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This study addresses the development of a prototype software system for analysis of horizontally curved steel I-girder bridges using open-section thin-walled beam theory. Recommendations are provided for the use of three-dimensional (3D) grid idealizations in analyzing curved I-girder bridge structural systems. The 3D grid idealizations account for the general displacements and rotations common within complex curved I-girder bridge structures, i.e., none of the displacement and rotational degrees-of-freedom are arbitrarily assumed to be equal to zero. Also, these idealizations account for the warping (or cross-bending) deformations of the I-girder flanges that dominate typical girder torsional responses. An approximate approach is investigated for capturing the influence of girder web distortion on composite I-girder responses. A key focus of this research is the development of prototype methods for simulating the construction of curved steel I-girder bridges, including erection of the steel and staged casting of the slab. The resulting capabilities allow engineers to evaluate the deflections, reactions and/or stresses at different stages of the steel erection or concrete slab construction, determine required crane capacities, tie-down, jacking or come-along forces, and calculate incremental displacements due to removal of temporary supports. Also, the capabilities can be used to determine the influence of different steel detailing methods on the bridge geometry, such as the web plumbness under the steel or total dead load. Key requirements necessary to ensure accuracy of the analysis results are addressed.

Many electromagnetic problems can be simulated by FDTD method. Mainly, we use orthogonal cartesian coordinate in normal situations when we deal with the electromagnetic problems. Because in most situations, the structures simulated are simply rectangular. But sometimes we may need to simulate the structures which are not rectangular like the sharps of arc and circle. For this kind of problems, the tranditional FDTD method no longer works, so the tranditional FDTD method must be modified to fit the simulation of irregular structures. Besides the FDTD method we mention above, we even combine it with non-uniform grid method in more applications. And the time to apply it is when the object simulated both has the rectangular and curved structures in the same time like the microstrip fed by the coaxial cable. The situations like that would be a good time to apply it.

ABSTRACT This research uses Taguchi Method, combined with Computer Aided Design and Manufacturing, processing the work piece into the saddle type. Next, diverse sampling methods are applied to measure the profile of surface with Coordinate Measuring Machine, with an aim to analyzing the main factors that influence cutting and seeking the last conditions for cutting out the curved surface; in addition, I will probe into the contribution rate of each factor which influences the precision during the process of measurement. The following results of this research are expected to be offered to the circles of vocational education as a basis of processing and measuring instruction. In this way, it will not take too much time to try and error and therefore, the practice course can be more efficient. 1. With reference to the documents that are focused on the factors affecting the cutting, this thesis, by means of Taguchi Method, shows that during the process of cutting saddle-type curved surface, the rotating speed of the axle is the most influential, whose contribution rate is 59.38%. 2. Since most documents are on circles, balls or cone objects, this thesis will aim at the measurement of saddle-type curved surface, with an intention to further the measuring technique. 3. It is found that as to the saddle-type curved surface, random sampling can get the profile of surface with minimal errors, and has no such trouble as using HSS or LHS, which can reduce time and cost. 4. In the experiment of Taguchi Method, according to analysis of variance, the influence of the sampling area is the greatest while the choice of sampling method only contributes to 3.46%.

9th German-Japanese Bridge Symposium, September 10-11, 2012, Kyoto, JAPAN (GJBS09)

Fused Deposition Modelling (FDM) is one of the most widely used Rapid Prototyping processes that uses the technique of depositing a semi-solid material in layers to build up a part and finds application in a variety of situations, be it making a mould for the rapid production of an industrial tool or the production of models for preoperative planning of complex cranial reconstructive surgery. When it comes to directly producing the end products, the process is still in its infancy, using inferior materials and flat layer deposition, bringing forth shortcomings such as poor surface quality, low strength for curved parts, and undesirably higher number of layers. Some of these shortcomings can be overcome if material deposition is modelled in curved layers as against the traditional flat-layer slicing and deposition. While the stair case effect can be significantly minimized, mechanical properties of the parts will also be enhanced due to continuity in fibres and the elimination of the inherent weakness between laminations. However, this being a fairly new idea, there are no existing facilities for practically implementing and experimentally testing this concept of Curved Layered Fused Deposition Modeling (CLFDM). The current research is to develop both hardware and software systems to build a working FDM system and implement CLFDM. The project involves the construction of an FDM system and then development of mathematical models for curved slicing. The numerical data generated from curved slicing algorithms is integrated with the hardware system for the practical implementation of CLFDM. Efficient curved slicing algorithms are developed and successfully used on the FDM system built for the practical implementation of CLFDM. Several case studies involving geometrical complications of increasing complexities have been successfully modelled and physically produced using CLFDM.

Fused Deposition Modelling (FDM) is one of the most widely used Rapid Prototyping processes that uses the technique of depositing a semi-solid material in layers to build up a part and finds application in a variety of situations, be it making a mould for the rapid production of an industrial tool or the production of models for preoperative planning of complex cranial reconstructive surgery. When it comes to directly producing the end products, the process is still in its infancy, using inferior materials and flat layer deposition, bringing forth shortcomings such as poor surface quality, low strength for curved parts, and undesirably higher number of layers. Some of these shortcomings can be overcome if material deposition is modelled in curved layers as against the traditional flat-layer slicing and deposition. While the stair case effect can be significantly minimized, mechanical properties of the parts will also be enhanced due to continuity in fibres and the elimination of the inherent weakness between laminations. However, this being a fairly new idea, there are no existing facilities for practically implementing and experimentally testing this concept of Curved Layered Fused Deposition Modeling (CLFDM). The current research is to develop both hardware and software systems to build a working FDM system and implement CLFDM. The project involves the construction of an FDM system and then development of mathematical models for curved slicing. The numerical data generated from curved slicing algorithms is integrated with the hardware system for the practical implementation of CLFDM. Efficient curved slicing algorithms are developed and successfully used on the FDM system built for the practical implementation of CLFDM. Several case studies involving geometrical complications of increasing complexities have been successfully modelled and physically produced using CLFDM.

