ESTG - Mestrado em Engenharia da Conceção e Desenvolvimento de Produto
Permanent URI for this collection
Browse
Browsing ESTG - Mestrado em Engenharia da Conceção e Desenvolvimento de Produto by Title
Now showing 1 - 10 of 106
Results Per Page
Sort Options
- 3D Printed Preforms for Manufacturing Flexible Cork CompositesPublication . Palmer, Jordan Richard Gordon; Simões, Fábio Jorge PereiraAs concerns around climate and carbon footprint are better understood, countries around the world are increasingly pricing carbon. Initiatives such as the Paris Accord are a good example. As pricing carbon becomes more important, within the context of the manufacturing industry, sustainable materials are going to be well positioned to out-perform traditional non-renewables. Recycled cork has the potential to serve as a substitute to current petroleum-based foams; and a more sustainable, lower carbon footprint alternative, at the same or similar cost. This thesis will discuss the need for a new approach to the mass production of cork polymer composite materials, and the potential for additive manufacturing techniques to satisfy this need and improve their performance, while also reducing their environmental impact. The proposed solution is a process for 3D printing cork preforms for compression molded TPE based cork polymer composites. This method will provide precise software-based density control, making it possible to fabricate highly flexible, lightweight composite parts without sacrificing durability.
- 3D Printing on a Large Scale for ConstructionPublication . Gomes, Ludmila Vago; Gaspar, Florindo José Mendes; Simões, Fábio Jorge Pereira
- Additive manufacturing machine for cork solesPublication . Pedro, Nuno Miguel Cordeiro; Neves, Carlos Fernando Couceiro de SousaThe combination of thermoplastics and natural organic fillers are being increasingly explored in recent times where the need of renewable resource products with low environmental impact is in great demand, especially in the consumer market. The use of cork is an example of a sustainable and renewable material, that has been used in the footware industry, but not in a large scale. This project proposes the development of an additive manufacturing (AM) machine to process a compound material with 78% of grounded cork, with its grains individually encapsulated in a thermoplastic matrix. The intended application of these products is the manufacturing of sole preforms for the footware industry, that will be processed afterwords by compression molding. Motivated by the necessity of increasing the consistency of the molded components and the need to control the hardness of the final products, additive manufacture is a possible tool to be used. The solution found was to develop a CNC device to move an infra-red light source that provides thermal energy, bonding the thermoplastic in the compound, creating the layer shape. Specific post processors were developed to adequately modify the machine code to the specific control needed of this process. Success was achieved in the production of an AM manufactured midsole, but further development is needed to improve the quality, especially in the areas of heat control and dimensional accuracy.
- Additive manufacturing of foamed structuresPublication . Mistry, Abhishek; Mateus, Artur Jorge dos Santos; Simões, Fábio Jorge PereiraThe major aim of this work was to develop an additive manufacturing method for obtaining foamed structures. There is limited research to understand the properties of the materials and the technology used to make foamed parts directly by additive methods. Initially a process was developed that involved using a syringe and DLP (Digital Light Processing) to create bubbles inside the photo-polymer resin. However, the results were unappealing, so upon further literature review, inspiration was found in a research paper in which the authors used an SLA (stereolithography) printer to create foamed parts by means of a polymer resin blended with a foaming agent that caused the part to expand after printing. Additionally, this research includes a thorough investigation of the mechanical characteristics of foams with various infill structures.
- Additive manufacturing of technical ceramicsPublication . Silva, António Miguel Rocha Raimundo; Barreiros, Fátima Maria Carvalhinhas; Vieira, Maria Teresa FreireAdditive Manufacturing (AM) is an area intrinsically linked to industry 4.0 because of its ability to meet some of the most significant challenges in the industry such as production of custom parts, complex geometries and direct processing (through cloud manufacturing). Due to its advantages, the market for functional parts based on inorganic materials via AM is in great development. The present study has focused on the Fused Deposition of Ceramics (FDC) process, which is suitable, in combination with post-processing steps such as debinding and sintering, for the consolidation of ceramic powder particles from filamentary materials. Although the volume content of ceramic powders is very limited, due to the absence of high pressures, the FDC has been of scientific and industrial interest due to its ability to eliminate some limitations imposed by other processes such as Selective Laser Melting (SLM), due to the sources of high energy consumption, and Powder Injection Molding (PIM), due geometric and mold cost limitations. The major challenges of this dissertation involved producing filaments for FDC, based on PIM or powder extrusion (PE) methodologies, joining the filaments of feedstock with optimized ratios of tungsten carbide powder (48.5%vol.) that should withstand the stresses involved in the FDC extrusion, and providing suitable extrusion fluidity. Afterwards, the challenges were overcome and the shaped parts through FDC were debinded and sintered. These processes led to the production of near net shape WC-10Co parts with characteristics and properties close to those resulting from conventional replicative processes of the powders.
