Dissertations / Theses on the topic 'Additive Manufacturing (AM) techniques'
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Schunemann, Esteban. "Paste deposition modelling : deconstructing the additive manufacturing process : development of novel multi-material tools and techniques for craft practitioners." Thesis, Brunel University, 2015. http://bura.brunel.ac.uk/handle/2438/13803.
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A novel paste deposition process was developed to widen the range of possible materials and applications. This experimental process developed an increasingly complex series of additive manufacturing machines, resulting in new combinations of novel materials and deposition paths without sacrificing many of the design freedoms inherit in the craft process. The investigation made use of open-source software together with an approach to programming user originated infill geometries to form structural parts, differing from the somewhat automated processing by 'closed' commercial RP systems. A series of experimental trials were conducted to test a range of candidate materials and machines which might be suitable for the PDM process. The combination of process and materials were trailed and validated using a series of themed case studies including medical, food industry and jewellery. Some of the object created great interest and even, in the case of the jewellery items, won awards. Further evidence of the commercial validity was evidenced through a collaborative partnership resulting in the development of a commercial version of the experimental system called Newton3D. A number of exciting potential future directions having been opened up by this project including silicone fabrics, bio material deposition and inclusive software development for user originated infills and structures.
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Hasting, William. "Geometric Effects of Free-Floating Technique on Alloy 718 Parts Produced via Laser-Powder Bed Fusion." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613751580039925.
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Whip, Bo Ryan. "Effect of Process Parameters on the Surface Roughness and Mechanical Performance of Additively Manufactured Alloy 718." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1526993831680976.
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Melpal, Gopalakrishna Ranjan. "Conformal Lattice Structures in Additive Manufacturing (AM)." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1535382325233769.
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Chandran, Ramya. "Optimization of Support Structures in Additive Manufacturing (AM) Processes." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479819006942462.
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Paul, Ratnadeep. "Modeling and Optimization of Powder Based Additive Manufacturing (AM) Processes." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378113813.
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Allavarapu, Santosh. "A New Additive Manufacturing (AM) File Format Using Bezier Patches." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1385114646.
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Ghazizadeh, Ali, and Suraj Lakshminarasimhaiah. "Additive manufacturing and its impacts on manufacturing industries in the future concerning the sustainability of AM." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-56058.
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With the emergence of modern technologies in manufacturing processes, companies need to adapt themselves to these technologies to stay competitive. Additive Manufacturing is one of the upcoming technologies which will bring major changes to the manufacturing process. AM (Additive Manufacturing) offers flexibility in design, production size, customization, etc., Even though there are numerous advantages from the implementation of AM technologies less than 2% of the manufacturing industries use them for production. The purpose of the thesis was to study the impact of AM on manufacturing industries in 5-10 years and the barriers it is facing for widespread diffusion. Additionally, its impact on Sustainability aspects is also studied. A literature review was conducted to understand the current AM processes, their applications in different manufacturing sectors, their impact on business strategies, operations, and Product Life cycle. From the study, it was concluded that AM technologies are still in their maturing state and has a lot of uncertainties that it must overcome. The most notable barriers being implementation costs, limited materials, and protection of Intellectual property. The thesis also presents the projection for AM in 2030. AM is advantageous for Environmental and Economic sustainability with very little research on Societal sustainability.
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Jeunehomme, Eric J. S. "Design of low cost biomimetic flexible robots using additive manufacturing techniques." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122313.
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Thesis: S.M. in Naval Architecture and Marine Engineering, Massachusetts Institute of Technology, Department of Mechanical Engineering, 2019Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2019
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 109-112).
In this thesis, I designed and fabricated robots leveraging additive manufacturing. This had two overarching purpose. One to make a testing apparatus that would allow the measurements of the influence of a flexible flapping foil onto a subsequent, in-line, foil with the optic of researching optimized propulsion solutions for under water vehicles. The second was to show that filament deposition modeling has advanced enough to produce bio-mimetic flexible robots of academic relevance that would allow, for a low price, the making of a number of experimental setup with specific measurements in mind. In order to reach those goals, two versions of a bio-mimetic archer fish of the genus Toxotes were modeled using various software. The models were modified to accept actuator assemblies and interface to the electronics and built using a modified hobby grade 3D printer.
by Eric J.S. Jeunehomme.
S.M. in Naval Architecture and Marine Engineering
S.M.
S.M.inNavalArchitectureandMarineEngineering Massachusetts Institute of Technology, Department of Mechanical Engineering
S.M. Massachusetts Institute of Technology, Department of Mechanical Engineering
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Sauter, Barrett. "Ultra-light weight design through additive manufacturing." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-45160.
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ABB Corporate Research was looking to redevelop one product to be manufactured via polymer additive manufacturing (AM), as opposed to its previously traditionally manufacturing method. The current product is cylindrical in shape and must withstand a certain amount of hydrostatic pressure. Due to the pressure and the current design, the cannister is prone to buckling failure. The cannister is currently produced from two cylindrical tube parts and two spherical end sections produced from solid blocks of the same material. For assembly, an inner assembly is inserted into one of the tube parts and then all parts are welded together. This product is also custom dimensioned for each purchase order. The purpose of investigating this redevelopment for AM is to analyse if an updated inner design unique to additive manufacturing is able to increase the performance of the product by increasing the pressure it can withstand from both a material failure standpoint and a buckling failure. The redevelopment also aims to see if the component count and process count can be decreased. Ultimately, two product solutions are suggested, one for low pressure ranges constructed in ABS and one for high pressure ranges constructed in Ultem 1010. To accomplish this, relevant literature was referred to gain insight into how to reinforce cylindrical shell structures against buckling. Design aspects unique to AM were also explored. Iterations of these two areas were designed and analysed, which led to a final design choice being decided upon. The final design is ultimately based on the theory of strengthening cylindrical structures against buckling through the use of ring stiffeners while also incorporating AM unique design aspects in the form of hollow network structures. By utilizing finite element analysis, the design was further developed until it held the pressure required. Simulation results suggest that the ABS product can withstand 3 times higher pressure than the original design while being protected against failure due to buckling. The Ultem simulation results suggest that the product can withstand 12 times higher pressure than the current design while also being protected against failure due to buckling. Part count and manufacturing processes are also found to have decreased by half. Post-processing treatments were also explored, such as the performance of sealants under pressure and the effects of sealants on material mechanical properties. Results show that one sealant in particular, an acrylic spray, is most suitable to sealing the ABS product. It withstood a pressure of 8 bar during tests. The flexural tests showed that the sealant did indeed increase certain mechanical properties, the yield strength, however did not affect the flexural modulus significantly. This work gives a clear indication that the performance of this product is feasibly increased significantly from redeveloping it specifically to AM.
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Strong, Danielle B. "Analysis of AM Hub Locations for Hybrid Manufacturing in the United States." Youngstown State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1495202496133841.
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Johansson, Matilda, and Robin Sandberg. "How Additive Manufacturing can Support the Assembly System Design Process." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Industriell organisation och produktion, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-30887.
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In product manufacturing, assembly approximately represents 50% of the total work hours. Therefore, an efficient and fast assembly system is crucial to get competitive advantages at the global market and have the right product quality. Today, the verification of the assembly system is mostly done by utilizing software based simulation tools even though limitations have been identified. The purpose of this thesis is to identify when the use of additive manufacturing technology could be used in assessing the feasibility of the assembly system design. The research questions were threefold. First, identifying limitations that are connected with the used assembly simulation tools. Secondly, to investigate when additive manufacturing can act as a complement to these assembly simulations. Finally, to develop a framework that will assist the decision makers when to use additive manufacturing as a complement to assembly simulations. The researchers used the method of case study combined with a literature review. The case study collected data from semi-structured interviews, which formed the major portion of the empirical findings. Observations in a final assembly line and the additive manufacturing workshop provided valuable insights into the complexity of assembly systems and additive manufacturing technologies. In addition, document studies of the used visualization software at the case company resulted in an enhanced understanding of the current setting. The case study findings validate the limitations with assembly simulations described in theory. The most frequent ones are related to visibility, positioning, forces needed for the assembly operator, and accessibility between different parts. As both theory and case study findings are consistent in this respect, simulation engineers should be conscious of when to find other methods than simulation for designing the assembly system. One such alternative method is the utilization of additive manufacturing. The thesis outlines a number of situations where additive manufacturing indeed could act as a complement to assembly simulation. The authors argue that the results and findings to a large degree are applicable to other industries as the automotive sector is very global and competitive in nature and encompasses a large variety of complex assembly operations. A structured framework was also developed that could act as a decision support. The framework takes into account three dimensions that are crucial for the decision; (1) the assembly simulation limitation, (2) the context of the assembly and which parts are involved and (3) the possible limitations of additive manufacturing in the specific context. This impartial decision framework could help companies with complex assembly systems to know when to use additive manufacturing, as well as for which parts and subparts additive manufacturing is applicable. To increase the longevity of the decision framework, new improvements of assembly simulation tools and additive manufacturing technologies, respectively, should be incorporated in the framework.
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Sreedhar, Aldric, and C. L. Kaushik Gupta. "Pre-study on the use of additive manufacturing to produce low volume complex parts and its environmental sustainability." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-52800.
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With the rapid increase in demand for more high-value customized products and a more sustainable approach to manufacturing, companies are focusing on being more flexible while also trying to minimize environmental impact. As it is not possible to meet these current demands using traditional manufacturing techniques, manufacturing industries are searching for better manufacturing alternatives to address these issues in order to stay competitive. In this thesis, the two issues of manufacturing complex, low volume parts and environmental sustainability were investigated with the use of the additive manufacturing (AM) technology and possible improvements/recommendations were suggested. The conclusions drawn suggested that AM could be used to produce complex parts more efficiently and also proved to be a more sustainable alternative with decreased energy and resource consumption when compared to traditional methods.
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Philip, Ragnartz, and Axel Staffanson. "Improving the product development process with additive manufacturing." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-40344.
