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1

Liu, Xinpei Civil &amp Environmental Engineering Faculty of Engineering UNSW. "Nonlinear in-plane behaviour of fixed arches under thermal loading". Awarded by:University of New South Wales. School of Civil and Environmental Engineering, 2006. http://handle.unsw.edu.au/1959.4/27236.

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This thesis presents the nonlinear in-plane behaviour of circular fixed arches subjected to thermal loading only. Due to the nonlinear prebuckling behaviour of arches and its effects, classical buckling theory which is founded on geometric prebuckling linearity can not predict the in-plane buckling of arches accurately. Based on a nonlinear formulation of the strain and displacement relationship and considering constant thermal distributions only, virtual work formulations are used to establish the differential equations of in-plane equilibrium and the statical boundary conditions, from which the nonlinear equilibrium equations are derived in closed form and which are suitable to use in design. By considering the adjacent buckled configurations, the differential buckling equilibrium equations are formulated from the principle of virtual work as well, and the analytical solutions for the nonlinear buckling of fixed arches are obtained. It is shown that nonlinear elastic buckling of a fixed in the plane of it curvature can not occur when it is subjected to thermal loading only, except if the arch is as a straight column. By using the algebraic representation of nonlinear in-plane equilibrium derived in this thesis, the elastic response of fixed arches at elevated temperatures and the attainment of first yield are examined in detail. The arch deflects transversely without bound in the elastic range at elevated temperatures, whereas it will yield first at the top extreme fibre of the cross section at the supports when a critical temperature is reached. The influence of several parameters such as the included angle is also considered. Based on the models of stress distributions at cross sections, the spread of yield both through the cross section and along the length of the arch is studied. It is indicated that the progress of yielding causes the first two hinges to form at the supports of the fixed arches, and then moment redistribution leads to the generation of the third hinge at the crown with an increase of temperature. Thus nonlinear plastic hinge analysis can be applied to the arch analysis under thermal loading.
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2

Ceran, H. Burak. "Seismic Vulnerability Of Masonry Structures In Turkey". Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612745/index.pdf.

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This study focuses on the evaluation of seismic safety of masonry buildings in Turkey by using fragility curves. Fragility curves for masonry buildings are generated by two behavior modes for load bearing walls: in-plane and out-of-plane. By considering the previous research and site investigations, four major parameters have been used in order to classify masonry buildings with in-plane behavior mode. These are number of stories, strength of load-bearing wall material, regularity in plan and the arrangement of walls (required length, openings in walls, etc.). In addition to these four parameters, floor type is also taken into account for the generation of fragility curves by considering out-of-plane behavior mode. During generation of fragility curves, a force-based approach has been used. In this study there exist two limit states, or in other words three damage states, in terms of base shear strength for in-plane behavior mode and flexural strength for out-of-plane behavior mode. To assess the seismic vulnerability of unreinforced masonry buildings in Turkey, generated fragility curves in terms of in-plane behavior, which is verified by damage statistics obtained during the 1995 Dinar earthquake, and out-of-plane behavior, which is verified by damage statistics obtained during the 2010 Elazig earthquake, is combined. Throughout the analysis, ground motion uncertainty, material variability and modeling uncertainty have also been considered. In the final part of the study, a single-valued parameter, called as &lsquo
vulnerability score&rdquo
, has been proposed in order to compare the seismic safety of unreinforced masonry buildings in Fatih sub province of Istanbul and to assess the influence of out-of-plane behavior together with the in-plane behavior of these existing masonry buildings.
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3

Chea, Ming Kai. "Investigating In-plane Shear Behaviour of Uncured Unidirectional Prepreg Tapes". Thesis, KTH, Lättkonstruktioner, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262011.

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Steering of prepreg tows in an automated fibre placement (AFP) process allows geodesic layup trajectory over a doubly-curved surface, as well as the potential to improve the efficiency of composite structures by tailoring their stiffness. However, defects (such as out-of-plane buckling and tow pull off) are commonly generated when the steering radius exceeds a critical limit, which impact the mechanical properties of the finished product. The in- and out-of-plane material properties of the prepreg tows have been shown to significantly influence the quality of the layup. In this thesis, in-plane shear behaviour of uncured IMA-M21 unidirectional (UD) prepreg was characterised using an off-axis tensile test to derive material parameters for process models to predict steering limits and defects. Test parameters, such as shear strain rates and temperatures, that were investigated were consistent to the actual AFP process. The results demonstrates the expected strain-rate and temperature dependencies related to the resins viscoelastic behaviour. Subsequently, a novel micro-mechanical finite element (FE) simulation of a 3-dimensional UD prepreg unit cell in pure shear was conducted to gain qualitative insights into the complex rheological behaviour at play. It effectively demonstrates how fibre friction, resin viscosity and shear strain rates influence the load transfer between fibres and melt, as well as the movement of fibres during the shearing process. These were reflected in the shear stress-strain curves generated in the simulation and elastic micro-buckling observed in the fibre elements. The results pave a way for future development of a robust material model for predicting the critical process parameters to achieve quality layups from AFP steering process.
Automated Fibre Placement (AFP) är en automatiserad metod för tillverkning av högpresterande fiberkompositkomponenter inom främst flygindustrin. AFP gör det möjligt att styra fiberupplägget genom att följa den geodetiska vägen ¨over dubbelkrökta ytor. Detta ger effektiva kompositstrukturer där fibrerna tillåts ligga i precis de rätta, skräddarsydda riktningarna för bästa möjliga mekaniska prestanda. Det finns dock begränsningar, speciellt när det gäller kritiska styrradier där defekter som fiberbuckling och fiber-släpp lätt uppstår. Dessa defekter påverkar den färdiga produktens mekaniska egenskaper. Skjuvegenskaperna i planet hos de ohärdade prepregens fiberbuntar och buckling ut ur planet har visat sig ha stor inverkan på kvalitén hos fiberuppläggen. I denna avhandling undersöks skjuvegenskaperna hos ohärdad IMA-M21 enkelriktad (UD) prepreg med hjälp av ett icke-axiellt dragprov. Syftet ¨ar att ta fram materialdata för simulering av fiberuppläggets begränsningar, för att kunna bestämma hur AFPn bör styras. Modellerna ska ¨aven prediktera de defekter som uppstår. Testparametrar så som skjuvhastigheter och temperaturer undersöks för att efterlikna den verkliga AFP-processen. Resultaten fångar det förväntade skjuvhastighet- och temperaturberoende som ges av matrisens viskoelastiska egenskaper. Baserat på dessa modeller tas en nya mikromekanisk modell fram som implementerad i Finita Element (FE) ger kvalitativ inblick i den komplexa reologin som inverkar. Modellen påvisar tydligt hur fiberfriktion, matrisens viskositet- och skjuvhastighet påverkar kraftföreningen mellan fiber och matris, så väl som förflyttningen av fibrer under skjuvprocessen. Resultaten banar väg för framtida utveckling av robusta materialmodeller för att kunna prediktera kritiska parametrar för att åstadkomma högkvalitativa
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4

Yahiaoui, Mohamed. "Crush behavior of flanged plates under localized in-plane loadings". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/39990.

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5

Hossain, Khandaker Muhammed Anwar. "In-plane shear behaviour of composite walling with profiled steel sheeting". Thesis, University of Strathclyde, 1995. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21963.

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This thesis introduces a novel form of double skin composite walling with profiled steel sheeting and an infill of concrete. This is a logical extension of research on composite slabs with profiled steel sheeting currently known as popular "Fastrack" construction. The composite walling is thought to be specially applicable as shear or core walls in steel frame buildings. The profiled steel sheeting will act as a temporary shear bracing to stabilise the frame against wind and destablising forces during construction and also act as a form work for infill of concrete. In the service stage, they will act as a reinforcement to carry axial, lateral and in-plane forces. This thesis investigates the behaviour of composite walls under in-plane shear so that they can be used as shear elements in buildings. The investigation includes analytical, numerical and small scale model tests. Design recommendations for the composite walls are the final aim of the research. The investigation is based on the concept that the in-plane shear strength and stiffness of the composite wall will be derived from the individual sheeting, concrete core and from the interaction between the two. Based on above, individual behaviour of the sheeting and concrete core was studied before considering the composite wall as a whole. A shear rig has been designed and fabricated to carry out the model tests of approximately 1/6 th scale using very thin sheeting (profiled in house) and microconcrete. Analytical equations for the shear strength and stiffness of the sheeting, profiled concrete and composite wall are derived. These equations are validated by model tests and finite element analysis. Finite element analysis included modelling of composite walling with full composite action and some parametric studies using interface elements. The stiffness of the composite wall is found to be greater than the individual summation of stiffness of the sheeting and concrete core. The profiled steel sheeting will provide sufficient shear bracing to the frame during construction. The composite wall is capable of taking high in-plane shear loads which is greater than the summation of individual capacity of the sheeting and concrete and confirms its potential to be used as shear elements in buildings. Simple equations for the calculation of shear strength and stiffness of the composite wall are derived which can safely be used for design purposes. Further research directions are also outlined.
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6

Samayoa, Avalos Julio Alfredo. "Semi-engineered earthquake-resistant structures: one-storey buildings built up with gabion-box walls". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11121/.

