In the aerospace industry, composite structures design rules and admissible criteria are not well known for strength sustainability after impact induced damage. Predictive numerical tools are thought to be used to reduce design and certification time and costs, and to determine links between the inner behaviour of the material and the outer designable behaviour of structures. In this frame, it is aimed in this study to compare real tests damage measurements and two kinds of numerical damage predictions: one with geometrical openings for delamination discontinuity modelling, and one without any mesh opening that represents damage in a continuous way. Our attention is focused on two types of pre-impregnated unidirectional materials: T700/M21S and T800/M21S both strain rate sensitive because of a high percentage of thermoplastics in the M21 resin. Quasi-static and dynamic characterization tests have been carried out on balanced angle ply [±θ] laminates using Split Hopkinson's Pressure Bars. A saturation of through ply cracking has been outlined and strain rate effect on T800/M21S coupons' strength has been established up to medium strain rates. User defined cohesive finite elements are implemented in the non-linear explicit finite element analysis (FEA) code LS-DYNA® to model the dynamic delamination opening. At the same time a user defined deterministic continuous damage unidirectional composite material model is developed on the basis of the Matzenmiller-Lubliner-Taylor model widely used for woven composites. Initiation and growth of damage are predicted up to saturation and fracture for various pure and coupled damage mechanisms including delamination and matrix cracking, with criteria based on the experimental characterization. Impact induced damage from experimental measurements and numerical predictions are compared for T800/M21S aeronautical samples impacted at different energy levels. The effect on internal damage and residual indentations of 2 different masses and velocities has been evaluated. It is shown that the cohesive discontinuous delamination and the continuous damage coupling numerical models give both a good prediction of the global flexural behaviour of the structure. Spatial extension in shape and dimensions of damage through the plates' thickness is well predicted by the continuous model while the cohesive model is more diffusive leading to "isotropic" delamination predictions. Also, the continuous model gives better correlations between predicted and measured residual indentations after impact.

A la fin des années 1880, le langage musical de Claude Debussy, influencé à la fois par Wagner, le symbolisme, et la poétique de Baudelaire, se transforme en profondeur.Le système tonal, alors unique horizon d'attente (Jauss) des institutions musicales européennes, est repoussé à l'arrière plan des mélodies du compositeur, par des associations avec des thèmes poétiques comme les souvenirs, l'humour, et l'enfermement.Cette thèse se concentre sur une analyse de ces transformations, et sur une comparaison de ce langage musical neuf avec celui des Serres chaudes d'Ernest Chausson, cycle de mélodies qui partage pourtant les mêmes influences poétiques et musicales. / In the late 1880's, Claude Debussy's musical language, influenced by Wagner, symbolism and Baudelaire's poetry, deeply transforms itself.The tonal system, still regarded as the unique horizon of expectations (Jauss) of European musical institutions, is pushed to the background in the composer's melodies by his characteristic associations with poetical themes like memories, humor, and reclusion.This thesis focuses on an analysis of these transformations and on a comparison of this new musical language with Ernest Chausson's Serres chaudes, which still shares the same poetic and musical influences.

Thesis (M.S.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 137-149).

The advances in additive manufacturing removed most of the limitations that were once stopping designers when it comes to the manufacturability of the design. It allowed designers to produce parts with high geometric complexity such as cellular structures. These structures are known for their high strength relative to their low mass, good energy absorption, and high thermal and acoustic insulation compared to their relative solid counter-parts. Lattice structures, a type of cellular structures, have received considerable attention due to their properties when producing light-weight with high strength parts. The design of these structures can pose a challenge to designers due to the sheer number of variables that are present. Traditional optimization approaches become an infeasible approach for designing them, which motivated researchers to search for other alternative approaches. In this research, a new method is proposed by utilizing the material density information obtained from the topology optimization of continuum structures. The efficacy of the developed method will be compared to existing methods, such as the Size Matching and Scaling (SMS) method that combines solid-body analysis and a predefined unit-cell library. The proposed method shows good potential in structures that are subjected to multiple loading conditions compared to SMS, which would be advantageous in creating reliable structures. In order to demonstrate the applicability of the proposed method to practical engineering applications, the design problem of a commercial elevator sling will be considered.

