Dissertations / Theses on the topic 'Trochoids'

Foi estudada a morfologia externa e interna de Calliostoma adspersum, C. depictum e C. hassler, procedentes da costa brasileira. Tegula viridula também foi estudada como parâmetro comparativo externo. Foi possível averiguar características anatômicas que diferenciam todas as espécies entre si. Diferenças significativas foram encontradas principalmente nas seguintes estruturas: concha; coloração e papilas do pé; musculatura do odontóforo; esôfago anterior; estômago; ceco em espiral e alça intestinal. Calliostoma, de acordo com dados preliminares, diferencia-se dos demais troquídeos por apresentar: redução ou perda dos lobos cefálicos; pseudoprobóscide; presença de ampola renal; uma alça intestinal fora da hemocela e o músculo m1d do odontóforo.
The external and internal morphology of Calliostoma adspersum, C. depictum and C. hassler, from Brazilian coast, was studied. Tegula viridula was also analyzed as outgroup. Anatomical characteristics that differentiate all species were found. The major differences were found mainly in the structures: shell; color and papillaes foot; odontophore musculature; anterior esophagus; stomach; spiral caecum and intestinal looping. Calliostoma, according to preliminary data, differentiates from other Trochidae in presenting: reduction or lost of cephalic lappets; pseudoproboscid; renal ampolla; intestinal looping outside haemocoel and m1d odontophore muscle

The assigned thesis is focused on the proposal of rationalization solutions to the component Bonnet, which is a standard representative of the most important sections of broader spectrum of customer´s components. The introduction part describes the component basis, according to which the standard representative was chosen, later on characterised from the point of view of seriality. The following large part of classfying the time comsumption in machinery is essential for the calculations as such, which are the essential part of this dissertation. The proposal of production rationalization is concerned with the exclusion of unnecessary losses and using existing ressources with the help of a higher level of machinery, technology, work organisation, production and management, which lead to a higher labour productivity. The technological production preparation ensures the documentation processing, the proposal of semi-finished product, machines, fastening, measuring and calculation of necessary technological specifications for ensuring the production. In the final part, there is to be found the technical and economical evaluation of rationalization proposals, which numerically evaluates the analysed outputs of this thesis.

This master's thesis deals with the design of FEM model of gear pair with an intention to find out how stiffness changes during meshing. It firstly describes the necessary knowledge needed to analyse the problem, like the geometry of an involute tooth and evaluation of meshing stiffness. Followed by a description of work procedures from the creation of models through settings of mesh, contacts and analysis to evaluating of results.

