The seismic design of buildings is usually performed using one-way analysis for each of main axes independently. However, seismic events have fairly random behaviour and impose bidirectional solicitations on structures. In this work, the study of the response in structures subjects to earthquake loads with irregularity of l-shaped plan and soft story is carried out. For this, the linear time-story analysis (LTHA) of these has been carried out imposing seismic solicitations in two orthogonal directions. Thus, the structural response with incidence angle variations of 10 is obtained and compared with the response derived from the unidirectional analysis. Variations of up to 50% and 72% are obtained for model structures with l-shaped plan and soft story respectively.

Over the years there have been many papers supporting the use of design patterns in a traditional data structures course. In support of this approach, we present an evolutionary sequence of five programming exercises, concentrating on problems that require the use of six different design patterns in the context of a data structures course. Included with these exercises are brief descriptions, code segments, and teaching tips to demonstrate the simplicity and power of design patterns to teach object-oriented design principles. UML class diagrams are used to visualize and supplement the discussions.

Les relations paraphrastiques entre plusieurs ensembles de paraphrasespeuvent se décrire en termes de suites de transformations textuelles. Pour qu’il aitparaphrase, il faut qu’une substitution lexicale noyau se mette en route entrainantd’autres modifications syntaxiques, lexicales et morphologiques.Après avoir décrit les mécanismes de paraphrasage récurrents, nous avons proposédeux formalisations. La première est théorique et explique les différentes relationsparaphrastiques entretenues par les paraphrases entre-elles. La deuxième,tournée vers des applications, formalise les structures paraphrastiques sous-formede prédicats-arguments. Nous considérons cette dernière adaptée au traitementautomatique de la paraphrase.Nous avons à la suite implémenté un système d’extraction de structures paraphrastiques.Il s’agit d’un système opérationnel appliqué à un volume de donnéesrelevant de notre domaine d’étude, et dont le but est de donner un exemple concretd’emploi possible de notre formalisation.Mots-clés : paraphrase, structures paraphrastiques, traitement automatique dela paraphrase, extraction des structures paraphrastiques / The relations between sets of paraphrases can be described as seriesof textual transformations. To rephrase, an initial lexical substitution starts, thentriggers other syntactic, lexical and morphological changes.After having described the frequent paraphrasing mechanisms in our corpus,we propose two formalisations. The first one is theoretical, explaining the differentparaphrasing relationships maintained by the paraphrases between each other. Thesecond formalises paraphrase structures as predicate-argument ones. We considerthe latter suitable for paraphrase processing.Finally we have implemented a paraphrase structures extraction system. Thisis a compact operational system for the volume of data within our domain, the aimof which is to provide a concrete example of a possible use of our formalisation.

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Secondary structures may have to endure severe vibration amplitudes under the influence of the primary structures on which they are mounted. A series of numerical case studies are presented in this thesis to investigate the effectiveness of a passive vibration controller which combines a conventional tuned absorber with an impact damper, to attenuate the excessive vibration amplitudes of light secondary structures. In addition, experimental measurements are reported for some selective cases and comparisons are made with numerical predictions. This suggested configuration seems to suit ideally as an add-on enhancer for existing conventional absorbers. Most of the Results are presented for random white noise excitation, and a few representative transient vibration cases are also studied. / Thesis / Master of Engineering (ME)

