WorldCat Identities

Landon, Yann (1975-....).

Works: 23 works in 33 publications in 2 languages and 34 library holdings
Roles: Thesis advisor, Other, Opponent, Author
Publication Timeline
Most widely held works by Yann Landon
Study and characterisation of surface integrity modification after ultrasonic vibration-assisted ball burnishing by Ramón Jerez Mesa( )

3 editions published between 2018 and 2020 in English and held by 3 WorldCat member libraries worldwide

This dissertation is an experimental research project into the mechanical effects of the ultrasonic vibration-assisted ball burnishing process on the surface integrity of surfaces machined through ball-end milling. Due to the lack of commercial tools able to perform this process, the study includes firstly the design and characterisation of a prototype to that effect. An experimental analysis is then undertaken, applying the process to AISI 1038 and Ti-6Al-4V surfaces of high industrial and aeronautical value. The experimental campaign is designed based on a Taguchi orthogonal array that includes five factors, namely: preload, number of passes, feed velocity, strategy and initial surface texture. Results are analysed in terms of topological characteristics, residual stress and hardness, in order to identify and understand the impact of process parameters on surface integrity, to define the best parameters for performing the process and to assess the positive effects caused by the introduction of vibrations as a means of assistance. Results reveal that the initial texture is the most influential parameter on all outcomes. Texture results show that the vibrations can enhance the roughness and texture results, as long as they have sufficient low initial amplitude. Furthermore, only the preload and number of passes influence the results, with a pair of values being found in all cases that serve a threshold from which further plastic strain is detrimental for the final surface topology. In terms of residual stress, all parameters are influential in the results, especially the burnishing strategy, through which a certain component of the residual stress tensor can be adequately reinforced. Finally, the burnishing operation proves to modify the hardness of deep layers down to 0.5 mm, applying the vibration-assisted process. The main conclusion is that the optimal parameters for performing the process are different with regards to the optimisation objective. Some useful combinations are proposed for performing the process depending on the desired target
Développement d'un modèle numérique sur l'étude de l'intégrité des surfaces en perçage by Mathieu Girinon( )

2 editions published in 2017 in French and held by 3 WorldCat member libraries worldwide

The surface integrity has a signifiant impact on the fatigue life of the machined parts. New requirements appear from manufacturers ans especially from aeronautical industrialists. Drilling holes are critical and can damage the component. Nevertheless, residual stresses are not studied a lot in drilling processes. The residual stresses created are a result of multi-physical phenomena during drilling processes. It is difficult to identify them due to the confinement of the hole. In the current study, experimental tests are realized and numerical model of drilling surface integrity was developed. First, experimental works were performed in several lubrication conditions to understand physical phenomena which lead to residual stresses in the drilled workpiece. The numerical developments are set-up about two sections. The first numerical model represents the drilling operation. The state of the art and initial study were shown that the actual numerical models are not able to simulate a drilling operation in an important drilling depth. So the first numerical model gives an estimation of loads induced by the drilling operation and necessary to compute residual stresses. Finally, the second numerical model simulates residual stresses in a drilled part taking in account loads provided
Caractérisation in-situ et modélisation des mécanismes et couplages thermomécaniques en usinage : application à l'alliage de titane Ti-6Al-4V by Mahmoud Harzallah( )

2 editions published in 2018 in French and held by 2 WorldCat member libraries worldwide