A subfamília Tegulinae é composta por 44 espécies viventes descritas em seis gêneros. Ocorrem nas águas tropicais e subtropicais do Pacífico Oriental, no Caribe, na costa pacífica da América, na costa atlântica da América do Sul e no leste da Ásia, habitando as regiões entre marés e infralitoral. Os tegulíneos foram definidos taxonomicamente por apresentarem: (i) opérculo com o crescimento da borda curto; (ii) perda da habilidade de depositar carbonato de cálcio no opérculo; (iii) rádula com dente raquidiano sem uma cúspide secundária ou aba para prover uma fixação adicional na fita radular. O posicionamento do táxon dentro de Trochoidea nunca foi bem estabelecido e a posição sistemática dos grupos internos de tegulíneos nunca foi investigada como objetivo primário. O presente trabalho abordado no Capítulo 1 apresenta um estudo morfológico detalhado de alguns representantes de Tegulinae e Trochoidea visando testar a monofilia da subfamília, bem como elucidar o posicionamento filogenético dos gêneros que a compõem e seu posicionamento em Trochoidea. Todos os gêneros, exceto Catallocostoma, foram incluídos. As espécies polimórficas Agathistoma hotessierianum, A. patagonicum e A. viridulum foram compostas em subunidades monomórficas, totalizando o grupo-interno em 23 terminais. O grupo-externo incluiu 24 terminais, com representantes das famílias de Trochoidea, além de uma espécie de Pleurotomarioidea (Perotrochus atlanticus), considerada a raiz. Uma análise cladística foi realizada, com buscas heurísticas com pesos iguais e pesagem diferencial. O resultado da análise demonstrou a monofilia de Tegulinae, grupo-irmão de Prisogaster niger, alocada na família Turbinidae. Os gêneros formaram grupos monofilético, embora Tegula excavata não demonstrasse um posicionamento bem definido nas análises alternativas. As espécies polimórficas não foram consideradas como espécies nominais distintas, pois foi constatado que os caracteres que separam cada espécie em subamostra têm alto grau de plasticidade. Caracteres morfológicos foram testados pela primeira vez em um grupo hierarquicamente baixo em Trochoidea e tiveram valor significativo na definição de linhagens internas. O Capítulo 2 teve como objetivo inserir todos os táxons analisados no Capítulo 1, na análise filogenética de Caenogastropoda de Simone (2011). A análise resultou em Vetigastropoda monofilético. A parafilia de Zeugobranchia foi corroborada com outras hipóteses filogenéticas, bem como a monofilia de Trochoidea. As famílias Calliostomatidae, Trochidae, Turbinidae e Margaritidae não formaram um grupo monofilético. A monofilia de Tegulinae foi corroborada, grupo-irmão do clado Prisogaster niger+, bem como os gêneros Intistoma aureotinctum, Norrisia, Chlorostoma e Agathistoma.
Tegulinae encompasses 44 extant species belonging to six genera. They occur in tropical and subtropical waters of the Eastern Pacific, Caribbean, on the Pacific coast of America, Atlantic coast of South America and East Asia, inhabiting intertidal to shallow sublittoral areas. Tegulines are taxonomically defined by (i) a short growing edge of operculum, (ii) inability to calcify the operculum and (iii) rachidian tooth lacking a secondary cusp or flap providing additional attachment to the radular ribbon. A consensual placement of tegulines within Trochoidea has not yet been reached, and the systematic positions of the genera have never been investigated as a primary objective. A cladistics analysis of the subfamily based on detailed morphology is presented herein on Chapter 1, aimed at testing the groups monophyly. Additionally, the phylogenetic positions of the genera are investigated along with the phylogenetic position of Tegulinae within Trochoidea. The sampled ingroup included representatives of all genera except for Cantallocostoma; the polymorphic species Agathistoma hotessierianum, A. patagonicum and A. viridulum were subdivided into monomorphic taxa, totaling 23 ingroup terminals. The outgroup comprised 24 terminals including representatives of trochoidean families. The Pleurotomarioidea were represented by Perotrochus atlanticus, which was also used as root. Cladistics analysis included heuristic searches carried with equal and differential weighting. Results presented here indicate that Tegulinae are monophyletic, being sister to Prisogaster niger and belonging to the family Turbinidae. The genera studied herein were supported as clades, despite the non-consensual position of Tegula excavata between alternative hypotheses. Polymorphic species were considered non-distinct nominal species, since the characters that divide them into subsamples are highly plastic. Morphological characters were used for the first time to support a hierarchically low-level group for Trochoidea and had significant value in the definition of internal lineages. On Chapter 2, the analyzed taxa from the previous chapter were added to Simones (2011) phylogenetic hypothesis of Canogastropoda in order to investigate the phylogenetic position of Trochoidea in a broader scenario. The results support the monophylies of Vetigastropoda and Trochoidea, and indicate the paraphyly of Zeugobranchia, corroborating previous hypotheses. Tegulinae is a monophyletic group, sister to Prisogaster niger+, Intistoma aureotinctum, Norrisia, Chlorostoma and Agathistoma.