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This thesis studies the static and seismic behavior of simple structures made with gabion box walls. The analysis was performed considering a one-story building with standard dimensions in plan (6m x 5m) and a lightweight timber roof. The main focus of the present investigation is to find the principals aspects of the seismic behavior of a one story building made with gabion box walls, in order to prevent a failure due to seismic actions and in this way help to reduce the seismic risk of developing countries where this natural disaster have a significant intensity. Regarding the gabion box wall, it has been performed some calculations and analysis in order to understand the static and dynamic behavior. From the static point of view, it has been performed a verification of the normal stress computing the normal stress that arrives at the base of the gabion wall and the corresponding capacity of the ground. Moreover, regarding the seismic analysis, it has been studied the in-plane and out-of-plane behavior. The most critical aspect was discovered to be the out-of-plane behavior, for which have been developed models considering the “rigid- no tension model” for masonry, finding a kinematically admissible multiplier that will create a collapse mechanism for the structure. Furthermore, it has been performed a FEM and DEM models to find the maximum displacement at the center of the wall, maximum tension stresses needed for calculating the steel connectors for joining consecutive gabions and the dimensions (length of the wall and distance between orthogonal walls or buttresses) of a geometrical configuration for the standard modulus of the structure, in order to ensure an adequate safety margin for earthquakes with a PGA around 0.4-0.5g. Using the results obtained before, it has been created some rules of thumb, that have to be satisfy in order to ensure a good behavior of these structure.
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7

Calata, Jesus Noel. "Densification Behavior of Ceramic and Crystallizable Glass Materials Constrained on a Rigid Substrate". Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/27645.

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Constrained sintering is an important process for many applications. The sintering process almost always involves some form of constraint, both internal and external, such as rigid particles, reinforcing fibers and substrates to which the porous body adheres. The densification behavior of zinc oxide and cordierite-base crystallizable glass constrained on a rigid substrate was studied to add to the understanding of the behavior of various materials undergoing sintering when subjected to external substrate constraint. Porous ZnO films were isothermally sintered at temperatures between 900°C and 1050°C. The results showed that the densification of films constrained on substrates is severely reduced. This was evident in the sintered microstructures where the particles are joined together by narrower necks forming a more open structure, instead of the equiaxed grains with wide grain boundaries observed in the freestanding films. The calculated activation energies of densification were also different. For the density range of 60 to 64%, the constrained film had an activation energy of 391 ± 34 kJ/mole compared to 242 ± 21 kJ/mole for the freestanding film, indicating a change in the densification mechanism. In-plane stresses were observed during the sintering of the constrained films. Yielding of the films, in which the stresses dropped slight or remained unchanged, occurred at relative densities below 60% before the stresses climbed linearly with increasing density followed by a gradual relaxation. A substantial amount of the stresses remained after cooling. Free and constrained films of the cordierite-base crystallizable glass (glass-ceramic) were sintered between 900°C and 1000°C. The substrate constraint did not have a significant effect on the densification rate but the constrained films eventually underwent expansion. Calculations of the densification activation energy showed that, on average, it was close to 1077 kJ/mole, the activation energy of the glass, indicating that the prevailing mechanism was still viscous flow. The films expanded earlier and faster with increasing sintering temperature. The expansion was traced to the formation of pores at the interface with the silicon substrate and to a lesser extent on aluminum nitride. It was significantly reduced when the silicon substrate was pre-oxidized at 900°C, leading to the conclusion that the pore formation at the interface was due to poor wetting, which in turn was caused by the loss of the thin oxide layer through a reaction with the glass.
Ph. D.
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8

Niraula, Manjil. "BEHAVIOR AND DESIGN OF THE CRITICAL MEMBER IN STRUCTURES WITH IN-PLANE DISCONTINUOUS BRACED FRAMES". OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2751.

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When a structure with an in-plane discontinuous frame is used, a discontinuous load path is formed due to the irregularity. This is continuous load path can lead to the failure of certain elements and the structure as a whole when the structure is exposed to lateral loading. In this study, an in-plane discontinuous frame structure is exposed to gravity as well as lateral loading due to which a discontinuous load path is formed. Due to the discontinuous load path, higher value of axial load is developed on a beam which is generally designed considering it as a flexural member. The main objective of this thesis is to determine if the beam can be designated as the critical member in the in-plane discontinuous frame and the comparison of the critical element with the corresponding element in a frame that has no structural irregularities. The objective is also to design the critical member considering it as a beam-column element considering the combined effect of bending and compression.
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9

Hawkins, Guy Lawrence. "The behaviour of bonded out-of-plane joints in fibre reinforced plastic structures". Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261750.

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10

Eva, Charles Almond. "Experimental evaluation of the in-plane seismic behavior of store-front window systems". Diss., [La Jolla, Calif.] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p1462129.

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Thesis (M.S.)--University of California, San Diego, 2009.
Title from first page of PDF file (viewed April 16, 2009). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 91-94).
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11

Prabha, K. R. Carleton University Dissertation Engineering Civil and Environmental. "Behaviour of webs of WWF shapes subjected to concentrated in-plane loads; analytical investigation". Ottawa, 1996.

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12

Stanway, Graeme Scott. "The behaviour and design of transversely stiffened plates subject to in-plane shear forces". Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/46562.

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13

Koundouros, Michael. "In-plane compressive behaviour of stiffened thin-skinned composite panels with a stress concentrator". Thesis, Imperial College London, 2005. http://hdl.handle.net/10044/1/8375.

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14

King, Michael J. (Michael James) 1978. "An energy-based constitutive model for the in-plane mechanical behavior of woven fabrics". Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89902.

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15

Stirling, Bradley James. "Flexural Behavior of Interlocking Compressed Earth Block Shear Walls Subjected to In-Plane Loading". DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/593.

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This thesis investigates the flexural behavior of interlocking compressed earth block (ICEB) shear walls. In-plane cyclic tests were conducted to evaluate the performance of three flexure dominant large scale ICEB specimens: a slim wall with a 2:1 height to width aspect ratio, a flanged wall, and a wall with an opening at the center. Following the experimental investigation, two types of analyses were conducted for calculating the ultimate strength of flexure dominant ICEB walls: a nonlinear static analysis model assuming lumped plasticity and a plastic analysis model. In addition, incremental dynamic analysis was conducted to address the seismic performance of flexure dominant ICEB buildings. Based on the database from the incremental dynamic analysis, the collapse potential of demonstration ICEB buildings were compared for the countries of interest.
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16

BU, JLDAIN HAFETH. "Behaviour and Inspection of Novel Non-Crimp Dry Thick Reinforcement Fabrics". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32383.

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Aerospace structural components made from polymer matrix composites (PMCs) offer numerous advantages. Their high stiffness and high strength combined with low densities enable lower fuel consumption coupled with higher payloads. As a result, PMCs provide an important economic advantage over typical metallic airframes. Textile reinforcements for PMCs are made by assembling reinforcement fibres, typically carbon. Then, the textile reinforcements are typically cut into smaller pieces, stacked, draped and assembled into a dry assembly called a preform, the shape of which generally approaches that of the PMC part to be made. This manufacturing process is labour intensive and expensive. Novel thick, net-shape, drapable, high vf textile reinforcements used toward manufacturing aerospace PMCs are being developed at the University of Ottawa. The technology enables the manufacturing of flat, drapable multilayered near net-shape preforms. The bending and in-plane shear behaviours of such novel thick reinforcement textiles was investigated to understand and define the behaviour of such thick fabric reinforcements when formed into required shapes. A bending apparatus was developed for investigating the bending behaviour of these novel thick reinforcement fabrics and an articulated frame shear rig was used for investigating the in-plane shear behaviour. A non-destructive inspection method using infrared imaging was used for investigating and identifying flaws and defects in these thick, dry textile reinforcements, aiming at increasing the quality and reproducibility of the final PMC parts made from these reinforcements.
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17

Wilson, Timothy James. "Modeling of In-Plane and Interlaminar Fatigue Behavior of Glass and Carbon Fiber Composite Materials". Thesis, Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/wilson/WilsonT0507.pdf.