This work develops an experimental and numerical strategy in order to investigate material removal of titanium alloy Ti-6Al-4V during machining process. It therefore intends to tackle a complex and strongly coupled problem, involving thermal and mechanical aspects at small scales (micrometric). The lack of measuring means dedicated to such scales in terms of time and space (rapid and strongly local phenomena) does not allow yet to precisely apprehend the thermomechanical phenomena involved during the chip formation. As a result, a specific device, called VISIR, that addresses this issue has been set-up. The experimental aspect of this work has therefore been oriented towards a more precise understanding of the material removal mechanisms. It allowed to observe the evolution of mechanical and thermal quantities during the chip formation and more precisely the strong coupling between the temperature and the strain rate. Based on these experimental insights, the thermomechanical behavior of this alloy has been studied through dynamic shear tests using hat-shaped specimens. It allowed to identify through inverse method a new constitutive equation coupled in temperature and strain rate. In addition, a study on damage is conducted. It is based on the identification and the evaluation of eight criteria commonly used in the material forming process. This leads to proposing a new damage equation, inspired from the Tresca criterion and coupled to material plastic behavior. All of these formulations along with a Stick-Slip friction model have finally been implemented in a 3D FE orthogonal cutting model. Experimental/numerical comparison in terms of mechanical and thermal quantities revealed the robustness and predictive aspect of the developed FE model. Finally, the results of this study allowed to develop a detailed discussion on the material removal mechanisms and more particularly the complexe cracks paths
Caractérisation et optimisation du perçage orbital du Ti6Al4V et d'empilages CFRP/Ti6Al4V by Pierre-André Rey( Book )

2 editions published in 2016 in French and held by 2 WorldCat member libraries worldwide

The study presented in this thesis deals with the orbital drilling of Ti6Al4V titanium alloy and CFRP carbon fiber composite. This case study is taken from an industrial problem, from the Airbus company wishing to incorporate parts CFRP to reduce its mass. But the combination of these two materials with antagonistic properties poses many problems for drilling. This is why new alternatives to conventional drilling have been sought. Among these alternatives, orbital drilling with micro-lubrication showed interesting prospects. That is why it was chosen in this industrial application. But this process is still relatively unexplored and there is little feedback and many developments to achieve. Orbital drilling process is very different from the conventional axial bore. The bore is machined with a smaller diameter tool than the hole, which describes a helical path in the material. All work presented focus on the characterization for the optimization of the orbital drilling process. To achieve this, several aspects were discussed. First, a geometric modeling and kinematics of operation has been developed. The inclusion of the exact geometry of the tool and cutting conditions helped to define the geometry of the chip at every moment. This knowledge is important for understanding the achieved material removal mechanism, it allows to estimate the loading of the tool and the conditions in which machining is performed. From this first geometric modeling, modeling of cutting forces was established. For this, a model of mechanistic type of effort was used. Its application was adapted to orbital drilling in order to best represent the operation. The thus modeled efforts were compared to those observed experimentally in order to validate the proposed model. This allowed to consider the use of this model for a better understanding of this material removal process. The influence of model inputs, namely the cutting conditions and tool geometry was studied. Another contribution of this work is the characterization of the orbital drilling of CFRP stacks / Ti6Al4V. Indeed, many tests were developed to characterize the orbital drilling process. Experimental procedures have therefore been put in place. First of all, the instrumented test means had to be characterized so that it better corresponds to the means used by the manufacturer and above all it allows to carry out reliable and repeatable testing. The experimental design implemented subsequently helped to define the influence of cutting parameters on the efforts and realized diameters. In this phase of characterization, the bore in errors have also been studied. Thus, the trends have been observed. The results obtained in this work in the meeting helped to consider the process optimization of routes, through the control of advances, the drilling strategy, but also the geometry of the tool. Tracks have been proposed and are subject to further study. modeling implementation and the identification of phenomena occurring during the operation have also laid the foundation for process monitoring. This can be considered passively, to monitor the smooth running of the operation, but also actively to act in real time to the control of the process, based on identified phenomena, to ensure the desired quality
Contribution à la modélisation de la qualité géométrique des surfaces générées en perçage vibratoire : application au cas de pièces aéronautiques en alliage de titane Ti6Al4V by Raphaël Lorain( Book )

2 editions published in 2021 in French and held by 2 WorldCat member libraries worldwide