Positive displacements pumps, as currently designed, produce significant flow pulsations that result in pressure pulsations. These pulsations contribute to the global noise generated by the installation. Moreover, they interact with the system where the pump is connected shortening the life of both the pump and circuit components. Rotary trochoidal gear pump, a type of rotary positive displacement machine, has characteristics that make it suitable for many applications fields. Nowadays, in cases like additivation and dosage, these applications have not been completely developed, and present a growing potential in the industrial world, such as in new diesel engines generation or in medical applications. The thesis presents a set of design tools applied to trochoidal gear pumps, from the viewpoint of the fluid dynamical performance of the pump. These design tools are aimed to help improving two of the main performance indices of the pump: the volumetric capacity and the flow irregularity, leading the designer to more efficient new designs of gerotor pumps. On the one hand, the volumetric capacity is related with the pump's efficiency, and increases in this particular index result in a higher efficiency of the pump. On the other hand, flow irregularity measures de flow ripple generated by the pump, and by reducing this index, the life of both the pump and the installation can be extended, as phenomena like fatigue are attenuated. This is achieved through the use of analytical, simulation and experimental procedures. From the analytical side, two new modules of GeroLAB Package are created, Minimum Clearance Module and Effective Port Areas. Also, a dynamical simulation through BondGraph is conducted, studying the influence of the port areas geometry. In the present thesis, the model has been improved by adding the information of the effective port areas, thus making it more realistic. Regarding the numerical simulation, a three-dimensional with deforming mesh Computational Fluid Dynamics model is presented. The model includes the effects of the manufacturing tolerance and the leakage inside the pump. Also, the influence of simulating the contact points is studied. A new boundary condition is created for the simulation of the solid contact in the interteeth radial clearance, established as a fluid-dynamic condition. The experimental study of the pump is carried out by means of Time-Resolved Particle Image Velocimetry. This technique is developed in order to adapt it to the gerotor pump, and measurements are captures in the outlet pipe and in the chambers between trochoidal profiles. Results are qualitatively evaluated thanks to the analytical and simulation tools. The presented experimental procedure meets the need of a methodology to directly measure the flow ripple generated by the pump, with a non-intrusive technique. It constitutes an alternative to the Secondary Source Method, and it is the first approach of Time-Resolved Particle Image Velocimetry applied to a trochoidal gear pump, according to the author's knowledge.
Las bombas de desplazamiento positivo, en su diseño actual, producen pulsaciones de caudal significantes que resultan en pulsaciones de presión. Estas pulsaciones contribuyen al ruido global generado por la instalación. Además, interactúan con el sistema al cual se encuentra conectada la bomba, reduciendo la vida útil tanto de la bomba como de los componentes del circuito. La bomba rotativa de engranajes trocoidales, un tipo de máquina rotativa de desplazamiento volumétrico, tiene características que hacen que sea adecuada en muchos campos de aplicación. Actualmente, en casos como la aditivación o la dosificación, estas aplicaciones no han sido completamente desarrolladas, y prestan un creciente potencial en el mundo industrial, como en nuevas generaciones de motores diesel o en aplicaciones médicas. La tesis presenta un conjunto de herramientas de diseño aplicadas a bombas de engranajes trocoidales, desde el punto de vista del comportamiento fluidodinámico de la bomba. Estas herramientas de diseño están orientadas a ayudar a la mejora de dos de los principales índices de la bomba: la capacidad volumétrica y la irregularidad en el caudal, dirigiendo al diseñador a nuevos diseños de bombas gerotor más eficientes. Por un lado, la capacidad volumétrica está relacionada con la eficiencia de la bomba, e incrementos en este índice resultan en una mayor eficiencia de la bomba. Por otro lado, la irregularidad en el caudal mide el las fluctuaciones en el caudal generado por la bomba, y reduciendo este índice, la vida útil de la bomba y de la instalación puede ser aumentada, ya que fenómenos como la fatiga se ven atenuados. Esto se consigue a través del uso de procedimientos analíticos, de simulación y experimentales. Desde el punto de vista analítico, se han creado dos nuevos módulos para el software GeroLAB Package, denominados Minimum Clearance Module y Effective Port Areas. También se ha llevado a cabo una simulación dinámica de BondGraph, estudiando la influencia de la geometría de las lumbreras. En esta tesis, el modelo se ha mejorado añadiendo la información de las secciones efectivas de las lumbreras, obteniendo así un modelo más realista. En relación con la simulación numérica, se presenta un modelo de dinámica de fluidos computacional (CFD) tridimensional y con malla deformable. El modelo incluye los efectos de las tolerancias de fabricación y las fugas en el interior de la bomba. Además, también se estudia la influencia de simular los puntos de contactos entre dientes. Se crea una nueva condición de contorno para la simulación del contacto sólido en las holguras radiales entre dientes, establecida como una condición fluidodinámica. El estudio experimental de la bomba se lleva a cabo mediante resolución en tiempo de Velocimetría de Imágenes de Partículas (TRPIV). Esta técnica se adapta a la bomba gerotor, y las medidas obtenidas son capturas en la tubería de salida y en las cámaras entre perfiles trocoidales. Los resultados se evalúan cualitativamente gracias a las herramientas analíticas y de simulación. El procedimiento experimental presentados responde a la necesidad de una metodología para medir de manera directa el caudal generado por la bomba, con una técnica no intrusiva. Constituye una alternativa al método de la fuente secundaria, y es la primera aproximación de TRPIV aplicado a una bomba de engranajes trocoidales, de acuerdo con el conocimiento de la autora

Tato diplomová práce byla vypracována v průmyslovém kontextu, během stáže ve firmě Metso. Zlepšení obráběcího procesu zajišťovacích šroubů bylo cílem této práce, aby byla umožněna budoucí automatizace zakládání obrobku do stroje. Zlepšení bylo zhodnoceno na základě úrovně autonomie během obrábění, eliminace neprogramovaných zastavení stroje operátorem a dostačujícího odvodu třísek. Implementace automatických systému do číslicově řízeného obráběcího centra umožňuje zvýšení produktivity. Před automatizováním obráběcího procesu však musí být proces optimalizován. Zejména dostatečná fragmentace třísek a jejich evakuace jsou klíčové. Dlouhé nedělené třísky můžou poškodit systémy jako například automatický měnič nástrojů, dopravník třísek nebo průmyslového robota. Dostatečná lámavost třísek může být zaručena správným výběrem technologie a strategie obrábění, výběrem řezného nástroje a řezných podmínek pro daný materiál obrobku.

