Masters Degrees (Industrial Engineering)
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Browsing Masters Degrees (Industrial Engineering) by Subject "Additive manufacturing"
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- ItemAdditive manufacturing for the spare part management of classic cars(Stellenbosch : Stellenbosch University, 2022-04) Paskert, Lukas; Sacks, Natasha; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.ENGLISH ABSTRACT: The maintenance of older vehicles can be challenging since the supply of spare parts by the original equipment manufacturer is not guaranteed throughout the lifespan of a vehicle. Thus, there is a need to improve the current spare part supply chain for the automotive industry specifically for outdated products like classic cars. Within the automotive industry additive manufacturing (AM) technology is already being implemented in the production cycle of new cars. The need to improve the supply of spare parts for classic cars and the increased use of the AM technology raised the question whether additive manufacturing can have an impact on the spare part management of classic cars. In order to answer this question, this research study started with the review of literature. Three critical scoping literature reviews were undertaken to analyse the current performance of the spare part management of classic cars and to identify spare part attributes for the ranking of spare parts according to their potential for additive manufacturing. To fully understand the spare part management of classic cars, a first literature study on the classic car market was conducted. A second literature review on spare part management within the automotive industry utilized a performance measurement model to measure the impact of adopting additive manufacturing. Based on this, the applicability of additive manufacturing was the subject of the third literature review. Results show that a potential for additive manufacturing exists, and it can be measured with spare part attributes. Based on these results, it was decided to follow an exploratory research design approach. A survey was conducted with classic car owners to identify sourcing problems of spare parts and to assess their willingness to adopt additive manufacturing. The data from the survey was analysed using a ranking methodology from science which was modified toward the application of additive manufacturing on the spare part management of classic cars. The outcome of the ranking highlighted that small parts (e.g. switches) and batches are best suitable for additive manufacturing. A Delphi survey with subject-matter experts validated the ranking method. A case study was carried out in which a speedometer gear was reverse-engineered, additive manufactured and tested under realistic conditions. The case study highlighted that additive manufacturing is feasible to produce spare parts on demand and on a decentralized implementation strategy. Overall, this research has shown that additive manufacturing has a high potential to impact the spare part management of classic cars. The research result showed that unsatisfied customer demand is recognised. Additive manufacturing is a technologically feasible solution to produce many spare parts and has the high potential to increase the supply chain performance of classic car spare parts.
- ItemDevelopment of a digital rapid training course for improving the additive manufacturing adoption rate - fused filament fabrication(Stellenbosch : Stellenbosch University, 2022-04) van Wageningen, Roelof Pienaar; Hagedorn-Hansen, Devon; Von Leipzig, KonradENGLISH SUMMARY: Additive Manufacturing (AM) technologies, such as Fused Filament Fabrication (FFF), have a slow adoption rate. Training on these AM technologies is typically not included in primary to tertiary education curriculums and studies have shown that the lack of education on it, negatively affects the adoption rate. This issue was addressed in this study by developing a digital rapid training course on FFF. A literature study was first performed to gain a better understanding of the different AM technologies and the adoption thereof. The focus was then shifted to a set of learning methods and platforms that are used in the educational sphere. After completing the literature study, it was concluded that training users in FFF can help improve the adoption rate of the technology. The knowledge gained through the literature study was then used to develop a cross-platform digital training course (Web, iOS, and Android), aimed at introducing users to and educating them in FFF. The course consists of teaching sessions, tests, and questionnaires. The course was made available to the general public (free of charge) for a year with no specific target group, allowing users with and without FFF experience to participate. The training course automatically gathered quantitative and qualitative data by recording users’ answers during tests and questionnaires respectively. The course was completed by 198 participants. This data was then analysed to determine whether the training course increased the users’ knowledge of, confidence to engage with, and likelihood to adopt the FFF technology. From the group of participants, 87% claimed that their level of knowledge and understanding of FFF increased by participating in the course. The majority (94%) of the participants stated they are more likely to interact with the technology after participating. The users with no prior knowledge/experience with the technology were found to have benefited the most from the course. Such individuals can be targeted during the development and deployment of AM courses to have the biggest impact on the adoption rate. It was concluded that the training course increased the majority of users’ knowledge of, confidence to engage with, and likelihood to adopt the FFF technology.