The use of forced vibration drilling process has grown widely in the aircraft industry in recent years. This technology allows good chip fragmentation and limits heat production, in particular when drilling titanium alloys. Forced vibration drilling process is often used on Automatic Drilling Unit (ADU). These devices offer a low radial rigidity. Thus, the combination of a flexible machine and a discontinuous cutting process induces a significant risk of radial oscillations of the drill during the different phases of the drilling which, in fine, results in geometric deviations in the cylindricity and the dimension of the holes generated.Obtaining a good geometric quality of the holes using these devices depends on a set of interacting factors, such as the grinding of the tool tip, the particular kinematics of the operation linked to the use of vibration drilling process, the mechanical characteristics of the material drilled, and the characteristics of the machine used to perform the operation.The works presented in this thesis is divided in two parts. The first part aims to characterize the geometry of holes surface. An original method, having a strong discriminating capability, is proposed. It identifies the critical parameters that control the dynamics of the process. The implementation of this method has shown its ability to quantify the influence of the drill-bush and the influence of the web-thinning geometry.The second part of the work focuses on proposing an analytical modelling of the forced vibration drilling process dynamics taking into account the forces distribution along the cutting edges, and more particularly at the centre of the tool (web thinning). The objective of this analytical model is to predict the lateral displacements of the tool tip during the full material penetration phase, given the major impact of this step in controlling the geometric quality of the holes
Etude et optimisation du perçage orbital robotisé pour l'assemblage des structures aéronautiques by Landry Kamgaing Souop( Book )

2 editions published in 2020 in French and held by 2 WorldCat member libraries worldwide

This thesis addresses the orbital drilling of AA2024-T351 aluminum alloy parts. This case study arose from an industrial problem encountered by various aircraft manufacturers who wish to integrate this process into their manufacturing processes. Despite the multiple advantages of orbital drilling compared to conventional axial drilling, there is still a very important technological barrier: the lower fatigue strength of drilled aluminum alloy parts. This is due to the non-optimization of residual stress levels within the boreholes produced by this process. There is currently no means of optimizing orbital drilling cutting parameters. The overall objective is to improve the fatigue life of drilled parts by introducing during drilling compressive residual stresses and strain-hardening, which are both beneficial to components fatigue life. The work presented in the thesis focuses firstly on the orbital drilling cutting parameters optimization, based on the specific cutting forces and energies minimization. An innovative mechanical surface treatment was introduced within the project: orbital deep rolling. Its characterization had been carried out using Finite Element Method. These models allowed to study further its parameters influence on boreholes surface integrity, particularly on residuals stress. A comparison with experimental results is achieved in order to validate the various numerical simulations implemented. Experimental characterization of the surface integrity of the boreholes performed with orbital drilling under optimized cutting conditions and with orbital deep rolling proved not only the feasibility of the orbital deep rolling process, but also compliance with aeronautical requirements. All this is completed by a fatigue life study of AA2024-T351 aluminum alloy drilled samples
Aide au choix du posage en usinage 5 axes continus par la modélisation du comportement cinématique des machines-outils by Xavier Pessoles( Book )

2 editions published between 2010 and 2017 in French and held by 2 WorldCat member libraries worldwide

Ces travaux s'inscrivent dans le cadre de l'amélioration de la productivité en usinage 5 axes continus. La moélisation d'un centre d'usinage et de sa commande numérique est proposée en 3 axes et 5 axes continus. Un simulateur est alors réalisé. Il permet de prévoir la vitesse de déplacement sur chacun des axes et de modifier les vitesses de consigne afin de mieux respecter les besoins spécifiés par le programmateur FAO. De plus les sources de perte de productivité du processus sont identifiées. Dans le but de réduire le temps d'usinage, une optimisation de l'orientation et du positionnement de la pièce dans la machine est donc proposée. Pour cela des cartographies en couleur sont réalisées. Elles permettent à un opérateur de choisir aisément un posage optimisé. L'ensemble des modélisations et des optimisations sont validées expérimentalement. Un choix optimal de posage associé à une modification de la vitesse au cours du programme permettent de réduire de plus de 50% le temps d'usinage
Contribution à l'amélioration de la qualité d'usinage en fraisage 3 axes sur machines-outils à commande numérique par la mise en place d'un compagnon virtuel by Yann Landon( Book )