Aircraft designed for naval aircraft carriers experience great airframe stress during landing due to the high vertical velocities that they must maintain as a consequence of the extremely short runway and shallow landing angle of attack. This creates a need for structural rigidity to counteract the forces that land-based aircraft never experience. This is not ideal if it otherwise limits the performance and flying capabilities of the aircraft that are otherwise necessary for the environments they might find themselves in. As such, a new approach to protecting the aircraft from the immense loads they experience during landing could be to add flexibility to the airframe and landing gear, promoting deflection instead of failure. This thesis aims to investigate this idea, starting with an elementary set of tests, looking into material flexibility, and then moving on to adding this concept to progressively more advanced structural systems. Using balls of varying material, preliminary drop tests indicated that material flexibility could assist the dissipation of landing energies, showing that the coefficient of restitution increases with the stiffness. Drop tests involving mass-spring-damper systems as well as cantilever plates and transverse beams also indicated that the strain energy a body can absorb from a set load case can be increased if its flexibility also grows. This finding led to the important conclusion and finding that a flexible body can transfer and store at least 10 times its initial contribution of energy to a system in the form of strain energy. Through these tests, it was shown that flexible structures can be a beneficial design feature in combatting and dissipating vertical landing energies. / Master of Science / Historically, airplanes landing on naval aircraft carriers are subject to high impact loads when they land because the plane is traveling at a high velocity downward and has a short runway to stop on. This impact on the runway is so severe that it requires the structure of the airplane to be reinforced, which in turn makes the plane heavier and less capable in flight. This reinforcement also implies that the plane is quite stiff in all of its components. One solution to this issue is to reverse the design logic historically taken, and impose flexible structures into the main body of the plane, which can bend and absorb some of the vertical energy that the plane possesses. This theory was investigated using a series of drop tests, starting with ball drop tests of varying materials. These tests showed that the material of a ball can affect the energy that it absorbs and how much is kept by the ball after it collides with the ground. Next, more complex structures were tested, using shock absorbers, metal plates, and metal beams. These components were combined to form drop systems, which were dropped to measure the bending in the plates and beams, as well as the shock absorbers. The conclusion made from these tests is that a more flexible structure can absorb a higher percentage of energy compared to its initial contribution, than its stiffer and heavier counterpart. This important conclusion shows that the application of flexible structures could be a vital step in improving the design of airplane wing and body structures to promote the longevity of the structure of the aircraft.

This thesis discusses the optimization of non-periodic open structure continuous-fibre PMFRC parts where yarns extend along 3D paths that maximize the specific structural performance of the resulting part for specific load cases. The work focuses on optimizing the geometry of dry yarn structures using steepest ascent (SA) methods and calculating structural performance of the resulting PMFRC parts using finite element analysis (FEA).

<p> This THESIS comprises the core of Chapter I and a self-contained excerpt from Chapter II of the author's work "Fibred Categories and the Theory of Structures". As such, it contains a recasting of "categorical algebra" on the (BOURBAKI) set-theoretic frame of GROTHENDIECK-SONNERuniverses, making use of the GROTHENDIECK structural definition of category from the beginning. The principle novelties of the presentation result from the exploitation of an intrinsic construction of the arrow category C^2 of a VL -category C. This construction gives rise to the adjunction of a (canonical) (VL-CAT)-category structure to the couple (C^2, C), for which the consequent category structure supplied the couple (CAT(T,C^2), CAT(T, C)) for each category T, is simply that of natural transformations of functors (which as such are nothing more than functors into the arrow category).</p> / Thesis / Doctor of Philosophy (PhD)

<p> An X-ray study of the various phases of anhydrous sodium pyrophosphate has been carried out. The system began with an ordered structure in orthorhombic space group P212121 and ended with a completely disordered structure in hexagonal space group P63/mmc, All the intermediate phases were partially disordered.</p> <p> The crystal structure of the first two phases of the system were determined while the rest were only partially solved due to the complexity of the disorder involved. A discussion on the symmetry aspects of the phase transformations was given and a model for the disorder of the hexagonal phase was proposed.</p> <p> As an integral part of the study the room-temperature phase of sodium diarsenate was also investigated.</p> / Thesis / Doctor of Philosophy (PhD)

Page 190 was not included in the thesis. / <p> A research program is presented for assessing the plastic collapse load and shake-down load of reinforced concrete continuous beams. This investigation attempts to establish a range of validity of simple plastic theory when applied to the under-reinforced concrete beams and to determine the sensitivity of such structures to variable repeated loading. In attempt for more accurate prediction of the behaviour of reinforced concrete beams when subjected to variable repeated loading, the numerical beam analysis was developed.</p> <p> An experimental program was conducted on 10 reinforced concrete continuous beams. Deflections and strains of these specimens of nearly prototype size were measured and compared with predicted values at critical cross-sections. Resulting conclusions and recommendations for further research are made.</p> / Thesis / Master of Engineering (MEngr)