- ItemDevelopment of a selection program for additive manufacturing systems(Stellenbosch : University of Stellenbosch, 2010-03) Husam, Shames; Dimitrov, D. M.; Van der Merwe, A. F.; University of Stellenbosch. Faculty of Engineering. Dept. of Industrial Engineering.ENGLISH ABSTRACT: Additive Manufacturing (AM) refers to the technologies that use Computer Aided Design (CAD) data to produce plastic, metal, ceramic, paper, wax or composite materials parts. Their ability to join thin layers of liquid, powder or sheet materials together permits the production of parts, which are difficult or even impossible to produce, using any other manufacturing method. Even though these technologies are still developing, they are considered a major breakthrough in industry. One of the main problems that is facing the improvement and the spread of AM technologies, and its benefits worldwide, is the lack of knowledge about them. Still a lot of countries, educational and industrial organizations do not even know about AM technologies. This lack of knowledge of such technologies is keeping their cost artificially high, which is limiting the access to more AM advanced technologies and materials. It also makes it difficult to market the technologies and those who do not use AM technologies yet become unable to compete against those who do. The numbers of AM systems are continually growing, their capabilities and applications are improving and their cost is decreasing. Today there are more than 40 companies that produce over 100 different systems in Canada, China, France, Germany, Israel, Italy, Japan, South Korea, Sweden and the United States. These systems vary in their strengths, defects, applications, functions and limitations. This growth has led to an increase in current and potential users of AM from both the manufacturing and educational sectors. These users are however facing increasing complex problems when it comes to selecting the most appropriate commercial system(s) to suit their needs. The aim of this study is to develop an AM system selection program. The program will serve both as an educational tool and a decision making support tool to assist any potential purchasers in both the educational and industrial sectors. The AM system selection program is divided into two sections: the learning section and the selecting section. The learning section introduces the AM technologies by imparting knowledge to the new users; moreover, it inspires them to start using these technologies to get their benefits. Having a background in AM technologies enables the new users to make educated decisions and to discuss technical issues about the systems with the providers. The selecting section offers a decision making support tool to help the users to decide which system best suits their needs. This study can contribute to the promotion of AM technologies and their benefits worldwide, especially for the countries and organizations that have not yet used such technologies.
- ItemThe effects of machine parameters on the integrity of WC-Ni coatings deposited onto titanium parts with laser additive manufacturing(Stellenbosch : Stellenbosch University, 2019-04) Van Coller, Marius Cornelius; Oosthuizen, Gert Adriaan; Sacks, Natasha; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.ENGLISH ABSTRACT: Part quality specifications are of the utmost importance within industries that include specialized applications, for instance the medical, aerospace, nautical and mining industries. Attributable to the high costs of specialized parts and the risks involved in operation, such as the loss of human lives and company integrity. Parts are expected to showcase consistent properties throughout their life cycle as catastrophic consequences may ensue if they do not align with industry specifications. The goal of today’s part manufacturers is to extend part lifecycles and mitigate unwanted occurrences like crack formation, deformation or creep in the material. To maintain the highest achievable production rate and most efficient use of resources, consistent material homogeneity of components within stark operating conditions is a crucial pursuit. Titanium and its alloys have become popular contributors within these industries due to their advantageous material properties, e.g. biocompatibility, corrosion resistance and high strength. This said, titanium has poor tribological properties, which restricts its range of applications in environments where friction and wear is prevalent. Titanium’s high temperature wear and oxidation resistance is poor and to solve these inefficiencies, surface treatments have been applied to titanium and its alloys. These modifications largely incorporate the use of hardened coatings, like carbide composites, and employ laser beam technologies for application because of its high energy density, coherence and good directionality. Little research exists on the application of laser additive manufacturing technologies for production of carbide coated parts. In the pursuit to improve the current supply chain capabilities for carbide strengthening and refurbishment, this study investigated the feasibility of depositing tungsten carbide onto titanium parts using laser melting technology. Nickel was employed for the binder material in the cermet as an alternative to cobalt, which is conventionally used for additive