Metal matrix composites have seen a rise in demand within the last decade. Aluminum alloy reinforced with silicon carbide particles is a type of particle metal matrix composite that has seen applications in the aerospace, ground transportation, and electronics industry. However, the abrasive SiC particles have made this material difficult to machine through conventional machining strategies. This research will focus on using computer aided manufacturing with trochoidal tool paths to maximize machining productivity and extend the tool life of CVD diamond coated end mills. The focus of this research will be on AlSiCp with a high volume fraction of reinforcement (30%) to expand the potential applications of this pMMC. The cutting experiments are divided into three parts: cutting test, confirmation test, and endurance test. Taguchi method will be used to perform an analysis of variance and signal-to-noise ratio to optimize a combination of material removal rate, average cutting forces, and surface roughness. The optimal cutting conditions were found to be 254 mm/min, 30°, and 9500 r/min for MRR+AvgFxy+Ra, 1524 mm/min, 30°, and 9500 r/min for MRR+AvgFxy, and 1524 mm/min, 90°, and 9500 r/min. The cutting conditions for MRR+AvgFx+Ra was not considered for the endurance tests as the machining productivity was too low to be considered a feasible option in the industry. It was concluded that trochoidal milling under wet cutting conditions produced nearly half the tool wear as previous research with conventional milling strategies. However, the longer the CVD diamond coated end mills were engaged in the AlSiCp workpiece, the more dominant the abrasive wear mechanisms appear and cause tool damage. It was concluded that square end mills may not be suitable for machining AlSiCp and that future research should focus on varying the tool geometry or utilizing ball end mills.

After a huge amount of success within the military, the benefits of the use of unmanned aerial systems over manned aircraft is obvious. They are becoming cheaper and their functions advancing to such a point that there is now a large drive for their use by civilian operators. However there are a number of significant challenges that are slowing their inevitable integration into the national airspace systems of countries. A large array of emergency situations will need to be dealt with autonomously by contingency management systems to prevent potentially deadly incidences. One such emergency situation that will need autonomous intervention, is the total loss of thrust from engine failure. The complex multi faceted task of landing the stricken aircraft at a potentially unprepared site is called a forced landing. This thesis presents methods to address a number of critical parts of a forced landing system for use by an unmanned aerial system. In order for an emergency landing site to be considered, it needs to be within glide range. In order to find a landing site s reachability from the point of engine failure the aircraft s glide performance and a glide path must be known. A method by which to calculate the glide performance, both from aircraft parameters or experiments is shown. These are based on a number of steady state assumptions to make them generic and quick to compute. Despite the assumptions, these are shown to have reasonable accuracy. A minimum height loss path to the landing site is defined, which takes account of a steady uniform wind. While this path is not the path to be flown it enables a measure of how reachable a landing site is, as any extra height the aircraft has once it gets to the site makes a site more reachable. It is shown that this method is fast enough to be run online and is generic enough for use on a range of aircraft. Based on identified factors that make a landing site more suitable, a multi criteria decision making Bayesian network is developed to decide upon which site a unmanned aircraft should land in. It can handle uncertainty and non-complete information while guaranteeing a fast reasonable decision, which is critical in this time sensitive situation. A high fidelity simulation environment and flight test platform are developed in order to test the performance of the developed algorithms. The test environments developed enable rapid prototyping of algorithms not just within the scope of this thesis, but on a range of vehicle types. In simulation the minimum height loss paths show good accuracy, for two completely different types of aircraft. The decision making algorithms show that they are capable of being ran online in a flight test. They make a reasonable decision and are capable of quickly reacting to changing conditions, enabling redirection to a more suitable landing site.

The main aim of master’s thesis was to handle the computing proposal and the construction design of the powertrain of racing Wankel rotary engine with 300 kW power output and in the case of 9000 speed per minute. On the basic of these values was made the primary design of the rotary engine, design of the eccentric shaft and rotor housing. Mechanical stress and torsional vibrations of the eccentric shaft were analyzed by using the course of indicator diagram.