2 editions published in 2003 in French and held by 2 WorldCat member libraries worldwide

Influence du procédé de perçage sur l'intégrité de surface et la tenue en fatigue de pièces percées en AA2024-T351 by Alexandra Lacombe( Book )

2 editions published in 2021 in French and held by 2 WorldCat member libraries worldwide

Dans les structures aéronautiques, les trous percés constituent des zones critiques à partir desquelles des endommagements peuvent s'initier en fatigue. En fonction des paramètres et des procédés de perçage employés, les industriels constatent des différences significatives de tenue en fatigue des structures percées. Ces travaux de thèse visent à apporter des éléments de compréhension à cette problématique industrielle, pour le cas pièces percées en AA2024-T351. Ils portent sur l'étude de configurations de perçage industrielles et se focalisent sur deux procédés de perçage : le perçage orbital qui est un procédé présentant de nombreux avantages économiques potentiels et le perçage axial qui est le procédé de perçage conventionnel. L'objectif des travaux est d'évaluer l'impact de la configuration de perçage sur la tenue en fatigue de la pièce percée, mais aussi sur l'intégrité de surface du trou percé. Cela doit permettre d'identifier les paramètres de l'intégrité de surface pilotant la tenue en fatigue et les paramètres majeurs du procédé de perçage contrôlant l'intégrité de surface. La première étape des travaux a été de mener des essais de fatigue afin d'évaluer la performance en fatigue de différentes configurations de perçage. Ceux-ci ont révélé des écarts significatifs de durée de vie en fatigue entre certaines configurations de perçage. La seconde étape a consisté à caractériser expérimentalement l'intégrité de surface des trous percés. Celle-ci a été guidée par un modèle éléments finis prédictif de la profondeur de matériau affectée en sous-surface du trou et de nouvelles méthodes d'analyse (comme la "HOCT") ont dû être envisagées pour certains aspects de l'intégrité de surface dû à la faible profondeur affectée. Cette campagne a montré l'influence prépondérante des aspects internes de l'intégrité de surface (écrouissage et contraintes résiduelles) sur la tenue en fatigue. Enfin, la dernière étape des travaux visait à étudier l'impact des paramètres du procédé de perçage sur l'intégrité de surface. Pour cela, un modèle éléments finis de coupe orthogonale a été développé. L'influence prépondérante de la géométrie de l'outil sur l'intégrité de surface a été montrée
Contrôle actif des vibrations en fraisage. by Feriel Kochtbene( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

This thesis deals with the fields of study which are important for our objective (different usual vibration reduction techniques in machining, active control methods) before validating the principle of active control of milling in a fixed reference. We then developed a state space model of an Euler Bernoulli beam excited at one point and corrected in another one by a piezoelectric actuator. This model allowed us to obtain several compensators, according to different control strategies. We then proceeded from an experimental point of view to study a device similar to our need from an actuating point of view and levels of magnitude (mechanical amplification, frequency range, etc.). ). The robust control strategies that we have developed to attenuate the vibratory displacements of this beam have led to conclusive results presented in the same chapter, first in simulation (which allowed us a comparative study), with and without the cutting process and then experimentally. The robustness of these control strategies was studied (in simulation) by adding uncertainties to the model in different ways. Then we have identified the model of the system, calculated the corresponding compensators and tested them on the test bench in order to validate the good functioning of the different control strategies used in this thesis. Finally, in order to use these strategies in rotating reference (active control tool holder), we have modeled and implemented the same steps for the case where the actuation is located in rotating reference and concerns two axes simultaneously, located in the XY plane of the tool holder. We first studied the transverse vibrations of a rotating beam in the general case before neglecting the inertia and gyroscopic phenomena. Actually, we are interested in the active control of milling, particularly in finishing applications, where long tools of small diameters are used. The new expressions of the two transfer functions of the system have been determined to obtain its state space representation, key of the active control. Projection of the cutting process on the rotating reference is essential to perform milling simulations with the active tool holder. This last chapter highlights the prospects of this thesis,that is the active control of the milling for all kinds of milling operations as well as for different tools with a mechatronic tool holder aimed for this kind of operation
étude des chargements thermomécaniques induits par le resserrement du trou en perçage du Ti6Al4V sous assistance cryogénique by Johan Merzouki( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