- Análise de Próteses da Anca CimentadasPublication . Pedrosa, Ângela Soares; Rúben, Rui Miguel BarreirosEste trabalho apresenta o estudo computacional de características que podem ser adicionadas às secções transversais de hastes femorais cimentadas para a substituição total da articulação da anca. A inserção de flanges no aspecto lateral e a assimetria tem sido efectuada em próteses comerciais com sucesso clínico, mas ainda existem poucos estudos acerca do seu desempenho. O objectivo deste estudo é comparar hastes simétricas e assimétricas, com e sem flanges. As secções transversais das diferentes hastes femorais cimentadas são definidas através de parâmetros geométricos com o auxílio da programação de 24 variáveis geométricas. São aplicadas forças iguais em cada tipo de haste a fim de comparar as tensões de contacto na interface cimento-haste, cimento-osso, a tensão no próprio manto de cimento e a remodelação óssea. A presença de flanges nas hastes femorais cimentadas permite uma melhor fixação inicial da prótese, aumentando o seu desempenho.
- Análise do efeito da temperatura do sistema de injeção nas peças plásticas obtidasPublication . Raposo, Márcio José Esteves; Correia, Mário António Simões; Almeida, Henrique AmorimNeste trabalho avalia-se de forma numérica a distribuição da temperatura de um sistema de injeção num molde de injeção plástica, como ferramenta para a produção de peças plásticas, sendo que o enfoque é dado nas zonas da peça plástica, cavidade e bucha. A motivação deste trabalho vem da necessidade de apresentar um estudo nesta área da injeção de plásticos, sendo que não há muita informação proveniente de trabalhos científicos e experimentais, nomeadamente no domínio do sistema de injeção por canais quente, do ponto de vista da análise puramente térmica e não reológica. As análises térmicas são cada vez mais uma ferramenta de trabalho na indústria em geral e neste sector em particular, auxiliam de forma efetiva as fases de dimensionamento, análise e projeto, na conceção e desenvolvimento de novos artigos fabricados por injeção de termoplásticos. Nesse sentido, este trabalho visa analisar e estudar do ponto de vista académico essas áreas de atividade, e surge como prolongamento de algumas questões, que frequentemente são colocadas pela indústria de fabrico de moldes e de peças plásticas: Qual é a influência da temperatura do sistema de injeção no molde de injeção e na peça plástica a injetar? Em que medida o calor gerado pelo sistema de injeção influência de forma colateral a qualidade da injeção? Assim, neste trabalho começa por fazer-se uma apresentação geral da indústria de transformação de plástico, bem como a maioria das máquinas e ferramentas utilizadas no setor. Seguidamente, faz-se uma exposição sobre os tipos de moldes e finalmente sobre os conceitos e tipos de sistemas de injeção. De seguida expõem-se a temática das simulações e faz-se uma análise aprofundada dos vários tipos de simulações existentes e também uma apresentação dos mecanismos de transferência de calor. Apresenta-se de seguida as metodologias adotados no caso de estudo onde o molde de injeção, sistema de injeção e a peça plástica em estudo é descrito. O procedimento numérico é igualmente apresentado. Por fim, este trabalho termina com a apresentação e discussão dos resultados obtidos nas várias simulações térmicas realizadas no software de simulação NX/Siemens.