L'augmentation de la productivité sur machine à commande numérique passe, entre autre, par l'amélioration de la programmation de celles-ci. Le langage sur lequel se base actuellement cette programmation date du début des années 80 avec la norme 6983 qui définit les principes du code G. Ce dernier présente certains inconvénients aux vues des nouvelles stratégies d'usinage et crée une rupture de la chaîne numérique au niveau de la fabrication. Un nouveau format émergeant, le STEP-NC, voit le jour actuellement dans le but de palier aux manques du code G et d'intégrer complètement la chaîne CAO-FAO-CN.
Nos travaux ont pour objectif d'implanter deux nouvelles stratégies d'usinage, le tréflage et l'usinage trochoïdal, au sein du format STEP-NC. Pour ceci, nous nous basons sur une description des trajectoires à l'aide de courbes à motif. La construction de ces courbes se fait par répétition d'un motif le long d'une courbe guide. Pour mettre en avant la faisabilité de l'implantation de ces stratégies à motifs dans le format STEP-NC, nous avons développé une chaîne numérique complète permettant, à partir du modèle CAO, de créer le fichier STEP-NC, de générer les trajectoires et d'usiner la pièce sur machine à commande numérique. Une partie de l'intégration de l'usinage trochoïdal et du tréflage dans le format STEP-NC a été réalisé par implémentation dans le logiciel PosSFP, en collaboration avec le laboratoire de l'université de Postech en Corée. Plusieurs pièces tests ont ensuite été usinées pour valider l'ensemble de la chaîne numérique STEP-NC complète dans le cas de l'usinage trochoïdal.

Jean Thibaud est né à Lyon en 1901. Ingénieur électricien, il se dirige vers la recherche fondamentale en soutenant une thèse sous la direction de Maurice de Broglie en 1924, alors directeur du laboratoire de physique des rayons X. Thibaud travaille en particulier, sur les tout premiers dispositifs accélérateurs de particules, linéaires et circulaires, entre 1931 et 1933. Il précise en 1933, grâce à une technique expérimentale qu'il met au point (la méthode de la trochoïde), les caractéristiques physiques du positron ; la première antiparticule, découverte par C.D Anderson en 1932. De conserve avec Frédéric Joliot, il parvient en usant de la technique de la trochoïde, à observer pour la première fois, l'annihilation du positron. En 1935-1936, Jean Thibaud créer l'Institut de Physique atomique de Lyon, rue Raulin tout en occupant une chaire de physique expérimentale à la Faculté des Sciences de Lyon. Ce laboratoire constitue le premier laboratoire de province dédié à l'étude de l'atome. Treize chercheurs, techniciens et assistants composent ce laboratoire en 1937. Le 1944. Thibaud profitera de la dotation de 20 millions de francs qui lui sera faite après la guerre, pour acquérir un générateur de Cockcroft-Walton. Cet instrument sera installé, avec le concours de l'armée, au fort de la Vitriolerie à Lyon. En contrepartie, Thibaud acceptera de mettre son expertise et celle de ses collaborateurs au profit de la formation en physique atomique d'officiers et de techniciens de l'armée de terre, de 1951 à 1960. Parallèlement Thibaud travaille sur les plans de son nouveau laboratoire, projeté sur le domaine de la Doua, à Villeurbanne. Il ne verra pas sortir de terre ce nouveau laboratoire — inauguré en 1963 — qui constitue l'actuel Institut de Physique Nucléaire de Lyon. Jean Thibaud apparaît pourtant comme une figure méconnue du XXe siècle scientifique. Mise à part le Prix Thibaud, décerné par l'Académie des Sciences, Belles- Lettres et Arts de Lyon tous les deux ans, aucune instance ou artefact universitaire n'en garde la mémoire. Aucune rue ou amphithéâtre n'en porte le nom, pas même à Lyon, sa ville natale. Pour comprendre la marginalisation de Jean Thibaud dans la mémoire savante et dans la mémoire locale, nous articulons les différents registres d'activités de Jean Thibaud autour de trois bifurcations qui nous semblent avoir marqué son existence. Sa non participation au congrès Solvay 1933 marque la première bifurcation. Les directions d'institutions scientifiques durant le régime de Vichy et l'Occupation constituent la seconde bifurcation. La dernière est associée à une affaire de plagiat devant l'Académie des sciences, en janvier 1951
Jean Thibaud was born in Lyon in 1901. An electrical engineer, he goes to basic research in a thesis under the direction of Maurice de Broglie in 1924, then he becomes the director of the X-ray physics laboratory. Thibaud worked in particular on the first particle accelerator devices, linear and circular, between 1931 and 1933. He states in 1933, thanks to an experimental technique he developed (the method of the trochoid), the physical characteristics of the positron ; the first antiparticle, discovered by C.D Anderson in 1932. Independently with Frédéric Joliot, he succeeds in making use of the technique of trochoïde to observe for the first time, the annihilation of the positron. In 1935-1936, Jean Thibaud created the Atomic Physics Institute in Lyon, rue Raulin, while occupying a chair of experimental physics at the Faculty of Sciences of Lyon. This laboratory is the first province laboratory dedicated to the study of the atom. Thirteen researchers, technicians and assistants built up this laboratory in 1937. The laboratory will be partially destroyed during the Allied bombing of 26 May 1944. Thibaud benefited from the allocation of 20 million francs to be made after the war, to acquire Cockcroft-Walton generator. This instrument will be installed, with the assistance of the army, at the top of the Vitriolerie in Lyon. In return, Thibaud agreed to put his expertise and that of his employees to the benefit of the training in atomic physics of officers and technicians in the Army from 1951 to 1960. Meanwhile Thibaud was working on the plans of his new laboratory planned to be built on the field of La Doua, in Villeurbanne. He will not see the new laboratory spring up - it was inaugurated in 1963- which is the current Institute of Nuclear Physics of Lyon. Jean Thibaud yet appears as a little-known figure of the twentieth century science. Apart from the Thibaud Prize, awarded by the Academy of Sciences, Arts and Belles-Lettres de Lyon every two years, no proceeding or university artifact keeps his memory. No street or amphitheater bears his name, not even in Lyon, his hometown. To understand the marginalization of Jean Thibaud in scholarly memory and in local memory, we can articulate the different registers of Jean Thibaud’s activities around three bifurcations that his existence seems to have taken. His non-participation in the 1933 Solvay conference marks the first bifurcation. The directions of scientific institutions during the Vichy period and the Occupation constitute the second bifurcation. The latter is associated with a plagiarism case at the Academy of Sciences in January 1951