On account of the major economic and ecological stakes to which the aeronautic industry stakeholders had to react during the last decades, the composite mass percentage in aircrafts never stopped to increase and reached more than 50% in 2013 for the Airbus A350. Indeed, the aim always being to build lighter aircrafts, aluminum alloys (which represented more than 75% of the total mass in the 70') were gradually replaced by other materials which were considered to have more advantageous mechanical properties to weight ratios and especially by CFRP (Carbon Fiber Reinforced Plastic). Since the CFRP/titanium alloy pair demonstrates a better thermal and electrochemical compatibility compared to the CFRP/aluminum alloy pair, the use of titanium alloys in aircraft increased as well.Therefore, many assembly cases are currently CFRP/Ti6Al4V hybrid stacks for which the goal is to be able to drill them in one shot, just as it was done for metal/metal stacks. Studies were carried out concerning hybrid stacks drilling and highlighted that the elevated temperatures during the Ti6Al4V drilling were mainly responsible for the non-fulfilment of aeronautical specifications. Based on these observations, the idea of using the cryogenic assistance emerged: cooling down the cutting area by using liquid nitrogen instead of classic modes of lubrication and cooling.Indeed, the latent heat that liquid nitrogen absorbs when it vaporizes makes it an excellent candidate to efficiently cool the cutting zone. Moreover, since it evaporates quickly at room temperature, it eliminates the need to clean the parts and to recycle the fluids while being neutral for the planet and the machine operator.This Ph.D thesis revolves around the study of cryogenic assistance effects in Ti6Al4V drilling and focuses especially on its impact on hole shrinkage. Indeed, the shape and dimensions of the drilled hole, as well as the thermomechanical loads induced by the operation depend on this little-known phenomenon. Therefore, this thesis proposes to highlight the key role of hole shrinkage in Ti6Al4V drilling and to give elements of analysis and understanding on the phenomenon, for dry and cryogenic cutting conditions
Etude de la coupe en perçage par le biais d'essais élémentaires en coupe orthogonale : application aux composites carbone-époxy by Florent Blanchet( )

1 edition published in 2015 in French and held by 1 WorldCat member library worldwide

L'assemblage de pièces de structures composites, notamment en carbone/époxy, est souvent réalisé par liaison boulonnée. Ceci nécessite le perçage des logements de fixations. Cette opération de perçage doit répondre à des contraintes de fiabilité, de productivité et de qualité d'usinage. L'opération de perçage doit donc être maitrisée, ce qui passe par une meilleure compréhension des phénomènes présents en perçage. Mais l'étude de ces phénomènes se heurte à des obstacles tels que l'aspect confiné de l'opération, la géométrie complexe et variable du foret, la variation de vitesse le long de l'arête principale de coupe... Afin de s'affranchir de ces obstacles, des essais élémentaires représentatifs de la coupe en perçage peuvent être proposés. Ce travail de thèse s'inscrit dans cette optique. Ce travail s'articule autour de trois axes. Le premier concerne une étude de la représentativité des différents essais élémentaires vis-à-vis du perçage. Un outil d'identification de géométrie d'outil est proposé ; il permet d'identifier l'évolution de la géométrie locale des outils coupants et ainsi de proposer des essais élémentaires qui soient géométriquement et cinématiquement représentatifs de la coupe en perçage. Le second axe développé propose une étude des phénomènes présents en coupe orthogonale quasi-statique. Cela permet de s'affranchir des effets liés à la vitesse. Dans ce cadre, des essais de corrélation d'images en coupe orthogonale sont proposés. Ils permettent l'analyse des champs de déplacements et de déformations. Une analyse des efforts générés, de la morphologie des copeaux et des états de surfaces obtenus en fonction de l'angle de coupe et de l'angle ?2 entre la vitesse de coupe et la direction des fibres est également réalisée. Deux types de modèles numériques, macro- mécanique et micro-mécanique, sont proposés. Ils sont confrontés aux résultats expérimentaux. Le dernier axe de travail présente l'analyse des phénomènes liés à la vitesse de coupe en coupe orthogonale. Le modèle macro-mécanique est modifié afin d'intégrer des phénomènes tels que la variation des contraintes à rupture de la matrice en fonction de la vitesse de déformation, ou encore l'évolution du frottement en fonction de la vitesse de glissement. Les résultats du modèle sont confrontés aux résultats expérimentaux
Développement d'un modèle généralisé d'efforts de coupe pour l'usinage de l'alliage de titane Ti6Al4V. Application aux techniques de tournage et fraisage by Théo Dorlin( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