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This thesis presents the results of a modeling study of the fatigue behavior of fiberglass and carbon fiber reinforced epoxy composite materials intended primarily for wind turbine blades. The modeling effort is based on recent experimental results for infused glass fiber laminates typical of current blades, and hybrid carbon prepreg laminates of potential interest for future blades. There are two focus areas: in-plane performance represented by stress-life (S-N) curves, and out-of-plane ply delamination at details including ply drops and joints, based on fracture mechanics. In-plane fatigue models for both the mean performance and a statistically fit model with a 95/95 confidence limit were developed for three laminates, each representative of lower cost materials with applications in the wind turbine industry. These include polyester and epoxy resin infused glass fabrics and a hybrid carbon prepreg; two of the materials were tested in the axial and transverse directions. Models were adapted for the S-N results at several uniaxial loading conditions, including special treatment of the time dependence at high loads. Materials are compared in terms of their fatigue exponents, constant life diagrams and in the context of a wind loads spectrum. The second part of this work contains a modeling study of delamination crack development in various composite structure detail regions using finite element analysis. Geometries include various ply joints, ply drops, and material transition areas, all using relatively thick glass and carbon fiber prepregs typical of lower cost applications. Two dimensional finite element models were used to determine the strain energy release rates, GI and GII, of delamination cracks by virtual crack closure with contact elements. Results are correlated with experimental data and approximate models where available. The model results, while static in nature, offer insight into trends observed for delamination under fatigue loading for various geometries and material variations, including a more detailed study of tapered ply drops. The results support and help explain experimentally observed trends of fatigue delamination resistance with material (glass and carbon), ply thickness, and crack locations. The influence of ply mis-orientation and ply drop location on the GI (opening mode) component is also explored.
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18

Xie, Min. "Behaviour and design of transversely stiffened plates subjected to combined shear and direct in-plane loading". Thesis, Imperial College London, 2001. http://hdl.handle.net/10044/1/7657.

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19

Atli, Veltin Bilim Gandhi Farhan S. "Effect of geometric parameters on the in-plane crushing behavior of honeycombs and honeycombs with facesheets". [University Park, Pa.] : Pennsylvania State University, 2009. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-4582/index.html.

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20

Cavigli, Marco. "In-Plane cyclic behavior of substandard confined masonry: full-scale experiments, finite elements modeling and incremental dynamic analysis". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/5503/.

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21

Prowse, Dayle (Dayle Jennifer) Carleton University Dissertation Engineering Civil and Environmental. "Behaviour of slender webs of WWF shapes and stiffened bridge girders subjected to concentrated in-plane loads; experimental investigation". Ottawa, 1996.

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22

Aldemir, Alper. "A Simple Seismic Performance Assessment Technique For Unreinforced Brick Masonry Structures". Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612418/index.pdf.

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There are many advantages of masonry construction like widespread geographic availability in many forms, colors and textures, comparative cheapness, fire resistance, thermal and sound insulation, durability, etc. For such reasons, it is still a commonly used type of residential construction in rural and even in urban regions. Unfortunately, its behavior especially under the effect of earthquake ground motions has not been identified clearly because of its complex material nature. Hence, the masonry buildings with structural deficiencies belong to the most vulnerable class of structures which have experienced heavy damage or even total collapse in previous earthquakes, especially in developing countries like Turkey. This necessitates new contemporary methods for designing safer masonry structures or assessing their performance. Considering all these facts, this study aims at the generation of a new performance-based technique for unreinforced brick masonry structures. First, simplified formulations are recommended to estimate idealized capacity curve parameters of masonry components (piers) by using the finite element analysis results of ANSYS and regression analysis through SPSS software. Local limit states for individual masonry piers are also obtained. Then, by combining the component behavior, lateral capacity curve of the masonry building is constructed together with the global limit states. The final step is to define seismic demand of the design earthquake from the building through TEC2007 method. By using this simple technique, a large population of masonry buildings can be examined in a relatively short period of time noting that the performance estimations are quite reliable since they are based on sophisticated finite element analysis results.
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23

Lanata, Patrizia. "Full-field experimental characterization of mechanical behaviour and failure in a porous rock in plane strain compression : homogeneous deformation and strain localization". Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAI040/document.

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Ce travail présente une caractérisation expérimentale du comportement mécanique et de la rupture par localisation de la déformation dans un grès des Vosges. L'évolution temporelle de la localisation a été caractérisée par des mesures de champs. Une nouvelle cellule triaxiale vraie a été développée au Laboratoire 3SR (Grenoble), qui permet une visualisation des échantillons sous chargement pour réaliser de la corrélation d'image numérique (CIN). Les essais ont été réalisés par compression en déformation plane (confinement de 20 à 50 MPa). La transition d'une déformation diffuse à localisée a été finement étudiée. Une analyse comparative a été ensuite effectuée entre les mesures de champs et la microstructure à l'échelle des grains observée par microscope (MEB). Enfin, une étude théorique basée sur une analyse en bifurcation a été menée pour comparer observations des bandes de cisaillement et prédiction sur la localisation de la déformation
This work aims an experimental characterization of the mechanical behaviour and failure by strain localization on a Vosges sandstone. The time evolution of strain localization has been characterized by full-field measurements. A new true-triaxial apparatus has been developed at Laboratoire 3SR (Grenoble), which enables the observation of the specimens during mechanical loading for application of digital image correlation (DIC). Tests have been performed in plane strain compression (confining pressure from 20 to 50 MPa). The transition from diffuse to localised deformation regimes has been extensively studied. Then, a comparative analysis has been done between the strain fields (DIC) and microscope (SEM) observations to determine how closely the DIC fields are related to deformation mechanisms detected at the grain scale. Finally, a theoretical bifurcation analysis is presented to compare the experimental observations of shear bands with strain localization prediction
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Chen, Jian [Verfasser], Edgar [Akademischer Betreuer] Dörsam i Samuel [Akademischer Betreuer] Schabel. "Investigation on the Mechanical Behavior of Paper and Paper Stacks in the out-of-plane Direction / Jian Chen ; Edgar Dörsam, Samuel Schabel". Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2016. http://d-nb.info/1120014646/34.

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El, Nabouch Ranime. "Comportement mécanique des murs en Pisé soumis à la poussée progressive". Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAA014/document.

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La détermination des comportements mécaniques des murs en pisé est d’une importance capitale dans un contexte où il y a un regain d’intérêt pour l’utilisation de matériaux de construction à très faible impact environnementaux. D’une part, cette étude contribue à trouver des moyens appropriés pour la conservation et la restauration du patrimoine bâti et, d’autre part, permet d’établir de nouvelles recommandations pour la conception de nouvelles structures en pisé dans le respect des règlements de la construction (réglementation thermique et réglementation parasismique).Dans ce contexte, cette thèse étudie le comportement des murs en pisé soumis à des sollicitations horizontales. Quatre murs de terre en pisé non stabilisés ont été testés sous une combinaison de charge verticale et horizontale monotone (type pushover) jusqu'à la rupture. Le comportement au cisaillement et les modes de ruptures de ces murs sont étudiés à l’aide d’une technique de corrélation d’images à grande échelle. Les résultats ont montré que le pisé est caractérisé par un comportement mécanique non linéaire très significatif et une ductilité remarquable. D’une manière générale, les murs ont subi une rupture de cisaillement due à une fissuration principale au niveau de la bielle de compression. Des fissures à l'interface entre les différentes couches ont également été observées.L'évaluation de la performance de ces murs a été effectuée sur la base de la méthodologie pushover. Le travail expérimental a été complété avec la détermination des caractéristiques mécaniques du matériau pisé en compression puis une étude en cisaillement directe (cohésion et angle de frottement) à l’aide de deux boites de Casagrande de tailles différentes. Enfin, l’importance de ces paramètres a été analysée en réalisant des simulations numériques à l’échelle du mur
Determining the mechanical behavior of rammed earth walls is a highly important feature giving that there is a renewed interest in the use of the natural material in building construction. On one hand, it contributes to finding suitable and appropriate ways for the conservation and restoration of these building and on another hand, it draws new recommendations for the conception of new rammed earth structures with respect to new building regulations (earthquake building guideline, new thermal regulation).In this context, this thesis investigates the behavior of rammed earth walls subjected to lateral loading. Four unstabilized rammed earth walls were tested under a combination of vertical and monotonic pushover tests up to failure. The shear behavior of these walls is studied along with the failure modes by means of digital image correlation. Results showed that the response of the rammed earth is characterized by significant non-linear behavior with a remarkable ductility. In general, the walls experienced a shear failure due to the failure of diagonal struts. Cracks at the interface between the bottom layers were also observed.The performance of these walls was assessed based on the pushover methodology. The experimental work was completed with the determination of the mechanical characteristics of rammed earth in compression and an investigation of the shear components: cohesion and friction angle of the rammed earth through shear box tests on a different scale. Finally, the relevance of these parameters was tested by performing a numerical model that aims to simulate the experimental tests done on the scale of the walls
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26

Bui, Thi Loan. "Contribution à l'étude de murs maçonnés renforcés par matériaux composites (FRP et TRC) : application aux sollicitations dans le plan". Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10133/document.