Cette thèse a pour objet l'étude des paires de feuilletages complexes. Plus précisément, on s'intéressera aux paires de feuilletages complexes de codimension 1 dans deux situations différentes : d'un côté il s'agira de germes de feuilletages au voisinage de l'origine de C (la situation "locale"), de l'autre il sera question de feuilletages définis dans un voisinage de dimension 2 d'une courbe complexe (la situation "semi-globale"). Le problème semi-global a pour but la compréhension des voisinages de courbes dans des surfaces complexes ; on obtiendra ainsi des résultats de classification des voisinages particuliers que sont les voisinages munis de deux feuilletages. Pour obtenir cette classification, on aura d'abord besoin d'étudier les paires de feuilletages d'un point de vue local. On présentera ainsi certains résultats à propos de la classification des paires de germes de feuilletages au voisinage d'un point dans C2. Certains des résultats locaux donnent par généralisation des résultats de classification de paires de germes de fonctions en toute dimension ; on présentera plus particulièrement une étude détaillée des paires de germes de fonctions de Morse en toute dimension. / This thesis has for goal the study of pairs of complex foliations. More precisely, we will discuss pairs of codimension 1 complex foliations in two different situations: on one side we will have germs of foliations in the neighborhood of the origin of C (the "local" situation), on the other side the foliations will be defined on a dimension 2 neighborhood of a complex curve (the "semi-global" situation). The semi-global problem has for goal the understanding of neighborhoods of curves in complex surfaces; we will thus obtain classification results for the particular neighborhoods that are equipped with two foliations. In order to obtain this classification, we will first need to study pairs of foliations from a local point of view. Hence, we will present some results about classification of pairs of germs of foliations in a neighborhood of a point in C2. Some of the local results give by generalisation classification results for pairs of germs of functions in any dimension; in particular, we will present a detailed study of pairs of germs of Morse functions in any dimension.

No description available.

Yes / Twelve reinforced-concrete continuous deep beams having web openings within interior shear spans were tested to failure. The main variables investigated were the opening size and the amount of inclined reinforcement around openings. An effective inclined reinforcement factor combining the influence of the amount of inclined web reinforcement and opening size is proposed and used to analyse the structural behaviour of continuous deep beams tested. It was observed that the end support reaction, diagonal crack width and load capacity of beams tested were significantly dependent on the proposed effective inclined reinforcement factor. As this factor increased, the end support reaction and increasing rate of diagonal crack width were closer to those of companion solid deep beams. In addition, a higher load capacity was exhibited by beams having an effective inclined reinforcement factor above 0.077 than the companion solid deep beam. A numerical procedure based on the upper-bound analysis of the plasticity theory was proposed to estimate the load capacity of beams tested. Comparisons between the measured and predicted load capacities showed good agreement.

Extensive comparative studies have been undertaken on various theoretical approaches used for analysing spiral strands, in order to identify their appropriate ranges of applicability. Based on the findings of this exercise, a theoretical model is proposed for analysing the coupled axial/torsional response of a stranded wire rope with either an independentwire rope or fibre core. A theoretical model is also proposed for the analysis ofaxial/torsionai coupling of locked coil cables, regarding which, there was previously a . paucity of reliable analytical or experimental information, despite their wide range of applications. Axial hysteresis of locked coil cables is estimated, and it is shown that it is significantly higher than the axial hysteresis associated with spiral strands. Simplified routines which are amenable to hand calculations are developed for obtaining the no-slip stiffness coefficients for the coupled axial/torsional stiffness matrix of axially preloaded spiral strands, with the effect of hydrostatic pressure on sheathed strands catered for. Moreover, the concept of orthotropic sheets for calculating the pattern of interwire/interlayer contact forces in spiral strands is used to determine the recovery length of a broken wire in any layer of a multi-layered spiral strand. Wherever possible, the final theoretical results are compared with experimental data from the available literature and very encouraging correlations have been found in all cases.