manufacturing of hardened carbides. The research study was aimed at designing an experiment to determine which machine parameters result in the optimal adhesion characteristics between titanium alloy Ti-6Al-4V and tungsten carbide in a 10% nickel binder (WC-Ni). The machine parameters evaluated were the laser power, scanning speed and hatch spacing. The experimentation consisted of both a single-track screening experiment and single layer depositions. From the screening, suitable hatch spacings and a process window for scanning speed and laser power was deduced. These results were incorporated into further experimentation that evaluated layered depositions by varying the three parameters under study. The parameter combinations were tailored to maintain a consistent volumetric energy density range between 28.85 J/mm3 and 88.33 J/mm3 to test the individual effects of input parameters at a constant energy input. The evaluated responses were: 1) the surface quality of coatings, 2) penetration and diffusion of the deposition into the substrate, and 3) the consistency of coating material at the substrate interface. Optimal quality coatings yielded between 20wt.% and 40wt.% tungsten carbide at layer surfaces, while maintaining a layer thickness between 30μm and 60μm; diffusion depths of up to 50μm were also achieved. Higher energy densities resulted in deeper penetration and good diffusion of the coating into the substrate but lacked sufficient presence of the coating material at the substrate surface. It was concluded that higher laser powers and high hatch spacings combined with intermediate scan speeds produced the most desirable coatings. This corresponded to depositions in the energy density range of 28 J/mm3 and 58 J/mm3. Furthermore, the validity of the volumetric energy density equation as a predictive metric in laser additive manufacturing was addressed, as significant differences in layer quality were achievable by varying parameter values at identical energy densities.
- ItemFreeform support-free additive manufacturing with continuous fiber reinforced photopolymer.(Stellenbosch : Stellenbosch University, 2023-03) Kirkman, Daniel Mark; Van der Merwe, André Francois; Campbell, Robert Ian; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.ENGLISH ABSTRACT: Continuous reinforcement fibres have been shown to drastically increase the strength of polymer components produced by additive manufacturing (AM). Material extrusion (MEX) methods of AM are particularly suited to the inclusion of continuous fibres. However, MEX methods are limited to planar, layer-wise build strategies. Fibre reinforced MEX processes will therefore still show some of the mechanical strength limitations of conventional MEX processes. Consequently, the improvements in mechanical properties promised by the inclusion of continuous fibres cannot be fully realized except for simple geometries and load cases. The aim of the study presented in this dissertation was to develop an AM system capable of the support-free deposition of continuous fibre reinforced polymer along freeform toolpaths. It was theorized that such an approach to AM could circumvent the limitations of layer-based AM methods to enable the AM of structurally optimized parts with load path aligned reinforcement fibres. A photopolymer resin and E-glass fibres were selected as respective matrix and reinforcement materials. The first extruder iterations were designed to extrude only a photopolymer gel, while the final iteration made use of inline impregnation for combining the matrix and reinforcement materials. Estimated fibre volume fractions of 35 % were achieved. Ultraviolet lasers were used to cure the matrix as it exited the extruder nozzle. Toolpath planning and generation algorithms, which facilitated the semi-automatic generation of 5-axis toolpaths for simple geometries, were implemented using MATLAB. Toolpaths were executed by a moving build platform attached to a robotic arm. Preliminary testing demonstrated the AM process for simple geometries. Results from preliminary tests were used for motivating improvements to the extruder design, and for the development of improved toolpath planning approaches. A series of tests was conducted using the final extruder iteration to determine suitable values of the critical process parameters identified during preliminary testing. Toolpaths were then generated for a more complex geometry resulting from a topology optimization considering continuous fibre reinforcement. Mechanical testing of this part verified that its strength and stiffness were significantly higher than that of a similar unreinforced part manufactured using a SLA 3D printer. Micro-CT scan and microscope analyses were performed on this part to assess the microstructure and to identify defects. Although the system which was developed was restricted with respect to the achievable geometric complexity, the continuous fibre reinforced support-free AM of a simple optimized part, using freeform toolpaths and load path aligned reinforcement fibres, was demonstrated. Suggestions for future research include the development of improved matrix and reinforcement materials, the automation of the freeform toolpath generation process for complex geometries, and further optimization of process parameters for improved geometric accuracy and mechanical properties.