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Les présents travaux, à caractère numérico-expérimental, visent à approfondir la connaissance relative au comportement de murs maçonnés, principalement ceux renforcés par matériaux composites vis-à-vis de sollicitations dans leur plan (flexion composée). Ils s'inscrivent dans le cadre de la réhabilitation du patrimoine bâti vis-à-vis du risque sismique notamment du fait de la reconsidération du zonage en France rendu depuis peu plus exigeant. Aussi, d'un point de vue technologique, cette thèse vise à apprécier, évaluer et hiérarchiser l'intérêt et les potentialités de solutions de renforcement mobilisant des matériaux composites, à base polymère ainsi que des composites textile-mortier de nouvelle génération, couplés à des ancrages mécaniques ayant vocation à mieux valoriser ce type d'options. Deux échelles d'analyse ont été retenues dans le cadre de la partie expérimentale. A l'échelle du matériau, dans le but de caractériser finement les matériaux constitutifs de la maçonnerie de briques de béton creux et de générer des jeux de données aussi pertinents que fiables, notamment en prévision de la modélisation numérique, des essais de compression uni-axiale et de push-out à l'échelle « réduite » ont été conduits et ont permis de souligner, en accord avec la littérature, la nécessité de tenir compte de l'interaction brique-mortier, de consolider la compréhension des mécanismes d'endommagement et de rupture des éléments de maçonnerie tout en mettant en lumière l'importance relative des dispersions obtenues. A l'échelle du composant de structure, une campagne expérimentale de flexion composée portant sur six murs, dont un mur témoin, a été conduite sous sollicitations de flexion composée dans le plan des murs avec pour impératif la nécessité de restituer les conditions limites et de sollicitations sous séisme, tout en limitant le champ de l'étude au volet statique monotone en vue d'éprouver les solutions valorisées (matériaux composites et ancrage).Cette partie a permis, audelà de la mise en avant des bonnes dispositions en termes de capacité portante, d'une part, de caractériser comparativement le comportement de ces éléments tant à l'échelle globale (déplacement, capacité de déformation et de dissipation d'énergie, etc.) qu'à l'échelle locale (endommagement, déformations localisées, etc.) via une instrumentation judicieuse, et d'autre part de cerner l'importance des ancrages mécaniques vis-à-vis des sollicitations étudiées. L'approche numérique, de type éléments finis, a été mise à profit dans un deuxième temps pour tenter de restituer le comportement des murs (à l'échelle locale et globale). Sur la base d'une lecture bibliographique critique c'est l'approche micromécanique qui a eu nos faveurs. La modélisation a été conduite en trois dimensions (3D) à l'aide du logiciel ANSYS. Ainsi, les briques et le mortier sont modélisés indépendamment mais liés parfaitement. Deux variantes ont été proposées pour la modélisation de la maçonnerie saine et leur adéquation a été évaluée. Le premier modèle s'appuie sur un couplage entre le modèle de béton d'Ansys en traction et un comportement multilinéaire en compression pour modéliser le mortier, les briques sont supposées pourvues d'un comportement élasto-plastique bilinéaire pour lequel la résistance en compression de la brique est le seuil de la phase élastique. Dans le deuxième modèle, plus en phase avec les constats expérimentaux, seul le comportement des briques est modifié en introduisant un comportement post-pic adoucissant. En ce qui concerne la modélisation des murs renforcés par matériaux composites, ces derniers (FRP et TRC) ont été considérés comme parfaitement liés au substrat de maçonnerie. Toutefois, si le renfort de type FRP est modélisé par un comportement homogène orthotrope, le TRC, rarement modélisé jusqu'à lors, est simulé via deux approches (homogène et hétérogène) dans le but d'apprécier leur pertinence
This study, using both experimental and numerical approaches, will help to better understand the behaviour of masonry walls. It especially focuses on walls reinforced with composite materials under in-plane loading conditions. In France, more stringent seismic design requirements for building structures have taken effect. So, this research has been initiated in an effort to define reliable strengthening techniques. The selected reinforcement materials are (1) – fiber reinforced polymer (FRP) strips using E-glass and carbon fabrics and (2) – an emerging cementbased matrix grid (CMG) system. The composite strips are mechanically anchored into the foundations of the walls to improve their efficiency. The experimental program involves different levels of analysis. Small-scale models of block masonry structures, carried out with less than ten bricks, are tested. The objective is to obtain a coherent set of data, characterizing the elementary components (hollow bricks and mortar) and their interface, in order to provide realistic values of the parameters required in the foreseen modelling. Shear bond strength has been obtained from triplets and 7-uplets and compressive masonry strength from running bond prisms. These experimental results improve the knowledge of the main damage mechanisms and failure modes of masonry but they suffer from high scattering. At laboratory (large) scale, six walls have been submitted to shear-compression tests - five of them are reinforced and the last one acts as a reference. All the walls share the same boundary and compressive loading conditions, which are chosen to ensure a representative simulation of a seismic solicitation. Nevertheless, masonry walls performances and anchor efficiency are only evaluated under monotonic lateral loadings. A comparative study on global behavior (displacements, deformation capacity, energy dissipation,…) as well as on local mechanisms (local strains, damage,…) is carried out and highlights in particular that strengthened walls exhibit a high increase in shear resistance. Moreover, a 3D finite-element analysis using ANSYS has been performed to help understand the behaviour of unreinforced and strengthened walls. A micro-mechanical approach is adopted: bricks and mortar are modelled separately and linked together by a perfect bond. The Ansys concrete model, capable of cracking, is coupled with a multi-linear plasticity model in compression to describe mortar joints. In a first attempt, bricks exhibit a bilinear behavior law where the brick compressive strength is the elastic threshold; but this model fails to reproduce the resistances of the strengthened walls. To compensate for these overestimations and capture the experimental resistances, a post-pic softening behaviour is preferred for the bricks. To model strengthened walls, all composite strips are supposed to be perfectly linked with the masonry and a linear elastic law is used for the FRP reinforcements. TRC strips are either described by means of a linear law or represented using a heterogeneous approach where matrix and textile grids are modelled separately. In this case, grids are represented using a smeared approach and are embedded within the matrix mesh. So, displacement compatibility is totally satisfied between the textile and the cementitious matrix. The proposed numerical model tends to underestimate walls capacity deformation but ultimate loads and failure modes are in coherence with experimental results. Finally, existing analytical methods have been applied to assess unreinforced and strengthened walls performances. The results are then compared with the experimental data and a critical review is proposed. Existing models could be refined by taking into account more realistic behaviour laws and by relying on energy approaches to better reproduce dissipative mechanisms of TRC materials
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27

Matthews, Russell Stuart. "The structural behaviour of brick sewer pipes in soft ground : the examination of brick and reinforced plastic pipes, in granular soil, and under plane strain conditions, using fully non-linear finite element models and a large-scale physical testing prog". Thesis, University of Bradford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287758.

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28

Tang, Wei-Chien, i 湯偉乾. "Seismic Behavior of Braces Buckled In-Plane". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/53282713888940038786.

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碩士
國立交通大學
土木工程系所
101
This paper aims to design bracing members to achieve in-plane buckling of the braces while subjected to compression, and to study the strength and hysteretic behavior. The ways to lead the brace buckle in-plane are either reducing brace section at both ends of the brace to form a hinge, or using a connecting plate between the gusset plate and the brace to create a rotational area to buckle the brace in-plane. Finite element analysis was conducted to establish the numerical model for parametric study. On the basis of the analytical results, six specimens were designed and tested to validate the hysteretic behavior of the specimens. The results of the finite element analysis indicate that for the brace with reducing brace section and a single gusset plate the formation of the plastic hinge is not distinct because of the distinguish local deformation of the brace web to which the gusset plate was welded; however, the local deformation of the brace web can be attenuated by adding stiffeners. The brace with reducing brace section and double gusset plate can form expected hinge at both ends of the brace. Among the design variables, the depth of the reducing section has major effect of the strength and local behavior of the brace, while the width of the reducing section has minor effect. The brace designed to have connecting plate can achieve in-plane buckling; however the stress concentration occurred at the connection between brace and connecting plate may cause the failure of the brace. The test results demonstrated that all six specimens attained stable nonlinear behavior and dissipating energy. Four specimens with reducing section achieved 4 to 5% rad of the interstory drift angle, buckled in-plane, and fractured at the middle of the brace as predicted in the analysis. One specimen behaved premature failure of the fracture due to the crack occurred at the middle of the brace because of the less reducing section causing higher stiffness at the brace ends and large deformation at brace middle part. Moreover, the braces in-plane deformation of the brace with double gusset plate is larger than those with single gusset plate. The test results revealed that one of the specimens with connecting plate fractured at the connecting plate owing to the direct force transferring between gusset plates and brace flanges, losing the concept of the effective width of the connecting plate. The other specimens with connecting plate failed due to fracture occurred at the weld between the brace and connecting plate, causing by the weld defect. In summary, the brace designed by reducing section at both ends can achieve in-plane buckling of the brace, possesses typical inelastic behavior, and dissipate energy.
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29

Martins, João Pedro Simões Cândido. "Behaviour of cylindrically curved panels under in-­plane stresses". Doctoral thesis, 2014. http://hdl.handle.net/10316/26980.