Les applications tribologiques des matériaux cellulaires en présence de liquide nécessitent une connaissance de leurs modes d’endommagement, mais elles restent peu connues à l’heure actuelle. L’étude, la compréhension et la modélisation du comportement d’un matériau composite cellulaire nécessitent une approche pluridisciplinaire due au caractère hétérogène du matériau qui reste difficilement caractérisable. Ce matériau peut être analysé suivant 3 axes bien distincts : les propriétés rhéologiques (analyses sous état de déformation complexe en compression et en cisaillement avec des rhéomètres adaptés), la morphologie des alvéoles (analyses 3D optiques et tomographiques), les propriétés tribologiques (analyse en frottement de l'interface et des particules d'usure). L’intérêt majeur de notre approche est d'aborder simultanément ces 3 axes et de comprendre leurs interactions respectives. La tomographie aux rayons X, suivie d’un traitement mathématique assisté par ordinateur, complété par l'analyse des particules d'usure a permis d'identifier les morphologies responsables des fonctions spécifiques du matériau cellulaire. Un tribo-abrasimètre innovant avec des surfaces abrasives modèles a mis en évidence l’importance des cinématiques dans l’endommagement du matériau. Des méthodes de caractérisation ont été mises au point afin de quantifier la dégradation tribologique du matériau permettant également de mesurer l’impact du vieillissement (chimique, thermique et mécanique)
Tribological applications of cellular materials in the presence of liquid require acknowledge of their modes of damage, but they remain little known at present. The study, understanding and modeling the behavior of a composite cell requires a multidisciplinary approach due to the heterogeneity of the material that is difficult to characterize. This material can be analyzed along three distinct axes: the rheological properties (analysis in complex state of deformation in compression and shear with adapted rheometer), the morphology of the cells (3D optical tomographic analysis), the tribological properties (analysis in interface friction and wear particles). The major advantage of our approach is to simultaneously address these three areas and to understand their interactions. The X-ray tomography, followed by computer-assisted mathematical treatment, supplemented by the analysis of wear particles identified morphologies responsible for specific functions of cellular material. A tribo-abrasimeter with innovative models abrasive surfaces highlighted the importance of kinematics in the damage of the material. Characterization methods have been developed to quantify the tribological degradation of the material can also measure the impact of aging(chemical, thermal and mechanical)

Cycloidal drives are compact, high-ratio gear transmission systems used in a wide range of mechanical applications from conveyor drives to articulated robots. This research hypothesises that these drives can be successfully applied in dynamic loading situations and thereby focuses on the understanding of differences between static and dynamic loading conditions where load varies with time. New methods of studying the behaviour of these drives under static and dynamic loading circumstances were developed, leading to novel understanding and knowledge. A new model was developed to facilitate research and development on Cycloidal drives with potential benefits for manufacturing, robotics and mechanical-process-industries worldwide.

The aim of the diploma thesis "History of selected math problems" is to explore specific math issues, which famous mathematicians dealt with in the past, using up-to-date knowledge and methods. For each issue there is explained history and diagrams describing its origin and solution.

碩士
國立交通大學
理學院碩士在職專班應用科技學程
97
This thesis is the research of the geometric transformstion between Lissajous and trochoidal curves. Lissajous and trochoidal curves are important in geometric curves. However there is not any connection between Lissajous and trochoidal curves in early researches. Firstly, we start from the simple harmonic motions, and the solution is found as Lissajous parametric curves. Furthermore, by means of the transformation, the matrix SU(2) in group theory , a series of curves between Lissajous and trochoids are demonstrated. They have not been discussed until now. Through the concept of SU(2), we obtained the intriguing geometric curves. Importantly, the physics of the transformation is worthy to discussed further in the future.