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The following report consists of a master thesis (30 credits) within product development. The thesis is written by Philip Ragnartz and Axel Staffanson, both studying mechanical engineering at Mälardalens University. Developing new components for a production line is costly and time consuming as they must be made from manual measurements and must go through all the conventional manufacturing (CM) steps. Eventual design mistakes will be discovered after the component have been manufactured and tested. To fix the design a completely new component must be designed and therefore double the overall lead time. The purpose of this thesis is to establish how additive manufacturing (AM) can best be used to minimize the cost and lead time in the development of new components. The study was performed by looking at the current product development process in the automotive industry at a large company, here by referred to as company A. 56 components already manufactured at company A´s own tools department was examined and compared to different AM methods. The aim of this was to get a larger pool of data to get an average on production time and cost and see how this differ to the different AM methods. Additionally, two work holders were more closely examined in a case study. Work holder one is a component in the production line that occasionally must be remanufactured. It was examined if this problem could be solved with a desktop plastic printer to hold up for a production batch. Work holder two was the development of a new component, this was to examine the use of printing the component in an early stage impact the development process. The findings from this study is that AM can today not be used in a cost efficient way in manufacturing or development of simple components. This is due to the cost of a metal 3D-printer is still very high, and the building material even higher. This results in components that gets very expensive to make compared to producing them with CM. For design evaluation to be cost efficient there will have to be a design fault in over 12 % of the newly design components for it to be cost effective to print the design for validation before sending it to be manufactured. There are however a lot bigger potential savings in the lead time. Producing the end product with a metal 3D-printer can cut down the lead time up to 85 %. This is thanks to the fact that the printer will produce the component all in one step and therefore not get stuck in between different manufacturing processes. The same goes for design evaluation with printing the component in plastic to confirm the design and not risk having to wait for the component to be manufactured twice. Despite the facts that it is not cost efficient to use AM there are other factors that play an important role. To know that the designed components will work will create a certainty and allow the development process to continue. In some cases it will also allow the designer to improve the design to function better even if the first design would have worked. As AM is expanding machines and build materials will become cheaper. Eventually it will become cheaper to 3D-print even simple components compared to CM. When this occurs, a company cannot simply buy a 3D-printer and make it profitable. There is a learning curve with AM that will take time for the designers to adapt to. Therefore, it is good to start implementing it as soon as possible as it allows for more intricate designs and require experience to do so.
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Wang, Zhiping. "Constructive generative design methods for qualified additive manufacturing." Thesis, Ecole centrale de Nantes, 2021. https://tel.archives-ouvertes.fr/tel-03670417.
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Les technologies de fabrication additive (FA) donnent de plus en plus de liberté de conception aux concepteurs et aux ingénieurs pour concevoir et définir des géométries et des compositions de matériaux très complexes. En raison d'un traitement couche par couche, les contraintes, méthodes, outils et processus de conception en FA sont différents de ceux des processus de fabrication traditionnels. Les méthodes et outils de conception traditionnels ne peuvent pas répondre aux besoins de la conception en FA. Par conséquent, un nouveau domaine de recherche, la conception pour la FA (Design for AM - DfAM), a émergé pour répondre à ce besoin. Cependant, les méthodes de DfAM existantes sont soit des lignes directrices, soit des outils de calculs, qui ont une prise en compte limitée des contraintes couplées le long de la chaîne de traitement numérique de la FA et peinent à garantir la fabricabilité de la conception en FA. Pour contribuer à l’obtention d’une conception qualifiée en FA, ce travail de thèse se concentre sur trois problèmes existants typiques dans le domaine du DfAM : premièrement, com-ment assurer la fabricabilité dans le processus d’optimisation topologique ? Deuxièmement, comment concevoir des structures de supports allégées, faciles à retirer pour le post-traitement et de diffusion de chaleur conviviales pour assurer la précision de la forme et améliorer la rugosité de surface des pièces imprimées ? Enfin, comment éviter les pertes de précision lors de la préparation de l'impression de structures en treillis complexes et assurer leur fabricabilité lors de la conception ?Pour résoudre les trois problèmes identifiés, ce travail de thèse propose un ensemble de nouvelles méthodes de conception générative constructive : 1. Méthode de conception générative basée sur un modèle CSG pour assurer la fabricabilité dans l'optimisation de la topologie de la structure allégée ; 2. Méthode de conception générative constructive basée sur des modèles pour optimiser la conception de la structure de supports et 3. Conception constructive inversée basée sur les « parcours d'outils » pour obtenir directement des modèles de traitement de structures poreuses ou de réseaux complexes correspondants avec des « parcours d'outils » pour obtenir directement des modèles de traitement de structures poreuses ou de réseaux complexes correspondants avec des « parcours d'outils » d'impression qualifiés. Les trois méthodes proposées intègrent les contraintes de processus de FA, réalisent un contrôle paramétrique et économisent des coûts de calcul dans le processus de conception pour obtenir un ensemble de solutions de conception candidates avec une fabrication garantie. Un ensemble d'études comparatives avec les méthodes DfAM existantes et quelques études de cas expérimentaux dans des applications médicales ont démontré les avantages des méthodes proposées. Ces méthodes constructives peuvent avoir un grand potentiel d'application pour être adoptées comme outils de conception et de prise de décision pour d'autres applications industrielles lorsqu'un DfAM qualifié est requisAdditive manufacturing (AM) technologies give more and more design freedom to designers and engi-neers to design and define highly complex geometries and material compositions. Due to a layer-by-layer processing, the constraints, methods, tools and processes of design in AM are different from that in traditional manufacturing processes. Traditional design methods and tools cannot meet the needs of design in AM. Therefore, a new re-search field, design for AM (DfAM), has emerged to serve this need. However, existing DfAM methods are either guidelines or pure computation-based, which have limited consideration of coupled constraints along the AM digital processing chain and are difficult to ensure manufactura-bility of design in AM. To obtain qualified design in AM, this research focuses on three typical existing problems in DfAM domain: Firstly, how to ensure manufacturability in (topology optimization) TO process? Secondly, how to design support structures with lightweight, easy-to-remove for post-processing and friendly heat-diffusion properties to ensure shape accuracy and improve surface roughness of printed parts? Finally, how to avoid accuracy loss in print-ing preparation of complex lattice structures and ensure their manufacturability in design?To solve the three identified problems, this research developed a set of new constructive genera-tive design methods: 1. CSG-based generative design method to ensure manufacturability in light-weight topology optimization; 2. Pattern-based constructive generative design method to optimize support structure design and 3. Toolpath-based inversed constructive design to directly ob-tain processing models of corresponding complex lattice or porous structures with qualified print-ing toolpaths. The three proposed methods can well embed AM process constraints, realize para-metric control and save computation cost in design process to obtain a set of candidate design solutions with ensured manufacturability. A set of comparison studies with existing DfAM meth-ods and a couple of experiment case studies in medical applications demonstrated the methods’ advantages. These constructive methods may have large application potential to be adopted as design and decision making tools for other industrial applications when qualified DfAM is required
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Woods, Adam Xavier. "Exploring Combinatorial Libraries for Material Screening Techniques via Additive Manufacturing: Design, Fabrication, & Applications." University of Akron / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=akron1594772957272505.
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Hamad, Aamir Hamed. "Additive Manufacturing Techniques to Enhance the Performance of Electronics Created on Flexible andRigid Substrates." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1598253714624332.
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Al, Mortadi Noor. "Computer Aided Design/Aided Manufacture/Additive Manufacturing applications in the manufacture of dental appliances." Thesis, Cardiff Metropolitan University, 2014. http://hdl.handle.net/10369/6527.
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Vaidya, Rohit R. "Image Processing (IP) Assisted Tools for Pre- and Post-Processing Operation in Additive Manufacturing (AM)." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1470757856.
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Ingman, Richard. "ADAPTION OF A HEATSINK TO ADDITIVE MANUFACTURING. : INCLUDING A GUIDE TO INDUSTRIAL STARTUP OF AM." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262655.
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This thesis is an investigation of the current status of additive manufacturing (AM) regarding different technologies, the level of implementation in industry and the future obstacles for further implementation. As a secondary objective, an existing heatsink for electronic equipment was redesigned, adapted to and improved using the design advantages of AM, and was later manufactured through 3D-printing in aluminium (AlSi10Mg). The thesis resulted in a summarized roadmap of recommended actions for Saab Surveillance in Järfälla in the near future. And a redesigned heatsink, which was tested to hold a static pressure of 30 bar, and simulated to achieve the same pressure drop in the channel and withstand the same vibration load as the old heatsink. At the same time, the new design reduced the total weight by 20% and increased the heat transferring surface area of the channel by 100%, potentially doubling the heat transfer capability.Detta examensarbete har undersökt den nuvarande statusen hos additiv tillverkning (AM) vad gäller olika teknologier, hur långt implementeringen i industrin kommit och framtida hinder som måste lösas för vidare implementering. Som sekundärt mål för projektet har en existerande elektronikkylare designats om och förbättrats med hjälp av designfördelarna hos AM, och tillverkades sedan genom 3D-printning i aluminium (AlSi10Mg). Arbetet har resulterat i en sammanfattad ’roadmap’ med rekommendationer för vad Saab Surveillance i Järfälla bör göra inom AM den närmaste tiden, samt en ny kylare som framgångsrikt trycktestades upp till 30 bar. Genom simuleringar visades den uppnå samma tryckfall och klara samma vibrationer som den tidigare kylaren, samtidigt som den väger 20% mindre och har en 100% ökning av kylkanalens våta area vilket potentiellt innebär en dubblering av kylförmågan.
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Karlsson, Mattias, and Axel Magnusson. "Wire and Arc Additive Manufacturing : Pre printing strategy for torque arm." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-79176.
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Wire and Arc Additive Manufacturing (WAAM) is a novel Additive manufacturing method. It is a high deposition rate process which can be suitable for producing low to medium quantities of medium to large sized components. Because it is such a novel method, there are still somechallenges to solve for the method to be useful. This project have been focusing on how to dealwith these challenges and how to manufacture a torque arm with WAAM. This includes the process on how to go from a CAD model to a printed product. Tests have been done during the project parallel with the design of the torque arm. The design have been modied according to the results from the tests. The result of the project was a more specic description how the softwares can be used to optimizethe process for a successful print. The used slicing software, Simplify3D, have some limitations and other options should be considered. Some limitations for the part design have been identied and some known challenges have been solved. The torque arm was successfully printed but with more time and refinement, the added offset could be reduced. The process was time consuming and needs to be more automated in the future. Some proposals on what should be further tested and evaluated is also stated in this report.
