In this thesis, two-dimensional floating structure consists of single rectangular impermeable pontoon and single cable is studied.The purpose of this study is to obtain the motion analysis of incident waves acting on a floating with cable-restrained. All boundary conditions are linearlized in the problem which is separated into a scattering problem and radiation problem with unit motion amplitude. The method of separation of variable is used to solve for velocity potentials. Divide two kinds of discussions in cable-restrained¡G1¡BWith sag effective and flexural rigidity. 2¡BNO sag effective and no flexural rigidity. The boundary value problem with nonhomogeneous boundary condition beneath the structure is solved by using a solution procedure proposed by Lee(1995). By combining the scattering solution, radiation solutions of three degrees of freedom, and equations of motion of the floating structure, an analytic solution for the problem is developed.

In this paper¡Athe cable structures considering sag effect and flexural rigidity are used to the series of dynamic analysis.It dedatees on vibration of the cables by the harmonic force and win¡Ðrain induced vibration. Using the finite element method to analyze the effect of the sge and the effect of the sag and the flexural rigidity¡Aincluding frequencies of the cable and displacement of every nodes at arbitrarily time.

The thesis is divided in three parts based largely on published articles or on manuscripts submitted for publication. First we propose a new method which is called the shooting-bead method. This method is a fast and easy experimental technique for evaluating cantilever stiffness and flexural rigidity of semi-flexible to semi-rigid rod-like biological and nano-filaments based on the measurement of just two distances. The method is based on applying a force normal to the filament with a microsphere bead trapped in the laser tweezer followed by its sudden release. Through a simple measurement of the distances that the bead moves, the flexural rigidity of the filament can be found from the formula derived in this paper. Then we take into account the effects of the viscous drag force exerted on the filament itself. To this end, we have defined a key variable, called the filament energy-loss factor (or filament drag factor) that accounts for all the energy-loss effects. It has been shown that the effect due to the consideration of filament energy-loss factor on calculation of the flexural rigidity increases with increasing the flexibility of the filament. Finally, in the third part we discuss the effect of ultrasound on the microtubules. Here we have analytically solved equations of motion for the vibrational dynamics of an MT that is attached at its two ends. This is especially relevant for MTs during mitosis when they attach to chromosomes and centrosomes. Our analysis applies to MTs present inside a viscous solution and when driven by an ultrasound plane wave. We have shown that with using ultrasound plane waves the resonance condition for the MT treated as a rigid rod cannot be provided, and in order to achieve resonance we should excite a single mode of the MT with a harmonic number larger than a threshold value introduced in this thesis. Single mode excitation not only helps to transfer the minimum amount of energy to the surrounding medium compared with multi-mode excitation but it also allows for a simultaneous high-amplitude and high-quality factor which is impossible when using plane waves.

No description available.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23885号 / 工博第4972号 / 新制||工||1776(附属図書館) / 京都大学大学院工学研究科マイクロエンジニアリング専攻 / (主査)教授 横川 隆司, 教授 安達 泰治, 教授 井上 康博 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Knitting is a class of techniques for production of textile fabrics by inter-looping yarns withthe use of hooked needles. The new loops are created when the yarns drawn through thepreviously formed loops. An apparatus for two needles with adjustable geometry resemblingthe knitting process in weft knitting machines has been constructed and mounted in anordinary tensile testing machine in order to study stress build-up, fibre damage, needle wearetc. The merits of the knittability test-rig set-up are the possibilities to test the performance ofthe yarns with the geometry of the machine and to simulate and identify some of the problemsthat can occur between needles and yarn in the knitting process. Well-defined mechanicalconditions with the static pre-load weight and the possibilities to identify the location of theevents of damage on the fibres during the testing of the specimens and to do furtherexamination before knitting are some obvious merits. The knittability of some extreme yarns,PET-monofilaments, carbon fibre roving and aramid yarn has been studied with respect tofriction and bending stiffness. Friction and bending characteristics exhibit viscoellasticfeatures. The needles have diameters of the same order of magnitude as the diameters ofmonofilaments for example for use in knitted spacer fabrics and the results of this workillustrate strong influence of the fibre diameter on the knittability. / <p>Program: Magisterutbildning i textilteknologi</p><p>Uppsatsnivå: D</p>