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Tese de doutoramento em Engenharia Civil, na área de Construção Metálica e Mista, apresentada ao Departamento de Engenharia Civil da Faculdade de Ciências e Tecnologia da Universidade de Coimbra
The objective of this work is to analyse the stability behaviour of cylindrically curved steel panels under generalised in‐plane compressive stresses and to develop design rules which overcome some limitations of current European Standards. For the simplest case of pure compressive axial stresses, the most relevant works have been revisited and analysed. In what concerns the elastic critical stress of cylindrically curved panels, it was concluded that the expressions which are currently available return non‑negligible errors. Relying on the finite element method and, at the same time, on an analytical formulation based on energy methods, new expressions presenting significant improvements and allowing obtaining the elastic critical stress also for panels under non‑uniform in-­plane loading are presented. Concerning the ultimate resistance, the proposed method also shows improvements, but its main contribution is that it allows obtaining the ultimate resistance also for panels under pure in-­plane bending and a direct application to cross‑sections. Finally, it is worth mentioning that, albeit it is not proposed any new method to compute the ultimate load of cylindrically curved panels under biaxial loading, the behaviour of curved panels under this type of loading is analysed relying exclusively on numerical methods.
O objectivo do presente trabalho é a análise da estabilidade de painéis cilín-dricos metálicos sujeitos a tensões de compressão no seu plano médio e o desenvolvimento de regras de dimensionamento que colmatem as limitações que as normas europeias actualmente apresentam. Para o caso mais simples, o da compressão uniaxial uniforme, os principais estudos foram reanalisados tendo-se concluindo que, no que respeita a tensão crítica elástica de painéis cilíndricos metálicos, as expressões disponíveis apresentam erros consideráveis. Recorrendo ao método dos elementos finitos e, paralelamente, a uma formulação analítica baseada em métodos energéticos, foram desenvolvidas novas expressões que melhoram significativamente os valores obtidos para tensão crítica e que permitem, também, calcular a mesma para painéis sujeitos a carregamentos de compressão não uniforme. Em relação à tensão última, o método agora proposto apresenta também melhorias significativas, mas é o primeiro a incluir a possibilidade de calcular a tensão última de painéis cilíndricos metálicos sujeitos a flexão pura no seu plano médio e a permitir uma aplicação directa a secções. Finalmente deve referir-se que, apesar de não se propor nenhum método para a obtenção da tensão última, o comportamento último de painéis cilíndricos sujeitos a compressão uniforme biaxial é caracterizado recorrendo a métodos exclusivamente numéricos.
FCT - SFRH/BD/70424/2010
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30

Manco, Tiago Jorge da Cruz. "Behaviour of unstiffened and stiffened curved steel panels under in-plane and out-of-plane actions". Doctoral thesis, 2018. http://hdl.handle.net/10316/83818.

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PhD thesis in Steel and Composite Construction submitted to the Faculty of Sciences and Technology of the University of Coimbra
Despite being increasingly used in several engineering fields, design provisions to predict the strength of steel curved panels are mostly empirical and with a small range of application. Consequently, the main aim of this thesis is to predict the nonlinear behaviour and ultimate strength of stiffened and unstiffened cylindrically curved steel panels under in-plane and out-of-plane loading based on a physically robust approach, through semi-analytical methods (SAM). The main advantage of this approach, in comparison to the usual approaches, like the Finite Element Method (FEM), is allowing to identify the key parameters that influence the behaviour of the curved panels and to develop expressions purely based on the physical background of the problem, which have a large practical interest. However, the FEM is also used for two reasons: i) to characterize thoroughly and realistically the behaviour of the panels through a wide parametric study; in this case, an innovative way to model imperfections is developed, being more unfavourable than the default approach in shell structures, in a large part of the cases; and ii) to validate the semi-analytical formulation developed for the curved panels. The analysed parameters are found to change dramatically the behaviour of the panels, which, in some cases, may lead to unexpected results. For example, it may be quite unsafe to design a curved panel as if it was a flat plate. In contrast, in other cases, significant gains in resistance are obtained with the increase in curvature. This shows that the design of curved panels has to be performed with a deep knowledge of this complex behaviour. Although only uniaxial in-plane compression (the key aspect in the stability of thin walled structures) and out-of-plane pressure are studied in this thesis, the formulation is developed to account for generalized loading. A large deflection formulation with a multi degree-of-freedom (MDOF) solution and imperfections is implemented. Additionally, the SAM accounts for in-plane constrained and unconstrained simply supported boundary conditions. This requires a rigorous solution of boundary value problem of the fourth order nonlinear partial differential equations. Despite the complex behaviour identified for the curved panels, the SAM is able to account accurately for all the geometric parameters, boundary and loading conditions. Although the panels with larger curvatures benefit from the implemented MDOF solution, closed-form expressions, based on a SDOF approximation, are able to provide accurate results for the equilibrium paths of unstiffened and stiffened curved panels with practical significance under in-plane and out-of-plane loading. The SAM is then used, with a yield criterion, to predict the resistance of unstiffened curved panels under compression. Expressions are derived to calculate the ultimate load of these panels, showing good agreement with the FEM.
Apesar de serem cada vez mais usados em vários campos da engenharia, as provisões para prever a resistência de painéis curvos são maioritariamente empíricas e com reduzida gama de aplicação. Consequentemente, o principal objetivo desta tese é prever o comportamento não-linear e carga última de painéis curvos cilíndricos não reforçados e reforçados com base numa abordagem fisicamente robusta, através de métodos semi-analíticos (MSA). A principal vantagem desta abordagem, comparativamente às abordagens usuais, como o método dos elementos finitos (MEF), é permitir identificar os parâmetros-chave que influenciam o comportamento dos painéis curvos e desenvolver expressões puramente baseadas no contexto físico do problema, as quais têm um enorme interesse prático. Contudo, o MEF é também usado por duas razões: i) para caracterizar detalhada e realisticamente o comportamento dos painéis curvos através de um estudo paramétrico alargado; neste caso, é desenvolvida uma forma inovadora de modelar as imperfeições, sendo esta mais desfavorável, numa grande parte dos casos, que a abordagem padrão utilizada em estruturas de casca; e ii) para validar a formulação semi-analítica desenvolvida para os painéis curvos. Os parâmetros analisados mostram-se capazes de alterar drasticamente o comportamento dos painéis, os quais, em alguns casos, podem conduzir a resultados inesperados. Por exemplo, pode ser bastante inseguro dimensionar um painel curvo como se fosse uma placa plana. Contrariamente, em outros casos, são obtidos ganhos significativos da resistência com o aumento da curvatura. Isto mostra que o dimensionamento de painéis curvos deve ser realizado com um profundo conhecimento deste complexo comportamento. Embora apenas compressão uniaxial no plano (o especto-chave na estabilidade de estruturas de parede fina) e pressão fora do plano sejam estudadas, a formulação é desenvolvida para ter em conta carregamento generalizado. É implementada uma formulação de grandes deslocamentos com uma solução de multi-graus de liberdade (MGDL) e imperfeições. Adicionalmente, o MSA tem em conta condições de fronteira simplesmente apoiadas restringidas e não restringidas no plano. Isto requer uma solução rigorosa do problema de valor de fronteira das equações diferenciais parciais não-lineares de quarta ordem. Apesar do complexo comportamento identificado para os painéis curvos, o MSA é capaz de ter em conta, de forma precisa, todos os parâmetros geométricos, condições de fronteira e carregamento. Embora os painéis com maiores curvaturas beneficiem da solução MGDL implementada, expressões de forma fechada, baseadas numa aproximação de um único grau de liberdade (UGDL), são capazes de fornecer resultados precisos para as trajetórias de equilíbrio de painéis curvos não reforçados e reforçados com significância prática, sob carregamento no plano e fora do plano. O MSA é seguidamente usado com um critério de cedência para prever a resistência de painéis curvos não reforçados sob compressão. São derivadas expressões para calcular a carga última destes painéis, mostrando bom acordo com o MEF.
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31

Hsiue, Kai-Yuan, i 薛凱元. "In-Plane Behavior of Slender Unreinforced Masonry Walls in RC Frames". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/27651443336417954198.

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碩士
國立成功大學
建築學系碩博士班
96
Slender unreinforced masonry (URM) walls can easily be found in typical RC school buildings in Taiwan, in-filled between RC frames and doors or windows due to the need for opening. Since the walls are only 60~100cm wide with a slenderness ratio more than 1 and lack of vertical boundary members, they are usually damaged by flexural bending in earthquakes. Based on the failing behavior investigated from in-site tests and the concept from former researches, an analytical model for flexural cracking and ultimate strength of slender URM walls is established in this thesis. From the observation in in-site tests for existing school buildings, it is found that when the slender URM wall is subjected to lateral loading comes from the top slab, horizontal flexural cracks appears along its top and bottom edges at once due to lack of tensile capacity. However, with sufficient vertical confinement by RC boundary frame, an inclined strut can form between the top and bottom compressive zones and provide lateral resistance by arching action. In the analytical model, the lateral resistance is derived from equilibrium of the couple by eccentric resultant compression at the top and bottom compressive zones and the moment resulted from lateral load. By assuming the wall is nearly rigid between cracked sections, the strain and depth of compressive zone can be derived geometrically. A stress-strain relationship for masonry is then employed to calculate the compressive stress and resultant compression. The lateral load-drift curve can be obtained by repeating the calculation for any given drift and the maximum load in the curve means the flexural ultimate strength of the wall. The model shows that analytical flexural ultimate strength of URM walls is proportional to its uniaxial compressive strength and almost inversely proportional to the slenderness ratio. The effect by simultaneously applied axial loading is also considered in this model. It appears that the analytical flexural strength increases slightly with the increase of initial axial loading less than about 60% of the ultimate axial strength but decreased rapidly after axial loading exceeds the range. Determination of analytical failure mode by introducing an existing model for shear strength is presented in the thesis as well. Comparison with experimental results shows that the analytical flexural strength and load-drift curves are conservative and reasonable.
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32

Jian-Guang, Lai, i 賴建光. "The Asymptotic Behavior of Analytic Dynamical Systems in Complex Plane". Thesis, 1997. http://ndltd.ncl.edu.tw/handle/08551064984959032322.