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Hayagrivan, Vishal. "Additive manufacturing : Optimization of process parameters for fused filament fabrication." Thesis, KTH, Lättkonstruktioner, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-238184.
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An obstacle to the wide spread use of additive manufacturing (AM) is the difficulty in estimating the effects of process parameters on the mechanical properties of the manufactured part. The complex relationship between the geometry, parameters and mechanical properties makes it impractical to derive an analytical relationship and calls for the use of a numerical model. An approach to formulate a numerical model in developed in this thesis. The AM technique focused in this thesis is fused filament fabrication (FFF). A numerical model is developed by recreating FFF build process in a simulation environment. Machine instructions generated by a slicer to build a part is used to create a numerical model. The model acts as a basis to determine the effects of process parameters on the stiffness and the strength of a part. Determining the stiffness of the part is done by calculating the response of the model to a uniformly distributed load. The strength of the part depends on it's thermal history. The developed numerical model serves as a basis to implement models describing the relation between thermal history and strength. The developed model is suited to optimize FFF parameters as it encompass effects of all FFF parameters. A genetic algorithm is used to optimize the FFF parameters for minimum weight with a minimum stiffness constraint.Ett hinder för att additiv tillverkning (AT), eller ”3D-printing”, ska få ett bredare genomslag är svårigheten att uppskatta effekterna av processparametrar på den tillverkade produktens mekaniska prestanda. Det komplexa förhållandet mellan geometri och processparametrar gör det opraktiskt och komplicerat att härleda analytiska uttryck för att förutsäga de mekaniska egenskaperna. Alternativet är att istället använda numeriska modeller. Huvudsyftet med denna avhandling har därför varit att utveckla en numerisk modell som kan användas för att förutsäga de mekaniska egenskaperna för detaljer tillverkade genom AT. AT-tekniken som avses är inriktad på Fused Filament Fabrication (FFF). En numerisk modell har utvecklats genom att återskapa FFF-byggprocessen i en simuleringsmiljö. Instruktioner (skriven i GCode) som används för att bygga en detalj genom FFF har här översatts till en numerisk FE-modell. Modellen används sen för att bestämma effekterna av processparametrar på styvheten och styrkan hos den tillverkade detaljen. I detta arbete har strukturstyvheten hos olika detaljer beräknats genom att utvärdera modellens svar för jämnt fördelade belastningsfall. Styrkan, vilket är starkt beroende på den tillverkade detaljens termiska historia, har inte utvärderats. Den utvecklade numeriska modellen kan dock fungera som underlag för implementering av modeller som beskriver relationen mellan termisk historia och styrka. Den utvecklade modellen är anpassad för optimering av FFF-parametrar då den omfattar effekterna av alla FFF-parametrar. En genetisk algoritm har använts i detta arbete för att optimera parametrarna med avseende på vikt för en given strukturstyvhet.
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Brandemyr, Gabriella. "Powder bed additive manufacturing using waste products from LKAB's pelletization process : A pre-study." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75421.
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This report is the result of a bachelor thesis project executed at Luleå University of Technology(LTU). The purpose of the project was to investigate the possibility to use the metal powder wasteproducts from LKAB’s pelletizing process for additive manufacturing as this would meaneconomic benefits for the sake of LKAB as well as environmental benefits.Two different powders were used in the experiments and were referred to as crush and dust. Theexperiments were made through the selective laser melting (SLM) method with varying laserparameters to observe their effect. These included the laser power and laser speed. Scanningelectron microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and opticalmicroscopy were used for the analysis of the samples.The analysis of the chemical compositions showed that the powders were inhomogeneous anddiffered from each other. The crush powder contained phosphor and carbon which was lacking inthe dust and also had higher amounts of silicon and potassium. In spite of the inhomogeneouspowder and getting some agglomerations of half-melted grains on the tracks, the tracks tended tobe mostly homogenous. It was also observed that the tracks have a higher amount of carboncompared to the powder which probably derives from the substrate plate.The adherence of the tracks was greatest at a laser power between 200-300 W and a laser scanningspeed 0.5-1.75 m/min.The metal powder waste products from LKAB’s pelletization process could likely be used inadditive manufacturing, however, more work is needed in order to ensure the obtained results andcontinue with further experiments.
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Ariadi, Yudhi. "Facilitating consumer involvement in design for additive manufacturing/3D printing products." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/21763.
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This research investigates the potential of the general public to actively design their own products and let consumers either manufacture by themselves or send the files to manufacturers to be produced. This approach anticipates the rapid growth of fabrication technology, particularly in Additive Manufacturing (AM)/3D printing. Recent developments in the field of AM/3D printing have led to renewed interest in how to manufacture customised products and in a way that will allow consumers to create bespoke products more easily. These technologies can enhance the understanding of non-technology compliant consumers and bring the manufacturing process closer to them. Consequently, to make AM/3D printing more accessible and easier to employ by the general public, design aspects need to be developed to be as simple to operate in the same manner as AM/3D printing technologies. These technologies will then attract consumers who want to produce Do-It-Yourself (DIY) products. This study suggests a Computer-aided Consumer Design (CaCODE) system as user- friendly design software to simplify the Computer Aided Design (CAD) stages that are required to produce 3D model data required by the AM/3D printing process. This software will be an easy-to-operate design system where consumers interact with parameters of designed forms easily instead of operating conventional CAD. In addition, this research investigates the current capabilities of AM/3D printing technologies in producing consumer products. To uncover the potential of consumer-led design and manufacturing, CaCODE has been developed for consumer evaluation, which is needed to measure the appropriateness of the tool. In addition, a range of consumer product samples as pens has been built using a range of different materials, AM/3D printing technologies and additional post-processing methods. This was undertaken to evaluate consumer acceptance of the AM/3D printed product based on products perceived quality. Forty non-designer participants, 50% male and 50% female, from 5 to 64 years old, 6-7 participants per ten-year age groups in 6 groups, were recruited. The results indicated that 75% of the participants would like to design their own product using consumer design software. The study compared how consumers interacted with the 3D model to manipulate the shape by using two methods: indirect manipulation (sliders) and direct manipulation (drag points). The majority of the participants would prefer to use the direct manipulation because they felt it was easy to use and enabled them to enjoy the design process. The study concluded that the direct manipulation was more acceptable because it enabled users to touch the digital product and manipulate it, making it more intuitive and natural. The research finds that there is a potential for consumers to design a product using user-friendly design tools. Using these findings, a consumer design tool concept was created for future development. The study indicated that 53% of participants would like to use products made by AM/3D printing although they still wanted the surface finish of injection moulded parts. However, the AM/3D printing has advantages that can fulfil the participants preference such as multi-materials from the material jetting method and it is proved that additional post-processing can increase participants acceptance level.
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Cronskär, Marie. "The use of additive manufacturing in the custom design of orthopedic implants." Licentiate thesis, Mittuniversitetet, Institutionen för teknik och hållbar utveckling, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-14390.
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Koskenniemi, Isak. "Preparing parts for Wire and Arc Additive Manufacturing (WAAM) and net-shape machining." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-74296.
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WAAM is a relatively unexplored additive manufacturing method. Although research in this area has been performed for some years and the hardware is relatively cheap, the method is not widely used. As the name suggest, it uses wire and an arc welding equipment to deposit beads on top of each other to create a geometry. As WAAM is a near net-shape method, the parts must be machined to its net-shape after the beads has been deposited. BAE Systems Hägglunds AB are investigating the use of WAAM in an industrial robot cell and this Master’s thesis has been written with the purpose of enabling the use of WAAM for manufacturing parts at the company. This report investigates how a part is prepared for WAAM and near net-shape machining. A formula for approximating the cost of manufacturing a part is investigated. A software for slicing a .STL file for generating a toolpath is developed in Matlab. The software then exports the toolpath to a code that the robot can read. It can also generate a digital model of the work piece for net-shape machining through CATIA macro. A model for calculating the cost of using the WAAM-cell once the toolpath for a part is known is presented. The investigated areas and the developed software are then applied to a part, and the results of the report is discussed.
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Lenner, Lukas. "Engine Redesign Utilizing 3D Sand Printing Techniques Resulting in Weight and Fuel Savings." Youngstown State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1472734710.
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Biancoli, Giacomo. "Additive manufacturing: ricerca sui principali fattori che influenzano il comportamento a fatica." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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Gli obiettivi di questo elaborato sono fondamentalmente caratterizzare dei provini (realizzati in Maraging steel e Stainless steel attraverso DMLS) a fatica oligociclica, distinguerne il comportamento in base all'orientamento di costruzione ed analizzare tutti i fattori che possono influenzare la vita di un provino. Esaminando questa caratterizzazione, è possibile avvicinarci all'idea di impiegare direttamente nel processo produttivo pezzi realizzati e montati direttamente in produzione.
Dopo una breve introduzione sull'additive manufacturing e sul suo sviluppo nel corso degli anni con le varie tecnologie di stampa (analizzandone i relativi vantaggi e svantaggi), vengono accennati i costi della tecnologia di cui ci occuperemo. Dopo una prima introduzione sui materiali impiegati, vengono introdotti i provini protagonisti dell'esperienza, la macchina utilizzata e lo svolgimento della prova. Segue un'illustrazione dei vari orientamenti di costruzione del provino e di come variano le proprietà meccaniche quando sottoposto a fatica. In seguito sono analizzate le tensioni residue sui provini (post sinterizzazione) ed i trattamenti eseguibili, presentando la loro influenza sulle proprietà meccaniche. Infine è analizzata la meccanica della frattura, in particolare la propagazione della cricca. Tradizionalmente, si è sempre analizzato il comportamento dei provini secondo i due orientamenti classici, orizzontale e verticale: in questo elaborato verrà presentato, per quanto reperibile dai documenti scientifici, anche il loro comportamento a 45°. Grazie a queste nuove caratterizzazioni, è sempre più possibile analizzare a pieno il comportamento delle proprietà meccaniche di ogni prodotto realizzato mediante questa tecnologia, facendo riferimento (nel caso di analisi di forme geometriche complesse) ai modelli più semplici già analizzati.
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Lerebours, Augustin. "Use of additive manufacturing techniques for the production of customized implants with complex geometry : application to reparative hand surgery." Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2531.