- Aplicação do método FMEA na análise de riscos potenciais para o utilizador em equipamentos e postos de trabalhoPublication . Soares, João Carlos Cordeiro; Ferreira, Irene Sofia Carvalho; Sampaio, Álvaro Miguel do Céu Gramaxo OliveiraA evolução da indústria de produção tem conduzido a um aumento significativo de tecnologias de apoio aos trabalhadores nas suas funções. A procura por melhorias nas condições de trabalho tem-se relevado importante não só para a satisfação dos trabalhadores das empresas como também para o aumento da produtividade e qualidade dos produtos finais. As grandes empresas que lideram os mercados já se aperceberam da importância da adaptação dos equipamentos e postos de trabalhos focados nos trabalhadores. No entanto, o tecido industrial é maioritariamente composto por Pequenas e Médias Empresas (PMEs) que, ao contrário das empresas de grande dimensão, não possuem equipas ou meios especializados ou dedicados ao estudo e desenvolvimento de melhores condições de trabalho para os seus colaboradores. A informação disponível e os profissionais de áreas ligadas aos fatores humanos ainda são muito limitados nas PMEs, o que torna difíceis, demorados e onerosos os procedimentos de identificação e análise de riscos e de medidas corretivas. Isto, aliado à falta de regulamentação obrigatória relativa às condições de trabalho faz com que as PMEs continuem a ignorar algumas das necessidades dos seus trabalhadores. Assim, propõe-se nesta dissertação adaptar o método de Análise de Modo e Efeitos de Falha (FMEA) de forma a poder identificar e avaliar os principais riscos ergonómicos, de usabilidade e segurança provenientes da interação entre o trabalhador e o seu equipamento ou posto de trabalho.
- Assistive technology for the visually impaired: How to provide independence and ease to meal preparation?Publication . Serafimova, Ina Dimitrova; Matias, João ManuelDisabilities are a reality many don’t think about too much unless one, or someone one knows, is affected by them. This work is motivated by this fact and is focused on attempting to improve the quality of life (QoL) of persons with visual impairment or blindness by facilitating the execution of one of the activities of daily living (ADL) – cooking independently. As this work will show, cooking with severe sight loss could prove easier or more difficult depending on various factors, the main one of which is time spent living with limited sight and, of course, proclivity for this activity. Easier, however, not easy. This is why the subject of this work is to provide a set of reliable, simple, and easy to use dispensers for oil and spices equipped with elements for identification of the various products. In order to, offer adequate results, this work began with contextualizing the target market by presenting statistics. This was followed by a glimpse of the reality of living with the limitations of visual impairment by examining the neural pathways that allow for multisensory processing (MP) and how that applies in the investigation and development of sensory substitution devices (SSD). Leaving the purely scientific and experimental part, this work proceeded to examining the evolution of assistive technology throughout the centuries and concluded by analyzing the current products on the market today. This analysis led to the compiling of plausible hypotheses for the solutions proposed by the author followed by final proposals and the development of proof-of-concept prototypes. The work concluded by presenting a business plan around the proposed products.
- Automatic volume inspection for glass blow mouldsPublication . Ferreira, Tiago André Roriz; Neves, Carlos Fernando Couceiro de Sousa; Simões, Fábio Jorge PereiraIn the glass bottle mould making industry, volume control is done by measuring the amount of water needed to fill the mould. This process has several issues. Firstly, it requires a trained operator to properly seal the mould. Secondly, different operators will lead to different volume values. Another issue is related to the time and work necessary for the procedure, which can take up to 20 minutes for a single mould, making it unsuitable to inspect several moulds of the same series. These issues can be solved by automating the procedure. By using reverse engineering systems to obtain the internal cavity surfaces, comparative studies can be done, such as wear study, enabling the optimization of the moulds. The goal of this project is to establish a system to automate the inspection of the moulds which will result in the acquisition of the moulding surfaces. Then, the volume of the moulds and surface deviations in specific areas can be measured. The development of this project focused in two main areas: the development of a script, where the volume is calculated and the surface is inspected, from cloud points, to determine if the mould is in an acceptable state; and the study of technologies capable of acquiring the mould’s surface while simultaneously being automatable. As for this study, several case studies using laser and structured light are performed to understand the abilities and limitations of these technologies. The first study was done using polished cast iron moulds to determine the ability to acquire the surface and obtain the volume. Then, the ability to present proper comparative results is explored by using a set of unpolished cast iron moulds and then these same moulds once polished to verify if the used systems can obtain the deviations between the two situations. Finally, the validation of the technologies was done using a demo bronze mould, where surface deviations were inspected as well as a ring gauge where the inner cylinder was used for inspection. From these cases, the used laser scanner was able to obtain the volumes of the moulds as well as proper comparative results without spray. As for the used structured light system, it proved unable to acquire the surfaces of the moulds and of the ring gauge, requiring spray. Despite this performance, the system is quite automatable and a state-of-the-art structured light system, using blue light, could be used for this purpose. The laser is also a viable solution, but the cost and complexity to automate can be higher than the structured light system.