In order to control complex parts industrialization, cutting forces can be relevant data. Although cutting force prediction is a well-known subject by the scientific community, it still exists some ways of improvement. This research work focuses on the cutting force modelling enhancement according to two main points. Firstly, an analysis of clearance face contact conditions, linked to part geometry, effect on cutting forces. Secondly, the effect of flank wear on cutting force evolution with respect to the time. Based on experiments, in order to highlight relevant parameters to introduce in the new model, cutting force and flank wear models are formulated according to mechanistic approach. These developments are applied in milling, turning (boring, cylindrical turning and face turning) onTi6Al4V titanium alloy. Methodologies presented in this study can be easily adapted to others titanium alloys shades in order to cover large industrial range of applications
A decision support model in mass customization( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

Highlights: Decision support model in mass customization. Analysis of customer preference, product features and cost. Optimization using genetic algorithm. Abstract: Mass customization (MC) is one of the leading strategies used in production industries in today's market filled with competition. MC is an oxymoron of controlling production costs and satisfying customers' individual requirements. It is well known that economy of scale and economy of scope is a pair of conflicts, and how to get the balance between them is the key issue to promote enterprises' competition. By analyzing and processing information of customer preference, product features and cost, this paper proposes a decision support model in mass customization to obtain the optimized production solution. Genetic algorithm is used for optimization, and the results of an illustrative example show that the model is efficient in production industries
Impact de l'usinage par CFAO sur l'intégrité de surface des prothèses dentaires coronaires by Nicolas Lebon( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

The rehabilitation of dental function following the fitting of prostheses obtained by CAD/CAM is one of the major challenges of modern restorative dentistry. The quality of these prostheses can be assessed using roughness, corresponding to a major surface integrity (SI) component in dentistry. This thesis work aims to evaluate and quantify the influence of the characteristics associated with various milling tools, the materials used, and the parameters associated with the milling process on the residual roughness. The achieved results obtained during this work show a rather limited influence of the feedrate on the roughness, whereas those related to the size of the tool micro-geometry, the tool/prosthesis inclination, and the biomaterials are more significant. The importance of using a roughness parameters set in order to obtain a maximum of information relating to the surface topology is also demonstrated. This in turn leads to the definition of machining process performance indicators for the multi-physical and multi-indicator SI evaluation. The validation of the approach through a case study shows that a topological decomposition of the crown is necessary in order to better respect the prosthetic specifications and to provide valuable assistance to the practitioner or the laboratory technician. Each topological region can thus be machined using different machining strategies, be evaluated by a set of its own roughness parameters set, and undergo a post-processing polishing treatment, if necessary
Contribution à la modélisation du perçage assisté par vibration et à l'étude de son impact sur la qualité d'alésage : application aux empilages multi-matériaux by John Le Dref( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

Contribution to the modelling of vibration assisted drilling and to the study of its impact on hole quality
Modélisation du procédé de perçage assisté par vibrations forcées : prise en compte de l'environnement Pièce-Outil-Machine. by Mathieu Ladonne( )

1 edition published in 2016 in French and held by 1 WorldCat member library worldwide