We consider the curved N-body problem, N > 2, on a surface of constant Gaussian curvature κ ≠ 0; i.e., on spheres S2κ, for κ > 0, and on hyperbolic manifolds H2κ, for κ < 0. Our goal is to define and study relative equilibria, which are orbits whose mutual distances remain constant during the motion. We find new relative equilibria in the curved N-body problem for N = 4, and see whether bifurcations occur when passing through κ = 0. After obtaining a criterion for the existence of quadrilateral configurations on the equator of the sphere, we study two restricted 4-body problems: One in which two bodies are massless , and the second in which only one body is massless. In the former we prove the evidence for square-like relative equilibria, whereas in the latter we discuss the existence of kite-shaped relative equilibria. We will further study the 5-body problem on surfaces of constant curvature. Four of the masses arranged at the vertices of a square, and the fifth mass at the north pole of S2κ, when the curvature is positive, it is shown that relative equilibria exists when the four masses at the vertices of the square are either equal or two of them are infinitesimal, such that they do not affect the motion of the remaining three masses. In the hyperbolic case H2κ, κ < 0, there exist two values for the angular velocity which produce negative elliptic relative equilibria when the masses at the vertices of the square are equal. We also show that the square pyramidal relative equilibria with non-equal masses do not exist in H2κ. Based on the work of Florin Diacu on the existence of relative equilibria for 3-body problem on the equator of S2κ, we investigate the motion of more than three bodies. Furthermore, we study the motion of the negative curved 2-and 3-centre problems on the Poincaré upper semi-plane model. Using this model, we prove that the 2-centre problem is integrable, and we study the dynamics around the equilibrium point. Further, we analyze the singularities of the 3- centre problem due to the collision; i.e., the configurations for which at least two bodies have identical coordinates. / Graduate

À la frontière entre l'optoélectronique et la conception des systèmes optiques, les matrices de détecteurs possèdent aujourd'hui une forme plane, liée aux technologies standard de la microélectronique. Or, la courbure sphérique de la surface de détection permettrait un gain substantiel sur les systèmes optiques en termes de volume, de masse et finalement de coût. Cette solution est par ailleurs largement répandue dans le monde vivant (œil camérulaire humain, yeux composés des mouches, etc).Des travaux de thèse précédents ont mis en évidence l'intérêt de la rétine courbe bio-inspirée en réalisant une matrice de microbolomètres infrarouge hémisphérique.Pendant la thèse, le procédé de courbure de composants en silicium (e.g. les bolomètres) a été optimisé et stabilisé à l'aide d'un plan d'expérience et d'une simulation par éléments finis incluant l'anisotropie du silicium. Des formes sphériques convexe et concave sans défauts (pliures et méplat) ont été démontrées sur des puces carrées et rectangulaires en tirant profit de leur flexibilité aux faibles épaisseurs.D'autre part, un nouveau procédé de courbure pour les composants hybrides (flip-chip) a permis la réalisation de plusieurs matrices fonctionnelles de détecteurs quantiques en CdHgTe courbes. Des formes sphériques concaves, convexes et cylindriques concaves à des rayons compris entre 550 et 100 mm ont été obtenues avec succès malgré la fragilité mécanique du CdHgTe.Des mesures optoélectroniques nécessitant de multiples adaptations pour ces nouveaux composants courbes ont démontré leur bonne opérabilité (>97 %) en termes de courant photonique, réponse, bruit et courant d'obscurité. Une simulation par éléments finis de la mise en forme, intégrant l'anisotropie du CdHgTe, a permis de mettre en relation les contraintes et déformations avec les propriétés optoélectroniques de ce semi-conducteur II-VI. La localisation et l'émergence de lignes de glissement ainsi que l'identification des dislocations mises en jeu sont notamment discutées.Le premier prototype de caméra compacte infrarouge à détecteurs courbes a été réalisé et confirme le bon fonctionnement du composant et son potentiel. / At the optoelectronics and optical systems conception boundary, focal plane arrays have a planar shape because of microelectronics technologies. Yet spherical focal plane arrays would simplify optical systems conception and reduce volume, weight and total cost. This shape is widespread in Nature - human concave eye, arthropods convex compound eyes, etc.The advantages of the bio-inspired curved retina have been established in previous works, where a spherical infrared microbolometers array was manufactured.During this thesis, the silicium-based devices curving proccess (e.g. bolometers) has been optimised thanks to a design of experiments and a finite element simulation including silicium anisotropy. Convex and concave shapes without defects (folds and flat part) have been demonstrated with square and rectangular chips due to their flexibility at small thicknesses.Then, a new and different curving proccess for hybrid devices (flip-chip) was developed. Several curved CdHgTe focal plane arrays were obtained and fully fonctionnal. Concave and convex spherical shapes as well as concave cylindrical shapes have been successfully achieved despite a high CdHgTe fragility.Optoelectronic measurements such as photonic current, responsivity, noise and dark current were performed with some adaptation for curved devices. High operabilities have been demonstrated (> 97 %). In addition a finite element simulation of the proccess has been conducted with the CdHgTe anisotropy. Direct relations between induced stress and strain, and optoelectronic properties, have been proved in this II-VI semiconductor. Location and surfacing of slip lines as well as dislocations identification are discussed.Finally, a compact infrared camera prototype with a curved CdHgTe focal plane array has been manufactured for the first time. It confirms that the device is fully fonctionnal and has a great potential for high value applications.

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