Les microtubules sont des composants structuraux de cellules et gouvernent des fonctions cellulaires essentielles telles que les mitoses et le transport des vésicules. Ils sont composés de deux sous-unités non identiques (tubulines α et β), formant un dimère, et sont arrangés de sorte à former une structure tubulaire de 20nm de diamètre. Généralement, ils sont constitués de 13 ou 14 protofilaments arrangés en spirale. Les liaisons longitudinales entre dimères sont plus rigides et fortes que les liaisons latérales. Aussi, les microtubules sont des structures fortement anisotropes. Dans ces travaux de thèse, nous avons pour but de définir l'ensemble des coefficients élastique qui permet de reproduire leur comportement atomistique ainsi que de rendre compte de leur réponse mécanique selon des chemins de chargement variés. En négligeant la discontinuité hélicoïdale souvent observée, un microtubule est représenté par une structure triangulaire de dimères à partir desquels un volume élémentaire représentatif est défini. Un potentiel harmonique est utilisé pour décrire les interactions entre dimères voisins. A partir de l'estimation des constantes élastiques et de l'utilisation de la méthode proposée par Arslan et Boyce (2006) -alors pour analyser le comportement mécanique d'un réseau triangulaire de spectrines composant les membranes des globules rouges-, un modèle continu de comportement mécanique est présenté pour reproduire le comportement des parois des microtubules. Un modèle numérique éléments finis est ensuite créé pour modéliser le comportement d'un microtubule dans sa globalité. Des éléments coques sont utilisés pour reproduire les fines parois des microtubules. Les propriétés du modèle éléments finis sont ajustées à partir des résultats du modèle présenté ainsi qu'aux données expérimentales provenant de la littérature. La rigidité de flexion calculée au cours de simulation des tests de flexion 3 points est en accord avec les valeurs de la littérature. Ces tests révèlent les mécanismes de déformation en fonction de la longueur utile du tube utilisé: Flexion et cisaillement locaux de la paroi gouvernent la déformation pour de "petits" tubes. Pour des longueurs "moyennes" le cisaillement et la flexion du tube prédominent. Enfin, dans le cas de tubes "longs", la déformation est uniquement associée aux effets de flexion. Ces résultats témoignent de l'influence de l'anisotropie du tube sur la réponse observée selon différents mode de sollicitation. Ils permettent également d'expliquer l'évolution de la rigidité de flexion avec la longueur utile du tube, comme reportée dans la littérature. Enfin, des micrographes montrent la propension des extrémités des microtubules à diverger radialement -"à boucler"-. Une telle géométrie est causée par des instabilités propres aux microtubules et implique un état précontraint. Un «modèle d'interactions» est alors proposé de manière à considérer un état précontraint et ainsi reproduire la cinétique des instabilités des microtubules au cours de la polymérisation/dépolymérisation.

Cold-formed steel purlin systems are widely used in modem building construction, for supporting the roof and floor structures. The rotational behaviour of beam-to-beam bolted connections, which are used between the sections, significantly affects the performance of purlin systems and is hard to predict. The behaviour models currently available for the connections only offer linear or multilinear predictions with low levels of accuracy. The aim of the research presented in this thesis is to develop and propose a nonlinear, more accurate behaviour model for the sleeved modified Z bolted connections, by means of experimental and numerical analysis. Finite element models are presented for the single-bolt, single-lap connection, sleeved modified Z connections in the simply supported arrangement, and a six-span purlin system. Based on the numerical results that have been validated by the experiments, a nonlinear behaviour model is proposed for the sleeved modified Z connections. In the model, the behaviour of the connections is divided into four stages, based on the dominant mechanism that provides the resistance to the rotation. Different formulas are used in different stages to determine the behaviour of the connection, boundary conditions, and magnitudes of bolt forces. The new model reflects well the true behaviour of the connections, and provides a good understanding of what happens inside the connections. The model reveals the failure pattern of the connections and enables optimization in the design of purl in systems, for improving efficiency in material usage.

No description available.

O presente trabalho é uma contribuição para o esclarecimento e a quantificação das influências na deformabilidade e na capacidade portante de elementos unidimensionais de concreto armado em solicitação plana, decorrentes da não-linearidade física dos materiais concreto e aço, bem como da fissuração e do enrijecimento da armadura tracionada, também na sua fase plástica. Para aplicações práticas determinam-se a rigidez à flexão e a capacidade de rotação plástica dos elementos estruturais, o que permite limitar com mais precisão e coerência a demanda de rotação plástica obtida na análise. De início, descrevem-se os comportamentos não-lineares do concreto e do aço, aplicando-se conceitos da Mecânica da Fratura, bem como a atuação conjunta destes materiais, sob os aspectos de aderência e de fissuração. O núcleo deste trabalho concentra-se na obtenção do diagrama momento-curvatura e dos seus pontos principais, e na subseqüente determinação da capacidade de rotação plástica dos mencionados elementos. Consideram-se as seções geradas a partir da seção duplo T assimétrico, com várias camadas de armadura, sujeitas à flexão composta normal. Com dados deste diagrama e através do modelo da viga equivalente simétrica, posteriormente estendido à viga equivalente assimétrica e às vigas contínuas de pórticos planos, determina-se a capacidade de rotação plástica, considerando-se nesta suas múltiplas influências. Por fim, comparam-se os resultados teóricos e experimentais da capacidade de rotação plástica, e resumem-se as principais conclusões encontradas e os pontos que exigem subseqüente desenvolvimento. / The present study is a contribution to the enlightenment and evaluation of the influences on deformability and load carrying capacity of one-dimensional elements of reinforced concrete subject to in-plane loading, arisen from the constitutive non-linearity of concrete and steel, as well as from the concrete cracking and the tension stiffening of the reinforcement, prior and after yielding. For practical applications, the flexural rigidity and the plastic rotation capacity of structural elements are determined, which makes it possible to limit, more precisely and coherently, the plastic rotation demand coming from the analysis. Firstly, the non-linear behaviors of concrete and steel are described, applying concepts of Fracture Mechanics, and then the joint action of both materials concerning bond and cracking is studied. The core of this study lies on obtaining the bending moment-curvature diagram, specially its main points, and on the subsequent determination of the plastic rotation capacity of the aforementioned elements. The cross-sections generated from an asymmetric double T cross-section are considered, with several layers of reinforcement, acted upon simple or combined bending about one principal axis. With data based on this diagram and through the model of equivalent symmetric beam, later extended to equivalent asymmetric beam and to continuous beams of plane frames, the plastic rotation capacity is determined, considering its multiple influences. Finally, theoretical and experimental results of plastic rotation capacity are compared, and the main conclusions and points in need of subsequent development are summarized.