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L’arthrose est une pathologie entraînant la dégénération des surfaces articulaires. Dans le cas particulier de l’articulation trapézo-métacarpienne, l’arthrose déforme de façon irréversible l’os trapèze entraînant perte de la mobilité et amoindrissement de la force de préhension couplé à des douleurs à la base du pouce. Les solutions thérapeutiques ne sont cependant pas satisfaisantes avec des reprises fonctionnelles limitées entraînant une perte de qualité de vie du patient. Dans le cas de la main, la personnalisation des implants semble être pertinente du fait de la grande variabilité des caractéristiques mécaniques articulaires et des spécificités musculo-squelettiques. Ce travail de thèse porte sur la méthodologie de réalisation d’implant trapézo-métacarpien patient-spécifique, basé sur les potentialités des technologies de fabrication additive métal. Il s’agit plus globalement de développer, analyser et valider les étapes de réalisation d’un implant à géométrie complexe quelconque depuis l’imagerie médicale jusqu’à l’implantation. Les travaux se concentrent dans un premier temps sur l’identification de paramètres spécifiques du patient afin de « rajeunir » numériquement son os déformé à son stade pré-pathologique pour concevoir l’implant idéal et l’adaptation du modèle à la fabrication d'additive (DfAM). La fabrication de l’implant et les post-traitements sont également étudiés d’un point de vue biologique (cytocompatibilité, réaction du système immunitaire), mécanique (microstructure, propriété de frottement) et morphologique (quantification des déviations géométriques). L’approche d’implantation chirurgicale est abordée au travers de divers tests sur des cadavres permettant de mieux intégrer les bénéfices/risques pour le patient. Une étude sur la psychologie du patient souffrant de la rhizarthrose et de ses attentes clôture ce manuscrit. Les résultats ont donné lieu aux dépôts de 2 brevets et à la rédaction de 6 articles scientifiquesOsteoarthritis is a pathology that causes the degeneration of joint surfaces. In the particular case of the trapezo-metacarpal joint, osteoarthritis irreversibly deforms the trapezium bone, causing loss of mobility and reduced grip strength coupled with pain at the base of the thumb. However, therapeutic solutions are not satisfactory with limited functional recovery resulting in a loss of quality of life for the patient. In the case of the hand, the personalization of implants seems to be relevant because of the great variability of the joint mechanical characteristics and the musculoskeletal specificities. This thesis work focuses on the methodology for creating a trapezio-metacarpal implant patient-matched, based on the potentialities of additive metal manufacturing technologies. More generally, it involves developing, analyzing and validating the steps involved in the manufacture of any complex geometric implant from medical imaging to implantation. The work initially focuses on identifying specific patient parameters in order to numerically "rejuvenate" the deformed bone in its pre-pathological stage to design the ideal implant and adapt the model to additive manufacturing (DfAM). Implant manufacturing and post-treatment are also studied from a biological (cytocompatibility, immune system response), mechanical (microstructure, friction property) and morphological (quantification of geometric deviations) point of view. The surgical implantation approach is addressed through various tests on cadavers to better integrate the benefits / risks for the patient. A study on the psychology of the patient suffering from rhizarthrosis and his expectations for a therapeutic solution concludes this manuscript. The results have led to 2 patents and the writing of 6 scientific articles
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Palmer, Andrew. "The Design and Development of an Additive Fabrication Process and Material Selection Tool." Master's thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3635.
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In the Manufacturing Industry there is a subset of technologies referred to as Rapid Technologies which are those technologies that create the ability to compress the time to market for new products under development . Of this subset, Additive Fabrication (AF), or more commonly known as Rapid Prototyping (RP), acquires much attention due to its unique and futuristic approach to the production of physical parts directly from 3D CAD data, CT or MRI scans, or data from laser scanning systems by utilizing various techniques to consecutively generate cross-sectional layers of a given thickness upon the previous layer to form 3D objects. While Rapid Prototyping is the most common name for the production technology it is also referred to as Additive Manufacturing, Layer Based Manufacturing, Direct Digital Manufacturing, Free-Form Fabrication, and 3-Dimensional Printing. With over 35 manufacturers of Additive Fabrication equipment in 2006 , the selection of an AF process and material for a specific application can become a significant task, especially for those with little or no technical experience with the technology and to add to this challenge, many of the various processes have multiple material options to select from . This research was carried out in order to design and construct a system that would allow a person, regardless of their level of technical knowledge, to quickly and easily filter through the large number of Additive Fabrication processes and their associated materials in order to find the most appropriate processes and material options to create physical reproductions of any part. The selection methodology used in this paper is a collection of assumptions and rules taken from the author's viewpoint of how, in real world terms, the selection process generally takes place between a consumer and a service provider. The methodology uses those assumptions in conjunction with a set of expert based rules to direct the user to a best set of qualifying processes and materials suited for their application based on as many or as few input fields the user may be able to complete.M.S.
Department of Industrial Engineering and Management Systems
Engineering and Computer Science
Industrial Engineering MS
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Swartz, Paul. "Evaluation of Tensile Properties for Selective Laser Melted 316L Stainless Steel and the Influence of Inherent Process Features." DigitalCommons@CalPoly, 2019. https://digitalcommons.calpoly.edu/theses/2024.
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Optimal print parameters for additively manufacturing 316L stainless steel using selective laser melting (SLM) at Cal Poly had previously been identified. In order to further support the viability of the current settings, tensile material characteristics were needed. Furthermore, reliable performance of the as-printed material had to be demonstrated. Any influence on the static performance of parts in the as-printed condition inherent to the SLM manufacturing process itself needed to be identified. Tensile testing was conducted to determine the properties of material in the as-printed condition. So as to have confidence in the experimental results, other investigations were also conducted to validate previous assumptions. Stereological relative density measurements showed that the as-printed material exhibited relative density in excess of 99%. Optical dimensional analysis found that the as-printed tensile specimens met ASTM E8 dimensional requirements in 14 out of 15 parts inspected. Baseline tensile tests indicated that the yield stress of the as-printed material is 24% higher than a cold-rolled alternative, while still achieving comparable ductility. The location of a tensile specimen on the build plate during the print was not found to have a significant effect on its mechanical properties. Theoretical behavior of notched tensile specimens based on finite element models matched experimental behavior in the actual specimens. Unique fracture behavior was found in both the unnotched reference and the most severe notch after microscopic inspection, and a root cause was proposed. Finally, extrapolating from previous studies and observing that experimental results matched theoretical models, it was determined that features inherent to SLM parts were not detrimental to the static performance of the as-printed material.
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Antonysamy, Alphons Anandaraj. "Microstructure, texture and mechanical property evolution during additive manufacturing of Ti6Al4V alloy for aerospace applications." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/microstructure-texture-and-mechanical-property-evolution-during-additive-manufacturing-of-ti6al4v-alloy-for-aerospace-applications(03c4d403-822a-4bfd-a0f8-ef49eb65e7a0).html.
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Additive Manufacturing (AM) is an innovative manufacturing process which offers near-net shape fabrication of complex components, directly from CAD models, without dies or substantial machining, resulting in a reduction in lead-time, waste, and cost. For example, the buy-to-fly ratio for a titanium component machined from forged billet is typically 10-20:1 compared to 5-7:1 when manufactured by AM. However, the production rates for most AM processes are relatively slow and AM is consequently largely of interest to the aerospace, automotive and biomedical industries. In addition, the solidification conditions in AM with the Ti alloy commonly lead to undesirable coarse columnar primary β grain structures in components. The present research is focused on developing a fundamental understanding of the influence of the processing conditions on microstructure and texture evolution and their resulting effect on the mechanical properties during additive manufacturing with a Ti6Al4V alloy, using three different techniques, namely; 1) Selective laser melting (SLM) process, 2) Electron beam selective melting (EBSM) process and, 3) Wire arc additive manufacturing (WAAM) process. The most important finding in this work was that all the AM processes produced columnar β-grain structures which grow by epitaxial re-growth up through each melted layer. By thermal modelling using TS4D (Thermal Simulation in 4 Dimensions), it has been shown that the melt pool size increased and the cooling rate decreased from SLM to EBSM and to the WAAM process. The prior β grain size also increased with melt pool size from a finer size in the SLM to a moderate size in EBSM and to huge grains in WAAM that can be seen by eye. However, despite the large difference in power density between the processes, they all had similar G/R (thermal gradient/growth rate) ratios, which were predicted to lie in the columnar growth region in the solidification diagram. The EBSM process showed a pronounced local heterogeneity in the microstructure in local transition areas, when there was a change in geometry; for e.g. change in wall thickness, thin to thick capping section, cross-over’s, V-transitions, etc. By reconstruction of the high temperature β microstructure, it has been shown that all the AM platforms showed primary columnar β grains with a <001>β.
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Gustavsson, Bengt. "Effect of Beam Scan Length on Microstructure Characteristics of EBM Manufactured Alloy 718." Thesis, KTH, Materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-225416.
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Additive Manufacturing (AM) as a method is on the rise and allow for a high freedom to create unique shapes without being limited by conventional machining methods. The Electron Beam Melting method, developed by Arcam AB in Mölndal, Sweden, use Powder Bed Fusion together with an electron beam and at an elevated temperature (+1000ºC) to lower stress due to thermal gradients. The purpose of this paper is to study the influence of Scan Length during Electron Beam Melting of Alloy 718 in regards to the appearance of shrinkage, porosity, primary carbide precipitation (mainly NbC), primary dendrite width and hardness. Samples built had the dimensions of 10x15xVar mm3 (Height x Depth x Width) with widths ranging from 10 mm in steps of 5 mm up to a maximum of 90 mm. The parameters were set as a single entry within the build project and as such each layer was melted as a single unit. A Light-Optical Microscope (LOM) and a Scanning Electron Microscope (SEM) was used to obtain images for manual counting to calculate the fraction of porosity and NbC-precipitates as well as the columnar grain width. The space between lines of interdendritical precipitation of NbC was used to determine the dendrite arm widths and a series of Hardness Vickers (500g for 15s) indents was performed. An Energy-Dispersive X-Ray Spectroscope (EDS) was used to help identify precipitates and phases. Columnar grain width and the spacing between vertical bands of interdendritical NbC was measured according to ASTM112-13 while porosity and hardness was measured according to ASTM562-11. Both of these only looked at the XZ-plane instead of all three planes. The columnar grain width was measured in the 10 mm, 40 mm and 90 mm samples at a distance of 4 mm from the top and with a slight spread over the sample width according to ASTM112-13 but using only one plane for counting. No significant change to columnar width was found. Primary dendrite arm width was measured on the 10 mm, 40 mm and 90 mm samples at about 5 mm from the top. An average for all samples was found to be 7.82 μm ± 2.89. No significant trend could be found with increased sample width. A total average porosity of 0.33% ± 0.16 was found. Variations between samples were less than the standard deviation. Even though the variations were not high enough to be significant, no obvious trend could be seen in regards to sample width, position on the base plate or heat transfer through the build. The presence of NbC was investigated in all samples with a total average of 0.36% ± 0.23 with variations between sample lengths being within the standard deviation. An insignificant trend could be seen between the smaller samples together with the wider samples having a higher degree of NbC compared to the middle samples. No significant trend could be seen in NbC based on row. Across all samples, the mean hardness was found to be 406.75 HV0.5 ± 16.53. No significant trend could be seen with increased sample width. Based on sample rows no significant trend could be seen.
