because both the strength and ductility differs for opening and closing joints. The loss of stiffness at joints has a significant effect on the inelastic deformations. The non-linear finite element (FE) program developed takes into account the loss of stiffness at joints and the falling branch behaviour of the material stress-strain relationships. Constant, linear, and parabolic variation in flexural rigidity (EI) and axial rigidity (EA) are taken into consideration along the element length. The combined effect of material and geometric non-linearity is considered. The FE program may use either calculated momentcurvature relationship of different elements or the experimental data obtained from tests. The results show good agreement between the theoretical and experimental beam moment-curvature relationships. Horizontally loaded frame analysis, which involves opening and closing joints, shows that ignoring the joint effect over-estimates the strength. In the case of vertically loaded frames, which involves two closing joints, ignoring the joint effects had little or no influence. The results show good agreement between the theoretical and experimental frame force-displacement relationships throughout the loading range providing the change of stiffness at joints is taken into account for horizontally loaded frames.
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Stloukal, Štěpán. "Zesílení ŽB sloupu pomocí ocelové bandáže". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265384.
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The steel bandage is an economical and effective widely used method for strengthening RC columns. Diploma thesis reviews most common design proposals for the types of the bandage with directly loaded and not directly loaded steel angles. This work also includes a comparison of the different constitutive laws for confined concrete. In order to simulate real behaviour of strengthened structure the numerical analysis has been carried out using non-linear software ATENA. According to the European standards and adopted hypotheses the simplified analytical model has been derived to be able to calculate load-bearing capacity of a strengthened column under normal force and bending moment. The proposed model considers the contribution in confinement pressure caused by steel bandage and the contribution of directly loaded angles. In addition, the direct application on real frame structure has been performed.
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Davis, Clayton Paul. "Understanding and Improving Moment Method Scattering Solutions". Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd620.pdf.
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