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碩士
中原大學
數學研究所
86
From Robert B. Burchel's "An Introduction to Classical Complex Analysis" and Peter Henrici's "Applied and Computational Complex Analysis", we can see that the behavior of analytic dynamical systems on open unit disc are very rich and interesting. So, it is desirable for us to study this kind of dynamical systems deeply. In this thesis, we study analytic dynamical systems from open unit disk to itself by iteration. Set f*=I, the identity function. Inductively, we define f*(z)=f(f(z)),.... We call f* the n-th iterate of f for each non-negative integer n. This thesis is organized as the following: In part one, we discuss all kinds of behavior of analytic dynamical systems from open unit disc to itself. They are classified into the following types: a. f is an analytic mapping from open unit disk into itself. b. f is a conformal mapping from open unit disk to itself. c. f is a non-conformal mapping from open unit disk to itself. We find that either there exists a constant in unit disk such that the dynamical system converges to it or the dynamical system is a generalized rotation. Moreover, we prove the behavior of dynamical systems from open unit disk to itself never be chaotic.A generic property of dynamical systems from open unit disc to itself is investigated in part 2, We call f is simple if there is a fixed point in open unit disk such that the sequence {f*(z)} converges to the fixed point for all z in open unit disk. We prove that if f is simple then any perturbation g of f is also simple. Consequently, S={f| f is analytic and simple dynamical system from open unit disc to itself} is dense and open in F={f | f is analytic dynamical system from open unit disc to itself}.In part 3, by using Riemann Mapping Theorem and Osgood-Taylor-Carathdory Theorem, we extend the results of the analytic dynamical systems defined on open unit disk to the analytic dynamical systems defined on simply connected domains whose boundaries are Jordan curves. And by Montel's Theorem, some results of analytic dynamical systems from open unit disk to the compact set in itself is extended to the analytic dynamical systems which are defined on open connected domain in complex plane. In the last part, we use the results in previous sections and the concept of generating function P(x) to determine the probability of the generation of particles in branching processes. We find if P'(1)>1 then then there exists a constant in [0,1) such that the sequence {P*(x)} converges to the constant, otherwise the particles extinct, where the constant is the probability for the particles to survive.
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33

Safiee, N. A., N. A. M. Nasir, Ashraf F. Ashour i N. A. Bakar. "Behaviour of interlocking mortarless hollow block walls under in-plane loading". 2018. http://hdl.handle.net/10454/16855.

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Yes
Experimental study of five full scale masonry wall panels subjected to prescibed pre-compressive vertical loading and increasing in-plane lateral loading is discussed. All five walls were constructed using interlocking mortarless load bearing hollow concrete blocks. The behaviour of wall in term of deflections along the wall height, shear strength, mortarless joint behaviour and local and overall failures under increasing in-plane lateral loading and pre-compressive vertical loading are reported and analysed. Simple strut-and-tie models are also developed to estimate the ultimate in-plane lateral capacity of the panel walls tested. The results indicate that, as the pre-compressive load increases, the in-plane lateral load capacity of walls increases. All walls tested failed due to diagonal shear and/or moderate toe crushing depending on the level of the pre-compressive load. The proposed strut-and-tie models were able to give reasonable predictions of the walls tested.
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34

Furtado, André Filipe Castanheira Alves. "Seismic vulnerability assessment and retrofitting strategies for masonry infilled frame buildings considering in-plane and out-of -plane behaviour". Tese, 2020. https://hdl.handle.net/10216/127205.

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35

Furtado, André Filipe Castanheira Alves. "Seismic vulnerability assessment and retrofitting strategies for masonry infilled frame buildings considering in-plane and out-of -plane behaviour". Doctoral thesis, 2020. https://hdl.handle.net/10216/127205.

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36

Souza, Jean Marcos Teixeira de. "In-plane thermo-mechanical behavior of curved steel beams with constant curvature". Master's thesis, 2019. http://hdl.handle.net/10198/23322.

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Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Curved steel beams and arches are structures originated from mechanical processes of curving straight members, usually I or H profiles, in order to get a desired geometry to attend aesthetics or project requirements. This type of elements behave differently when compared to regular straight members, with specific instability modes and different responses to various types of loading conditions. For these reasons, such structural members may react distinctively when submitted to fire conditions or elevated temperatures. This paper studies the stability and collapse load of steel curved beams and arches, curved by their major axes, through numerical Finite Element analyses for in-plane buckling at natural and elevated temperatures, simulating a fire event. Firstly, it was developed an analytical method to compute the internal forces based in energy methods for pin-supported arches under two point loads applied at one fourth of the length measured from the supports. Subsequently, linear elastic and nonlinear elasto-plastic buckling and ultimate load analyses were performed at both natural and elevated temperature conditions with the ANSYS Mechanical APDL Finite Element software package, for a variety of span and rise-to-span ratio values, support conditions and steel classes. These results were then compared to critical buckling load formulations found in the literature and to simplified methods presented in Eurocode 3 for elements under bending moments and axial forces. It is seen that support conditions play an important role in the thermo-mechanical response of steel arches, where fixed supports yielded much higher critical load results for every geometry and temperature case. However, even though superior steel classes provide higher resistant loads, regarding responses to thermal loads it was found that support condition is also more significant in this case. Moreover, the standard Eurocode 3 methodology for straight members was compared to the numerical results, which showed a good fit for lower bound loads except for higher slendernesses under elevated temperatures, where numerical solutions yielded result points under the standard resistance curves. Also, an analytical and experimental study on the cold-curving process of straight steel beams into arches using point loads was conducted, aiming to analytically define a post-curving residual stress profile and investigate the influence of elastic springback in the final shape of an arch.
Vigas curvas e arcos de aço são estruturas originadas de processos mecânicos de curvamento de membros retos em curvos, geralmente perfis I ou H, a fim de obter a geometria desejada para atender a requisitos estéticos ou de projeto. Esse tipo de elemento comporta-se de maneira diferente quando comparado a membros retos regulares, com modos de instabilidade específicos e respostas diferentes a várias condições de carregamento. Por esses motivos, esses membros estruturais podem também reagir diferentemente quando submetidos a condições de incêndio ou temperaturas elevadas. Este trabalho estuda a estabilidade e a carga de colapso de vigas e arcos curvos de aço, curvados em seus eixos de maior resistência, através de análises numéricas de elementos finitos para encurvadura no plano à temperaturas ambiente e elevadas, simulando um evento de incêndio. Primeiramente, foi desenvolvido um método analítico para calcular as forças internas baseadas em métodos de energia para arcos bi-rotulados sob cargas pontuais aplicadas em um quarto do comprimento medido a partir dos suportes. Posteriormente, foram realizadas análises de encurvadura linear elástica e de carga última não-linear elasto-plástica em condições de temperatura naturais e elevada com o pacote de software ANSYS Mechanical APDL de elementos finitos, para uma variedade de valores de vão e relação altura-vão, condições de suporte e classes de aço. Esses resultados foram comparados com as formulações de carga crítica de encurvadura encontradas na literatura e com os métodos simplificados apresentados no Eurocódigo 3 para elementos submetidos a momentos fletores e forças axiais. Observa-se que as condições de suporte desempenham um papel importante na resposta termomecânica dos arcos de aço, onde os suportes fixos produzem resultados de carga crítica muito mais altos para cada caso de geometria e temperatura. Ademais, embora classes de aço superiores proporcionem maior resistência mecânica, em relação às respostas à cargas térmicas, verificou-se que a condição de suporte também é mais significativa neste caso. Além disso, a metodologia padrão do Eurocódigo 3 para membros retos foi comparada com os resultados numéricos, que mostraram um bom ajuste com os limites impostos pela metodologia padrão, exceto para esbeltezas mais altas sob temperaturas elevadas, onde as soluções numéricas produziram resultados abaixo das curvas de resistência padrão. Também, um estudo experimental e analítico foi conduzido acerca do processo de curvamento a frio de vigas de aço retas em arcos utilizando cargas concentradas, com objetivo de definir analiticamente um perfil de tensões residuais póscurvamento e investigar a influência do retorno elástico na forma final de um arco.
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37

Dai, Xianghe. "Numerical Modelling and Analysis of Structural Behaviour of Wall-stud Cold-formed Steel Shear Wall Panels under In-plane Monotonic Loads". 2012. http://hdl.handle.net/10454/11605.