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Gustafsson, Christopher. "Lead-time reduction and rapid prototyping of tools and fixtures, therefore I AM : A case study about additive manufacturing in the automotive industry." Thesis, Mälardalens högskola, Innovation och produktrealisering, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-44762.
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The purpose of this thesis is to investigate how to decrease lead-times of conventionally manufactured prototypes of tools and fixtures. Which could lead to increased knowledge of how an operations site within the automotive industry could utilize additive manufacturing when producing company specific prototypes of tools and fixtures. The research approach applied in this case study combines a literature review to systematically find relevant literature aligned with the research topic of additive manufacturing or 3D printing related to lead-time reduction and generative design terms. With the help of interviews and observations profound knowledge was gained as preparation before continuing the research. Thereafter, a pre-study was conducted in order to further enhance the understanding of the industrial context of the two chosen fixtures (study objects). Rapid prototyping activities with additive manufacturing processes and technologies of experimentation character was conducted iteratively with both 3D CAD and 3D printing software and hardware. Analysis of the data was conducted through a comparison between lead-times of conventionally manufactured and 3D printed prototypes of the two chosen fixtures. Moreover, identifying potential effects with additive manufacturing of prototypes have with a SWOT analysis. The case study found that additive manufacturing could significantly decrease lead-times when producing prototypes compared to conventional manufacturing. Furthermore, the results showed that the effects of additive manufacturing are plenty and rather complex due to the fact of this new way to manufacture prototypes. Therefore, the term design for additive manufacturing need first class priority if next steps were to be taken in the additive manufacturing field to enhance industrial and academic benefits. The research on this subject is strongly constrained by the scarcity of empirical experience and, consequently, by the scarcity of available empirical data. Research publication on the topic are fruitful and plenty but their findings specified to their chosen study objects. This case study gives an up-to-date contribution to the topic of additive manufacturing with endless possibilities to reduce lead-time with rapid prototyping activities that utilizes additive manufacturing. Moreover, the research approach used in this thesis combines 3D CAD data through theoretical concepts and physical objects with additive manufacturing practice. Overall, the results can be used to improve academic research in the topic and promote discussion among different actors entering or within the additive manufacturing field.
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Nakládalová, Tereza. "Konstrukční optimalizace výrobní linky využitím aditivní technologie SLS." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-382472.
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This diploma thesis is focused on additive manufacturing, especially on technology Selective Laser Sintering (SLS) and the implementation of additive manufacturing into existing departments of industry, where current elements of systems are supplemented or directly replaced by new parts produced by these technologies. This thesis solves specific project of manipulation unit for manufacturing line. The main goals of the issue are analysis of current construction design and its deficiency, designing and optimalization of this unit in relation to SLS manufacturing technology, product realization and final evaluating of reached results. Part of the thesis is also design documentation.
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Di, Sannio Christian. "Ricerca di tecniche e materiali innovativi per il settore aerospaziale: caratterizzazione meccanica e sviluppo di provini in cromo-cobalto prodotti in additive manufacturing." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
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In questa tesi sperimentale si è effettuata un’attività di ricerca e di sviluppo di provini realizzati in cromo-cobalto-molibdeno con una tecnologia additiva di tipo SLM, dei quali è, inoltre, stata effettuata una caratterizzazione meccanica.
L’additive manufacturing è una tecnologia innovativa già utilizzata in differenti settori, come il settore aerospaziale, biomedicale e automotive. Il cromo cobalto è una lega con proprietà estremamente ricercate, soprattutto nei settori aerospaziale e biomedicale. La combinazione di un tale materiale con una simile tecnica non è stata ancora ampiamente sviluppata nel settore aerospaziale; tuttavia da un’accurata ricerca bibliografica è emerso che questa scelta potrebbe portare significativi vantaggi tecnologici al settore.
Il seguente elaborato è strutturato in tre sezioni principali: ricerca bibliografica, attività sperimentale, risultati. Viene, inizialmente, mostrato lo stato attuale della ricerca su additive manufacturing e cromo-cobalto: in particolare pregi, difetti e varie tecniche per migliorarne le caratteristiche. Segue, poi, un resoconto accurato dell’attività pratica svolta nei laboratori: produzione dei provini, trattamento termico e prove di trazione. Infine vengono confrontati i risultati ottenuti in laboratorio dai vari provini (trattati termicamente e non).
Si sottolinea che questo lavoro di tesi è il punto di partenza per un progetto più ampio, che verrà effettuato in collaborazione con l’Università del Witwatersrand.
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Barsing, Jonas. "A Cost Breakdown and Production Uncertainty Analysis of Additive Manufacturing : A Study of Low-Volume Components Produced with Selective Laser Melting." Thesis, Blekinge Tekniska Högskola, Institutionen för industriell ekonomi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-16730.
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Background: Additive manufacturing has recently gained cogency as a final part manufacturing technique. The method uses a layer-upon-layer technique to build three-dimensional objects. This technique has many advantages creating new opportunities regarding production. Purpose: The purpose of the study is to investigate cost elements, cost drivers, their weight distribution, and to explore production uncertainties of the additive manufacturing process. The production uncertainty parameters of the explored uncertainties are then evaluated to investigate how some of them impacts the production cost of the case component. Method: The following study have used qualitative data collection methods in terms of interviews together with a pre-study and a sensitivity analysis tool to identify cost impacts of uncertainty parameters. Five primary interviews were performed with employees at the company with relevant knowledge of the studied field. Results: The result shows that the product cost can be divided into two categories of material cost and manufacturing costs, these two categories then have different cost elements that drives cost. The explored uncertainties of the process consist of both aleatory and epistemic uncertainty. The explored production uncertainty parameter that affects the final product cost the most is the time needed to finish the AM build. Conclusions: Considering production uncertainty is important in order to have reliable and accurate cost estimations. The three explored production uncertainties that have the most significant impact on the final product cost is the yearly machine running time, the SLM machine time needed to finish the component, and reduced manning time in the operations. These three uncertainty parameters should, therefore, have a larger focus than variables that do not have the same impact on the final product cost, to create better cost estimations.Bakgrund: Additiv tillverkning har på senaste tiden fått slagkraft som en produktionsteknik för slutprodukter. Additiv tillverkning använder en lager på lager teknik för att bygga tre-dimensionella objekt. Denna teknik har många fördelar som skapar många nya produktionsmöjligheter. Syfte: Syftet med studien är att undersöka kostnadselement, kostnadsdrivare, fördelningen av kostnader och att utforska produktionsosäkerheter inom additiv tillverkning. De utforskade osäkerhetsparametrarna inom processen är sedan studerade för att se hur de påverkar den slutgiltiga produktkostnaden. Metod: Följande studie har använt kvalitativa datainsamlingsmetoder i form av intervjuer tillsammans med en förstudie och ett utvecklat känslighetsanalysverktyg för att identifiera kostnadsförändringar på grund av förändringar i osäkerhetsparametrar. Fem stycken intervjuer har genomförts med anställda på företaget som har relevant kunskap inom området. Resultat: Resultatet visar att produktkostnaden kan delas upp i två kategorier, materialkostnad och tillverkningskostnad. Dessa två kategorier består sedan av olika kostnadselement som driver kostnader. De utforskade produktions osäkerheterna inom processen består av två typer av osäkerheter beskriven i teorin. Den produktionsosäkerhetsparameter som har störst påverkan på produktens slutkostnad är SLM maskintiden som krävs för att bygga komponenten. Slutsatser: Att beakta produktionsosäkerheter i kostnadsuppskattningar är viktigt för att uppskattningarna ska vara tillförlitliga och korrekta. De tre studerade produktionsosäkerheterna som har störst påverkan på den slutgiltiga produktionskostnaden är årlig maskinanvändning, SLM maskintiden som krävs för att bygga komponenten och bemanningstiden för operationerna. Dessa tre osäkerhetsparametrar bör därför ha ett större fokus eftersom de har störts påverkan på slutresultatet.
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Patibandla, Sivani. "Layer-to-Layer Physical Characteristics and Compression Behavior of 3D Printed Acrylonitrile Butadiene Styrene Metastructures Fabricated using Different Process Parameters." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1547231646016662.
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Le, Van-Thao. "Proposition d'une stratégie soutenable pour donner une nouvelle vie à une pièce en s’appuyant sur les techniques de fabrication additive." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI038/document.