Vibrations assisted drilling is a process which ensures chip shape control in order to increase reliability during drilling operations. The adding of axial oscillation, controlled with amplitude and frequency, introduce two new parameters which must determinate according to the conventional parameters (feed and speed rotation). The optimal setting of vibrations assisted drilling is not obvious. To provide an optimization-tool of the process, a new model which take into account the “Tool-Workpiece-Machine” environment, is proposed. Drill geometry, Tool-Workpiece interactions and dynamic behavior of the Machine are incorporated in the model. Tis specificity allows adjusting behavior of the process with the case of application. An identification methodology is presented to characterize the environment. Simulation's results and experimental results are compared to validate the model. This model thus allows predicting process behavior in order to optimize the operational parameters
Développement d'un modèle d'efforts de coupe multi-opérations et multi-matériaux. Application au tournage du cuivre pur dans différents états métallurgiques. by Sébastien Campocasso( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

The cutting forces have to be known as accurately as possible in order to predict the characteristics of the workpiece as the geometry, the roughness or the material integrity.Numerous models have been yet developed; however, the majority cannot be used for the various industrial cutting operations and remain confined for a single machined material.The objective of this study is to develop a cutting forces model applied to any turning operation and taking into account some mechanical characteristics of the machined material.First, a geometrical model based on homogeneous transformations is presented. Then, the effects of some parameters, like the workpiece diameter, the cutting edge angle and the nose radius, are studied by using new cutting configurations, in order to improve the cutting laws.The multi-material aspect is approached by modifying the metallurgical state with thermo-mechanical treatments, especially by using the equal channel angular extrusion process in order to harden the material in the mass. Finally, the coefficients of the local cutting relations are compared to mechanical characteristics obtained from tensile and high compression tests
Optimisation du perçage de multi-matériaux sur unité de perçage automatique (UPA) by Jérémy Jallageas( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

L'allégement des structures aéronautiques conduit à associer par stratification les composites aux métaux : on parle alors de multi-matériaux. L'assemblage mécanique des empilages nécessite au préalable des opérations de perçage qui s'effectuent majoritairement sur Unité de Perçage Automatique (UPA). L'objectif des travaux présentés dans ce mémoire est d'optimiser les opérationsde perçage effectuées sur UPA dans des multi-matériaux CFRP-7175-TA6V. Trois axes de recherche ont ainsi été étudiés. Le premier concerne l'optimisation de l'outil. L'utilisation d'une méthode de conception adaptée a conduit vers plusieurs pistes d'améliorations de la géométrie d'un foret. Le deuxième axe traite de la modélisation du perçage vibratoire. Cette méthode consiste à ajouter un mouvement de vibration axiale, au mouvement de coupe. Le dernier axe développe la technique du perçage auto-adaptatif. Une nouvelle méthode est proposée pour identifier les différents matériaux constituants l'empilage
Développement d'un procédé de fabrication additive à base de matériaux expansifs pour des pièces de grandes dimensions by Elodie Paquet( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Scientific work focuses on the development of a new 3D printing process from expansive materials, allowing the production of large-shaped complex parts. This process is called FAM (Foam Additive Manufacturing) and operated with robotic means it will be used for application cases in the fields of construction and boating. This FAM technology consists in depositing along a trajectory a polymer in the liquid state which will expand and solidify in just a few seconds. On this first layer of solidified material, new layers of material will be able to be printed, and so on until the final part. The objectives of the thesis are to develop digital models to simulate the additive manufacturing process by controlling the expansion of the material, identify the influencing parameters, develop the digital chain and optimize the manufacturing process. After identifying the intrinsic parameters of expansion of the material, the models that have been developed make it possible to obtain the geometry of the deposited beads and the temperature fields with respect to the rate of deposition of material layer by layer. For producte digital models, it is possible to analyze the influence of the operating parameters on the different observables and therefore to have a better understanding of the phenomena involved in order to propose an optimized 3d printing strategy solution to guarantee 3D geometry of the part, the material health and the manufacturability according to the printing machinery
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