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No
This paper presents a numerical modelling method to predict the shear behaviour of typical wall-stud cold-formed steel wall panels subjected to in-plane monotonic loads. In the research presented in this paper, different material and mechanical properties for cold-formed steel sheets, self-drilling screwed connectors and wall fixing boundary conditions were considered to explore the influence of sheath sheeting, connectors and fixing boundary conditions on the structural behaviour of selected wall panels. After the FE model being validated against experimental results, a parametric study was conducted and the comparison and analysis highlight the effect of different sheaths, connectors on to the structural shear behaviour of typical wall-stud cold-formed steel wall panels.
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38

Soon, Sandra. "IN-PLANE BEHAVIOUR AND CAPACITY OF CONCRETE MASONRY INFILLS BOUNDED BY STEEL FRAMES". 2011. http://hdl.handle.net/10222/14327.

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Masonry infilled walls have been commonly used as interior partitions as well as exterior walls infilled in either steel or reinforced concrete frames in the modern building constructions. In recent years, much research involving both experimentation and numerical modeling has been conducted in an effort to better understand the infill-frame interaction and to provide some rational design approaches. Studies have shown that infill walls can develop a number of possible failure mechanisms, depending on the strength and stiffness of the bounding frames with respect to those of the infills and the geometric configuration of the framing system. Most of models proposed for analysis of infill walls focused on one type of mechanism or the other, and they were not universally applicable to all infilled structures.
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39

Tsung-HuaChuang i 莊宗樺. "Seismic Behavior of Slender Partially-Confined Masonry Panels Subjected to In-plane Force". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/80199675644686520274.

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博士
國立成功大學
建築學系碩博士班
101
In Taiwan, confined masonry wall (CM) walls are often divided into several slender partially-confined masonry (SPCM) panels due to the needs of openings. SPCM panels can be classified into piers or wing-walls by the restraint conditions. Since SPCM panels are obviously weaker then complete CM panels without openings, the SPCM panels usually govern the capacity of resisting earthquake of a building. However, because of the difficulty in analysis, the contribution of SPCM panels is usually ignored in practical seismic assessment, causing over-conservative results. Most of current analytical models are not suitable for this kind of panels. Therefore, the objective of this thesis is to investigate the seismic behavior and to establish an analytical model of SPCM panels. A series of static lateral-load tests for SPCM panels had been conducted in the laboratory of National Center for Research on Earthquake Engineering (NCREE). All specimens are full-scaled, including two piers and seven wing-walls. The two pier specimens were identical and subjected to different axial force during the test. The test factors of wing-wall specimens include the number and the length of the panels, the position of the column and the loading type. The test results suggest that the seismic behavior and failure mode of the pier specimens are obviously different from the wing-wall specimens due to the interaction between the panel and the column. The lateral strength of pier specimens is proportional to the axial force., but the ductility is lower when the axial force is higher. The wing-wall specimens with longer panels have higher initial stiffness, higher strength, and lower ductility. The lateral strength of wing-wall specimens is approximately proportional to the total length of the panels, even though the failure modes are not the same. Although axial load were applied to all the wing-wall specimens during the test, uniform tensile cracks were observed on the columns, indicating that the columns were subjected to tension while the masonry panels were subjected to additional compression. No matter which side the masonry panel was placed, the single wing-wall specimens showed similar lateral resistance, indicating that the custom of neglecting masonry panels on the “tensile” side in analysis is not reasonable. According to the test results and former researches, the failure modes of SPCM panels can be classified as shear failure and flexural failure and shear failure includes diagonal tension failure, diagonal compression failure and bed-joint sliding failure. The load resistance mechanism of the SPCM panels is also generalized. The piers resist lateral loading with double-hinged arch mechanism, while the wing-walls can be considered as strut-and-tie systems. Analytical models for both piers and wing-walls had been established on the basis of structural behavior summarized from the test result. The model for pier can be applied to fixed-vertical restraint or fixed-axial-force conditions. It is used to evaluate the piers failed by flexure and display rocking behavior. In the comparison with existing test results, the analytical model shows accurate and reasonable evaluation for the load-displacement curve of piers. The model for wing-wall considers the additional compression due to panel-column interaction and the contribution of the column. It was established by modifying existing models. The ultimate strength, the failure mode, and the form of load-displacement curve are determined by the minimum between the strengths of three failure modes. The comparison with test results shows that the analytical model can accurately evaluate the ultimate strength and failure mode of wing-walls, but error in load-displacement curve becomes obvious when a wing-wall reaches its ultimate strength as initial cracking happens. Generally, the analytical model shows reasonable and conservative estimation.
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40

Leigh, David Keith. "Effect of in-plane voiding on the fracture behavior of laser sintered polyamide". Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-12-4609.

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Laser Sintering, a method of additive manufacturing, is used in the production of concept models, functional prototypes, and end-use production parts. As the technology has transitioned from a product development tool to an accepted production technique, functional qualities have become increasingly important. Tension properties reported for popular polyamide sintering materials are comparable to the molded properties with the exception of elongation. Reported strains for laser sintered polyamide are in the 15-30% range with 200-400% strains reported for molding. (CES Edupack n.d.) The primary contributors to poor mechanical properties in polyamide materials used during Selective Laser Sintering® are studied. Methods to quantify decreased mechanical properties are compared against each other and against mechanical properties of components fabricated using multiple process parameters. Of primary interest are Ultimate Tensile Strength (UTS) and Elongation at Break (EOB) of tensile specimens fabricated under conditions that produce varying degrees of ductile and brittle fracture.
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41

Lin, Hsuan-Pai, i 林宣百. "Out-of-Plane Seismic Behavior of Unreinforced Masonry Infilled Walls in RC Frames". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/07475701989160419135.

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碩士
國立成功大學
建築學系碩博士班
94
In Taiwan, many people live in RC buildings that were constructed with un-reinfroced infilled masonry walls in RC frames. The existing seismic assessment for such structures usually emphasizes only on in-plane capacity of the infilled walls. However, the damage reports for earthquakes tell that sometimes the infilled masonry walls collapse at out-of-plane direction before they can contribute in-plane capacity. In this thesis, failing behavior of infilled masonry walls and interaction between the walls and RC boundary frames when they were subjected to out-of-plane loading were investigated from results of in-site tests. Analytical models were developed for estimating out-of-plane cracking and ultimate strength and displacement of the infilled masonry walls. From 2 in-site tests, it is found that when the infilled masonry walls were subjected to out-of-plane concentrated loading, the top and bottom of walls bended and cracks happened at the tensile side. Out-of-plane displacement measured show that after the cracking happened, region between top and bottom cracks remained rigid, therefore the walls behave like 2-force members with hinges at both ends. The analytical model assumes that infilled masonry walls are subjected to only concentrated loading. The cracking strength and displacement can be calculated simply by material and geometric properties, while the ultimate strength and displacement are developed by strut model. The ratio of height to thickness and compressive strength of brick piers are found to be main factors of the out-of-plane ultimate strength. Analytical P-Δ curves of infilled masonry walls are compared with the experimental ones. Analytical model presented in this thesis shows conservative but better prediction than other analytical models. It shows that the analytical model presented in this thesis is reasonable and applicable.
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42

Chen, Chi-Tien, i 陳其田. "Electrophoretic Behavior of a Spherical Colloidal Particle to a Plane in Carreau Fluid". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/42523145513874433869.

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碩士
國立臺灣大學
化學工程學研究所
92
In this study, we investigated the electrophoretic behavior of a charged spherical colloidal particle in polymeric fluid with the presence of a planar surface. We adopted Carreau model to describe the polymeric fluid, which is widely used on describing polymeric fluid with shear-thinning nature. The corresponding electrokinetic equations are further linearized based on the assumptions of low zeta potential and weak applied field, and solved simultaneously by pseudo-spectral method. We found several interesting phenomena which can not be observed in typical Newtonian cases. For instance, under lower (the power law exponent) or higher (the relaxation time constant), the higher the mobility. This is because the fluid property deviates from Newtonian, the shear thinning nature is more obvious. On the other hand, the closer the planar surface to the colloidal is, the mobility will become higher than that in the case of Newtonian fluid. This is because the shear-thinning effect is enhanced by the presence of the boundary.
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43

Dai, Xianghe. "Structural Behaviour of Cold-formed Steel Cassette Wall Panels Subject to In-plane Shear Load". 2013. http://hdl.handle.net/10454/11604.

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No
This paper presents the structural behaviour of cold-formed steel cassette wall panels subjected to in-plane shear loads. To understand the influence of configuration, lining material and connector arrangement on the overall shear behaviour of typical cassette wall panels, different lining materials, fastener spacing and positions, edge stiffeners and specific boundary conditions were assumed in the numerical simulations. The comparison and analysis presented in this paper demonstrate typical effect factors to the load-bearing capacity of selected wall panel systems. In particular, the effect of wall opening to the structural shear behaviour of wall panels is highlighted.
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44

Petersen, Robert. "In-plane shear behaviour of unreinforced masonry panels strengthened with fibre reinforced polymer strips". 2009. http://hdl.handle.net/1959.13/44603.