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Actuellement, les matériaux collectés à partir de produits en fin de vie sont recyclés en matière première pour être réutilisés dans un nouveau cycle de production. Cependant, la consommation énergétique des filières de recyclage reste importante. Le processus du recyclage fait aussi perdre la valeur ajoutée et l’énergie utilisée durant la fabrication de pièces originales. Aujourd’hui, les techniques de fabrication additive sont suffisamment performantes et permettent une fabrication de produits avec un matériau compatible avec l’usage. La prise en compte des performances de ces nouvelles techniques dans une stratégie soutenable peut ouvrir des pistes pour modifier les pièces et les réutiliser directement sans retourner au niveau de matière première. Cette thèse a pour objectif de développer une stratégie soutenable, qui permet de donner une nouvelle vie à une pièce en fin de vie (ou une pièce existante) en la transformant directement en une nouvelle pièce destinée à un autre produit. Afin de développer une telle stratégie, les travaux menés de la thèse visent à résoudre les verrous scientifiques suivants :Le premier verrou scientifique est lié à la faisabilité technologique : est-il possible de déposer de la matière sur une pièce existante en utilisant les techniques de fabrication additive pour obtenir la nouvelle pièce avec une bonne santé de matière ? Cette question a été résolue en réalisant une étude expérimentale sur l’observation de microstructures et de propriétés mécaniques des éprouvettes, qui sont fabriquées par ajout de nouvelles entités sur une pièce existante en EBM. Le deuxième verrou scientifique est lié à l’étude de la chaîne complète de fabrication d’un point de vue technologique. Comment concevoir des gammes de fabrication en combinant intelligemment des opérations additives et soustractives pour obtenir la pièce attendue à partir de la pièce existante ? Une méthode de conception des gammes de fabrication combinant les procédés additifs et soustractifs a été proposée en s’appuyant sur le concept d’entités de fabrication additive et soustractive. Le troisième verrou scientifique est lié à la soutenabilité et la stratégie présente-t-elle des avantages par rapport à la stratégie conventionnelle en termes de soutenabilité ? Une approche s’appuyant sur la méthode d’Analyse du Cycle de Vie (ACV) a aussi été développée pour évaluer des impacts environnementaux. Des critères permettant de qualifier le domaine de la stratégie proposée vis-à-vis de la stratégie conventionnelle ont été identifiésCurrently, materials collected from end-of-life (EoL) products are recycled into raw material for reusing in a new production cycle. However, energy consumptions of recycling sectors remain important. The added values and energy used in the manufacture of original parts are also lost during the material recycling process. Nowadays, additive manufacturing techniques are sufficiently efficient and allow the manufacture of products with a material compatible with the use. Taking into account the performances of these techniques in a sustainable strategy can open the ways to modify parts and reuse them directly without returning to the raw material level. This thesis aims to develop a sustainable strategy, which allows giving a new life to an EoL part (or an existing part) by transforming it directly into a new part intended for another product. In order to develop such a strategy, the works of the thesis aims to solve the following scientific issues : the first scientific issue is related to the technological feasibility : is it possible to deposit material on an existing part using additive manufacturing technologies to obtain the new part with good material health ? This question is solved by carrying out an experimental study on the observation of microstructures and mechanical properties of the samples, which are manufactured by adding new features into an existing part in EBM. The second scientific issue is related to the study of the complete manufacturing chain from a technological point of view. How to design the process planning for additive and subtractive manufacturing combination to manufacture the expected part from the existing part ? To solve this question, a methodology to design the process planning for combining these manufacturing processes has been proposed based on the concept of additive manufacturing and machining features.The third scientific issue is linked to the sustainability and does the new strategy have advantages in comparison to the conventional strategy in terms of sustainability ? An approach based on the Life Cycle Assessment (LCA) method has also been developed to assess environmental impacts. The criteria for qualifying the domain of the proposed strategy vis-a-vis the conventional strategy were also identified
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Westbeld, Julius. "Investigation of support structures of a polymer powder bed fusion process by use of Design of Experiment (DoE)." Thesis, KTH, Lättkonstruktioner, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-243867.
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In this thesis, support structures of a polymer powder based process called XXXXXXXX™ are examined. These structures are crucial for most additive manufacturing processes. The effects of several factors on five industrially important characteristics of support structures are examined by use of the Design of Experiment (DoE) method. It describes the planning as well as the analysis of the experiments. The experiments are planned in a fractional factorial 211-5 design with 64 specimens, resulting in a resolution of IV. The analysis of the data is done by use of the ANOVA method, with which the significance of effects and interaction effects are checked.I detta examensarbete undersöks stödstrukturer för en polymer-pulverbaserad process kallad XXXXXXXX. Dessa strukturer är väsentliga för de flesta aditiv tillverkning. Med hjälp av metoden "Design of Experiment" (DoE) undersöks effekten av flera faktorer på fem industriellt viktiga egenskaper för stödstrukturer. DoE beskriver både planeringen och analysen av experiment. Experimenten planeras i en fraktionerad faktoriell 211-5 design med 64 provexemplar vilket resulterar i en upplösning av IV. Dataanalysen genomförs med hjälp av ANOVA-metoden, med vilken signifikansen av effekter och interaktionseffekter kan undersökas.
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Sarlak, Shannon. "Möjligheter för produktion med additiv tillverkning : - En fallstudie." Thesis, Högskolan i Skövde, Institutionen för handel och företagande, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-17739.
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Background: Additive manufacturing is a manufacturing process that has for the past 30 years been used substantially within the branch of industry. By adding material layer-by-layer, an object will be designed, and this method is called 3D-printing. Despite the advantage of building an object without assemblage as in traditional manufacturing, there is a lot of limitations with this additive manufacturing. Are there more opportunities than difficulties with additive manufacturing or is this manufacturing process too advanced too take over the traditional manufacturing process once and for all? Purpose: The purpose with this study is to increase understanding for promises and challenges with additive manufacturing and in which context it is adequate to use. Which elements makes it more appropriate and which are less, with additive manufacturing. Implementation: In the theoretical frame of reference, an integrative review study has been formed, by collecting and working with data from precious studies. The focus applies on the content of additive manufacturing, differences between traditional manufacturing and additive manufacturing only in theoretical frame of reference, promises and challenge with AM-processes, logistical aspects that focuses on the service elements that interact between organizations and customers but also the quality issues that concern additive manufacturing, order qualifiers and order winners that makes the establishment unique also adequacy of materials for different AM-processes. The empirics contain data and information from two concerned organizations that utilize additive manufacturing, but also how they go about to achieve competitive advantages. The analysis compiles the theoretical frame of reference that is formed by the data from previous additive manufacturing studies. Together with the empirics that has been brought by the concerned companies. Through the question formulation and a designed survey study that was given to the two companies, an information rich integrative review was embodied. Conclusion: This case study shows, as well as other studies that concern additive manufacturing, the conclusion is the same. The conclusion shows that additive manufacturing leads to elements such as cost reduction regarding manufacturing, reduced tied capital, to shorten the lead time, less haul, more environmentally friendly and to make complex geometric objects that are hard to design through traditional manufacturing. There are differences between the companies chosen AM-processes, because each AM-process uses different material. Material offering is more considerable to Company A that uses plastics than to Rise Swecast AB that uses powder within metal production. Adequacy for additive manufacturing applies more to build geometric complex objects, manufacturing of lower production volumes. It applies less to larger production volumes, limit of material supplies of different AM-processes and also for building larger objects. There are also quality issues that concern the printout, thus there is no feedback equipment, but this controls after each printout to avoid variations between printouts and between AM-processes. Additive manufacturing will take more place in the industry branch, in the future, and eventually replace processes within the traditional production. There are great opportunities for additive manufacturing that will lead to profitability for companies and customers through decentralization, meaning that organizations do not need to invest in a whole factory.Bakgrund: Additiv tillverkning är en tillverkningsprocess som har på de senare åren börjat användas avsevärt det senaste 30 åren, inom industribranschen. Genom att addera material lager-för-lager bildas ett objekt och denna metod kallas för 3D-printing. Trots fördelen med att kunna tillverka ett objekt komplett utan att behöva montera ihop delar som i traditionell tillverkning, finns det många begränsningar med additiv tillverkning. Finns det fler möjligheter än svårigheter med additiv tillverkning eller är tillverkningsprocessen för avancerat för att ta över den traditionella tillverkningsprocessen helt? Syfte: Rapportens syfte är att öka förståelsen för möjligheter och svårigheter med additiva tillverkningsprocesser samt i vilken kontext det är lämpligt att använda. Vilka faktorer gör det mer eller mindre lämpligt med additiv tillverkning. Genomförande: I studiens teoretiska referensram har en fallstudie utförts genom att samla in och bearbeta data från tidigare studier. Här utformas studiens teori med fokus på innebörden av additiv tillverkning, jämförelse mellan traditionell tillverkning samt additiv tillverkning enbart i TR, möjligheter och svårigheter med tillverkningsprocessen, logistiska aspekter som fokuserar på den leveransserviceelement som samspelas mellan företag och kunder samt att detta inkluderar kvalité problem som uppstår med AM, orderkvalificerare och ordervinnare som gör företagen unika samt lämplighet av material för olika additiva tillverkningsprocesser. I empirin hittas data och information från två berörda företag som använder sig av additiv tillverkning inom produktionsområden och hur de går tillväga för att uppnå konkurrensfördelar. I analysen sammanställs den teoretiska referensram som utformats med hjälp av data från tidigare studier om additiv tillverkning, tillsammans med empirin som tagits fram med hjälp av dessa två berörda företag. Genom ett frågeställningsformulär och en utformad enkätstudie som gavs till respektive företag, kunde en informationsrik litteraturstudie utföras. Slutsats: Denna fallstudie visar likaså majoriteten av tidigare studier som berör additiv tillverkning, samma slutsats. Slutsatsen visar att additiv tillverkning leder till faktorer såsom kostnadsreducering gällande produktion, minskad bundet kapital, förkortade ledtider, färre transportsträckor, mer miljövänligt, skapa komplexa geometrier som är svårt att skapa på traditionellt vis. Det finns även skillnader mellan företagens valda AM-processer då företagen använder sig av olika tillverkningsprocesser och olika 3D-printer samt material. Materialutbudet är större hos Företag A som använder sig av plaster än hos Rise Swecast AB som använder sig av kvartssand vilket används inom metalltillverkning. Lämpligheten för additiv tillverkning passar mer vid uppbyggnad av komplexa geometrier, tillverkning av låga produktionsvolymer. Men lämpar sig mindre vid stora produktionsvolymer, begränsning vid materialval av olika AM-processer samt vid tillverkning av stora objekt. Det fanns även kvalitetsproblem gällande utskrifter då det inte finns några återkopplingsverktyg, men detta kontrolleras vid varje utskrift för att undvika variationer mellan utskrifter och processer. Additiv tillverkning kommer i framtiden att ta alltmer plats inom industribranschen och kommer även eventuellt att ersätta andra processer inom den traditionella tillverkningen just för att den bidrar med både med lönsamhet för företag samt kunder genom decentralisering, det vill säga att man inte behöver vara långt ifrån kunden samtidigt som man inte behöver investera i en hel fabrik.