This work reviews the current knowledge of the synthesis , properties , structures and biological activities of isatogens. The unequivocal 2 C NMR assignment of 2-phenylisatogen 1S reported and used to assign the spectra for a range of 2-(4-substituted-phenyl)isatogens. Molecular dynamics of 2-phenylisatogen in chloroform are reported and indicate that there is little if any inter-ring mesomeric resonance in this compound. 1~C , ~N NMR and UV-Visible spectroscopic data are reported for a range of 2-(4-substituted-phenyl)isatogens. Analysis of this data indicates a small but significant degree of inter-ring mesomeric resonance is present in these compounds especially those with strongly electron donating or withdrawing substituents. An interesting correlation is found between ~sN substituent chemical shifts and molar absorbtivity of the visible transitions. The X-ray crystal structure of 2-(4-chlorophenyl)isatogen is reported and shows a small but significant shortening of the inter-ring bond length compared to 2-phenylisatogen , further supporting the hypothesis of inter-ring mesomeric resonance in these compounds. 1 H and ~C NMR data are reported for the 2-(pyrid-2-inium)isatogen cation and indifate the presence of intramolecular interaction between the ~---H and N~O groups in the molecule. The X-ray crystal structure of the perchlorate salt of the cation and the ~H solid state NMR spectrum both support this conclusion. The molecular structure indicates that the intramolecular interaction is comprised of coulombic and hydrogen bonding interactions leading to a near coplanar structure for the cation compared to the noncoplanar structure for the parent base, 2-(pyrid-2-yl)isatogen. A hypothesis is put forward to explain molecular packing and configuration differences in 2-heteroarylisatogens. The molecular packing and configuration is controlled by a balance of intermolecular dipole attraction and repulsion. Predictions of molecular packing and configuration are made for a number of 2-heteroarylisatogens. The X-ray crystal structure of 2-(pyrid-3-yl)isatogen is reported and found to be in complete agreement with the predictions of the hypothesis. Further studies are proposed involving the synthesis of ~N and ~~O labelled isatogens , the study of inclusion complexes with cyclodextrins and the study of isatogens with the potential for increased mesomeric interactions. ,

The response of steel-framed structures to applied loading depends to a large degree on the behaviour of the joints between the columns and beams. Traditionally designers have assumed that these joints act either as 'pinned', with no ability to transmit moments from beam to column, or as 'rigid', providing perfect continuity between the connected members. Advances in analysis, and developments in modem codes of practice, permit designers to account for the real behaviour of steel joints where this is known or can be predicted. Even though experimental studies of joints conducted at many research centres around the world have provided a large bank of test data, the vast number of variables in joints (beam and column sizes, plate thicknesses, bolt sizes and spacing, etc.) often means that data for a specific joint arrangement does not exist. As a result, researchers have turned their attention to ways of predicting the behaviour of such joints. One approach which has gained acceptance is based on the "Component Method" in which overall joint behaviour is assumed to be produced by the responses of its various simpler components. To date, data on the response of joints at elevated temperatures has been gathered from full-scale furnace tests on cruciform arrangements, which have concentrated exclusively on moment-rotation behaviour in the absence of axial thrusts. However, when steel-framed structures are subjected to fire, the behaviour of the joints within the overall frame response is greatly affected by the high axial forces which are created by restraint to the thermal expansion of unprotected beams. If momentrotation- thrust surfaces were to be generated this process would require prohibitive numbers of complex and expensive furnace tests for each joint configuration. The alternative, and more practical, method is to extend the Component Method to the elevated-temperature situation. The basic theme of the Component Method is to consider any joint as an assembly of individual simple components. Each of these components is simply a non-linear spring, possessing its own level of strength and stiffness in tension, compression or shear, and these will degrade as its temperature rises. The main objective of this study was to investigate experimentally and analytically the behaviour of tension and compression zones of end-plate connections at elevated temperatures. A series of experiments has been carried out and a simplified analytical model has been developed, and this has been validated against the tests and against detailed finite element simulations. The simplified model is shown to be very reliable for this very common type of joint, although similar methods will need to be developed for other configurations. The principles of the Component Method can be used directly in either simplified or finite element modelling, without attempting to predict of the overall joint behaviour in fire, to enable semi-rigid behaviour to be taken into account in the analytical fire engineering design of steel-framed and composite buildings.