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Research Doctorate - Doctor of Philosophy (PhD)
Inserting fibre reinforced polymer (FRP) strips into pre-cut grooves in the surface of masonry walls is an emerging technique for the retrofit of unreinforced masonry (URM) structures. This method, known as near surface mounting (NSM), provides significant advantages over externally bonded FRP strips in that it has less of an effect on the aesthetics of a structure and can sustain higher loading before debonding. As this technique is relatively new, few studies into the behaviour of masonry walls strengthened using this technique have been conducted. A combined experimental and numerical program was conducted as part of this research project to study the in-plane shear behaviour of masonry wall panels strengthened with NSM carbon FRP (CFRP) strips. In this project the FRP strips were designed to resist sliding along mortar bed joints and diagonal cracking (through mortar joints and brick units). Both of these failure modes are common to masonry shear walls. Different reinforcement orientations were used, including: vertical; horizontal; and a combination of both. The first stage of the project involved characterising the bond between the FRP and the masonry using experimental pull tests (18 in total). From these tests the bond strength, the critical bond length and the local bond-slip relationship of the debonding interface was determined. The second stage of the project involved conducting diagonal tension/shear tests on masonry panels. A total of four URM wall panels and seven strengthened wall panels were tested. These tests were used to determine: the effectiveness of the reinforcement; the failure modes; the reinforcement mechanisms; and the behaviour of the bond between the masonry and the FRP in the case of a panel. The third stage of the project involved developing a finite element model to help understand the experimental results. The masonry was modelled using the micro-modelling approach, and the FRP was attached to the masonry model using the bond-slip relationships determined from the pull tests. Reinforcement schemes in which vertical FRP strips were used improved the strength and ductility of the masonry wall panels. When only horizontal strips were used to reinforce a wall panel, failure occurred along an un-strengthened bed joint and the increase in strength and ductility was negligible. The vertical reinforcement prevented URM sliding failure by restraining the opening (dilation) of the sliding cracks that developed through the mortar bed joints. The finite element model reproduced the key behaviours observed in the experiments for both the unreinforced and FRP strengthened wall panels. This model would potentially be useful for the development of design equations.
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45

Lai, Meng-Sheng, i 賴孟昇. "Behavior Anomaly Detection in SDN Control Plane: A Case Study of Topology Discovery Attacks". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/smbt8h.

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碩士
國立中央大學
資訊工程學系
107
With the rapid development of information technology and the popularity of smart devices, users' demand for instant processing of network services and diversified services has also increased significantly, making the architecture of traditional network services unable to meet the rapidly changing network architecture of emerging services Demand. Software-defined Networking (SDN) and Network Function Virtualization (NFV) have therefore been proposed to transform complex network architectures into virtual and programmable architectures to reduce network complexity, bringing about major changes to the traditional network architecture. SDN controller use OpenFlow Discovery Protocol (OFDP), which detects the links between the OpenFlow switches by generating Link Layer Discovery Protocol (LLDP) packets, to collect comprehensive network topology status for the routing and switching of packets. However, OFDP is not a completely secure protocol and can be used by attackers to perform topology discovery injection attack, topology discovery man-in-the-middle attack and topology discovery flood attack, thereby confusing the network topology.
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46

McCarthy, Katelyn Barbara. "Experimental in-plane behavior of a generic scale model drag embedment anchor in Kaolinite test beds". Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-05-3417.

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The trajectory and capacity are key components of the design of drag embedment anchor and drag-in vertically loaded anchors. This experimental testing program quantifies two factors that describe the anchor trajectory and capacity: the equilibrium bearing factor (Ne) and the tangential bearing factor (Ne). These factors can aid in the development of a numerical model of anchor behavior. A magnetometer device is used to track the orientation and location of the anchor during drag embedment. The results of the experimental testing program were compared with the results from a predictive model. The experimental program consisted of drag embedment tests with various testing conditions including different anchor line diameters and different initial pitch orientations. The results with the different anchor lines indicated that thinner anchor lines cause the anchor to dive deeper in the soil. The different initial pitch results indicate that regardless of the initial pitch of the anchor, the anchor rotates to a unique pitch trajectory within 2 fluke lengths.
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47

Feng, Chung-tsung. "Controlling chaos in a sagittal plane biped model using the Ott-Grebogi-Yorke method". Thesis, 2012. http://hdl.handle.net/10413/8923.

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Controlling a system with chaotic nature provides the ability to control and maintain orbits of different periods which extends the functionality of the system to be flexible. A system with diverse dynamical behaviours can be achieved. Trajectory flows of chaotic systems can be periodically stabilised using only small perturbations from the controlled parameter. The method of chaos control is the Ott-Grebogi-Yorke method. In non-chaotic systems large system parameters changes are required for performance changes. A sagittal plane biped model which is capable of exhibiting periodic and chaotic locomotion was researched and investigated. The locomotion was either periodic or chaotic depending on the design parameters. Nonlinear dynamic tools such as the Bifurcation Diagram, Lyapunov Exponent and Poincaré Map were used to differentiate parameters which generated periodic motion apart from chaotic ones. Numerical analytical tools such as the Closed Return and Linearization of the Poincaré Map were used to detect unstable periodic orbit in chaotic attractors. Chaos control of the model was achieved in simulations. The system dynamic is of the non-smooth continuous type. Differing from other investigated chaotic systems, the biped model has varying phase space dimensions which can range from 3 to 6 dimensions depending on the phase of walking. The design of the biped was such that its features were anthropomorphic with respect to locomotion. The model, consisting of only the lower body (hip to feet), was capable of walking passively or actively and was manufactured with optimal anthropometric parameters based on ground clearance (to avoid foot scuffing) and basin of attraction simulations. During experimentation, the biped successfully walked down an inclined ramp with minimal aid. Real time data acquisitions were performed to capture the results, and the experimental data of the walking trajectories were analysed and verified against simulations. It was verified that the constructed biped exhibits the same walking trend as the derived theoretical model.
Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.
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48

Chang, Ming-Kang, i 張明康. "Analytical Study of In-Plane Shear Behavior of Steel-Plate Composite Wall with Boundary Elements". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/bj74k8.

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碩士
國立臺灣大學
土木工程學研究所
105
Currently, AISC N690s1-15 (2015) provides the method for predicting the in-plane shear strength of steel-plate composite wall (SC wall). On the other hand, Booth et al. (2015) also provides another prediction method based on AISC N690s1-15 (2015) to improve the underestimate for predicting the in-plane shear strength of SC wall with boundary elements. Nevertheless, whether AISC N690s1-15 (2015) or Booth et al. (2015), they both simply take the dimension of horizontal cross section and the parameters of materials into consideration, neglecting the effect of aspect ratio. It means that SC walls with the same dimension of horizontal cross section but different height have the same in-plane shear strength. The prediction is different from the experimental result. This research uses above result as a starting point, taking the effect of aspect ratio, providing a method with physical meaning for predicting the in-plane shear strength of SC wall with boundary elements. To make a further understanding of the behavior of SC wall, this research uses the finite element method software LS-DYNA as the analytical tool, developing a prediction model. The shear strength of SC wall can be calculated directly by the contribution of faceplate and concrete strut respectively. Furthermore, prediction model uses the depth of compression zone which is more convenient to get by cross-sectional analytical software XTRACT to replace the depth of concrete strut. Finally, this research simplifies the prediction model by observing the analytical result by XTRACT. Comparing the simplified method suggested by this research with other prediction methods, simplified method is more accurate than other prediction methods. For evaluating the in-plane shear strength of SC wall with boundary elements, simplified method is a more accurate, convenient, and physically prediction method.
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49

Cheng, Yu-Cheng, i 鄭與錚. "An Experimental Study of In-Plane Behavior of Steel-Plate Composite Walls with Boundary Elements". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/97287363412792422270.

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碩士
國立臺灣大學
土木工程學研究所
104
Steel-plate composite (SC) walls are being used in the third generation of nuclear power plants. SC walls are composed of steel faceplates, connectors and infill concrete, where the connectors are typically constructed from cross-wall tie rods and shear studs welded to the faceplates. The connectors used to transfer shear between faceplate and concrete. The AISC N690s1 provides recommendations for in-plane shear strength, out-of-plane shear strength and out-of-plane flexure strength for steel-plate composite walls, but not for in-plane flexure strength. A recent study concludes that the in-plane shear strength of steel-plate composite walls with boundary elements was underestimated in AISC N690. The behavior of four SC walls with boundary elements subjected to cyclic in-plane loading is summarized in this study. The experiment was executed in the laboratory of National Center for Research on Earthquake Engineering (NCREE) in Taiwan. Thick steel plates were used as boundary elements of the four specimens. The specimens were designed to study two kinds of failure modes, including 1) shear critical walls with an aspect ratio of 0.75 and a thickness of 3 cm for boundary elements; and 2) flexure critical walls with an aspect ratio of 1.22 and a thickness of 2 cm for boundary elements. The test results were compared with the recommendations of AISC N690s1 and selected literatures. The impact of wall aspect ratio, concrete compressive strength and wall thickness on the in-plane shear strength and in-plane flexure strength of SC walls with boundary elements were discussed.
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50

Chen, Bo-An, i 陳柏安. "An Experimental Study of the In-Plane Cyclic Behavior of Low-Aspect-Ratio Steel-Plate Composite". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/67491595044973658336.

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