碩士
國立高雄應用科技大學
模具工程系碩士班
95
Trochoid rotor mechanism is a kind of rotary positive-displacement pump, which is widely used to meet the need of many industrial processings, such as semiconductor industry, optical industry, food industry, turning round type engine…etc. Through building and constructing out its mathematical model and relative design, the profile characteristic of pump could be analyzed. The profile of trochoid rotor mechanism discussed in the paper is set up from four different types. Focus on the relative relationship of the generating rotor and generated rotor, and then set up its relative motion coordinate system by homogeneous coordinate matrix, depict the relative motion relation between two rotors, and utilize the concepts of envelope theory of the curve and family curve to obtain the rotor profile mathematics model. In this paper, one roller is also added in the four types. First, generate base trochoid curve by roller envelope and then build generating curve from base trochoid curve. Make classification and analysis on researches of profile curve with roller. The influence of input parameters on rotor profile is discussed. Finally, address the explanation against the current trochoid rotor mechanism application implementation example.

碩士
國立臺灣大學
機械工程學研究所
101
This thesis develops design methods for new claw rotor profiles with variable trochoid ratio epicycloid curves. Each claw profile of a rotor consists of an epitrochoid, two arcs, an epicycloid with variable trochoid ratio, and a conjugate curve corresponding to the epicycloid. The rotor profile consists of several identical claws and the claw rotor pair consists of two identical rotor profiles. The profile of a single claw is determined by four basic design parameters and one adjusting coefficient. The four basic design parameters include pitch radius, rotor radius, number of claws and a conformity angle. The adjusting coefficient with value between 0 and 1 is used for adjusting the smoothness of the claw rotor profile. Two types of modified claw-shape are also proposed, one uses portion of a cycloid gear tooth profile, the other uses portion of a modified cycloid gear tooth profile. The proposed modified claw-shape has better sealing property between rotors than the similar types of modified claw-shape. The proposed modified claw-shapes can avoid the crash and locking between the rotor pair because of the smooth contour.

博士
國立中正大學
機械工程所
94
The trochoidal derives is widely used in the industry. This thesis mainly discusses the trochoidal curve on the geometry design of Roots pump, gerotor, compressor and cycloidal speed reducer. In the Roots pump design, we propose a new method that is an extended cycloid curve with a variable trochoid ratio. A design flow is presented on how to achieve high volumetric efficiency, and a design procedure on how to make a high sealing rotor is also discussed. In the cycloidal speed reducer design, two types of design on the mathematical model with tooth differences are proposed. One is a pin wheel epitrochoid meshing and the other is a pin wheel hypotrochoid meshing. Using the parameters of the design result, then compare the analysis on their contact forces and assesses curvature which determines whether the cycloidal wheel has a non-undercutting or continuous condition on the tooth profile. For these two designs, simple dimensionless equations of non-undercutting would be derived and the feasible design regions without undercutting or interference between the adjacent pins would then be developed. In addition, the two proposed mathematical models could be applied to the gerotor pump as well. The design with greater pump efficiency and sealing, and its feasible design region without undercutting would be determined by the undercutting analysis. Besides, the ideas of envelope and offset are also added to the gerotor design. After the two conjugate curves are generated, their envelope curves would be proposed. The enveloped profiles could be exercised not only on the gerotor pump but also the compressor. Finally, the comparison with pump performance, such as volumetric efficiency and the sealing, would be presented for these designs, which include envelope and non-envelope rotor profiles.

碩士
國立高雄應用科技大學
模具工程系
105
Computer-Aided Manufacturing (CAM) and CNC play a major rule in today’s machining industry. In order to adapt to the high-efficient environment, machining industry keeps looking for the new strategies to reduce the cycle time and improve the efficiency for competitive advantages. Among those strategies, trochoidal milling is an efficient one for rough machining. This paper proposed a novel tool path generation strategy to the tool path of trochoidal milling, due to the complicated tool path and the difficulty of generating the machining code, by using chord height model. Three different types of trochoidal milling operations and their modelling are implemented. Comparisons between material removal rate、surface roughness and cusp height are performed by machining experiments. Experiment and measurement results show that the semi-circular chord height model has the large material removal rate, but the cusp height gives a largest tolerance between measured results and calculated results. The material removal rate and surface roughness of the circular chord height model are the lowest. As for the trochoidal model, which has the most complicated tool path, shows the lowest surface roughness compared with other types of chord height model and cusp height gives a lowest tolerance between measured results and calculated results.