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Costa, Neto Inácio. "Elaboração de um mapeamento de boas práticas de fabricação para manufatura aditiva no laboratório de tecnologias 3D do núcleo de tecnologias estratégicas em saúde da UEPB." Universidade Estadual da Paraíba, 2017. http://tede.bc.uepb.edu.br/jspui/handle/tede/3074.
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This work seeks to perform a mapping of the production process for Good Manufacturing Practices in Additive Manufacturing in the Laboratory of Three Dimensional Technologies of the Nucleus of Technology for Health of the State University of Paraíba based on chapter five of RDC 16/13, in order to Possible future preparation of a manual of good manufacturing practices of this laboratory. This is a theoretical work in order to guarantee methodologies to extract the maximum quality of the process in question, aiming to provide guarantees of reliability, reproducibility and predictability of the biomodels produced, through standards, manuals, methods and resolutions when manufacturing medical products Such as surgical guides, temporary or permanent prostheses and orthoses. This work is justified on the assumption that biomodels are already being manufactured, but that they do not follow the necessary method in order to optimize the manufacturing process, thus spending too much time and financial resources. With this, it was possible to guarantee that the process is carried out following a layout for the laboratory that will facilitate the manufacture of the biomodel, and the creation of a flow chart proper to good manufacturing practices, allowing each agent to have its own function.
Este trabalho busca realizar um mapeamento do processo de produção para as Boas Práticas de Fabricação em Manufatura Aditiva no Laboratório de Tecnologias Tridimensionais do Núcleo de Tecnologia para Saúde da Universidade Estadual da Paraíba baseando-se no capítulo cinco da RDC 16/13, a fim de possibilitar a futura elaboração de um manual de boas práticas de fabricação deste laboratório. Trata-se e um trabalho teórico a afim de garantir metodologias que permitam extrair a máxima qualidade do processo em questão, objetivando proporcionar garantias de fidedignidade, reprodutibilidade e previsibilidade dos biomodelos produzidos, por meio de normas, manuais, métodos e resoluções ao fabricar produtos médicos específicos como guias cirúrgicos, próteses provisórias ou permanentes e órteses. Justifica -se esse trabalho a partir do pressuposto que já existem biomodelos sendo fabricados, mas que não seguem o método necessário a fim de avalizar a fabricação de maneira otimizada, gastando assim tempo e recursos financeiros em demasia. Com isso, foi possível garantir que o processo seja realizado seguindo um layout para o laboratório que facilitará a manufatura do biomodelo, e a criação de um fluxograma próprio para as boas práticas de fabricação, permitindo que cada agente tenha sua própria função.
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Tamburrini, Simone. "Produzione e caratterizzazione di componenti in WC-Co mediante selective laser melting." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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Uno dei temi chiave della ricerca sull’Additive Manufacturing (AM) è l’accrescimento del campo di materiali processabili. La tecnologia garantisce diversi vantaggi rispetto alle normali tecniche di lavorazione ma richiede esperienza nella lavorazione e conoscenza del materiale. Nello studio oggetto di questa dissertazione si mostrano i risultati di un primo approccio alla lavorazione di WC-Co (carburo di tungsteno in matrice di cobalto) attraverso Selective Laser Melting (SLM). Lo scopo è di gettare le basi per un processo che permetta la produzione di utensili da taglio in WC-Co. Lo studio si è incentrato su un’attenta analisi microstrutturale di diversi gruppi di campioni processati attraverso SLM e prodotti a partire da due polveri a diverso contenuto di Co (9% e 17%). Le densità, le durezze e le microstrutture ottenute sono state confrontate con quelle relative a prodotti sinterizzati industriali. Lo studio ha portato a nuove conoscenze sulla microstruttura del materiale derivante dalla lavorazione ed ha permesso di stabilire relazioni tra parametri di processo e densità del prodotto finale. Per l’ultimo gruppo di campioni prodotto (17% di Co) si è ottenuto un miglioramento in termini di qualità del materiale prodotto, nel particolare si è incrementata la densità e ridotta l’estensione di difetti microstrutturali quali cricche e porosità.
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Parasa, Sairaj, and Mohammed Abujan Rehman Basha. "Adoption of Additive Manufacturing in the Medical Industry within Sweden : Stakeholder analysis in the process of adoption of AM in the medical industry and their influence on each other." Thesis, Uppsala universitet, Institutionen för samhällsbyggnad och industriell teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-448050.
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Additive manufacturing (AM) is a printing technology which can produce 3-dimensional solid object by adding layers of material from 3D model data. AM has numerous benefits and can bring a new industrial revolution. To have a smooth transition in the technology, organizations must consider involved stakeholders’ interests. However, different stakeholders have different interests and influences. As more affected stakeholders resist adopting new technology as it will affect the firm directly or indirectly. These diverse interests cause barriers to the adoption of technology. This research aims to find out the primary and secondary stakeholders and how they influence each other in the adoption of AM, and what are the barriers caused due to these influences. The two sources of primary data are gathered from the research participants and analyzed thematically. Our findings reveal that the primary stakeholders are material suppliers, regulators bodies, and medical device/pharmaceutical companies and have a high influence on the adoption of AM as these stakeholders are hard to replace and need constant collaboration with each other. The secondary stakeholders are AM designers, insurance companies, educational and training organizations, funding organizations, NGOs. AM designer and insurance companies have less power and influence, while academic and training organizations and NGOs have a high influence since they are knowledge and training providers. Barriers faced in the adoption of AM technology are immature technology, less raw material availability, changes in the regulation, knowledge gap. This study implies that there is immense scope to explore the technology to gain maximum benefits. This study stands to give an understanding of stakeholder involvement, their influence, and their barriers in the adoption of AM technology.
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Desai, Prathamesh. "Tribosurface Interactions involving Particulate Media with DEM-calibrated Properties: Experiments and Modeling." Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/1123.
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While tribology involves the study of friction, wear, and lubrication of interacting surfaces, the tribosurfaces are the pair of surfaces in sliding contact with a fluid (or particulate) media between them. The ubiquitous nature of tribology is evident from the usage of its principles in all aspects of life, such as the friction promoting behavior of shoes on slippery water-lubricated walkways and tires on roadways to the wear of fingernails during filing or engine walls during operations. These tribosurface interfaces, due to the small length scales, are difficult to model for contact mechanics, fluid mechanics and particle dynamics, be it via theory, experiments or computations. Also, there is no simple constitutive law for a tribosurface with a particulate media. Thus, when trying to model such a tribosurface, there is a need to calibrate the particulate media against one or more property characterizing experiments. Such a calibrated media, which is the “virtual avatar” of the real particulate media, can then be used to provide predictions about its behavior in engineering applications. This thesis proposes and attempts to validate an approach that leverages experiments and modeling, which comprises of physics-based modeling and machine learning enabled surrogate modeling, to study particulate media in two key particle matrix industries: metal powder-bed additive manufacturing (in Part II), and energy resource rock drilling (in Part III). The physics-based modeling framework developed in this thesis is called the Particle-Surface Tribology Analysis Code (P-STAC) and has the physics of particle dynamics, fluid mechanics and particle-fluid-structure interaction. The Computational Particle Dynamics (CPD) is solved by using the industry standard Discrete Element Method (DEM) and the Computational Fluid Dynamics (CFD) is solved by using finite difference discretization scheme based on Chorin's projection method and staggered grids. Particle-structure interactions are accounted for by using a state-of-the art Particle Tessellated Surface Interaction Scheme and the fluid-structure interaction is accounted for by using the Immersed Boundary Method (IBM). Surrogate modeling is carried out using back propagation neural network. The tribosurface interactions encountered during the spreading step of the powder-bed additive manufacturing (AM) process which involve a sliding spreader (rolling and sliding for a roller) and particulate media consisting of metal AM powder, have been studied in Part II. To understand the constitutive behavior of metal AM powders, detailed rheometry experiments have been conducted in Chapter 5. CPD module of P-STAC is used to simulate the rheometry of an industry grade AM powder (100-250microns Ti-6Al-4V), to determine a calibrated virtual avatar of the real AM powder (Chapter 6). This monodispersed virtual avatar is used to perform virtual spreading on smooth and rough substrates in Chapter 7. The effect of polydispersity in DEM modeling is studied in Chapter 8. A polydispersed virtual avatar of the aforementioned AM powder has been observed to provide better validation against single layer spreading experiments than the monodispersed virtual avatar. This experimentally validated polydispersed virtual avatar has been used to perform a battery of spreading simulations covering the range of spreader speeds. Then a machine learning enabled surrogate model, using back propagation neural network, has been trained to study the spreading results generated by P-STAC and provide much more data by performing regression. This surrogate model is used to generate spreading process maps linking the 3D printer inputs of spreader speeds to spread layer properties of roughness and porosity. Such maps (Chapters 7 and 8) can be used by a 3D-printer technician to determine the spreader speed setting which corresponds to the desired spread layer properties and has the maximum spread throughout. The tribosurface interactions encountered during the drilling of energy resource rocks which involve a rotary and impacting contact of the drill bit with the rock formation in the presence of drilling fluids have been studied in Part III. This problem involves sliding surfaces with fluid (drilling mud) and particulate media (intact and drilled rock particles). Again, like the AM powder, the particulate media, viz. the rock formation being drilled into, does not have a simple and a well-defined constitutive law. An index test detailed in ASTM D 5731 can be used as a characterization test while trying to model a rock using bonded particle DEM. A model to generate weak concrete-like virtual rock which can be considered to be a mathematical representation of a sandstone has been introduced in Chapter 10. Benchtop drilling experiments have been carried out on two sandstones (Castlegate sandstone from the energy rich state of Texas and Crab Orchard sandstone from Tennessee) in Chapter 11. Virtual drilling has been carried out on the aforementioned weak concrete-like virtual rock. The rate of penetration (RoP) of the drill bit has been found to be directly proportional to the weight on bit (WoB). The drilling in dry conditions resulted in a higher RoP than the one which involved the use of water as the drilling fluid. P-SATC with the bonded DEM and CFD modules was able to predict both these findings but only qualitatively (Chapter 11)
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Doan, Van Tu. "Modèles réduits pour des analyses paramètriques du flambement de structures : application à la fabrication additive." Thesis, Valenciennes, 2018. http://www.theses.fr/2018VALE0017/document.