Thesis (M.S.)--University of Tennessee, Knoxville, 2003.
Title from title page screen (viewed Sept. 22, 2003). Thesis advisor: Robert N. Compton. Document formatted into pages (viii, 97 p. : ill., charts). Vita. Includes bibliographical references (p. 85-87).

碩士
國立臺灣科技大學
機械工程系
106
With the progress of the times, aerospace industry is developed, and the importance of aerospace manufacturing has increased. Titanium alloys are widely used in the aerospace industry due to their high strength, high heat resistance, and good corrosion resistance. It is also difficult to process because of its characteristics, which in turn leads to high processing costs. Therefore, how to improve processing technology and reduce processing costs is the goal pursued by the current aerospace manufacturing industry.This experiment mainly discusses the machinability of the Ti-10V-2Fe-3Al by using trochoidal milling, and uses Taguchi experimental method to design the experimental parameters, and discusses the influence factors of the cutting characteristics and analyzes the influence factors. The experimental factors are cutting speed 20, 40, 60m/min, feed per tooth 0.045, 0.060, 0.075mm/tooth, trochoidal steps 0.9, 1.2, 1.5mm, trochoidal width 4, 8, 12mm. The experimental results show that the higher cutting speed, the smaller trochoidal width, the larger of feed per tooth and trochoidal steps can get the better the material remove rate. Tool wear part will use tool wear and cutting volume ratio as the result of the analysis. The results show that the slower cutting speed, the larger trochoidal width, and the proper per-tooth feed and trochoidal steps can get better result. As Tool wear result picture found that the faster cutting speed more likely to cause notch wear, the slower cutting speed more prone to cause adhesive wear. From the cutting simulation found that the larger trochoidal width can get the smaller contact angle between tool and workpiece.The surface roughness results show that the larger trochoidal width and trochoidal steps, the smaller feed per tooth and proper cutting speed can get the better surface roughness. At last, comparing the cutting performance of trochoidal and side milling methods, it was found that trochoidal method can have lower tool wear than side milling method.

碩士
龍華科技大學
機械工程系碩士班
104
The slot milling (width 26 mm*500mm) experiments were conducted on SCM415 substrate using ø6 mm, high speed steel end mill by means of modified trochoidal milling method. In this approach, the Taguchi method with orthogonal array. The experimental studies were conducted under different spindle speed, feed rate, cutting depth and cutting width. Results of the study in material removal rate, the best of cutting data: spindle speed 5251rpm, feed rate 0.09mm/Flute, cutting depth 12mm, cutting width 1.2mm, material removal rate 8515mm3/min, Flank Wear wear width is 0.39mm. Tool wear optimized parameters: spindle speed 4774rpm, feed rate 0.09mm/Flute, cutting depth 6mm, cutting width 1.2mm, Flank Wear wear width is 0.11mm.

碩士
台灣首府大學
工業管理學系研究所
104
Cycloid shining metal can significantly increase the efficiency of shining metal tub. By using the process on the components, it shows the significant effect on Cycloid shining metal in terms of the decrease of cutting force and cutting entropy. The main purpose of this study is to improve roughness of SKD11 by using differ cutting edges tungsten steel alloy cutting blade with high speed Cycloid process method. In order to decrease the processing time and the roughness, and minimize the wear and tear of the differ cutting edges of tungsten steel alloy cutting blade, which are the main goal of this research. The main content includes: improve the roughness of SKD11 using Cycloid process method by applying six sigma; determine the condition of wear and tear using different cutting edges of tungsten steel alloy cutting blade. The research mainly focuses on four parameters such as the rotational speed of axis, rate of forwarding, the depth of cutting, and the diameter of cutting tool to determine the difference of traditional digging method and Cycloid process method. The optimized experimental result is happened when the rotational speed was 6000 rpm, the speed of forwarding was 3000mm/min, the cutting forwarding step was 10%, the diameter of cutting tool was 10mm, and the cutting depth was 19mm. Consequently, the processing time decreases to one twelfth and the life of the cutting tool increases to twice compared with original method.

碩士
龍華科技大學
機械工程系碩士班
103
The slot milling (width 13 mm) experiments were conducted on SCM415 substrate using end mill (ø6 mm, high speed steel) by means of trochoidal milling method. In this approach, the Taguchi method with orthogonal array, signal-to-noise ratio and analysis of variance (ANOVA) were employed to study the trochoidal milling characteristics. The experimental studies were conducted under different spindle speed, feed rate, cutting depth and cutting width. ANOVA results shows that the spindle speed has a dominant effect on flank wear. The lower spindle speed lead to longer tool life. Furthermore, the feed rate is the most significant factor for material removal rate. An increase in feed rate results in high material removal rate during a specific period of time. The advantages of trochoidal milling are generate low cutting forces, the heat and wear are uniform leading to longer tool life than traditional slot milling.