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Le développement de la fabrication additive permet d'élaborer des pièces de forme extrêmement complexes, en particulier des structures alvéolaires ou "lattices", où l'allégement est recherché. Toutefois, cette technologie, en très forte croissance dans de nombreux secteurs d'activités, n'est pas encore totalement mature, ce qui ne facilite pas les corrélations entre les mesures expérimentales et les simulations déterministes. Afin de prendre en compte les variations de comportement, les approches multiparamétriques sont, de nos jours, des solutions pour tendre vers des conceptions fiables et robustes. L'objectif de cette thèse est d'intégrer des incertitudes matérielles et géométriques, quantifiées expérimentalement, dans des analyses de flambement. Pour y parvenir, nous avons, dans un premier temps, évalué différentes méthodes de substitution, basées sur des régressions et corrélations, et différentes réductions de modèles afin de réduire les temps de calcul prohibitifs. Les projections utilisent des modes issus soit de la décomposition orthogonale aux valeurs propres, soit de développements homotopiques ou encore des développements de Taylor. Dans un second temps, le modèle mathématique, ainsi créé, est exploité dans des analyses ensemblistes et probabilistes pour estimer les évolutions de la charge critique de flambement de structures latticesThe development of additive manufacturing allows structures with highly complex shapes to be produced. Complex lattice shapes are particularly interesting in the context of lightweight structures. However, although the use of this technology is growing in numerous engineering domains, this one is not enough matured and the correlations between the experimental data and deterministic simulations are not obvious. To take into account observed variations of behavior, multiparametric approaches are nowadays efficient solutions to tend to robust and reliable designs. The aim of this thesis is to integrate material and geometric uncertainty, experimentally quantified, in buckling analyses. To achieve this objective, different surrogate models, based on regression and correlation techniques as well as different reduced order models have been first evaluated to reduce the prohibitive computational time. The selected projections rely on modes calculated either from Proper Orthogonal Decomposition, from homotopy developments or from Taylor series expansion. Second, the proposed mathematical model is integrated in fuzzy and probabilistic analyses to estimate the evolution of the critical buckling load for lattice structures
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Taddei, Francesco. "Influence of pre-cure stage upon exothermic overshoot and defects from deposition of continuous CFRP tow in AM." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/24994/.
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This study investigates the influence of the introduction of a pre-curing stage in Additive Manufacturing of continuous CFRP tows upon the exothermic overshoot and the defects generated during the deposition of the pre-cured material. This additive process aims at combining benefits from AM of CFRP laminates with the necessity of reducing the temperature overshoot during the cure of thermosetting polymers.
Thermo-chemical properties of the epoxy resin XB3515 have been characterized. An FE model addressing the cure simulation has been also developed using the FE solver Abaqus, and validated. Pre-cured laminates have been manufactured to investigate the effect of the pre-cure level upon temperature overshoot and deposition-induced defects.
The findings point out that the introduction of a pre-curing unit can reduce the temperature overshoot within the Carbon/Epoxy laminate and, therefore, cure-induced residual stresses. However, the following deposition phase limits the choice of the pre-cure level. A value between 20% and 30% reduces the thermal gradient by more than 90% generating in-plane waves with a severity that should not compromise the mechanical performances of the component; in particular, the compressive strength should be reduced by 2%-10%.
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Neri, Marco. "Stylistic Design Engineering (SDE) applicato ad una berlina innovativa." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21979/.
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Il progetto Ford Eagle è un caso di studio sull’applicazione del metodo di progettazione strutturato, lo Stylistic Design Engineering (SDE), per la realizzazione di una nuova berlina elettrica innovativa. L’SDE è un approccio ingegneristico per la progettazione e lo sviluppo di progetti di design industriale, e trova una particolare applicazione nel mondo Automotive.
Per raggiungere l’obiettivo di innovazione e sguardo verso il futuro, sono stati scelti i prodotti per auto del segmento E, in particolare a seguito della necessità di colmare una lacuna nel mercato del marchio Ford, che necessita di una tipologia di modello che potrebbe avere successo nel mercato. Infatti, la Ford non possiede da anni un'ammiraglia berlina sportiva del segmento E, come la storica Falcon degli anni ‘60. Partendo da questo presupposto e dal fatto che le maggiori case automobilistiche attualmente stanno investendo fortemente sulle vetture del segmento E, è stato interessante pensare a un nuovo modello di punta dell’Ovale Blu, che sarà chiamata Ford Eagle. Nelle pagine seguenti verrà illustrato il percorso che ha portato alla realizzazione del prodotto finale, seguendo il metodo SDE ed altre varie tecnologie di progettazione che saranno ulteriormente spiegate in dettaglio, come il metodo Pininfarina, il Quality Function Deployment (QFD), il Benchmarking (BM) e la Top Flop Analysis (TPA).
I metodi caratterizzano la prima parte del presente elaborato, in cui si delineano le caratteristiche chiave della vettura e il grado di innovazione, si individua il segmento di mercato e si analizzano – e si applicano – le tendenze stilistiche più comuni del giorno d’oggi. Nella seconda parte, invece, si realizza lo styling esterno dettagliato del veicolo, attraverso l’utilizzo di strumenti – e non più metodi – come il CAD 3D, fino alla prototipazione e visualizzazione fisica del prodotto, con Additive Manufacturing (AM), e virtuale, con Augmented Reality (AR).
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Svensson, Fredrik, and Sebastian Wåhlstedt. "Metodutveckling av Additivt Tillverkade (AT) produkter med efterbearbetning i CNC styrda maskiner med enkel identifiering av nollpunkt." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-51789.
Full textAbstract:
Detta examensarbete har utförts i Karlskoga på två företag, Lasertech LSH AB och PartnerTech Karlskoga AB, där uppdraget bestod i att med en metodutveckling hitta ett generellt angreppssätt som man kan förhålla sig till för att förenkla efterbearbetningen av en additivt tillverkad (AT) detalj. Fortsättningsvis kommer additiv tillverkning att benämnas AT i texten. Svårigheten ligger i att spänna upp och mäta in en detalj i en CNC-maskin som nästan är färdig och saknar självklara inmätning- och inspänningsytor. Syftet med arbetet var att hitta en generell metod att använda sig av för att lösa dessa svårigheter vilket leder till en säkrare och effektivare tillverkning. Parallellt med problemlösningen gjordes även en fallstudie där bägge företagen har en AT produkt som ska bearbetas i CNC-maskin. Problemen klargjordes med hjälp av ett funktionsmedelträd och lösningar togs fram med hjälp av konceptgenerering för att få fram så många och bra lösningar som möjligt. Genom att ta fram dessa koncept och möjligheten att kombinera dessa med varandra skapades en metod som löser inmätning- och inspänningsproblemen och visade sig vara användbar i fallstudien. Dessa koncept ses som en generell och bra lösning på ovanstående problem. Fortsatt arbete och utbildning kommer att krävas för att ytterligare testa metoderna och ge ökad kunskap om AT för att underlätta tillverkningsprocessen.This thesis has been carried out in Karlskoga at the two companies, Lasertech LSH AB and PartnerTech Karlskoga AB, where the assignment consisted of using a methodological development to find a general approach that can be used to simplify the processing of an additive manufactured (AM) part. The challenge is to rig and calibrate a detail in a CNC machine that is nearly finished that lacks obvious faces to rig and calibrate the part in the machine. The aim of the work is to find a general method that can be used to resolve these difficulties, leading to a safer and more efficient manufacturing. Parallel to the solution of the problem, a case study will also be done where both companies have a product that will be additive manufactured (AM) and processed in the CNC machine. The problems were clarified by using a functional-medium-trees (funktionsmedelträd) and solutions were developed using the concept generation to get as many good solutions as possible. By developing these concepts and the ability to combine these with each other a method that solves the problems with the rigging and calibration was created and proved to be useful in the case study. We see these concepts as general and a good solutions to the problems above. Further work and training will be required to further test the methods and increase knowledge about AM production to facilitate the manufacturing process.
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Pooladvand, Koohyar. "Multifunctional Testing Artifacts for Evaluation of 3D Printed Components by Fused Deposition Modeling." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-dissertations/568.
Full textAbstract:
The need for reliable and cost-effective testing procedures for Additive Manufacturing (AM) is growing. In this Dissertation, the development of a new computational-experimental method based on the realization of specific testing artifacts to address this need is presented. This research is focused on one of the widely utilized AM technologies, Fused Deposition Modeling (FDM), and can be extended to other AM technologies as well. In this method, testing artifacts are designed with simplified boundary conditions and computational domains that minimize uncertainties in the analyses. Testing artifacts are a combination of thin and thick cantilever structures, which allow measurement of natural frequencies, mode shapes, and dimensions as well as distortions and deformations. We apply Optical Non-Destructive Testing (ONDT) together with computational methods on the testing artifacts to predict their natural frequencies, thermal flow, mechanical properties, and distortions as a function of 3D printing parameters. The complementary application of experiments and simulations on 3D printed testing artifacts allows us to systematically investigate the density, porosity, moduli of elasticity, and Poisson’s ratios for both isotropic and orthotropic material properties to better understand relationships between these characteristics and the selected printing parameters. The method can also be adapted for distortions and residual stresses analyses. We optimally collect data using a design of experiments technique that is based on regression models, which yields statistically significant data with a reduced number of iterations. Analyses of variance of these data highlight the complexity and multifaceted effects of different process parameters and their influences on 3D printed part performance. We learned that the layer thickness is the most significant parameter that drives both density and elastic moduli. We also observed and defined the interactions among density, elastic moduli, and Poisson’s ratios with printing speed, extruder temperature, fan speed, bed temperature, and layer thickness quantitatively. This Dissertation also shows that by effectively combining ONDT and computational methods, it is possible to achieve greater understanding of the multiphysics that governs FDM. Such understanding can be used to estimate the physical and mechanical properties of 3D printed components, deliver part with improved quality, and minimize distortions and/or residual stresses to help realize functional components.